The management of the memory is short. Management of memory. Methods, using algorithms. Method of fixed distribution

Functions of operational systems for managing computer resources.

Managing the resources of the calculating system using the most effective vikorystannya є the main features of any operational system.

The main resources of modern computing systems: processors and main memory. Resources are distributed between processes. Process (task) -program in the stage of the vikonannya. The program is a centralized object, which is a file with codes and data. The process is a dynamic object, like a win in the operating system, because of the fact that the operating system itself is “run the program on a visitor”, to create a new unit of calculating robot.

The main criteria of efficiency, depending on the operating system for organizing the management of computer resources: the throughput of the computing system and the hour of reaction.

Resource management includes the solution of offensive zagalnyh, but not to lie down according to the type of resource:

1 - plan for a resource - that is, a value for any process, if in any number (if a resource can be seen in parts), then there is a resource;

2 - supplying power to resources;

3 - the status of the country and the registration of the resource - so that the operational information about those borrowing a large resource and part of the resource is already distributed;

4 - display of conflicts between processes.

Most of the resource management functions are automatically detected by the operating system and are not available to the application programmer.

Management of memory.

Functions of the OS for managing memory; seeing the memory of the processes and the memory of the memory when the processes are completed; zagist memory; change of processes from the operative memory to disk, if the main memory of the deficiencies for the change in all processes, and turning them into the operative memory, if the memory is in one sound memory, and the address is also configured for a specific area yati.

Memory management includes the generation of obvious physical memory and the processes that are currently operating in the system at the moment, the assignment of the code and the given processes in the introduction of the memory area, setting the address-stored parts of the code areas of memory

skin process.

One of the most popular ways to manage memory in current operating systems is to monitor the mechanism of virtual memory, with all the data that the program uses to be stored on the disk and, if necessary, to be represented by parts (segments) It does not allow the programmer to write the program in such a way, as in the first order, there is one-time operative memory of the great debate, often changing overwhelmingly the obvious physical memory. When the codes and data are changed between the operative memory and the disk, the virtual memory display system will translate the virtual addresses, which were changed as a result of the compilation and layout of the operative memory, in the form of the main address. Even more importantly, all operations on the transfer of codes and data from the operative memory and disks, as well as the translation of the address, will be displayed by the OS well for the programmer.

Zachist memory - the whole point of protecting the viconuvan the task from writing down or reading the memory, assigned to the first task. Give yourself permission to take the memory, implemented in the operating system, to be guilty of unauthorized access of processes to foreign areas of memory.

Lecture 8. Memory management in OS

4.4.3. strategy of distribution

4.1. Understanding about organizing and managing physical memory in operational systems

The organization and management of the main (primary, physical, real) memory of the calculating machine is one of the most important factors that will initiate the operating systems. In English technical literature, memory is synonymous memoryі storage.

In operational systems, there are two types of memory: primary (primary) and primary (secondary).

Main memory(Main storage) - the operative memory of the central processor or part, which is a single memory space.

call memory(External storage) - memory, given in the availability of the central processor for additional input-output operations.

For a bezposeredny vikonannya program, or even the beating up to the date is necessary, and the stench was dispersed in the main memory. The name of memory is, as a rule, more of a memory, less basic, cheaper and more expensive and allowing for the collection of data and programs, which are ready for processing.

Krim the main and most recent memory in the current IOM is a simple dodatkova shvidkodiyucha memory, how to be called kesh-pam'yattyu.

All three recollections of memory the hierarchy of memory calculating machine (div. fig. 4.1).

Operational systems with the decile committee of the memory of the government and the intensity of the exchange of programs and data from the physical annexes of the memory of the old times. Such exchanges of system resources (for example, the hour of the central processor), as it is possible to become more productive.

The main memory is one of the resources of the search engine. During the development of the OS, the head staff should be involved in the optimal registration of the main memory on the basis of rational organization and management of it.

pid organizing memory those who are in the rank of will and how vikoristovuutsya are the main memory.

In the operating systems, the following views of the main memory are stored:

• fixed blocks of equal size;
• fixed pieces of unequal size;
• dynamic razdilas, the size of which fluctuate in the course of the robotic counting system.

Victory of the main memory can be found in the following ways:

• distribution in memory one-time only with one program of koristuvachiv;
• distribution in memory of one-hour decilkokh programs of koristuvachiv;
• distribution of programs of coristors in a specific preset to a given distribution of the main memory;
• razmіshennya skin programs koristuvach in one bezperervny (one-link) space of the main memory;
• the distribution of programs of the corystuvach in the inessential areas of the operational memory (with the same OS, there will be a change in the programs on some blocks and without the calls of the blocks in between them).

In operational systems, it is possible to fix whether a combination of reworking types of manifestation and methods of maintaining the main memory of the IOM.

Independently of the fact that the scheme of organizing memory is adopted for a specific OS, it is necessary to ensure that there is a strategy for achieving optimal performance.

Management strategies for memory It will start, as it will be useful to remember with a specific scheme of organizing during new approaches to the date of such meals:

· if you have put a new program into memory;

· in the same place of the main memory, the Chergov program will be expanded;

· like the development of the Chergov program in memory (from the minimization of the second memory, or from the maximization of the speed of promotion);

· As from the memory of the passengers, the program should be stored from the memory, as the new program needs to be connected to a new program, but the memory is already stored.

In current operating systems, the management strategies are implemented, in a rational way, they look at the food supply, but in the smallest step it is backed up by hardware and software tools that are explicitly in order.

Management strategies for the memory of advancing on the offensive categories:

· vibrating strategies;

· strategy of distribution;

· strategy of substitution.

Vibers have their own strategy on two categories:

· vibrating strategies for power supply (for vimoga);

· strategy of proactive vibration.

Vibirka strategies put your own for the meta of value, if you go to "shrink" the Chergov program (or block programs) or the data in the main memory.

strategy of distribution to put oneself for the meta of value, in the place of the main memory for the development of information, so that the program should be approached. Naybіlsh extensions є strategy of distribution, which realizes the principle of occupation of "the first coming", "the most coming" and "the most appealing" for the size of the vіlny dіlyanka memory.

strategy of substitution put sob for the meta of value, which block is a program or a given slid vivesti ("vishtovhnututi") from the main memory, so that it’s a good place to distribute is quiet, who’s going to run the program or don’t.

When realizing strategies for the distribution of operating systems, it is often necessary to ensure that the system has a vocal memory for programs and donations.

A clean memory card - such a rise in the main memory of the EOM, with a skin program of a loan, one uninterrupted (ringing) block in the middle of the memory.

Not so long ago, the memory of the memory - Such a breakdown of the main memory of the EOM, with which the program of the corystuvach breaks up into a number of blocks (segments, sides), which can be split into the main memory in the little boxes, is not bound by the suspensions one to one (in the non-boxes). For many people, it’s more effective to maintain the space of the main memory.

The effectiveness of this strategy of distribution can be assessed for the additional function of the Victory Day.

(4.1)

de V p - ob'єm memory, engaging with programs koristuvach; V op - a new obsyag of the main memory; V OS - obsyag memory, borrowing by the operating system; V pro is a pledge of memory, available for the rozpodilu.

4.2. The method of sounding the main memory

4.2.1. A clean memory card for one koristuvach

A clean memory card for one corystuvach, also called a single, uninterrupted one, can be stored in the EOM, which can be used in a batch single-program mode for the control of a simple OS.

The entire main part of the EOM, is not occupied by the programs of the operating system, is seen by the program of one at a given hour of the koristuvach. The size of the programs in the whole range is interconnected with the size of the available main memory, the protection of the possibility of displaying the program, the size of various changes of the size of the main memory, the mechanism of overlays.

The organization of the memory in case of a ringing rose for one corystuvach is shown in Fig. 4.2.

Koefіtsієnt vikorystannya pam'yatі for vyglynitsya vypadku calculated for the formula

h z1 = V p / V o, (4.2)

de V p - size of programs koristuvach; V pro - the exchange is available for the distribution of the main memory of the EOM.

