JP2014010585A - Data transmission method and data transmission apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmission method capable of preventing delay of communication processing.SOLUTION: According to one aspect, when an abnormality in a process having acquired a lock occurs, a processing process 5 requests a semaphore management unit 3 to obtain a lock of semaphore about itself which is to be unlocked by the semaphore management unit 3 and obtains the lock of the semaphore about itself from the semaphore management unit 3. When a processing process 5 of a transmission source transmits data to a processing process 5 of a transmission destination, the semaphore management unit 3 is requested to obtain a lock of semaphore about the processing process 5 of a transmission destination and then, if the lock can be obtained from the semaphore management unit 3, the processing process 5 of a transmission destination is reactivated and the data is transmitted thereto.

Description

  The present invention relates to a data transmission method and a data transmission apparatus.

  In a computer, various communications are realized by combining a plurality of processes divided for various communications functions. If any abnormality occurs in any of a plurality of processes that perform these communications, communication is impossible. Therefore, multiple processes that communicate with each other, in other words, multiple monitored processes are monitored, and if the monitored process is detected to have terminated abnormally or hanged up, the monitored process is restarted. To resume communication.

  For example, when the parent process sequentially starts a plurality of resident child processes P1 to Pn, the child processes P1 to Pn start operation after locking a common semaphore by the process activation notification means, and when all child processes are operated, The semaphore value of the semaphore becomes 0, the parent process finally activates the process monitoring means, monitors as the semaphore lock wait state, and when the child process is abnormally terminated, the semaphore lock is released and the process monitoring means immediately It has been proposed to detect and restart a child process that has been recognized and terminated abnormally.

  In addition, the management process and the managed process are connected by the socket interface, and when the managed process is running, the socket interface is blocked from being read by the management process. On the other hand, when the managed process is finished, the socket interface is closed. It has been proposed that the management process can read the socket interface, and when it is read, the managed process determines that the operation has ended.

Japanese Patent Laid-Open No. 9-44376 Japanese Patent Laid-Open No. 10-211096

  For example, when the status of each processing process is monitored by the process monitoring unit, a child process that has ended abnormally is detected and restarted, a certain amount of time is required from the occurrence of the abnormality to the detection of the abnormality by the process monitoring unit. As a result, communication processing may be delayed.

  In one aspect, an object of the present invention is to provide a data transmission method capable of preventing a delay in communication processing.

  The data transmission method according to one aspect includes process state information that is unlocked by a process state information management unit when an abnormality occurs in a process in which a first process acquires a lock, and the process for the first process The process state information management unit is requested to acquire the state information lock, and the process state information lock for the first process is acquired from the process state information management unit. When the second process transmits data to the first process, the process state information management unit requests the process state information management unit to acquire the lock of the process state information for the first process. If the process state information lock for the process can be acquired, the data is sent to the first process after restarting the first process.

  According to one aspect, communication processing delays can be prevented.

It is a figure which shows an example of a computer. It is explanatory drawing of semaphore and abnormality information. It is a figure which shows an example of a structure of the hardware of a computer. It is explanatory drawing of data transmission and process monitoring. It is explanatory drawing of data transmission and process monitoring. It is a process flowchart of a semaphore. It is a processing flowchart of data transmission and process monitoring. It is explanatory drawing of the process monitoring process which this inventor examined. It is explanatory drawing of the process monitoring process which this inventor examined.

  8 and 9 are explanatory diagrams of the process monitoring process studied by the present inventors.

  For example, as shown in FIG. 8, the plurality of processing processes 505 are processes that execute communication control. The plurality of processing processes 505 communicate with each other via the communication queue storage unit 507. For example, the processing process B as the transmission source stores the data # 501 in the communication queue storage unit 507, and the processing process A as the transmission destination acquires the data # 501 stored in the communication queue storage unit 507.

  The process management unit 510 monitors a plurality of processing processes 505. Specifically, the process management unit 510 periodically monitors each processing process 505 at a predetermined time interval T. If the process management unit 510 detects an abnormal end or hang-up of the processing process 505, the process management unit 510 restarts the processing process 505 that has ended abnormally, in other words, has gone down. As a result, the communication process is resumed and the downtime of the entire computer is minimized.

  Here, as shown in FIG. 9, it is assumed that an abnormality has occurred in the processing process A immediately after the first data # 501 is transmitted / received and the status monitoring of the processing process A by the process management unit 510 ends normally. . In this case, the processing process B cannot detect the abnormality of the processing process A, and therefore transmits the second data # 502. Thereby, data # 502 is stored in the communication queue storage unit 507.

  Thereafter, when the monitoring time interval T elapses from the status monitoring of the previous processing process A, the process management unit 510 monitors the status of the processing process A again. Up to this point, time t501 has elapsed since an abnormality occurred in the process A. For example, the process management unit 510 obtains a response from the processing process A, but cannot obtain a response from the processing process A, and thus detects an abnormality in the processing process A.

  Therefore, when the process management unit 510 detects the occurrence of an abnormality in the processing process A, the process management unit 510 restarts the processing process A. The restarted process A acquires data # 502 stored in the communication queue storage unit 507. Thereby, the communication process between the process A and the process B is resumed. Up to this point, time t502 has elapsed since processing process B transmitted data # 502.

