JPH06301593A - Buffer management system - Google Patents

Abstract

PURPOSE:To easily analyze the cause at the time of fault generation by performing weighting on a buffer acquisition request, cancelling the locked state due to the shortage of buffer preferentially corresponding to the request with highly important degree, and delaying the reuse of the buffer of highly important degree which is released during the processing. CONSTITUTION:A buffer management section 13 is provided between a system resource management section 2 and a program section 4. A buffer securing means 5 secures the specified number of buffers in a buffering section 15 from a system resource section 1 at the time of initializing. When the program section 4 fails to acquire the buffers from the system resource management section 2, a buffer acquiring means 8 segments the buffer from the buffering section 15 and lets it use if the weighting is high. A buffer release means 11 connects the released buffer to the tail of the buffering section 15 if the weighting is high and connects it to the head of it if it is low. A buffer processing end means 12 returns the buffers exceeding the specified number from the head of the buffering section 15 at the time of the end of the program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buffer management system, and more particularly to a buffer management system for managing acquisition and release of a buffer which is a unit of dividing system resources such as a main memory in a computer system.

[0002]

2. Description of the Related Art In the conventional buffer management system, when a buffer acquisition request and a buffer release request are issued when a program is executed, the program section directly requests the system resource management section to acquire and release the buffer.

FIG. 5 is a system configuration diagram showing an example of a conventional buffer management system. As shown in FIG. 5, the conventional buffer management system is composed of a system resource unit 1, a system resource management unit 2 and a program unit 4a. The system resource management unit 2 has a system resource acquisition means 6 for performing buffer acquisition processing. And a system resource releasing unit 10 for performing a buffer releasing process, the program unit 4a issues a buffer obtaining request unit 7a for issuing a buffer obtaining request, and an acquisition process for confirming success or failure of the obtaining request. The result notification unit 9, a buffer release request unit 13a for issuing a buffer release request, and a processing end unit 14a for ending the program are included.

First, the buffer acquisition operation will be described in detail with reference to the flowchart shown in FIG. When a buffer acquisition request is issued by the buffer acquisition request means 7a of the program section 4a (step S40), the system resource acquisition means 6 of the system resource management section 2 receives the buffer acquisition request and acquires the buffer from the system resource section 1. Instruct (step S41). Whether or not the buffer acquisition has succeeded based on this buffer acquisition instruction is determined in step S42.
If it is successful, the address is notified to the acquisition result notifying means 9 and the acquisition ends (step S43).
If the acquisition is not successful, the fact that the acquisition has failed is notified and the processing ends (step S44). When the buffer acquisition fails and the acquisition request is made again immediately, the buffer requests from each program repeatedly fail and the system often enters a deadlock state.

Next, the operation of releasing the buffer will be described in detail. Buffer release request means 1 of program section 4a
When a buffer release request is generated in 3a (step S4
5) In response to the buffer release request, the system resource releasing means 10 gives an instruction to release the buffer (step S4).
6), the buffer is returned to the system resource unit 1. When the processing of the program ends, if there is a buffer in use, the buffer release requesting means 13a releases it, and then the processing ending means 14a requests the end of processing (step S47). Then, other necessary processing is performed and the processing ends (step S4).
8).

[0006]

However, in the above-mentioned conventional buffer management system, if a program acquires one or two buffers and executes processing, more buffers in the program will be stored. Even if the buffer can be released, if the buffer of the system resource part is in a shortage state, the buffer acquisition request cannot be satisfied, so the shortage of the buffer cannot be resolved. When a buffer acquisition request is issued from a plurality of programs under such a buffer shortage condition, all buffer acquisition requests from each program repeatedly fail, resulting in a deadlock state of the entire system.

When a program releases a buffer release request, the used buffer is unconditionally released to the system resource section, and thus the released buffer may be immediately used for another purpose. If this buffer stores the information necessary for cause analysis when a failure occurs,
There is a problem that the analysis information disappears and the cause analysis becomes difficult due to lack of information.

A first object of the present invention is to provide a buffer management system capable of solving the above-mentioned first problem by giving a buffer preferentially to a buffer acquisition request satisfying a certain condition. It is in. Further, a second object of the present invention is to provide a buffer management system capable of simultaneously solving the above-mentioned second problem by considering the reuse order of the corresponding buffer in response to a buffer release request satisfying a certain condition. Is to provide.