OS functions in this type є:

· seeing the program of the memory that is necessary for the spaciousness;

· Zakhist memory;

· memory of memory.

The function of viewing the memory is created until the program is given all the available memory of the EOM.

Zachist memory in one-program systems of the field in the installation of memory areas occupied by the operating system, as a result of the program koristuvach. Qia function is implemented for the help of one register to cordon Embedded in the central processor. Register cordon to avenge either the senior address of the command, which is reported to the operating system, or the youngest address is accessible by the program of the main memory (addresses of the cob with programs). As soon as the program of the koristuvach intends to go into the area of ​​the operational system, then it will go through the transfer of memory, and the program will be terminated in an emergency.

4.2.2. Clear memory layout for multiprogramming

With multiprogramming, in the memory of the computer, the plant grows all at once. Rozpodil pam'yatі mіzh zdannyami in the whole vipad can be viconano an offensive rank:

· rozpodil fixed rods;

· rozpod_l with winter razd_la;

· rosodil with swapping.

ROSPODIL FIXED ROSES ma dvі modifications:

a) from the assigned programs in absolute addresses;

b) from the assigned modules, the modules are moved.

When the modules are locked, all the operative memory of the machine is broken up to a fraction of the number razdіlіv fixed size. Razmіri razdіlіv can not go away. At the skin razdіlі can only be sorted out only one zavdannya.

Once the program is locked up in absolute addresses, when it is ready, the address of the assigned program will be copied, and it will be copied from the cob address to the address, in which the program will be displayed.

At the time of the assignment of the changeover modules, in which case the system is changed, or the operating system automatically starts up, according to the implemented in the new strategic vibrator ("the first commanding", " zavdannymi.

In both cases, the monopoly on the whole of the operational memory was taken into account, in which there is an operational system.

The rates of registration of memory in case of distribution with fixed parts are calculated according to the formulas:

(4.3)

(4.4)

de h СMI - the conference for the memory of the i-th issue; V Оi - size of the i-th section; V Pi - additional dinner with programs, introduced into the i-th section; N F - number of pieces; V Pro is a general round-up of operational memory, available for distribution.

The main shortcomings in the memory of fixed distributions are the ineffective registration of resources in the calculating system, and through the possibility of a new building of the factory will appear, as to clear out the sound of a particular distribution at that hour, as they were distributed. A similar situation is shown in Fig. 4.3. The manager, who cleared out the distribution of C, could be distributed in the sections of A and B, however, the operating system does not allow this process, so in the case of information about the specific distribution of S.

The way to distribute memory by fixed parts can be used in operating systems of OS іC and IBM / 360 in MFT mode, in which the locked programs can be changed by modules.

To pick up a memory when you get a fixed piece of paper, you’ll be similar to picking up a memory for one koristuvach, only now you need to have a decile borderline registries - two registries for skin razdіl. In one of the boundary registers, the lower boundary is entered, and in the other, the upper boundary. As soon as the program of the koristuvach will be turned up to the tribute, we will change the pose of the region, the address of the given issue, then it will be violated according to the destruction of the memory.

Multiprogram systems with fixed razorbids are more susceptible to manifestation fragmentation of memory.

fragmentation of memory - appearing in the memory of the calculating machine of the working memory of the occupied and unintelligible (vilny) files of the operational memory.

When the fixed breaks are broken, the fragments of the fragmentation are explained to them, that, because the production of coristas will not result in the loss of visions, for the part of the breaks is not to be cleared.

Figure 4.4. the manifestation of fragmentation of operational memory is shown.

The level of fragmentation can be estimated fragmentation efficiency K f, which is virakhovuu to follow the formula

(4.5)

De V di - size of the i-th "dirka", tobto the i-th dilyanka of the new memory, surrounded by programs of koristuvachiv; N D - number of "dyrok", so that there are lots of memory, which lie between the programs of koristuvachiv; V o - a list of operational memory, available for the rozpodil.

Fragmentation of the memory є to the destruction of the one-to-one space of the memory of the EOM, to reduce the effectiveness of the memory of one of the main resources of the calculating machine.

Razpodil pam'yatі winter razdіla the designation for the improvement of the efficiency of the operational memory of the EOM. The essence of the way to distribute memory by changing glades is in the fact that the staff, if it smells like it, see such an obsyag of memory, which is needed, so that it is necessary to change the memory of the operational memory, so that it can be seen That "rewrite" the memory, as it is not possible to be seen in the case of the use of fixed breaks, is not spared in this way.

Є two modifications to the method of distribution with the help of winter parts:

· rozpod_l with small non-changeable parts;

· rozpod_l change by rozd_la.

With the growth of memory changeable unchanged parts(Dynamic breaks) the operating system of two tables: a table of the distribution of memory areas and a table of the regional memory areas ("track").

When a proper memory for a new building is introduced on the stage of the first building plan, and the memory is not seen from the table of the "path" in the view of the "coming" "). With a successful rise in the OS, the corrections of the offense tables are the development of the growth areas.

After the end of any development of the loan for him, the memory of the memory will sound, and the operational system will update the table of the regions that have been assigned, following the information about the end of the established data, and also "enter" the regions in the tables

The offensive butt is visible. Let the cob rose with the memory of the viconano wrinkles so that it is shown in Tables 4.1, 4.2 and in Fig. 4.5a. The development of the buildings A, B, C and D has become a large area of ​​such a size, which is necessary for the program, as it is possible to stand in the middle, in the whole region is not located.

Table 4.1.The table of the distribution areas

Number of distribution, the key to the hijacker	іm'ya razdіlu	Rosemir	Addresses	mill
		100K 200K 100K 400K 100K	50K 150K 350K 450K 850K	rozpodіleniy rozpodіleniy rozpodіleniy rozpodіleniy rozpodіleniy

Table 4.2.Values ​​table

vіlnoї number oblasts	Rosemir	Addresses	mill
	100K	950K	available

Admittedly, after a dozen hours the work of A and C (div. Ris.4.5b) ended. Tables of areas nabuvayut viglyad, readings in table. 4.3 and 4.4.

Table 4.3.Table of areas with different types of areas: finished plant A

Number of distribution, the key to the hijacker	іm'ya razdіlu	Rosemir	Addresses	mill
		200K 400K 100K	150K 450K 850K	Empty rozpodіleniy Empty rozpodіleniy rozpodіleniy

Table 4.4.Table of provincial areas: end of plant A

vіlnoї number oblasts	Rosemir	Addresses	mill
	100K 100K 100K	100K 350K 950K	available available available

You can bachiti, which is unimportant to the appearance of 274K of vivid memory, sufficient for the development of the factory E, but to stand first in the middle, the OS is not able to get it, for that it is good to have a memory split into two fragments, each 100K of leather , as to stand in the middle, it is uncomfortable. The whole butt іlustruє head is not very similar to the method of rozpodіlu wiggle unchangeable razorbіl - strength to the fragmentation of the main memory, which reduces the efficiency of the robotic calculating system.

With the growth of memory change by pieces the operating system is good for to the defenses of the memory, they are stored in the relocation of all occupied dalyanoks to one end of the main memory. The breeders will replace the great number of small "dyroks", which, when victoriously rostered, become unchanged, form a single (ringing) dilenca of a vivid memory. On the pic.4.5c readings, the result of the deflection, if the main memory of the B, D and E programs is located in the main memory of the program for the end of the program A and C. please stand in front of F. Tsey process is also called defragmentation memory.

The defragmentation of memory, how to become stagnant at the time of growth, is replaced by razdilas, there is little of its own:

• required additional vitrati for an hour;
• before the hour of memory loss, the system is guilty of accepting (accepting) all of the robots, which can often appear unacceptable;
• the need to relocate the staff in the memory of the memory of the significant information exchange, related to the change of the program in the memory, that the memory of the OS side;
• With an intensive flow of short programs, you may discover the need for frequent defragmentation of the memory, so focusing on the whole system of resources may turn out to be unjust obsessed with vigode.