  As described above, the time lag t501 exists from the occurrence of abnormality to the detection. This time lag t501 is the longest and is slightly shorter than the monitoring time interval T. In addition, the time t502 from the start to the completion of communication is the longest, which is a time obtained by adding the restart time of the processing process 505 to the monitoring time interval T. As a result, communication processing is delayed. Further, as a result of the delay of the communication process, the data stays in the communication queue storage unit 507 for a long time, so that the communication queue storage unit 507 may overflow, and data loss due to overflow occurs.

  In addition, it is possible to shorten the time for which the communication processing is delayed by setting the monitoring time interval T to be shorter. However, if the monitoring time interval T is set shorter for a plurality of processing processes 505, the CPU usage time for monitoring increases, for example, the CPU usage time for the original communication processing decreases. Therefore, the monitoring time interval T cannot be shortened so that the time t502 from the start to the completion of communication is approximately equal to the time from the start to the completion of communication when there is no abnormality.

  The following data transmission method prevents communication processing delays and prevents data loss due to communication queue overflow.

  FIG. 1 is a diagram illustrating an example of a computer that is a data transmission apparatus.

  The computer 1 is a data transmission device, a process execution device that executes processes, and a process execution monitoring device that monitors processes. The computer 1 includes an operating system (OS) 2, a semaphore management unit 3, a semaphore storage unit 4, a processing process 5, an abnormality information storage unit 6, and a communication queue storage unit 7.

  The OS 2 resides on the main memory of the computer 1 and is executed by an OS execution unit, for example, a CPU. The semaphore management unit 3 is actually included in the OS 2. The semaphore management unit 3 manages semaphores. The semaphore is stored in the semaphore storage unit 4. The semaphore storage unit 4 is a storage area on the memory, for example, used by the semaphore management unit 3.

  The semaphore management unit 3 is an example of a process state information management unit. The semaphore management unit 3 manages semaphores used for interprocess communication between the processing processes 5. The semaphore is an example of process state information indicating the current state of the processing process 5. The semaphore is information corresponding to the processing process 5 and indicating whether or not an abnormality has occurred in the corresponding processing process 5. A semaphore takes either a locked or unlocked state.

  The semaphore management unit 3 manages the state of the processing process 5, in other words, whether or not an abnormality has occurred in the processing process 5. When activated, the processing process 5 requests the semaphore management unit 3 to generate a semaphore corresponding to itself and acquire a lock of the semaphore corresponding to itself. Further, when an abnormality occurs, the processing process 5 notifies the semaphore management unit 3 that an abnormality has occurred. Accordingly, the semaphore management unit 3 can manage the state of the processing process 5 and can unlock the semaphore corresponding to the processing process 5 in which an abnormality has occurred. It should be noted that the processing process 5 may request the semaphore management unit 3 to release the lock of its own semaphore, in other words, unlock, instead of notifying that an abnormality has occurred.

  The semaphore management unit 3 locks the semaphore corresponding to the requested processing process 5 in response to a lock acquisition request from the processing process 5. A locked semaphore is in an exclusive state. In other words, a locked semaphore cannot be acquired by a processing process 5 other than the processing process 5 that has acquired the lock. The semaphore management unit 3 inseparably executes a process of locking the semaphore.

  In addition, when an abnormality occurs in the processing process 5 that has acquired the lock, the semaphore management unit 3 unlocks the semaphore corresponding to the processing process 5 in which the abnormality has occurred. The unlocked semaphore is in a non-exclusive state. In other words, an unlocked semaphore is allowed to be acquired by a processing process 5 other than the processing process 5 to which the semaphore corresponds. The semaphore management unit 3 inseparably executes the process of unlocking the semaphore.

  As the process status information, for example, a file advisory lock function of the OS 2 may be used instead of the semaphore. In other words, the process status information is a destination by using information obtained by the function of controlling the processing synchronization between the plurality of processing processes 5 and controlling the interrupt processing, which is the same function as the semaphore. The state of the processing process 5 may be detected.

  Further, a process state information management unit such as the semaphore management unit 3 may be provided outside the OS 2. In this case, information about control of processing synchronization and control of interrupt processing among a plurality of processing processes 5 is acquired from the OS 2 to generate information indicating lock / unlock status of the process status information. good.

  The processing process 5 is activated, for example, when the OS 2 executes a command. A plurality of processing processes 5 are generated and activated for each of various functions of communication in the computer, and by combining the plurality of processing processes 5, various communication processes in the computer are executed. The processing process 5 is executed in the corresponding processing process execution unit. Different processing processes 5 are executed in the same or different processing process execution units. In other words, different processing processes 5 are executed in the same or different physical CPU or logical CPU.

  The processing process 5 executes predetermined processing, for example, predetermined communication processing, in the computer 1. The computer 1 generates and starts a plurality of processing processes 5 divided into each layer such as each layer of communication protocols and each layer of an interface with an application, in other words, each function. Then, the computer 1 controls various communications by combining a plurality of processing processes 5 to correspond to communications with various connection destination computers.

  The processing process 5 is executed by a process execution unit, for example, a CPU. The processing process 5 holds the abnormality information about the interprocess communication performed by itself in the abnormality information storage unit 6. The abnormality information storage unit 6 is, for example, a storage area on a memory used by the processing process 5, and is provided corresponding to the processing process 5. The abnormality information storage unit 6 is acquired by the processing process 5 when the processing process 5 is activated, for example.