[0009]

A buffer management system according to a first aspect of the present invention is a system resource management system for instructing and executing a buffer acquisition and release to a system resource unit in response to a buffer acquisition and release request from a program unit. In a buffer management system having a section, a buffer securing means for acquiring a specified number of buffers at the time of initialization and holding the buffer in a buffer link section, and a buffer acquisition request when the buffer acquisition by the system resource management section fails at the time of a buffer acquisition request When the weighting of is high, buffer acquisition means for cutting out the buffer from the buffer link unit and using it,
Buffer release means for connecting the buffer released at the time of the buffer release request to the buffer link unit until the specified number is reached.

A buffer management system according to a second aspect of the present invention is a buffer management system having a system resource management unit for instructing and executing buffer acquisition and release to the system resource unit in response to a buffer acquisition and release request from the program unit. In the above, a buffer securing unit that acquires a specified number of buffers at the time of initialization and holds the buffer in the buffer link unit, and when the buffer acquisition request by the system resource management unit fails at the time of the buffer acquisition request, if the weight of the buffer acquisition request is high Is a buffer acquisition unit that cuts out a buffer from the beginning of the buffer link unit and uses it; if the weight of the buffer release request is high, all released buffers are connected to the end of the buffer link unit, and if the weight is low, Buffer releasing means connected to the head of the buffer link unit A buffer processing ending means for releasing the excess from the head of the buffer link to the system resource management unit when a buffer exceeding the specified number is connected to the buffer link unit in response to a processing end request And is configured.

A buffer management system according to a third aspect is the first aspect.
In the buffer management method according to claim 2, weighting for comparing the buffer acquisition and release requests from the program unit with a comparison table created in advance based on the program name, step number in the program, etc. It is characterized by having means.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing the system configuration of an embodiment of the present invention.

In the buffer management system shown in FIG. 1, in response to a buffer acquisition and release request from the program section 4, a system resource management section 2 for instructing and executing the buffer acquisition and release to the system resource section 1, It is composed of a program section 4 and a buffer management section 3 provided between the system resource management section 2 and the program section 4. In the buffer management unit 3, a buffer securing unit 5 that secures a specified number of buffers from the system resource unit 1 in the buffer link unit 15 via the system resource acquisition unit 6 at the time of initialization.
And mediates the acquisition request from the buffer acquisition request means 7,
When the buffer acquisition by the system resource acquisition unit 6 fails, if the weight given to the request is high, the buffer is cut out from the head of the buffer link unit 15 and the license acquisition is notified to the acquisition result notification unit 9. Upon receiving a release request from the means 8 and the buffer release request means 13, the buffer release means 11 for connecting the released buffer to the buffer link unit 15 once and the program termination request from the processing termination means 14 are received. When a buffer exceeding the specified number is connected to 15, a buffer processing ending unit 12 for instructing the system resource releasing unit 10 to release the excess from the head of the link to the system resource unit 1 is included. ing.

First, the operation at the time of buffer acquisition will be described in detail with reference to the flowchart of FIG.

When the system is activated, the buffer securing unit 5 of the buffer management unit 3 operates as an initialization operation, and the system receives a request for acquisition of a specified number of buffers to reserve in the buffer link unit 15 as a special frame. It is issued to the resource management unit 2 (step S1). In response to this, the system resource acquisition means 6 of the system resource management unit 2 makes the system resource unit 1
To obtain a buffer (step S2). In response to this buffer acquisition instruction, it is determined whether or not the buffer acquisition from the system resource unit 1 has succeeded (step S
3) If successful, the specified number of buffers (hereinafter referred to as a threshold value) that have been acquired are secured in the buffer link unit 15 (step S4). At this time, as shown in FIG. 4, the acquired buffers are linked and connected like a buffer link 18, and the acquired number is determined by the threshold value storage unit 16 and the held number storage unit 17.
Is set to each. If not successful, the buffer securing unit 5 ends abnormally (step S5).

A case will be described in which the system unit has been started and a buffer acquisition request is issued by the program unit 4 during execution of the program.

When a buffer acquisition request is generated by the buffer acquisition request means 7 inside the program section 4 (step S
6), the request is given to the system resource acquisition unit 6 of the system resource management unit 2 via the buffer acquisition unit 8 of the buffer management unit 3. Here, it is assumed that the buffer acquisition request issued from the program unit 4 is given weighting information indicating the degree of importance of the buffer acquisition request (step S7). The weighting information may be 1-bit information indicating whether the degree of importance is high or low, and is set in advance in the program. As described above, if the program acquires one or two buffers and executes the processing, the weighting information is set high if more buffers in the program can be released, and otherwise. Set to low.