Rozpodil memory with swapping (In English. Swapping - pidkachka) is characterized by the fact that, on the basis of the previously seen ways, the programs of the program do not become lost in the main memory until the moment of its completion. In simple systems with swapping at the skin moment, only one person's memory is in the main memory and borrowing until quiet time, as long as it can be seen, and then the memory is like a central processor for the offensive. In such a rank, the whole memory for a short period is seen by one employee, then at the singing moment of the hour it’s full time (vyshtovuєtsya, so that it’s okay to “get out of the way”), and the charity is introduced (to sniff, to get up). In the case of a sinister skin, it’s still up to its completion, if it’s a lot of times it’s pumped from the last memory to the main and back.

To secure swaping at the last OS memory, I open one or more files in pidkachki, de images of operational memory are located in the robots of the building of koristuvachiv. The way to generate memory with swap is stuck in the simplest operating systems, which can be used in hourly mode.

4.2.3. Strategies for distributing information in memory

Strategies for the distribution of information in memory are intended for the purpose of being important, in the place of the main memory, in order to help to find programs and data in case of generating the memory of unchanging pieces. Naybils often use the following strategies:

• distribution with the vibration of the first coming (strategy "the first coming"):
• razmіshennya with a vibor of the best coming (strategy "nykrashchy");
• the algorithm with the choice of the naymensh of the adjunct (the strategy "the most unacceptable").

Strategy "the first coming" polyagaє at the viconanny of the coming crocs:

• zrostannya address;
• Put the information into the first creation of the main memory with a size not less than necessary.

Strategy "best" I will come to the end of the day:

• arrange the table of the provinces in order growing rosmіrіv vilny areas:

The strategy "the most unavoidable" viconuє nasty dії:

• arrange the table of the provinces in order ubuvannya rozmіriv areas;
• Put the information into the first creation of the memory of the new memory with a size not less than necessary.

Strict proofs of the overvoltage of this strategy in front of the others are not real, so the stasis in the operating systems is based on the intuitive arguments of the OS developers.

4.3. Organization of virtual memory

4.3.1. Basic concepts of virtual memory

term virtual memory Let us associate with the possibility of addressing the space of memory, more and more, but less of the primary (real, physical) memory of a particular calculating machine. The concept of virtual memory was first implemented in a machine, launched in 1960 at the University of Manchester (England). However, the wider expansion of the system and virtual memory was deprived of the fourth and coming generations in the EOM.

There are two best ways of realizing virtual memory - storinkovaі segmental. The same combination is stagnant - side-segment organization of virtual memory.

All systems of virtual memory are characterized by the same addresses, which are formed by vicious programs, not necessarily linked to the addresses of the primary memory. Virtual addresses, as a rule, represent a larger, unalterable address, below in the first memory.

The essence of the concept of virtual memory Polyagaє in that, where the addresses, before which the processes take place, the processes are displayed, the address is actually present in the primary memory.

Addresses that really are in the first memory, are called real (physical) addresses.

The range of virtual addresses, up to which processes can be displayed, are called vast virtual address The fifth process.

The range of real addresses that can be found in a specific computerized machine, are called vastness of real address RЦієї ЕОМ.

Unimportant to those processes that turn only to virtual addresses, in the sense of the stench they are guilty of real memory. To establish the appearance of virtual and real addresses, the mechanisms of dynamic conversion of the address of the DPA (or DAT - in English) All subordinate systems of power (see figure 4.6) - summarized addresses of the virtual address space, the process will not necessarily be summous in real memory.

Tse power is called "piece summery". Tim himself must be aware of the need to look at the physical memory with unique characteristics.

The virtual memory will be, as a rule, for the courtyard scheme (see Figure 4.7).

The first rіven is a real memory, in which there are viconuvany processes and in which guilt changes are made, before which processes take place.

Another rіven is the price of memory of the great community, for example, accumulating on magnetic disks, created by the programs and data, since it is impossible to all at once be accommodated in real memory through the interconnection of the community. I call the memory of another rіvnya second abo zvnishnyoї.

In multiprogramming modes, the real memory is distributed among the bagatma processes. Oscillations of the skin process can have a larger space of virtual addresses, there is no real memory, then at the exact moment in an hour in real memory є the possibility of trimming is just a small part of the program codes and the data of the skin process, and the code is not very large 'linguistically, it will be developed as a subtle mass of real memory (power piece summity”).

Mechanism of dynamical re-adaptation of the address is given to the fact that the clichés of the virtual memory at the given moment are in the real memory and de itself the stink of change. Tse zd_ysnyuєtsya for the help of the image table, which is conducted by the mechanism of the DPA.

Information, how to move from virtual memory to real, by the mechanism of DPA to group in blocks, І system to follow the time, in some places of real memory there are different blocks of virtual memory. The size of the block is poured into those parts of the real memory of the DPA, which would be unproductive for their own purposes.

If the blocks are of the same size, then the stench is called sides sideways. If the blocks can be small, then the stench is called segments, And the type of organization of the virtual memory is called segmental... In some systems, offense must be combined, so that the segments are realized as an object of changeable sizes, so that they are formed from the sides of a fixed size. Such organization of virtual memory is called abo segment-line, abo side-segment.

Addresses in block-based imaging systems є two-component (double-sided). The wire is turned up to a specific element, the program will add a block, in which the element is removed, and the element is replaced with a block (see Figure 4.8). Virtual addresses n order for an additional orderly bet (b, d), de b is the number of the block, in which the given element is displaced, and d is the substitution of the apparently cob address block.

The re-creation of the address of the virtual memory n = (b, d) at the address of the real memory r to become an offensive rank (see figure 4.9). Kozhen process mas vlasnu block display table, yaku operational system is kept in real memory. The real address of the central table will be enlisted in the special register of the central processor, ranks register of cob addresses and tables of displaying blocks in the process.

The block display table should be placed one row for the skin block during the process, whereby the blocks are processed one after the other: from the list of block 0, then block 1, etc. The number to block b is assigned with the cob address and table, corresponding to the real address of the rows of tables for block b. The row is known to avenge the real address b on the cob block b in the real memory. To tsiy pobatkoy address b is given zsuv d, so to pretend shukaniy to the real address r = b '+ d.

All methods of block-by-block imaging, which are stagnant in systems with segmental, side-by-side and combined side-segment organization, similar to the image scheme, are shown in Fig. 4.9, called the direct display scheme.

4.3.2. Historical organization of virtual memory

For a purely side-by-side memory organization, the virtual address is set to a pair (p, d), de p is the side number at the virtual memory, and d is the change within the p side. The process can be displayed, if the flow line is located in the primary memory. The pages are rewritten from the last memory in the first place and are distributed in blocks, which are called side-by-side frames and it may be exactly the same size as that of the intruders. Side frames are repaired in real memory for addresses, multiple fixed frame sizes. The side can be placed in a kind of a side frame.

To secure the robotics, the mechanism of the image of the sides is formed by the table of the image of the sides, the skin row of what information about the visualization of the reverse of the virtual memory is formed:

r - signs of the presence of a side in the first memory (r = 0 - side in the first memory of the German; 1 - side is in the first memory):

S - address of the side of the last memory (at r = 0):

p 'is the number of the row frame in the primary memory, the virtual row with the number p has been de-spaced.

4.3.3. Segment organization of virtual memory

The virtual address in the segmental organization of the virtual memory - the pair n = (s, d) is ordered, de s is the number of the segment of the virtual memory, and d is the change within the same segment. The process can be displayed only in the same way, if the current segment is located in the primary memory, Segments are transferred from the primary memory to the primary memory. All midterms, like a segment, are occupied by summaries of addresses and primordial memory. To distribute, one needs to go from the first memory of segments in the first memory of the first memory. 3). Dynamically converting virtual addresses into real addresses 4.9.

4.3.4. Story-segment organization of virtual memory

Systems based on side-segmental organizing may show the merits of both ways of realizing virtual memory. Segments change the number of sides to the whole, and not necessarily, but all sides of the segment were in the first memory at once, and the sum of the sides of the virtual memory is not necessarily to blame for the first time in the first memory. In the system of side-segment organization, three-component (trivial) addressing is stuck. The virtual address n here starts out as the order n = (s, p, d), de s is the segment number, p is the part number, and d is the change within the part, if there is a necessary element.