  As described above, the processing process 5 performs communication using the communication queue storage unit 7 with other processing processes 5 for various communication with various connection destination computers. The communication queue storage unit 7 is a shared memory shared by a plurality of processing processes 5 and stores a communication queue for interprocess communication.

  For example, the processing process 5 that is the transmission source stores the transmission target data as a communication queue in the communication queue storage unit 7 shared by the plurality of processing processes 5. In other words, data is transmitted because the data to be transmitted is stored in the communication queue storage unit 7 as a communication queue, as described later, by locking the semaphore for the processing process 5 that is the transmission destination. This is the case when it cannot be acquired. The communication queue actually includes destination information in addition to data to be transmitted. The destination information is, for example, identification information of the destination process 5. The processing process 5 accesses the communication queue storage unit 7 and acquires a communication queue including its own identification information as destination information. As a result, data is transmitted from the processing process 5 as the transmission source to the processing process 5 as the transmission destination.

  Specifically, the processing process 5 requests the semaphore management unit 3 to generate a semaphore for itself when the processing process 5 is activated. The generation of the semaphore is requested with the activation of the processing process 5 as a trigger. The semaphore management unit 3 generates a semaphore for the processing process 5 based on a request from the processing process 5. Thereby, when the processing process 5 is activated, a semaphore corresponding to the activated processing process 5 is generated.

  In addition, when the processing process 5 is activated, the processing process 5 requests the semaphore management unit 3 to acquire the lock of the semaphore for the self, for example, following the generation of the semaphore for the self. The acquisition of the semaphore lock is requested after the request for generating the semaphore, triggered by the activation of the processing process 5. The semaphore management unit 3 gives the processing process 5 a semaphore lock for the processing process 5 based on a request from the processing process 5. Thereby, the processing process 5 acquires the lock of the semaphore about itself. Therefore, when the processing process 5 becomes the data receiving side after the activation, in other words, the data transmission destination, the processing process 5 as the transmission destination locks the semaphore about itself unless the lock is released due to an abnormality. It is in a state that has won.

  Instead of the semaphore management unit 3, the OS 2 may execute semaphore generation and semaphore lock acquisition or release.

  FIG. 2A is an explanatory diagram of a semaphore and shows an example of a semaphore.

  The semaphore storage unit 4 stores a plurality of semaphores. Each semaphore includes a semaphore ID, a process, and lock acquisition / release. The semaphore ID is identification information that uniquely identifies the semaphore. The process is the name of the processing process 5 corresponding to the semaphore. The name of the processing process 5 is identification information that uniquely identifies the processing process 5. Lock acquisition / release indicates the state of the semaphore. For example, when the lock acquisition / release is “1”, it indicates that the semaphore is locked, in other words, acquired. For example, when the lock acquisition / release is “0”, it indicates that the semaphore is unlocked, in other words, released.

  The semaphore management unit 3 generates and holds the semaphore by storing the semaphore ID, the process, and the lock acquisition / release in the semaphore storage unit 4 in response to the semaphore generation request from the processing process 5. The semaphore ID is given in the order of the request for generating the semaphore, for example. As the process, the name of the processing process 5 that requested acquisition of the semaphore lock is stored. The lock acquisition / release is set to “0” at the time of generation.

  As described above, the process 5 acquires a semaphore lock for itself when it is activated. On the other hand, when an abnormality occurs in the processing process 5 that has acquired the lock, the semaphore management unit 3 unlocks the semaphore corresponding to the processing process 5 in which the abnormality has occurred. Therefore, as long as no abnormality occurs in the processing process 5, the state where the lock of the semaphore is acquired should continue. In other words, “1” for lock acquisition / release indicates that no abnormality has occurred in the processing process 5 corresponding to the semaphore because the semaphore is not unlocked by the OS 2. The lock acquisition / release “0” indicates that an abnormality has occurred in the processing process 5 corresponding to the semaphore because the semaphore is unlocked by the OS 2.

  When receiving the data transmission request from the application, the processing process 5 as the transmission source transmits the data. When transmitting data to the processing process 5 that is the transmission destination, the processing process 5 that is the transmission source requests the semaphore management unit 3 to acquire a semaphore lock for the processing process 5 that is the transmission destination. The acquisition of the semaphore lock is requested not only when the processing process 5 is started but also when a data transmission request from the application or data transmission is triggered. A request for acquiring a semaphore lock triggered by data transmission is executed when the processing process 5 is a transmission source. The request for acquiring the lock of the semaphore triggered by the data transmission indicates whether the semaphore is abnormal in the processing process 5 or has not occurred, so the existence of the processing process 5 as the transmission destination is confirmed. It is processing.

  When the processing process 5 that is the transmission source cannot acquire the semaphore lock for the processing process 5 that is the transmission destination, the processing process 5 transmits the data to the processing process 5 that is the transmission destination. The fact that the processing process 5 which is the transmission source cannot acquire the semaphore lock for the processing process 5 which is the transmission destination means that the processing process 5 which is the transmission destination has acquired the semaphore lock, in other words, This indicates that no abnormality has occurred in the processing process 5 which is a transmission destination. Therefore, the processing process 5 which is a transmission source executes data transmission. As a result, the processing process 5 as a transmission source can transmit data after confirming that the processing process 5 as a transmission destination is normal.

