JP2011107813A - Device, method, and program for obtaining core file - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve shortening a core dump time and reducing the size of a core file. <P>SOLUTION: All stack frames are enumerated, and whether the stack frame is a dump object is determined for each stack frame, and only information which can be referenced from the stack frame determined as the dump object is output to a core file. Thus, the size of a core file is reduced and core dump time is shortened. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for outputting execution environment information to a core file when a failure occurs in a program.

  By saving the contents of memory when a failure occurs in a running program as a file, it is possible to analyze the file later and investigate the execution state of the program at the time of failure and the cause of the failure Become. A file storing execution environment information at the time of failure occurrence is called a core file, and acquiring a core file is called a core dump (see Non-Patent Document 1). A technique for improving the efficiency of analysis of a core file is also known (see Non-Patent Document 2).

"Debugging with GDB 10.17 How to Produce a Core File from Your Program", [online], [October 30, 2009 search], Internet <URL: http://sourceware.org/gdb/current/onlinedocs/gdb .html> "OSS Performance / Reliability Evaluation / Failure Analysis Tool Development OS Layer -Alicia-", [online], [October 30, 2009 Search], Internet <URL: http://www.ipa.go.jp /software/open/forum/development/download/051115/OS-Alicia.pdf>

  However, in the conventional technology, since all the information in the memory used by the program is targeted for dumping, there is a problem that it takes a long time to acquire the core file or the size of the core file becomes huge. It was. Non-Patent Document 2 improves the efficiency of analysis of a core file, but has no effect of reducing the acquisition time and size of the core file.

  Although it is possible to reduce the file size by specifying the dump target to be output to the core file, if you do not specify the dump target effectively, the information required for analysis will be excluded or there will be many dump targets and the file size May not be able to be reduced too much.

  The present invention has been made in view of the above, and an object thereof is to realize a reduction in the core dump time and a reduction in the size of the core file.

  A core file acquisition apparatus according to a first aspect of the present invention includes an execution unit that executes a program, a detection unit that detects a failure of the program, and a detection unit that detects each failure of the stack frame when the detection unit detects a failure of the program. The acquisition means for acquiring the execution position information, the storage means for storing the setting information describing the dump target determination condition, and for each stack frame, the execution position information of the stack frame and the setting information read from the storage means A determination unit that compares the dump target determination condition to determine whether or not the stack frame is a dump target, and obtains information that can be referred to from the stack frame that the determination unit determines to be the dump target from the execution unit. Output means for outputting to a core file.

  In the core file acquisition apparatus, the determination unit reads setting information from the storage unit when the detection unit detects a failure of the program.

  The core file acquisition method according to the second aspect of the present invention includes a step of detecting a failure of a program executed by the execution means, and a step of acquiring execution position information of each stack frame from the execution means when the failure of the program is detected And reading the setting information from the storage means storing the setting information describing the dump target determination condition, and comparing the stack frame execution position information with the dump target determination condition for each stack frame. And a step of acquiring information that can be referred to from the stack frame determined to be a dump target from the execution means and outputting the information to a core file.

  In the core file acquisition method, the setting information is read from the storage means when a failure of the program is detected.

  A core file acquisition program according to the third aspect of the present invention causes a computer to function as each means constituting the core file acquisition apparatus.

  According to the present invention, it is possible to reduce the core dump time and the size of the core file.

It is a functional block diagram which shows the structure of the core file acquisition apparatus in Example 1. FIG. 6 is a flowchart illustrating a processing flow of the core file acquisition apparatus according to the first embodiment. It is a schematic explanatory drawing for demonstrating the information output to a core file by the said core file acquisition apparatus. It is a functional block diagram which shows the structure of the core file acquisition apparatus in Example 2. FIG. It is a flowchart which shows the flow of a process of the core file acquisition apparatus in Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a functional block diagram illustrating the configuration of the core file acquisition apparatus according to the first embodiment. The core file acquisition apparatus 1 shown in the figure includes an execution unit 11, a detection unit 12, an acquisition unit 13, a determination unit 14, and a storage unit 15. Details of each part will be described below.

  The execution unit 11 includes an arithmetic processing unit, a memory, and the like, and executes the core dump acquisition target program. When a failure occurs in the core dump acquisition target program, the execution unit 11 transmits a failure occurrence notification to the detection unit 12. The failure that occurs in the core dump acquisition target program is, for example, that the value of a variable becomes an incorrect value.