The operating system for the skin process forms, according to the first, one table of segments in the process, and, in other words, tables of segments of the segments (one per skin segment for the process).

The table of segments in the process of placing in their rows information about the number of lines in the segments and about the addresses of the s' changing the tables of segments of the segments in the first memory of the EOM.

The skin side of the segment table should be placed in its rows with information about the cob address and the space in the first memory of the side frame for this side of the virtual memory.

Dynamically converting virtual addresses in systems with side-segment organizing is displayed from the conversion according to the scheme for more than one line of the calculated address, as shown in the diagram in Fig. 4.10, the process for the appearing side tables.

4.4. Management of virtual memory

4.4.1. Strategies for managing virtual memory

Strategies for managing virtual memory, as well as strategies for managing physical memory, are divided into three categories: pushing strategies, strategies for shifting, and strategies for vyshtovuvannya.

meteyu pushing strategyє By the way, at any moment you should rewrite the side or the segment from the secondary memory into the first one.

meteyu strategy distributionє By the way, in the place of the primordial memory, help to come up a side or a segment.

meteyu strategiy vishtovkhuvannyaє virishity, like a side, or a segment that is seen from the primary memory, it’s a point of sounding a place to try to find a side of a segment, which is the primary memory in the first place.

More strategic management of virtual memory is based on the concept locality, the essence of what polyaga is that rozpodil powering the processes for the cultivation to memory, as a rule, an uneven character with a high level of local concentration.

The power of locality is manifested both in the hour and in the vastness.

Locality per hour means, before the middle of the memory, before the brutality that was carried out for a long time, with the great imoving of the brutality in the most mighty.

Locality in space It means that, as a rule, the beastly before the memory, as a rule, concentrate in such a way, that at the time of the beastling before the action of the memory of the great memory, it is possible to ochikuvati the beastly to the lightest mid-range.

The power of localization is promoted not only in applied programs, but in the robotic programs of the operating system. Power is tse shvidshvidzhe empirichne (sposterіgaєt in practice), nіzh theoretically primed. Localism is not possible to guarantee, the protest is great. Those who have found a lot of localization є those who can effectively use the program, as well as in the first memory there is a lot of people, which include the most popular side of the segment.

To assess the effectiveness of memory management strategies in operational systems, the "space-hour" indicator should be used, which is used to follow the formula

S = Vch T, (4.6)

de S - indicator "space-hour"; V - the volume of the primary memory, the process of engaging; T - the triviality of the process of pumping the necessary side of the segment.

The decrease in the value of the indicator S for the decrease in the period of cleaning up by the process of the necessary parties or segments for the purpose of all strategic management of memory.

4.4.2. Pushing strategies (pushes)

The following strategies should be used to manage the investment:

· vshtovhuvannya (pidkachka) for a drink (for vimoga);

· vshtovhuvannya (pidkachka) z perrezhennyam (viperredzhennyam).

Vshtovhuvannya (pumping) behind the feed transferring, the check system is sent to the side or the segment is shown to the process and only when you see such a power to start rewriting the side or the segment to the first memory. Power supply for both positive and negative sides.

To the positive side, to include:

• it is guaranteed that only those parts (segments), which are necessary for the robot process, can be rewritten into the primary memory;
• overhead vitrati on those that are important, such as sides or segments that should be transferred to the primary memory, minimal.

Until a short supply, the fact that the process has accumulated in the first memory of the necessary side (segment) for one is taken into account. When a new side (segment) appears on the skin, the process is checked, if the side (or segment) is transferred to the primary memory. Due to the fact that some of the sides (segments) given to the process are already in the primary memory, while the period of clarification will be, as the formula (4.5) is used, it is more expensive, it will take a lot of time to clear up all the processes that will take place.

Vshtovhuvannya (payload) for the increase Transmission, the system will be maggated for the time being, up to any side or segment in the process. As soon as the memory of the temple and in the first memory is in the first place, then the sides will appear, or the segments will be rewritten in the first memory before that, as before them, the brutality will be clearly carried out. With the correct selection of links (segments) for the anticipatory pumping, the start hour is given to the process and change the value of the "space-hour" indicator.

Until the shortage of the strategy of increasing the rate of change, it is possible to introduce the fact that, as if from the theory of calculation, as if to transfer the paths, as if the process would develop, it would be unfortunate. That is, at all possible situations, if the decision about vibrating stanitsa (segments) through the process of proactive pumping will be taken in a large number of cases for one of the most decisive processes that need not be developed in the system, which will їм sidelines or segments.

4.4.3. strategy of distribution

In systems with sidelines organizing the virtual memory of the decision about the distribution of the new zavanazhivayutsya sides, it is easy to finish: the new side can be placed in a whitish side frame.

For systems z segmental Organizational virtual memory will also be stuck in the strategy of distribution, as vikoristovyvayutsya in the systems of memory for the memory of change (div. clause 4.2), and itself:

· razmіshennya with the vibration of the first incoming vіlnoї dilyanka;

· razmіshennya with a vibration of the most suitable vіlnoї dіlyanka;

· razmіshennya z vibor naymensh adjoining wіlnoї dіlyanka.

A detailed description of the process for the implementation of re-insurance strategies for distribution is given in clause 4.2.3.

4.4.4. strategy vishtovkhuvannya

In multiprogram systems, all primary memory is used, which, as a rule, is occupied. In the end of the memory management program, virishuvati is to blame, for any segment of the memory was seen from the primary memory, so that it was a point to get the side of a segment. In the Danish hour, the following strategies of vishtovkhuvannya (vidkachuvannya) sides (segments) will be fixed:

• vishtovhuvannya vypadkovyh sides and segments;
• vishtovhuvannya pershoi came from abo segment (FIFO);
• vishtovkhuvannya not vikoristovuvalasya sides abo segments (LRU);
• vyshtovhuvannya naimensh often vikorystvuvalysya sides abo segments (LFU);
• vyshtovhuvannya not vikoristovuyutsya staying hour, or segments (NUR).

Strategy of vishtovkhuvannya of vipadkovyh sides and segments є the easiest way to implement, there are little vitrates and not discriminatory in terms of performance before any processes that work in the system. From the point of view of the strategy of being either side of the segment or of being in the first memory, it can be secured for the development of the same image, in addition, there is a backward side of the segment, until the future memory of the most underestimated). Oskіlki is similar to strategy, by the essence, it is rooted in the "slap" luck, in real systems it’s stagnant.

The strategy of vishtovhuvannya of the first came to the side of the abo segment (FIFO-strategy) realizes the principle "the first priest - the first pishov". At the same time, at the moment of the proper skin side (segment), the first memory of the first (yom) memory is assigned to the hour. If there is a need to see the original memory, be it a side (segment), select that side (segment), at the same time the least meaningful is. An argument against such a strategy is vyshtovhuvannya є an argument that the given side already has a chance of getting a chance, and it’s time to give more versatility to the other side. However, the strategy of FIFO with a great sense of the future leads to the visible from the primary memory of actively victorious sides (segments), some of the fact that a side (segment) is in the first memory as a stretch of a trivial hour, a complete to be constantly in the robot.

Strategy vishtovkhuvannya found no vikorists transmission, which for vyshtovhuvannya slid vibrate the sides (segments), as they did not vikoristovuvali more than the others. The strategy of LRU vimag, schob in case of cutaneous malignancy to the sides (segments) of the mitts was taken for an hour. Tse can be tied with hundreds of vitrates, to that LRU-strategy, unimportant to its addiction, in the current operating systems realizable to finish pretty well. In addition, with the implementation of the LRU-strategy, it can be like that, but the side (segment), until it was not found a beast, in the realm of the offensive victorious side (segment), which is a great program until the whole moment of the Chergovy abo segments.

