CN103902466A - Internal memory pool capable of being dynamically adjusted - Google Patents

Abstract

The invention provides an internal memory pool capable of being dynamically adjusted and relates to the field of computer internal memory managing mechanisms. The internal memory pool has the advantages that an intermediate manner which is characterized in that internal memory is distributed during use and not immediately released after use is designed, when a program applies for an internal memory unit of similar size, the internal memory applied before can be directly used by the new request, releasing is delayed on the basis of chain tables so as to increase system efficiency, internal memory fragments generated during internal memory use are reduced, internal memory units of different lengths are organized by bidirectional link header arrays, and mutually exclusive access of each chain table is realized by the elements of mutex arrays.

Description

The memory pool that a kind of capable of dynamic regulates

technical field

the present invention relates to calculator memory administrative mechanism, the internal memory that specifically a kind of capable of dynamic regulates, uses suitable redesign to solve the problem that memory usage that frequent application and releasing memory bring and system effectiveness reduce.

Background technology

In operating system now, it is programmer's most thorny issue that the use of internal memory has been become, the release of internal memory and application internal memory length not equal improper use are tended to cause program crashing, memory overflow, also may occur the various strange problems such as the data that cause due to memory overwriting are incorrect.The mechanism such as the automatic Memory recycle of various language are also continually developed out.Even if application and releasing memory that can be correct, when frequently applying for and discharging also to cause following two problems.The one, on the impact of efficiency, application and releasing memory can need to do a lot of processing in inside in operating system, and efficiency is often not high.The 2nd, because Installed System Memory distribution mechanism problem causes, in the time that user asks an internal storage location to be less than a page, system can be on page storage allocation, but in the time that another memory request is greater than the remaining space of last page, system can be distributed the memory headroom of asking on new page, now the remaining space of first page will form fragment, forms after a large amount of memory fragmentations and can cause running efficiency of system to decline, and even causes program not move.Picture send the webserver of result more easily to go wrong for the frequent request Concurrency that receives very much, and the internal memory that exhausts that system can be very fast reduces running efficiency of system gradually, finally can not process request.

Frequent application and releasing memory unit can be to lowering efficiency, increase cpu expense, the expense that can use the abundant internal storage location mode of prior distribution to reduce application and discharge, but the shortcoming of storage allocation unit is we and the uncertain internal storage location size that we will use in advance, if the memory size of frequent demand is far smaller than the internal storage location of prior distribution, can cause the huge waste of internal storage location, if distribute in advance too many memory-to-memory pond simultaneously, when user not can not cause system and application program can not use this partial memory when memory request frequently, cause equally the waste of internal memory.Although the method can solve the problem of RAM fragmentation, but still it not effective solution.

Summary of the invention

By above analysis, it is not best settling mode that the prior distribution of internal memory and used time distribute, so should be by a kind of mid way of design, storage allocation while using a kind of use, the mode of releasing memory immediately not after being used to complete, in the time that program is applied for the internal storage location of similar size again, use directly to new request the internal memory of applying for before, the memory pool mode that realizes a kind of program oneself maintenance of compromise solves the deficiency of above two kinds of problems

Memory pool comprises a Two-way Chain gauge outfit array and each linked list head is carried out to the mutexes array of exclusive reference.Each linked list head and mutexes pairing are used.Each Two-way Chain gauge outfit is that different linked list heads are organized the internal storage location of different length in order to organize the internal storage location that each length is identical, needs exclusive reference, so need corresponding mutexes array due to the deletion of chained list with while adding new storage unit.The length of array of pointers and mutexes array equal in length, it depends on internal storage location scope and the internal storage location length interval of request.Less internal storage location interval can make memory usage higher, but the probability of mutual exclusion will be higher, and efficiency can be lower.