  On the other hand, the processing process 5 as the transmission source restarts the processing process 5 as the transmission destination when the semaphore lock for the processing process 5 as the transmission destination can be acquired. The fact that the processing process 5 as the transmission source has acquired the semaphore lock for the processing process 5 as the transmission destination means that the processing process 5 as the transmission destination has released the lock of the semaphore. In other words, it indicates that an abnormality has occurred in the processing process 5 that is the transmission destination. Therefore, the processing process 5 that is the transmission source restarts the processing process 5 that is the transmission destination without executing data transmission at this point. The processing process 5 has a function of restarting another processing process 5.

  Note that the processing process 5 that is the transmission source requests the semaphore management unit 3 to release the semaphore lock acquired for the processing process 5 that is the transmission destination prior to the restart of the processing process 5 that is the transmission destination. When the semaphore management unit 3 receives a request for releasing the semaphore lock for the processing process 5 that is the transmission destination, the semaphore management unit 3 releases the processing process 5 that is the transmission destination, that is, unlocks it. Thereby, the processing process 5 which is a transmission destination can acquire the lock of the semaphore about itself after restarting.

  After restarting the processing process 5 which is the transmission destination, the processing process 5 which is the transmission source executes data transmission. As a result, the occurrence of an abnormality in the processing process 5 can be quickly detected by checking the survival state of the processing process 5 at the transmission destination using data transmission as a trigger. In addition, the processing process 5 in which an abnormality has occurred can be restarted promptly. As a result, the occurrence of abnormality in the processing process 5 can be detected more quickly than in the case where periodic process monitoring is performed, and the delay in communication processing can be minimized.

  Here, when the processing process 5 that is the transmission destination is restarted, the processing process 5 that is the transmission source requests the semaphore management unit 3 to acquire the semaphore lock for the processing process 5 that is the restarted transmission destination. Instead, the data transmission is executed following the restart process of the processing process 5 as the transmission destination. This is because since almost no time has elapsed since the restart, it is considered that no abnormality has occurred in the process 5 after the restart. Thereby, data transmission can be executed promptly. On the other hand, the processing process 5, which is the restarted transmission destination, executes processing for acquiring the lock of its own semaphore.

  After restarting the processing process 5 that is the transmission destination, the processing process 5 that is the transmission source requests the semaphore management unit 3 to acquire the semaphore lock for the processing process 5 that is the transmission destination. good.

  Here, a certain amount of time elapses before the processing process 5 as the transmission destination is restarted. For this reason, if the acquisition of the semaphore lock is requested again for data transmission between the abnormality detection of the processing process 5 at the transmission destination and the restart, the lock can always be acquired, and the restart process Will be executed repeatedly. Therefore, the processing process 5 that is the transmission source acquires the semaphore lock from the abnormality detection to the restart of the processing process 5 of the transmission destination based on the abnormality detection history for the processing process 5 that is the transmission destination. Is suppressed. Thereby, it is possible to prevent the restart process of the processing process 5 as the transmission destination from being repeatedly executed.

  It should be noted that the parameters for starting up the processing process 5 may be set so that the time from the detection of the abnormality in the processing process 5 to the restart becomes shorter.

  The processing process 5 holds an abnormality detection history for other processing processes 5. As a result, the processing process 5 that is the transmission source can hold the abnormality detection history for the processing process 5 that is the transmission destination. The abnormality detection history is an example of abnormality information, and includes the time of abnormality detection.

  FIG. 2B is an explanatory diagram of abnormality information and includes an example of abnormality information.

  The abnormality information storage unit 6 stores a plurality of abnormality information. The abnormality information includes a process, an abnormality detection history, and an abnormality detection time, respectively. The process is the name of the processing process 5 that has become a communication partner in the communication processing, in other words, the transmission destination. The abnormality detection history is information indicating that an abnormality has been detected in the processing process 5 that is the transmission destination. The abnormality detection time is a time at which an abnormality is detected in the processing process 5 that is the transmission destination.

  When the processing process 5 that is the transmission source acquires the lock of the semaphore of the processing process 5 that is the transmission destination, the abnormality information storage unit 6 stores the process, abnormality detection history, and abnormality detection time, thereby obtaining abnormality information. Generate and hold The abnormality information is generated for each processing process 5 that is a transmission destination, and is updated each time an abnormality is detected. The case where the lock of the semaphore of the processing process 5 that is the transmission destination is acquired is when the abnormality of the processing process 5 that is the transmission destination is detected. As a result, the data is not transmitted, and thus the data transmission fails. is there.

  Actually, the processing process 5 as the transmission source updates the process, the abnormality detection history, and the abnormality detection time each time the semaphore lock for the processing process 5 as the transmission destination is acquired. For example, as the process, the name of the processing process 5 of the transmission destination that has acquired the semaphore lock is stored. As the abnormality detection history, for example, information indicating “abnormality occurrence” is stored. As the abnormality detection time, the time at which the semaphore lock for the processing process 5 as the transmission destination is acquired is stored.