Strategy of vyshtovhuvannya of the most victorious sides of abo segments (LFU-strategy) є One of the closest to the best LRU strategy. According to the LFU-strategy from the primary memory, the most frequent (most intensively) vikorisovyvayutsya naymensh until the end of the hour, or segments. Here the intensity of the traffic (segments) is controlled. For a whole skin side (segment), a pilot is assigned, meaning that it is one for a skin infection to a given side (segment). LFU-strategy, being intuitively true, has some shortcomings, but also the strategy of LRU: in the first place, it’s great that from the original memory there will be visible sideways or segments, as the process will be consumed by the future , on the other hand, the implementation may be tied to significant vitrates for organizing the control of the intensity of the reaction of the sides of the segments.

The strategy of vishtovkhuvannya was not vikoristovyvayas in the rest of the hour, but also segments (NUR-strategy) It is also close to the LRU strategy and is characterized by remarkably small vitrates in its implementation. NUR-strategy is well known from the primordial memory of those sides (segments), until the last hour. From the point of view of the power of the locality in hours (see clause 4.4.1) to the sides (segments), which were not corroded in the last hour, it is unlikely that there will be brutality in the closest possible, so it is possible to replace the sides for a new word.

Oskіlki bazhano replace these sides (segments), which during the period were not changed to the main memory, the implementation of the NUR-strategy of transmission was introduced two device bit-marks on the side (segment):

· bit-mark b 0 turn to side (segment);

· bit-sign b 1 modification of the side (segment).

The list of all b 0 and b 1 will be set to 0. When you turn to the side (segment), the displayed bit-sign b 0 will be set to 1. If you change from the side (segment), the displayed bit-to-mark b 1 will be transferred to 1. іsnuvannya chotiroh groups of sides (segments), shown in table. 4.5.

Table 4.5.Group of storinok (segments)

Group

In the first place, from the original memory, there are sides (segments), which should be assigned to groups of smaller numbers.

For an hour, stretching out to the sides (segments), there was no grain, there are periodic discounts in 0 all bit-signs, which are displayed by the operating system.

Practically, whether the strategy of vyshtovhuvannya sides (segments) does not involve non-rational decisions. It will be explained, the operating system cannot accurately predict the behavior of any processes that have come to it for processing.

Control food

1. Often, we share the opportunity to change the virtual memory for the process of communicating with the virtual address space, which is changing the communication of the real memory. Name the dignity of the virtual memory.

2. Who has the changes and shortcomings of the revision of the virtual address in the real world from the hour to the program? Yaka is a part of robots, according to the whole reconfiguration of the device, and the yak is an OS?

3. Also, it is important that the virtual memory can be saved only in the systems with the device dynamic translation of the address. Make it clear that it’s not so.

4. Why, at the joke of the great memory of the strategy, "the most beautiful" appears to be better, not "the first who comes".

5. Compare the segment and the line model of the virtual memory. How can you see them beautifully and why?

6. Additional guidance in the section 3.5. mіrkuvannya s drive vibrator size side.

7. Simulate the situation of storing the discipline of FCFS, in which an increase in the number of real links is brought up to an increase in the number of side views.

8. What is the same cluster feed of sideways? Why is it getting more and more popular in today's OS?

9. By the rank of OS, can it be that before which sides will the brutalization be the nearest hour?

10. The great scope of virtual memory can be made to the process until the table of links is not located in real memory. What is the problem in the current OS?

11. What is the rank of lowering the parity of memory injected into the discipline of managing memory?

12. What are the principles of change in the concept of memory, can you give rise to an increase in the size of the address?

OS functions for memory management

Pid memory (memory) here rely on respect for the operative memory of the computer. On the view of the memory of the hard disk, as it is called the new memory (storage), the operational memory for saving information will not need electricity.

Memory is the most valuable resource, which can be used for magic control from the side of a multiprogrammed operating system. A special role of memory is explained by the fact that the processor can display the instructions for etching only in the same way as the stench is found in the memory. The memory is distributed both between the modules of application programs, and also between the modules of the operating system itself.

In early operating systems, memory management was built simply until the programs were entangled with programs and given from the deyakogo zvnishnogo accumulator (perforated lines, magnetic lines, or a magnetic disk) in the memory. With the advent of multiprogramming in front of the OS, there will be a new factory installed, connected with the distribution of the explicit memory, and the decilcom will instantly display the programs.

OS functions for memory management in a multiprogram system є:

• vіdsthezhennya vіlnoї and vikoristanoi memory;
• seeing the memory of the processes and the sound of the memory after the completion of the processes;
• changing the code and given processes from the operative memory to disk (outside of the part), if the main memory is not enough for changing in any of the processes, and turning it into the operative memory, if
• tune the address by programs to a specific area of ​​physical memory.

In addition to the cobbled memory of the processes at the beginning of the OS, it is also responsible for the dynamic distribution of memory, so that it will be able to power up the additional memory for the first time. For that, as supplements cease to be required in supplementary memory, it is possible to turn the system. I saw the memory of the vipadkovoi dozhini in vypadkovy moments from the out-of-the-box pool of memory to the point of fragmentation and, as a result, to an ineffective vikoristannya. Defragmentation of memory is also the function of the operating system.

Before the hour of the robotic operating system, it is often brought up to new services and information structures, such as process and flow descriptors, resource allocation tables, buffers, which can be processed by processes for exchanging data. 'kti vimagayut memory' '' 'In some operating systems it is long ago (before the hour of installation) there is a storage of memory for system needs. In the same OS, there is a big nasty pidhid, with a memory for the system cells, it is seen dynamically. In such a way of operating system subsystems when their tables, objects, structures, etc. are installed.

Zachist memory is a very important task of the operational system, as it is not possible to allow the process of writing down or reading the data from the memory assigned to the process. This function, as a rule, is implemented by the software modules of the OS in a tricky interconnection with the hardware.

Functions of the OS for managing memory - understanding and seeing. Classification and special features of the category "OS functions for memory management" 2017, 2018.

Memory є is the most important resource, which can be controlled from the side of the multiprogrammed operating system. All operational memory is not occupied by the core of the operating system. Call the core of the operating system and roztashovuyutsya either in the youngest, or in the senior addresses themselves. Functions of the operational system and memory management є:

1. Vіdsthennya vіlnoy and vikoristanoi memory

2. Vision of memory to processes and memory of memory when processes are completed

3. Changing the processes from the operative memory to disk, if the main memory of the deficiencies for displacing in all processes and turning them into the operative memory, if there is a flash

4. Adjusting the address of the program to a specific area of ​​physical memory

The quality of the operating system, in the first place, can be judged by how efficiently the processes need to be remembered.

tipi address

Symbolic names, virtual addresses and physical addresses should be used for identifying winter teams. Symbolic names are assigned to koristuvach when written by programs. Virtual address and viroblyaє translator, scho translate the program into machine language. So, before the hour of translation into the out-of-the-box vipad, the program will be tampered with in the place of operational memory, then the translator will be attributed to the programs of the virtual (cleared) addresses, invoke vazhayuyu for the prompts, as soon as the program will be addressed. The combination of virtual addresses to the process is called virtual address space. The skin process is full of virtual space. The maximum size of the virtual address space is flanked by the size of the address, the power of the architecture of the computer, and as a rule not to be lost in the vast physical memory of the computer. Moving from a virtual address to a physical one can be done in two ways:

1. For the first time, I will replace the virtual address on the physical address of the special system program - change the transfer, then change the transfer on the display at the latest in the latest reports about the address of the transfer of the physical memory of the program replacing virtual addresses with physical

2. Another way of polling is that the program is locked into the memory in the invisible viglyad - in virtual addresses, with the whole operation of the system fiksuє zsuv deyysnogo roztashuvannya program code to the virtual address space. It takes an hour to see the programs in case of skin malignancy until the operative memory is to see the revision of VA in physical. Another way є more nasty is that the program is allowed to be changed by the program every hour of the day.

In some cases, in special systems, the program will be shown in advance exactly in the region itself of the operational memory. Todi translator of the form of displaying the code directly in the physical addresses.