The memory pool that capable of dynamic regulates, has realized initialization, destruction, application, release and scan routine,

Initialization routine is responsible for the initialization of linked list array and mutexes array and the initialization of scanning thread;

Destroy routine, be responsible for destroying intermittent scanning thread, destroy Two-way Chain gauge outfit array and corresponding mutexes array;

Application routine be responsible for first attempts to obtain internal storage location from memory pool chained list, in the time there is no suitable internal storage location from Installed System Memory application;

Discharge routine and be responsible for the internal memory of user's release to be reentered into storage pool, insert in chained list;

Scan routine is responsible for the each chained list of timing scan, searches the internal storage location not using for a long time, and returns to Installed System Memory after discharging;

Storage allocation when use, the mode of releasing memory immediately not after being used to complete, in the time that program is applied for the internal storage location of similar size again, directly gives new request use by the internal memory of application before.

The beneficial effect that the present invention produces is:

Improve system effectiveness as basis with delayed release take chained list, reduce the memory fragmentation that internal memory use procedure produces, realize the internal storage location with Two-way Chain gauge outfit array organization different length, realize the memory pool of the exclusive reference to each chained list with the element of mutexes array, improved the frequent application of program and discharged the problem that causes Efficiency Decreasing and memory fragmentation.

accompanying drawing explanation

Accompanying drawing 1 is memory management routine figure of the present invention.

Embodiment

The memory pool that capable of dynamic regulates, has realized initialization, destruction, application, release and scan routine,

Memory management routine:

Initialization routine needed first to carry out initialized operation before memory pool uses, and structure Two-way Chain gauge outfit array is also constructed corresponding mutexes array, and scanning thread of initialization registration is set scanning thread cycle length.

Destroy routine, be responsible for destroying intermittent scanning thread, destroy Two-way Chain gauge outfit array and corresponding mutexes array.

Internal storage location application, internal memory length l en as required, 2^ (n-1) <len<=2^n, the value of calculating n, using n as linked list head array indexing, check on the chained list of linked list head index and whether have internal storage location, if available free internal storage location, the internal storage location that is 2^n from system application length, if available free unit, chained list is locked, obtain this internal storage location from chained list and use.

Internal storage location discharges routine, the effect that internal storage location discharges routine is that the internal storage location that user is not re-used is put back in memory pool, first to lock to Two-way Chain gauge outfit corresponding to length, and internal storage location is inserted to doubly linked list tail, then discharge chained list lock, realized a kind of time delay releasing memory unit and realize the solution of compromise.

Scanning thread, scanning thread is one-period active thread, cycle can be according to using situation that suitable value is set, internal storage location on all bidirectional pointer chained lists of periodic scanning, check that internal storage location free time discharges this internal storage location in the time that internal storage location free time is greater than given time, internal memory is returned to system.System can continue to use this partial memory, in the time that memory pool is not used fast, is necessary by the rational internal memory time system of returning.Scanning is to be undertaken by linked list head array, first linked list head is locked, then each node in scan chain table, if find that node does not use for a long time, releasing memory unit, internal memory is returned to system, otherwise carried this internal storage location, only then carried out the surface sweeping of next chained list to having scanned a chained list.Each chained list has corresponding mutual exclusion lock, and how single chained list locks and all chained lists do not locked.

Claims (1)

1. the memory pool that capable of dynamic regulates, is characterized in that having realized initialization, destruction, application, release and scan routine,

Initialization routine is responsible for the initialization of linked list array and mutexes array and the initialization of scanning thread;

Destroy routine, be responsible for destroying intermittent scanning thread, destroy Two-way Chain gauge outfit array and corresponding mutexes array;

Application routine be responsible for first attempts to obtain internal storage location from memory pool chained list, in the time there is no suitable internal storage location from Installed System Memory application;

Discharge routine and be responsible for the internal memory of user's release to be reentered into storage pool, insert in chained list;

Scan routine is responsible for the each chained list of timing scan, searches the internal storage location not using for a long time, and returns to Installed System Memory after discharging;

Storage allocation when use, the mode of releasing memory immediately not after being used to complete, in the time that program is applied for the internal storage location of similar size again, directly gives new request use by the internal memory of application before.

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