  When the processing process 5 that is the transmission source transmits data to the processing process 5 that is the transmission destination, the processing process 5 that is the transmission destination refers to the abnormality information stored in the abnormality information storage unit 6 and the abnormality It is determined whether there is a detection history. The determination of the presence or absence of an abnormality detection history is executed prior to a request to the semaphore management unit 3 to acquire a semaphore lock for the processing process 5 that is a transmission destination.

  When there is no abnormality detection history for the processing process 5 that is the transmission destination, the processing process 5 that is the transmission source requests the semaphore management unit 3 to acquire a semaphore lock for the processing process 5 that is the transmission destination. As a result, if there is no abnormality detection history for the processing process 5 that is the transmission destination, the presence or absence of an abnormality in the processing process 5 that is the transmission destination is not known at all, so the state of the processing process 5 that is the transmission destination is determined by the semaphore. Is judged.

  On the other hand, when there is an abnormality detection history for the processing process 5 that is the transmission destination, the processing process 5 that is the transmission source determines whether or not an elapsed time from the time of abnormality detection is equal to or less than a specified value. The specified value is, for example, the time required for restarting the processing process 5.

  Then, when the elapsed time is equal to or less than the specified value, the processing process 5 that is the transmission source transmits data to the processing process 5 that is the transmission destination. When the elapsed time is equal to or less than the specified value, the restart of the processing process 5 is not completed and the restart is executed. Therefore, when the processing process 5 as a transmission destination is restarted, data can be received in a state where no abnormality has occurred. Therefore, the processing process 5 as a transmission source transmits data without requesting acquisition of a semaphore lock for the processing process 5 as a transmission destination. As a result, it is possible to suppress semaphore lock acquisition processing between detection of an abnormality in the processing process 5 at the transmission destination and restart, and data can be transmitted promptly.

  On the other hand, the processing process 5 that is the transmission source locks the semaphore for the processing process 5 that is the transmission destination when the elapsed time is not less than the predetermined value, in other words, when the time longer than the predetermined value has elapsed. Is obtained from the semaphore management unit 3. If the elapsed time is not less than or equal to the specified value, the restart of the processing process 5 is finished. Therefore, the processing process 5 as the transmission source transmits data after requesting the acquisition of the semaphore lock for the processing process 5 as the transmission destination.

  FIG. 3 is a diagram illustrating an example of a hardware configuration of a computer.

  The CPU 101 controls the computer 1 according to the OS 2 that resides on the main memory included in the memory 102. The CPU 101 executes a semaphore management program included in the OS 2 and a communication control program including a plurality of processing processes 5 existing on the main memory included in the memory 102. Thereby, the semaphore management unit 3 and the plurality of processing processes 5 are realized. The semaphore management program and the communication control program are stored in a portable storage medium 107 such as a CD (Compact Disc) or a DVD (Digital Versatile Disk), and the CD-ROM drive or DVD drive is driven from the portable storage medium 107. The data is input to the storage device 106 via the device 108 and loaded from the storage device 106 to the memory 102.

  The semaphore storage unit 4, the abnormality information storage unit 6, and the communication queue storage unit 7 are provided in the memory 102, for example. The semaphore storage unit 4, the abnormality information storage unit 6, and the communication queue storage unit 7 may be provided in the storage device 106.

  The input device 104 is a keyboard, for example, and may include a mouse or the like. The output device 105 is a display, for example, and may include an output device such as a printer. The CPU 101, the memory 102, the communication interface 103, the input device 104, the output device 105, the storage device 106, and the drive device 108 are connected to each other via a bus 109.

  The communication interface 103 is, for example, a transmission / reception device, is connected to a network, and is connected to another computer via the network. Thereby, the computer 1 communicates with other computers.

  The semaphore management program and the communication control program may be input via a network such as a LAN (Local Area Network) or the Internet, stored in the storage device 106, and executed by the CPU 101. Alternatively, the data may be input from the portable storage medium 107 storing the semaphore management program and the communication control program via the drive device 108, stored in the storage device 106, and executed by the CPU 101.

  4 and 5 are explanatory diagrams of data transmission and process monitoring. 4 and 5, the processing process 5 that is the transmission destination is referred to as processing process A, and the processing process 5 that is the transmission source is referred to as processing process B.

  For example, the processing process B as the transmission source stores the data # 1 and # 2 in the communication queue storage unit 7 in response to a data transmission request from the application. The processing process A that is a transmission destination acquires the data # 1 and # 2 stored in the communication queue storage unit 7, and transmits the acquired data # 1 and # 2 to another application. Further, it is assumed that an abnormality occurs in the processing process A after the data # 1 is transmitted and received between the processing process A and the processing process B.

  For example, when the processing process A and the processing process B are each started, the processing process A and the processing process B request the semaphore management unit 3 to generate a semaphore for themselves, and then acquire a semaphore lock for the self. 3 is requested. The semaphore management unit 3 generates semaphores for the processing processes A and B based on requests from the processing processes A and B, and locks the semaphores for the processing processes A and B. A and processing process B are given. As a result, the processing process A and the processing process B acquire the lock of the semaphore about itself.

  In this state, the processing process B that is the transmission source starts the transmission process of the data # 1 in response to a transmission request for the data # 1 from the application to the processing process A that is the transmission destination.