Classification of methods in the development of memory

Method of distributing into two groups:

1. Without the victorious name of the memory

a. fixed pieces

b. dynamical pieces

c. move around

2.To the vicarious memorials

a. side-by-side

b. segmental rose

c. Segment-sided rozpodil

Razpodil memory with fixed razdilami

The simplest way to manage the operational memory is to add to the number of distributions of fixed size. I will give the operator a chance to hand over the start of the system, or before the hour of the generation. Chergov's task is to come to a vison in the presence of a whole person, either in the back room, or in the room before the deyako razdilu.

Pidsystem of memory management in this method

1. Change the size of the programs, but it hoped for the release and the size of the wines of the selection

2. Zdіysnyu zavanazhennya programs in the whole distribution and set up the address

With the obvious overvoltage - the simplicity of the implementation, the method is short-lived, so as in the skin part it can be seen only one program of the multiprogramme for a long time, the number of rounds is small and not far from the side.

Rozpodil memory razdilami of great magnitude

In general, the memory of the car does not last long on the part. All the memory is good for a good deal, and for the skin it is necessary to see the tasks and to see the necessary memory. As long as there is a sufficient obsyag for the memory of the day, then the task will not be accepted for the visit, but at the end of the day, with the sound memory of the patron, you can come to the visit, after the completion of the memory task, the task of the goal In such a rank, at a certain moment of the hour, the operative memory є the last of the busy and vilnyh dalyanoks (razdіlіv) dovіlny size. Heads of the operating system in the implementation of this method є:

1. Provided a table of vilny and occupied regions, in which the cob addresses and razmіri of dіlyanok memorials

2. When a new task is appropriate - an analysis of the power supply, a re-examination of the tables of the provincial regions and the vibration of the distribution, the size of what is sufficient for the distribution was needed.

4. For the completion of the establishment of the corridor table of the rural and occupied regions

In this way, the program code does not change for an hour, so that a one-time setting of the address can be done by changing the mailbox. Vibir rozdilu for a new reliable manager can follow the new rules.

In the case of the method of growing the memory with fixed distributions of the Danes, the method is more tedious, but there is a little bit of it - the fragmentation of the memory.

Fragmentation is the manifestation of a great number of incompetent files in a memory even of a small size. Plants are small, but the program cannot be accommodated in them, the protector of fragments can be reduced to a value that will change the necessary amount of memory.

change of distribution

One of the methods of fighting with fragmentation є shifting all occupied distributions towards the younger or older ones, so that all the memory would be validated in one region. In addition to the functions of the vison, the operating system is used when the memory is broken by changing parts. In this case, she is guilty of periodically copying, instead of being distributed from one memory, in the same place, corrected tables of local and occupied regions. Qia procedure is named. Stressing can be seen if the skin is completed, or only todi, if for the knowledge the tasks are not necessary for a sufficient size. The first option needs less robots when correcting the tables, the other needs the very procedure of squeezing. So, as the programs move according to the operational memory in the course of their vikonannya, the address is revised from the virtual form in a physical way, guilty, vikonuvati in a dynamic way. If I want to bring the procedure to a more effective memory of the memory, it may take a significant hour, but I often go over the overwhelming of the given method.

Methods for the development of memory from the disk space.

Understanding the virtual memory

The development of the methods of organizing the calculation of the process called for the emergence of the method of living under the name "virtual memory". A virtual resource is a resource such as koristuvachev or koristuvalnitskogo programs are represented by Volodya's authorities as not Volodya's. So koristuvachev can be given a virtual operative memory of the size of what I explicitly translate into real memory in the system. Such a rank of virtual memory is the supremacy of the software-hardware devices, which allows the criminals to write with the programs, which will change the operative memory. For all, the system of virtual memory

1. Razmіshchuє danі in zapam'yatovoy annexes of a type type. For example, a part of the program is in the operative memory, and a part is on the disk.

2. Relocation according to the world of need for a given type of annexes

3. Reconsideration of VA in physical

All the events are displayed automatically, so that the mechanism of the virtual memory is discerned by the relationship to the koristuvach.

Naybіlsh extended realizations of the virtual memory є:

1. Stornkova

2. Segment

3.Side-segmented memory rose

side-by-side

In the case of a reverse skin process, the VAP of the skin process extends into parts of the same, fixed for the given system, and parts, called virtual sides. In the case of the outward-facing view of the size of the virtual address space, the process is not a multiple of the size of the side, and the rest of the skin size is supplemented by the functional area.

All the physical operative memory of the machine is so long itself into parts of such parts, called physical links or blocks. The size of the side is sensitively vibrated by the equal steps of the two. Tse will allow to simplify the mechanism of re-addressing. When the process is locked, a part of the virtual pages is placed in the operative memory, the other pages on the disk. With a large amount of virtual lines, it is not necessary to roztasovuyutsya in summery physical lines. When the operative system is locked for the skin process, the information structure is a table of links, in which the turnover between the numbers of the virtual and physical links is set, for the links to be processed in the operative memory, in order to work to disk. Krіm, in tablitsі storіnok mіstitsya keruyucha іnformatsіya, such yak Find our modifіkatsії storіnki, Find our nevigruzhaemostі - vivantazhennya deyakih storіnok Mauger Buti zaboronena, Find our zvertannya to storіnki (vikoristovuєtsya for pіdrahunku kіlkostі zvernen for Pevnyi perіod hour) that INSHI danі formuyutsya i vikoristovuyutsya mehanіzmom vіrtualnoї memory 'yati. When activating the check process, the special register of the processor will be assigned the addresses of the side tables of the given process. In case of skin infection, it is far to the memory of reading from the tables of information on the virtual side to what has been seen. If the virtual side is given to be in the operative memory, then the conversion of the VA is shown physically, if the virtual side is required at the moment it is not available, then it is called so called the side of the change. The process of being transferred to the camp of deception and activation of the process of the ready-made. At the same time, the program for processing the back-to-back conversion is required to have a virtual side on the disk and to re-enumerate it in the operative memory. As in the memory є there is a strong physical side, it is secured to be displayed in a secret way, if there are no free sides, it is necessary to take a decision about those, like the side of the vivantage from the operational memory. It is possible that vicoristano is rich in growing criteria, the most popular ones are:

1. More for everything the part was not victorious

2. Storinka until the next hour bulo the smallest zvernen

3. Persha had a meal on the side.

In the case of these systems, they are victorious to understand the robust, helpless sidelines. The work is ineffective for the skin process and is a transmutation of the most often vicious sides, which are responsible for the permanent transfer to the operative memory and do not allow for vivantation. For that, the yak is turned up, the side of the yak is guilty of leaving the operative memory to analyze the signs of modification. Whenever you want to see the part, at the moment the bullet is locked up, it is modified, it was rewritten to disk, and the part that is going to be displayed is going to be exposed. A virtual address in case of a reverse order can be represented by a number bet: first number is the number of the virtual side of the process, and another number is the change in the boundaries of the virtual side. I’ll look at those, where the size of the side of the road is two in the day of the world, the change of the middle side can be easily forgiven for the information of the youngest groups of two to write the virtual address. Rashta of the senior rozryady is a double record of the line number. In case of cutaneous malignancy to the operative memory, it is necessary to use apparatus to determine the onset of the action:

1. At the post office address of the side of the side (instead of the register of the address of the side tables) the number of the virtual side (old) New entries in the side tables

2. To start the address of the required record in the table. Please note the physical side number

3. To the number of the physical side, join the zsuv (youngest range of the virtual address)

On the productivity of the system from the side organizing memory, they pour in the time vitrati tied from the obsolete side reversal and the conversion of the virtual address into the physical

With frequent system transfers, the system can take less than an hour to swap pages. For a change in frequency, it is possible to change the size of the sides. Ale todi vikoristannya of the parties themselves will be less effective

The backlog of memory can be implemented in a simplified version - without the copying of the side to disk. Such an option, if you want no virtual memory or even more fragmentation, for the reason that the program can be trapped in an insane area.