The system resource acquisition means 6 that has received the request is
The system resource unit 1 is instructed to acquire the buffer according to the normal procedure regardless of the weighting information (step S
8) It is determined whether or not the buffer acquisition is successful (step S9). If the buffer acquisition is successful, the acquisition result notifying means 9 of the program section 4 is notified of the address of the acquired buffer, and the process ends (step S17). On the other hand, when it is not successful, the buffer acquisition unit 8 refers to the weighting information given to the buffer acquisition request and determines whether the weighting is high or low (step S10). If no weighting information is added to the buffer acquisition request, it is determined that the weighting is low.

In the case of a high weighted buffer acquisition request,
In step S11, the retained number stored in the retained number storage unit 17 of the buffer link unit 15 is compared with the requested number of buffer acquisition requests, and if (retained number ≧ requested number) is not satisfied, acquisition failure is acquired. The notification means 9 is notified (step S18). On the other hand, if (holding number ≧ requested number) is satisfied, the process proceeds to step S12 (holding number−
After calculating the required number) and updating the value in the retained number storage unit 17 with the calculated number as a new retained number (step S
13) Then, the requested number of buffers are acquired from the head of the buffer link 18 (step S14), the acquisition result notifying means 9 is notified, and the acquisition ends (step S17).

In the case of a buffer acquisition request having a low weight, the number of buffers currently secured in the buffer link unit 15 exceeds the threshold value, and it is possible to respond only when the excess can be dealt with. That is, in step S15, (holding number-
Threshold value), and the calculated value is set as the requested corresponding number, and the requested corresponding number and the requested number are compared in step S16,
If (the required number of requests ≧ the required number) is not satisfied, the acquisition fails (step S18). On the other hand, if (the required number of requests ≧ the required number) is satisfied, step S1
The process proceeds to step 2 to calculate (retained number-required number), and in steps S13 to S14, the retained number storage unit 17 is updated to acquire the buffer, the acquisition result notifying means 9 is notified, and the acquisition ends (step S17). ).

Next, the operation at the time of releasing the buffer will be described in detail with reference to the flowchart of FIG.

When a buffer release request is generated by the buffer release requesting means 13 in the program section 4 during the execution of the program (step S20), the request is given to the buffer releasing means 11 of the buffer management section 3. At this time, it is assumed that the buffer release request issued from the program unit 4 is provided with weighting information indicating the degree of importance of the buffer release request (step S21). The weighting information is 1-bit information indicating whether the degree of importance is high or low. It should be set in advance in the program. If the buffer to be released contains information effective for failure cause analysis, the weighting information is weighted. Set the information high, otherwise set it low. Therefore, when all the buffers used at the end of the program are released, the weighting information is set low.

The buffer releasing means 11 judges the weighting information of the given buffer releasing request (step S2).
2) In the case of a high weighted buffer release request, the buffer to be released is connected to the end of the buffer link 18 (step S23). On the other hand, in the case of a buffer release request with a low weight, the buffer to be released is set to the buffer link 1
8 is connected to the head (step S24), and the value in the held number storage unit 17 is updated with the value obtained by adding the released number to the conventional held number as the new held number (step S25).

At the end of the program, the program section 4
When a processing end request is issued from the processing end means 14 (step S26), the buffer processing end means 12 of the buffer management unit 3 causes the buffer number storage unit 1 of the buffer link unit 15.
7 is compared with the threshold value storage unit 16 (step S27), and if the number of holdings at that time is less than or equal to the threshold value, the program ends as it is (step S33), but if the number of holdings is greater than the threshold value, the excess is buffered. The processing is released from the section 15 to the system resource section 1 and the processing ends.

That is, if (holding number ≧ threshold value) is satisfied, (holding number−threshold value) is calculated in step S28 as the release corresponding number, and a buffer corresponding to the release number is acquired from the head of the buffer link 18 ( In step S29), the system resource management unit 2 is requested to release the number of buffers corresponding to the release (step S30). In response to this buffer release request, the system resource release means 10 instructs the system resource section 1 to release the buffer (step S31). After this, the buffer processing end means 12
The stored number storage unit 17 of the buffer link unit 15 is updated to the threshold value (step S33), and the process ends (step S).
33).

As described above, in this embodiment, the buffer of the special frame is secured in the buffer link unit 15 in advance, and if a small number of buffers are acquired, it is possible to release more buffers without delay. With respect to a high buffer acquisition request, the buffer link unit 15 preferentially allocates and uses the buffer, and therefore it is possible to prevent a deadlock condition due to a competition due to a buffer shortage. In addition, the buffer released from the program is connected to the end of the link for the high-weighted buffer that stores the information necessary for failure analysis, and to the top of the link for other buffers. Is returned to the system resource section 1.
Therefore, the number of buffers in the buffer link unit 15 does not greatly exceed the threshold value, and the probability that information will disappear in the buffer that stores important information is extremely low.