  First, the processing process B requests the semaphore management unit 3 to acquire a semaphore lock for the processing process A with the transmission of data # 1 as a trigger.

  However, since no abnormality has occurred in the processing process A at this point, the processing process A still has acquired the semaphore lock for itself. Therefore, the processing process B cannot acquire the semaphore lock for the processing process A. Therefore, the processing process B transmits data # 1 to the processing process A. Specifically, the processing process B stores data # 1 in the communication queue storage unit 7.

  The processing process A acquires data # 1 stored in the communication queue storage unit 7. Thereby, the inter-process communication between the process B and the process A is completed. The processing process A transmits the acquired data # 1 to another application.

  Thereafter, an abnormality occurs in the process A immediately after the first data # 1 is transmitted / received. The processing process A notifies the semaphore management unit 3 that an abnormality has occurred. In response to this, the semaphore management unit 3 unlocks the semaphore corresponding to the processing process A in which the abnormality has occurred because an abnormality has occurred in the processing process A that has acquired the semaphore lock. At this point, the processing process B has not detected an abnormality in the processing process A.

  In this state, the processing process B, which is the transmission source, starts transmission processing for data # 2 in response to a transmission request for data # 2 from the application to processing process A.

  First, the processing process B requests the semaphore management unit 3 to acquire a semaphore lock for the processing process A with the transmission of data # 2 as a trigger. At this time, it is assumed that there is no abnormality detection history for the process A.

  However, since an abnormality has occurred in the processing process A at this point, the semaphore for the processing process A is unlocked. Accordingly, the processing process B can acquire the semaphore lock for the processing process A.

  Therefore, the processing process B is able to acquire the semaphore lock for the processing process A, and therefore determines that the abnormality of the processing process A has been detected. Then, the processing process B restarts the processing process A that has detected the abnormality.

  Thereafter, the processing process B transmits data # 2 to the processing process A after a predetermined time has elapsed since the detection of the abnormality of the processing process A. Specifically, the processing process B stores data # 2 in the communication queue storage unit 7.

  The processing process A acquires data # 2 stored in the communication queue storage unit 7. Thereby, the inter-process communication between the process B and the process A is completed. The processing process A transmits the acquired data # 2 to another application.

  According to the above, in FIG. 5, there is a time lag between occurrence of abnormality and detection. This time lag is equivalent to the time lag t501 in FIG. However, in FIG. 9, since the process B stores the data # 2 in the communication queue storage unit 7 without knowing the abnormality of the process A, the time lag t501 is substantially equal to the time t502 from the start to completion of communication. It will be reflected in the length.

  On the other hand, in FIG. 5, after the process B detects an abnormality in the process A and restarts the process A, the data # 2 is stored in the communication queue storage unit 7. Accordingly, when viewed from the processing process B, the start of the time lag is considered to be, for example, the time when the abnormality of the processing process A is detected. Therefore, the time lag from the occurrence of the abnormality to the detection in FIG. 5 is not included in the time from the start to the completion of communication, and does not cause a problem.

  As a result, the processing process B only takes time t1 from detecting the occurrence of an abnormality in the processing process A to completing the transmission of data # 2. The time t1 includes the restart time of the processing process A. As a result, communication processing delay can be suppressed to a shorter time. In addition, since a delay in communication processing can be suppressed, data is prevented from staying in the communication queue storage unit 7 for a long time, and data loss due to overflow of the communication queue storage unit 7 is prevented. Can do.

  4 and 5, processing process B has acquired semaphore lock for processing process A prior to transmission of data # 2, so at this point in time, abnormality information about processing process A, particularly Update the abnormality detection time.

  Thereafter, when the processing process B receives a request for transmission of data # 3 to the processing process A, as described above, prior to the request for acquiring the semaphore lock for the processing process A, The presence / absence of an abnormality detection history and the elapsed time from the time of abnormality detection are determined, and based on the determination result, data # 3 is transmitted or semaphore lock acquisition for processing process A is executed. .

  FIG. 6 is a process flowchart of the semaphore.

  The OS 2 starts the processing process 5 by executing the start command (step S11). Note that the semaphore for the processing process 5 that is the data transmission destination is mainly the object of the description, and therefore, in the following description, the processing process 5 is referred to as the transmission destination process 5.

  When the transmission destination process 5 is activated, it requests the semaphore management unit 3 to generate a semaphore for itself (step S12). When receiving a request for generating a semaphore from the transmission destination process 5, the semaphore management unit 3 generates a semaphore for the transmission destination process 5 that has requested the generation of the semaphore (step S13).

  The destination process 5 requests the semaphore management unit 3 to acquire the semaphore lock for itself following the request for generating the semaphore (step S14). When the semaphore management unit 3 receives a request for acquiring the semaphore lock from the transmission destination process 5, the semaphore management unit 3 causes the transmission destination process 5 that has requested acquisition of the semaphore lock to acquire the semaphore lock (step S15). As a result, the activated transmission destination process 5 acquires the semaphore lock for itself after activation. Steps S12 to S15 are performed inseparably. As described above, the started transmission destination process 5 acquires the semaphore lock, and this state is maintained until an abnormality occurs in the transmission destination process 5.

  FIG. 7 is a processing flowchart of data transmission and process monitoring.