segmental rose

In case of reverse organization, the virtual address space extends to equal parts. Tse does not allow differentiation of the way of access to different parts by programs (segments), and the tse of power will be even more corny. For example, it is possible to use the programs for writing and reading in the code segment with programs, and for the segment of the data, allow only reading, so the software itself can be used in principle for one segment of the decalcom by processes. In case of segmental distribution, the virtual address space extends to the segments of the size of which visas are assigned by the programmer for the meaning of information to be included in them. The premium segment can be a software program, an array of tributes and so far. Inodi segmentation of the program is displayed in a way that is suggested by the compiler. When the process is locked up, some of the segments are placed in the OP, while for the skin segments of the OS, the incoming memory is received, and some of the segments are placed on disks. Segments with the same programs can take care of inane files. Every hour the system is set up with a table of segments in the process of analogous table of lines, in which for the skin segment the pochatka physical addresses, size of the segment, access rules, signs of modification, sign of update to the segment for the remainder of the hour If a VAP of a series of processes includes one and the same segment, then in the tables of segments of these processes, it will be assigned to one and the same folder of operational memory, in which segment will be entangled in one instance. System Segment іz organіzatsієyu funktsіonuє analogіchno system of storіnkovoї organіzatsієyu: perіodichno vіdbuvayutsya pererivannya pov'yazanі of vіdsutnіstyu potrіbnih segmentіv pam'yatі at neobhіdnostі zvіlnennya pam'yatі deyakі segment vivantazhuyutsya, skin zvernennі to operativnoї pam'yatі vikonuєtsya peretvorennya BA in fіzichnu. Moreover, when the memory is turned up to memory, it is necessary to change the access of the necessary type to the given segment. The shortage given to the method of fragmentation on equal segments and more (in the case of the original organization) is the re-implementation of the address.

Stornkovo-segmented rozpodil

The Danish method is a combination of linear and segmental memory. The VAP process is divided into segments, and the skin segment extends into virtual sides, which are numbered at the boundaries of the segment. Operational memory extends to the physical side. The entangled process is displayed by the post-work system, while the part of the part is moved to the operative memory, and the part is on the disk. For the skin segment, its own table of sideways is created, the structure of which is increased by the structure of the table of sideways that are vicious in case of sideways growth. For the skin process, a table of segments is included in the address and table of links for all segments of a given process. The addresses of the segment tables are assigned to the special register of the processor, if the process is active.

The architecture of the memory of the annexes. The principle of keshuvannya danih.

Kesh-memory is a way of organizing the social function of two types of memorials in the memory of annexes, which are often available for an hour, and it is possible to change the middle hour of memorials for the memory of yati. Kesh-pam'yattyu is often called not only the way of organizing the robot of two types of memory-attached attachments, but one of the attachments is a shvidku memory. Shvidka memory kostu dear and as the rule is usually small not obsyag. It is important that the mechanism of cash-memory є can be seen for other subsystems.

file system

The file system is a part of the operating system, which is meant to protect the computer's handheld interface when using data, to save it on a disk and to prevent it from keeping files on file by processes. In general, the file system includes:

1.supply of all files on disk

2.Get the structures given by the file manager for managing files, such as file directories, file descriptors, tables of a file and a busy message on disk

3. A complex of system software tools to implement the management of the files of the child: opening, maintenance, reading, recording, changing, pushing and operations on files

Name of files

Files are identified by names. Yogo koristuvachi dati yom files in symbolic names. At the same time, it is necessary to interconnect the operating system, both for vicarist symbols, and for even more. Until a relatively recent hour, the tsi mezhi boules will be filled with vuzkim. Name the files you can name the same symbolic names, in which case the file is unambiguously identified.

In some systems, one and the same file may be given a number of different names. In general, the operating system is attached to the file uniquely, as it correctly represents a numeric identifier. The application of such a unique name is the number of the index descriptor in UNIX systems.

see files

Files will see new species. Zvychayn_ files, special files, files-directories. Zvichini files in their own capacity are subdivided into texts and dvіykovі. Text files are stored in a row of symbols - there can be documents, such as the original text of the program, configuration files and so on. Dvіykovі files often conceal a collapsible internal structure. For example, the application code of the program or the archive file. Special files - files of associations with attachments to the input / output, which allow the operation of the input-output operation, the specific commands will be written to the file or read from the file. The command is processed with a set of programs of the file system, and then it is transformed into the command for managing the attachments.

Directory - a whole group of files shared by a file, or with a system, from the other side of a file to reveal system information about a group of files from a warehouse. The catalog has a list of files to enter before new and it will be established as a list of files and their characteristics (Attributes).

In other file systems, there can be vikoristovuvatsya in the quality of attributes in different characteristics, for example:

1.Information about access permissions

3. Vllassnik file

4. Create a file

5. Signs "only for reading"

6. Signs of "hooking"

7. Sign "system file"

8. Sign "time file"

9. Signs of blocking

10. Hours of the stem, the last access, the last snake

11. Stream size file

Directories can easily reconstruct the values ​​of file characteristics as is common in FAT systems, or look at tables to reveal the characteristics that are common in UNIX systems. Catalogs can be organized into an organizational structure for the purpose of which the catalog of the lower level can be included in the catalog of the higher level. The archives of catalogs can be made with a tree or with a hem. Directories set up a tree if a file is allowed to enter only one directory, or if a file can be entered directly into a directory's decal. As a directory file, it is not symbolic and unambiguously identifiable to store them, to place the lanterns of symbolic names in all directories through how to go through the path to the root to this directory.

Logical organization of files

The programmer can handle the logical organizing of files, representing the file at the top of the organized logical records. Logical recording - the price of the least element of the data, which can be operated by the programmer when exchanging information like a physical exchange with attachments to work with great odds of data The operating system will secure access to a logical one. Recordings can be fiksovanoy dozhini or zminnoy dozhini. Records can be updated in the file last, or in a larger folding order with the index tables, which will allow you to secure quick access to a logical record.

Physical organization and file addresses

Physical organization of viznachaє rules rostashuvannya file on the attachment of the memory (zokrem on disk). The file is stored from physical records - blocks. The block is the name of one of the tributes, which are known to be assigned to the operational memory. Bezperervne razmіshennya - the simplest version of physical addressing, when a file is given the last of the disk blocks, it will set up a single subset of the disk memory. To add the address to the file, add only the number of the cob block and the final file to the file. Perevagi method - simplicity, ale є two suttas of their shortcomings

1.from the hour of the opening of the file, not from the house of the last one, the memory is not required to be backed up

2. with this order of distribution, the inevitable fragmentation is inevitable.

The offensive method of physical organization is the separation of a knotted disk from the disk memory blocks. With this method, a pointer to the onset of the block is placed on the cob of the skin block. At the same address, the file can have tasks with one number - the number of the first block and the skin block can be added to the lance of any file, and the file can be changed every hour of its creation by increasing the number of blocks. In a short time є the ability to implement access to a pre-specified file. For example, if you want to read the 10th block in order, you need to look over the first 9 blocks afterwards, quilting the lancers of block numbers. In addition, with a great way, a number of given files can be found in one block, not by a road step of a two-track, but by a lot of programs to read data in blocks, size of which by a door step of a door. In an offensive way є victorianna tied to the list of indexes. The singing element - index - is ringing with the skin block. The index should be re-welded in the vicinity of the disc. If a block of distributions to a file is used, then the index block should be replaced with the number of the offensive block of the given file. With such a physical organization, it is necessary to take advantage of the best way, and to know the shortcomings: to access the most recent file of files, read only a block of indexes, see if you need a large number of files. In other words, dan files occupy a whole block, which means May obsyag rivny steps of two.

We will forgive the overhaul of the numbers in the blocks by the file. The operating system UNIX is a vikoristic version of this method, which allows you to preserve the fixed address and the size of the file. 13 fields have been seen to retrieve the address and file. If the size of the file is less than 10 blocks, then the number of blocks is reassured in the first 10 address fields. If the file size is more than 10 blocks, then the next 11th field will be set to the address of the block in which there can be more than 128 numbers in the upcoming blocks in the file. If the file is more than 10 + 128 blocks, then there are 12 fields in which there is a block number, 128 block numbers should be placed, and there are more than 128 block numbers in a given file. If the file is larger, then you will be left with the 13th field for indirect addressing.