The above-described embodiment prevents a deadlock state from occurring due to a buffer shortage at the time of a buffer acquisition request, and prevents the history information useful for failure cause analysis from disappearing due to reuse of the released buffer. To achieve these two purposes, as a means for responding to a buffer release request, the released buffer is placed at the end of the buffer link section in the case of a buffer release request with a high weight, and the head of the buffer link section is shown in the case of a low weight. And a buffer processing ending means for receiving a processing ending request from the program and returning a buffer exceeding a threshold value from the buffer link section to the system resource section. On the other hand, if you only want to prevent the deadlock condition that occurs due to the buffer shortage at the time of buffer acquisition request,
When the buffer release request is received, only the buffer releasing means for connecting the released buffer to the buffer link unit until reaching the threshold value is provided, and the buffer processing ending means is unnecessary.

Further, in the above embodiment, the weighting information has been described as being added in advance in the program section, but in order to add the weighting information without changing the program, the program management section should be provided in the buffer management section. When a buffer acquisition and release request is received from, the weighting means may be provided to set a weight by collating a comparison table created in advance based on the program name and the step number in the program.

[0030]

As described above, the buffer management system of the present invention secures a prescribed number of buffers as a special frame at the time of initialization, judges the weighting information given to the buffer acquisition request, and determines the buffer with a high weighting. When the acquisition request fails to acquire the buffer by the normal method, the reserved special frame buffer is allocated, so it is possible to prevent the occurrence of deadlock condition due to buffer shortage, and improve the system reliability. Has the effect of

Further, when the weight of the buffer release request is high, the released buffer is linked to the end of the link of the special frame, so that the reuse of the buffer storing the operation history of the program can be suppressed, and at the time of failure occurrence. This has the effect of facilitating cause analysis.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing a buffer acquisition operation of this embodiment.

FIG. 3 is a flowchart showing a buffer releasing operation of this embodiment.

FIG. 4 is an explanatory diagram showing an internal configuration of a buffer link unit of the present embodiment.

FIG. 5 is a system configuration diagram showing an example of a conventional buffer management system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 system resource part 2 system resource management part 3 buffer management part 4, 4a program part 5 buffer securing means 6 system resource acquisition means 7, 7a buffer acquisition request means 8 buffer acquisition means 9 acquisition result notification means 10 system resource release means 11 buffers Release means 12 Buffer processing termination means 13, 13a Buffer release request means 14, 14a Processing termination means 15 Buffer link section 16 Threshold storage section 17 Holding number storage section 18 Buffer link

Claims (3)

[Claims] 1. A buffer management system having a system resource management unit for instructing and executing a buffer acquisition and release to a system resource unit in response to a buffer acquisition and release request from a program unit, and a prescribed number at initialization. Buffer securing means for acquiring the buffer and holding it in the buffer link part, and when the buffer acquisition request by the system resource management part fails at the time of the buffer acquisition request, if the weight of the buffer acquisition request is high, the buffer is allocated from the buffer link part. A buffer management method comprising: a buffer acquisition unit that is cut out and used; and a buffer release unit that connects the buffer released at the time of a buffer release request to the buffer link unit until the specified number is reached. 2. A buffer management system having a system resource management unit for instructing and executing a buffer acquisition and release to a system resource unit in response to a buffer acquisition and release request from a program unit. Buffer securing means for acquiring the buffer of the buffer and holding it in the buffer link part, and the head of the buffer link part when the weight of the buffer acquisition request is high when the buffer acquisition request by the system resource management part fails at the time of the buffer acquisition request. Buffer acquisition means for cutting out a buffer from the buffer and using it, if the weight of the buffer release request is high, connect all the released buffers to the end of the buffer link section, and if the weight is low, add to the head of the buffer link section. The buffer releasing means to be connected and the above-mentioned in response to the processing end request When more buffers than the specified number are connected to the buffer link unit, a buffer processing ending unit for releasing the excess from the head of the buffer link to the system resource management unit is provided. Buffer management method. 3. A weighting means for setting the weighting by collating a preliminarily prepared comparison table based on the program name and step number in the program with respect to buffer acquisition and release requests from the program section. The buffer management system according to claim 1 or 2, which is characterized.