  The processing process 5 that is the data transmission source refers to the abnormality information storage unit 6 and determines whether or not the transmission destination process 5 has an abnormality detection history (step S21). In the following description, the processing process 5 that is a data transmission source is referred to as a transmission source process 5.

  When the transmission destination process 5 has an abnormality detection history (YES in step S21), the transmission source process 5 further has an abnormality detection time in the abnormality detection history in the transmission destination process 5, in other words, an elapsed time since the previous abnormality detection. Is less than or equal to a specified value (step S22).

  If there is no abnormality detection history in the transmission destination process 5 in step S21 (step S21 NO), and if the elapsed time is not less than the specified value in step S22 (NO in step S22), the transmission source process 5 is related to the transmission destination process 5. The semaphore management unit 3 is requested to acquire the semaphore lock.

  Thereafter, the transmission source process 5 determines whether or not the semaphore lock for the transmission destination process 5 could not be acquired after a predetermined time has elapsed from the request for acquisition of the semaphore lock (step S23). ).

  Acquisition of the semaphore lock for the transmission destination process 5 was not impossible. In other words, if acquisition was possible (NO in step S23), the transmission source process 5 may acquire the lock of the semaphore that should not be acquired originally. As a result, it is determined that an abnormality in the destination process 5 has been detected.

  Therefore, the transmission source process 5 updates the abnormality detection time in the abnormality detection history to the transmission destination process 5 (step S24), releases the semaphore lock for the acquired transmission destination process 5, in other words, locks the semaphore. Is canceled (step S25), and the transmission destination process 5 is restarted (step S26).

  Thereafter, the transmission source process 5 transmits the data by copying the transmission target data to the communication queue storage unit 7 (step S27).

  If the elapsed time is equal to or less than the specified value in step S22 (step S22 YES), the transmission source process 5 omits steps S23 to S26 and executes step S27. Further, if the semaphore lock cannot be acquired for the transmission destination process 5 in step S23, in other words, if it cannot be acquired (YES in step S23), the transmission source process 5 omits steps S24 to S26. Step S27 is then executed.

  For example, the transmission source process 5 sends the second data transmission request to the same transmission destination process 5 after executing the processing of steps S21 to S27 based on the transmission request of the first data to the transmission destination process 5. receive. In this case, since the abnormality detection time is updated in step S24 for the first data, the transmission source process 5 knows that the transmission destination process 5 has an abnormality detection history in the processing for the second data. If the elapsed time from the previous abnormality detection is less than the specified value, data is transmitted. If the elapsed time is not less than the specified value, processing is performed based on whether the transmission destination process 5 can acquire the semaphore lock. Run.

  The transmission source process 5 may receive a second data transmission request while executing the processes of steps S21 to S27 based on the first data transmission request. In this case, for example, the transmission source process 5 executes the processing of steps S21 to 27 for the second data after the processing of steps S21 to 27 for the first data.

  As described above, since no other process 5 can acquire the semaphore lock for the destination process 5 unless an abnormality occurs in the destination process 5, it is confirmed that no abnormality has occurred in the destination process 5. You can confirm and send data. Further, when an abnormality occurs in the destination process 5, the other processing process 5 can acquire the semaphore lock for the destination process 5, so the destination process 5 is restarted and then the data is transmitted. can do.

  As will be understood from the above description, the following embodiments are grasped.

(Appendix 1) The first process is
Process state information that is unlocked by the process state information management unit when an abnormality occurs in the process that acquired the lock, and the process state information management unit acquires the lock of the process state information for the first process. To request and
Obtaining a lock of the process state information for the first process from the process state information management unit;
The second process is
When transmitting data to the first process, the process state information management unit is requested to acquire the lock of the process state information for the first process,
When the process state information management unit can acquire the lock of the process state information for the first process, the data is transmitted to the first process after the first process is restarted. A data transmission method characterized by:

(Supplementary note 2) The supplementary note 1, wherein the data is transmitted to the first process when the second process cannot acquire the lock of the process state information for the first process. Data transmission method.

(Supplementary Note 3) When the first process is started, the first process requests the process state information management unit to acquire the lock of the process state information for the first process, and The data transmission method according to appendix 1, wherein the process state information lock for the first process is acquired.

(Supplementary Note 4) When the first process is activated, the first process requests the process state information management unit to generate the process state information for the first process, and
The data transmission method according to appendix 1, wherein the process state information management unit generates the process state information for the first process based on a request from the first process.

(Supplementary Note 5) When the first process is restarted, the second process requests the process state information management unit to acquire the lock of the process state information for the restarted first process. The data transmission method according to appendix 1, wherein the data transmission is executed subsequent to the restart process of the first process.

(Supplementary Note 6) Prior to the restart of the first process, the second process requests the process state information management unit to release the lock of the process state information acquired for the first process. ,
The process state information management unit unlocks the process state information for the first process when receiving a request for releasing the lock of the process state information for the first process. 2. The data transmission method according to 1.

(Supplementary note 7) The second process is an abnormality detection history for the first process, and holds an abnormality detection history including an abnormality detection time,
When the second process sends data to the first process, prior to the request to the process state information management unit to acquire the lock of the process state information for the first process, the process It is determined whether or not there is the abnormality detection history for the first process, and when there is the abnormality detection history, it is determined whether or not an elapsed time from the time of the abnormality detection is a specified value or less, The data transmission method according to appendix 1, wherein the data is transmitted to the first process when the elapsed time is equal to or less than a specified value.