File access rights

Visually, the right to access the file means that for the dermal coristiner there are a set of operations that can be stored before the given file. In other file systems, a list of differentiated access operations can be assigned. The whole list can include new operations:

1. Connecting to a file

2. Slaughtering the file

3. Displaying the file

4. Close the file

5. Reading the file

6. Write to file

7.Adding to the file

8. Post to files

9. Otrimannya attributes in the file

10. Setting new attribute values

11. Renaming files

12. Visiting the file

13. Reading catalog

14.Inshi operations with files and directories

At the top of the list, the right to access can be set aside by the matrix of access rights, in which hundreds of files are displayed, rows - to the permissions. Permission of operations will appear on the overturning of rows and hundreds of times. In some systems, corystuvachi can be distributed in the same category. For all persons belonging to the same category, one has one access right. For example, in UNIX systems, everyone is divided into three categories: the owner of the file, the members of this group, and all of them.

There are two main ways to increase access rights:

1. Vibrant pidhid - skin file and skin tone, the owner himself can be quite acceptable operations

2. Mandate pidhid - a system of supervising singing rights for the use of the skin resource, scho. In the given vypadku to the file, in the fallowness of that to which group of data.

keshuvannya disk

In some file systems, power up to the new annexes, in which addressing blocks are overridden by the intermediate software ball of the buffering system. Buffering subsystem є a buffer pool that can be installed in the operative memory and a complex of programmed cims by the pool. The skin buffer of the pool is sized for one block. For an hour, it will be fed to the readable block, the buffering system will look at the pool and if the necessary block is found, it will be copied to the buffer of the powered process. The operation of the introduction / vivedennya vvazhaєtsya viskonanim, I want the physical exchange from the attachment not to be added. Even though the required block is read out from the annex, and immediately after transferring it to the process, it is copied into one of the buffers in the buffering system. When there is a virtual buffer on the disk, the information is changed. In such a rank, the buffering system is based on the principle of cache memory.

The file system model is coarse

The function of any file system can be found in a bag of a small type, in a skin type there is a good interface for a set of functions for a file system, and he himself in his own room for displaying his own robots vicious interface.

Rivni from bottom to top

1. Physical rivn - to turn only before the introduction / vivod system. Yogo registration of the number of the physical block revenge the logical entry

2. Logic r_ven - Turn up to physical, yogo function - the value of the coordinates of the logical record in the file

3. Equivalence of access rights revision - the first revision of the validity of the specified operation to the specified file

4. Basic value - value based on the unique characteristics of the file

5. Symbolic r_ven - value based on the symbolic name of the file of the unique name

Visible in the memory of the file

At the occasion of access to the memory, the traditional access to the files of the viglyad is not handy. There are three reasons for the operation of the operating system and to prevent the display of files in the address space of the selected process. The price of rotating in the appearance of special system wikklikiv - map (display) and unmap (displaying the display), at the same hour, the need for a number of special wikkliks in the input / output system is displayed.

The current architecture of file systems

The vendors of new operating systems should not be able to protect the file system from the file system. The new smart file system is stored in storage warehouses, which include the file system in the traditional design. The new file system has a smaller structure, at the top of which the names of file systems are changed. In Windows, it is called the file system manager and IFS, it will take over the interface between the add-ons and the specific file system. Changing file systems will rewrite the file systems in the format. The skin component of the file systems of the vikoniya in the driver of the visual file system and the adaptable organization of the file system. The remixer is a single module that can be rolled up to the file system driver. To display their functions, the file system drivers are expanded before the introduction / release of the file system is set on the offensive ball of the file system and new art. Pidsystem for input / output of the warehouse part of the file system, and it is displayed for the interlocking, innovation and control of all modules of the lower levels of the file system.

A great number of filesystem architecture races will not prevent the dullness and independence of the file system's architecture. It is implemented through the lancers of system wikkliks, so that it allows you to add the types of files and folders to the foldability of the file system.

For memory here, rely on respect for operational memory.

Main OS functions for memory management:

1.vidzhennya vіlnoy and vikoristanoi memory

2.visible memory of processes and memory of memory and completion

3.Visnennya code in and given to the process of the OP on a hard disk, since the size of the OP is not enough for changing all the processes, and turning these processes in the OP in case of a sound mission

4. setting the program address for a specific area of ​​physical memory

Likewise, OS is guilty of taking over the dynamic memory of the memory, so that it will be able to power up the additional memory for the last hour of the robot.

Another important function of the OS is to defragment the memory, so that the vision of the memory of the vipadkovoj dojini at a certain moment in the hour from the out-of-town communication of the memory is brought to the point of fragmentation, which means trusting the robot of the system.

It is also important to save memory, to be implemented by OS software modules in a tight interconnection with hardware devices. Vona polyagє in that, you will not allow the process of writing or reading the data from the memory, which is intended for the process.

The development stage of KOMPUTERІV І OS, describing KOZHEN ETAP

Oscillations of the OS appeared and developed in the process of designing the computer, then the steps were historically linked one to one. See chotiri main steps:

1. First generation (1945-55)

Electronic lamps were installed in the relay. Managing the main functions of the vikonuvalasya behind the additional connection of the commutation panels with wires. About the presence of the OS is not boolean.

With the release of punched cards, it became possible to record and read programs.

2. Another generation (1955-65)

The appearance of the transistor has increased the reliability of the robotic machines, the power of the pre-production robots has appeared. Large and expensive computers appeared and were called mainframes. There was a system of batch processing of information and an effective registration of the machine hour (the selection of a great number of punched cards and preparation for an inexpensive computer, and the process of processing is already at a higher price).

Programming on movs Fortran and Assembler

3. Third generation (1965-80)

Vikoristannya of other-scale integration schemes, which gave an upgrade in price and quality. To the more important achievements, the problem of problem-solving has become.

4. Fourth generation (1980-our days)

It is implied that there is more growth in the development of both technical and software aspects of computers. The emergence of silicon microcircuits (processor), disk accumulators - became the most important achievements. Becoming progress from OS with text interface to OS with modern graphics. The computational effort and efficiency of the EOM robot is getting bigger and bigger.

ROZDIL I ARCHITECTURE ЕОМ

1 EOM heading structure diagram. Tipi and class EOM. Attach personal EOM.

2 Understanding about bagatomachine and bagatomprocessor computational systems.

3 See the information you have accumulated. Virtual memory. Backup copy.

4 Systemic software security.

5 Types of operating systems. Operating systems for personal computers.

6 Types of disk drives. Physical and logical pardons.

7 Views and signs of applied software security (text editors, graphical processors, utilities, systems and software).

8 Peripheral attachments for personal computers.

9 Mere transmissions of tributes. Global and Local. The possession is necessary for the establishment of local fences (cables, connectors, connecting annexes, routers).

10 Programmable cutout protocols. OSI model (hardware level, transport level, user level). Details about transport protocols on NetBEUI, IPX / SPX and TCP / IP applications.

11 Basic services of the Internet. Web-side (HTTP), file transfer (FTP), e-mail (SMTP, POP3), resource management (Telnet, SSH). Domain Name System (DNS).

12 Information security. Systemic and biometric authentication. Unauthorized access to tribute.

13 Merezhevі attacks on vіdmova in service providers (DOS, DDOS),

14 Attacks on the "sight of the stack".

15 Computer viruses, programs like "Trojan Kin"

OPERATING SYSTEMS

16 OS real hour, description and value.

17 Basic functions of OS, date description.

18 Viznachennya planuvannya. Main staff

19 Description of the algorithm based on priorities. bring the graph

20 Understanding the process and flow. WAP

21 Description of the algorithm based on quantum. bring the graph

22 Designated dispatching. Main staff

23 vitality and unwitting planning algorithms. Pererahuvati passages and shortcomings

24 Swap value and virtual memory. Advantages and shortcomings

25 Understanding of confidentiality, integrity and availability of data

26 Basics of symmetric encryption algorithm. butt

27 bases of non-symmetric encryption. butt

28 Main steps to close the backup

29 OS functions for memory management

30 Step of development of computers and OS, describe the skin step