(Supplementary Note 8) When there is no abnormality detection history for the first process, the second process acquires the lock of the process state information for the first process to the process state information management unit. The data transmission method according to appendix 7, wherein the data transmission method is requested.

(Supplementary note 9) When the second process is not equal to or less than a predetermined value, the process state information management unit is requested to acquire the lock of the process state information for the first process,
If the second process is able to acquire a lock on the process state information for the first process, after restarting the first process, the data is passed to the first process. The data transmission method according to appendix 7, wherein the data is transmitted to the first process when the process state information lock for the first process cannot be acquired.

(Supplementary note 10) In the supplementary note 9, when the second process is able to acquire the lock of the process state information for the first process, the time of abnormality detection is updated. The data transmission method described.

(Appendix 11) A process state information management unit that unlocks the process state information when an abnormality occurs in the process that has acquired the lock of the process state information;
Execute the first process, request the process state information management unit to acquire the lock of the process state information for the first process, and send the process state information about the first process from the process state information management unit A first process execution unit for acquiring the lock of
When executing a second process and transmitting data to the first process, the process state information management unit is requested to acquire a lock of the process state information for the first process, and the process state When the process state information lock for the first process can be acquired from the information management unit, the second process transmits the data to the first process after restarting the first process. And a process execution unit.

(Appendix 12) The first process is
Process state information that is unlocked by the process state information management unit when an abnormality occurs in the process that acquired the lock, and the process state information management unit acquires the lock of the process state information for the first process. To request and
Obtaining a lock of the process state information for the first process from the process state information management unit;
The second process is
When transmitting data to the first process, the process state information management unit is requested to acquire the lock of the process state information for the first process,
When the process state information management unit can acquire the lock of the process state information for the first process, the data is transmitted to the first process after the first process is restarted. A program characterized by

(Supplementary note 13) A storage medium for recording a program for executing inter-process communication,
The program is
The first process is
Process state information that is unlocked by the process state information management unit when an abnormality occurs in the process that acquired the lock, and the process state information management unit acquires the lock of the process state information for the first process. To request and
Obtaining a lock of the process state information for the first process from the process state information management unit;
The second process is
When transmitting data to the first process, the process state information management unit is requested to acquire the lock of the process state information for the first process,
When the process state information management unit can acquire the lock of the process state information for the first process, the data is transmitted to the first process after the first process is restarted. A storage medium characterized by:

1 Computer 2 Operating System (OS)
3 Semaphore management unit 4 Semaphore storage unit 5 Processing process 6 Abnormal information storage unit 7 Communication queue storage unit

Claims (8)

The first process is
Process state information that is unlocked by the process state information management unit when an abnormality occurs in the process that acquired the lock, and the process state information management unit acquires the lock of the process state information for the first process. To request and
Obtaining a lock of the process state information for the first process from the process state information management unit;
The second process is
When transmitting data to the first process, the process state information management unit is requested to acquire the lock of the process state information for the first process,
When the process state information management unit can acquire the lock of the process state information for the first process, the data is transmitted to the first process after the first process is restarted. A data transmission method characterized by: The data transmission of claim 1, wherein the second process transmits the data to the first process when the process state information lock for the first process cannot be acquired. Method. When the first process is started, the first process requests the process state information management unit to acquire the lock of the process state information for the first process, and the first process The data transmission method according to claim 1, further comprising acquiring a lock of the process state information for a process. When the first process is activated, the first process requests the process state information management unit to generate the process state information for the first process;
The data transmission method according to claim 1, wherein the process state information management unit generates the process state information for the first process based on a request from the first process. The second process is an abnormality detection history for the first process, and holds an abnormality detection history including an abnormality detection time,
When the second process sends data to the first process, prior to the request to the process state information management unit to acquire the lock of the process state information for the first process, the process It is determined whether or not there is the abnormality detection history for the first process, and when there is the abnormality detection history, it is determined whether or not an elapsed time from the time of the abnormality detection is a specified value or less, The data transmission method according to claim 1, wherein the data is transmitted to the first process when the elapsed time is equal to or less than a specified value. The second process requests the process state information management unit to obtain a lock of the process state information for the first process when the elapsed time is not less than a specified value;
If the second process is able to acquire a lock on the process state information for the first process, after restarting the first process, the data is passed to the first process. The data transmission method according to claim 5, wherein the data is transmitted to the first process when the process state information lock for the first process cannot be acquired. The data according to claim 6, wherein when the second process is able to acquire the lock of the process state information for the first process, the time of the abnormality detection is updated. Transmission method. A process state information management unit that unlocks the process state information when an abnormality occurs in the process that has acquired the lock of the process state information;
Execute the first process, request the process state information management unit to acquire the lock of the process state information for the first process, and send the process state information about the first process from the process state information management unit A first process execution unit for acquiring the lock of
When executing a second process and transmitting data to the first process, the process state information management unit is requested to acquire a lock of the process state information for the first process, and the process state When the process state information lock for the first process can be acquired from the information management unit, the second process transmits the data to the first process after restarting the first process. And a process execution unit.

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