  The detection unit 12 receives a failure occurrence notification from the execution unit 11 to detect a failure in the core dump acquisition target program and issues a core file acquisition request to the acquisition unit 13. The failure occurrence notification and the core file acquisition request include an identifier for identifying the core dump acquisition target program. The detection unit 12 may access the execution unit 11 to detect a failure.

  The acquisition unit 13 connects to the core dump acquisition target program in response to the core file acquisition request from the detection unit 12 and acquires execution position information of the stack frame. Then, the determination unit 14 is inquired as to whether or not it is a dump target in units of stack frames, information that can be referred to from the stack frame determined to be a dump target is acquired from the execution unit 11 and output to the core file 151. The stack frame is a storage area secured in the memory of the execution unit 11 when a method is called, and stores information such as variables used in the method. When another method is called in the method, a stack frame for another method is secured in the memory. The execution position information of the stack frame includes information such as a source file name, a line number in the source file, a class name, and a method name, and is information that allows the current execution position of the core dump acquisition target program to be known. The information that can be referred to from the stack frame is mainly variables. Not only the variables in the stack frame but also the variables in the stack frame refer to, and the variables that can be traced from the variables can be output to the core file 151. Information.

  The determination unit 14 determines whether the stack frame specified by the acquisition unit 13 is a dump target. Whether or not the stack frame is a dump target is determined by receiving execution position information of the stack frame determined from the acquisition unit 13 and comparing the received execution position information with the setting file 152 stored in the storage unit 15. Do that. The setting file 152 describes dump target determination conditions such as a source file name excluded from the dump target and a part of the class name. For example, when the source file name of the execution position information of a certain stack frame is described as an exclusion target in the setting file 152, it is determined that the stack frame is not a dump target. When a part of the class name is described in the setting file 152 in addition to the source file name, the source file name matches, and the class name of the execution position information is the class name described in the setting file 152. Is included, it is determined that the stack frame is not a dump target. The determination unit 14 may acquire the setting file 152 before the failure occurs. However, when the determination unit 14 acquires the setting file 152 when the detection unit 12 receives the failure occurrence notification, the core dump acquisition target program Since the setting file 152 is not acquired until a failure occurs in the system, there is almost no influence on the behavior of the core dump acquisition target program until the detection unit 12 actually detects the failure.

  In addition to storing the setting file 152 described above, the storage unit 15 stores the information output by the acquisition unit 13 in the core file 151.

  Next, the process flow of the core file acquisition apparatus 1 will be described. FIG. 2 is a flowchart illustrating a process flow of the core file acquisition apparatus 1 according to the first embodiment.

  First, when the detection unit 12 receives a failure occurrence notification from the execution unit 11 and detects a failure of the core dump acquisition target program, the detection unit 12 issues a core file acquisition request to the acquisition unit 13 (step S11). When the acquisition unit 13 receives the core file acquisition request, the acquisition unit 13 connects to the core dump acquisition target program, stops the operation of the core file acquisition target program, enumerates all stack frames, and performs the following processing for each stack frame. I do.

  The acquisition unit 13 acquires stack frame execution position information from the execution unit 11 (step S12). The acquired execution position information is output to the core file 151 in the storage unit 15. Since the acquisition time and size of the execution position information are considerably shorter than other dumping information, in this embodiment, the execution position information of all stack frames is stored in the core file 151 regardless of whether or not it is a dump target. Output. Of course, only the execution position information of the stack frame determined to be dumped may be output to the core file 151.

  Thereafter, when the acquisition unit 13 passes the execution position information to the determination unit 14, the determination unit 14 compares the execution position information with the dump target determination condition of the setting file 152 to determine whether the stack frame is a dump target. (Step S13). If the stack frame is not a dump target, the process proceeds to step S15 to process the next stack frame.

  When the stack frame is a dump target, the acquisition unit 13 acquires information that can be referred to from the stack frame from the execution unit 11 and outputs the information to the core file 151 (step S14).

  Then, it is determined whether or not all stack frames have been processed (step S15). If there is a stack frame that has not yet been processed, the process returns to step S12. When all the stack frames have been processed, the processing of the core file acquisition device 1 is terminated.

  FIG. 3 is a schematic explanatory diagram for explaining information output to the core file 151 by the core file acquisition apparatus 1. In the example shown in FIG. 3, five stack frames # 0 to # 4 are listed. A circle on the right side of the stack frame indicates information that can be traced from the stack frame. Among the listed stack frames, # 0 and # 3 are stack frames by other companies' programs. If the stack frames of # 0 and # 3 are excluded from dumping, dumping of information that is referenced only from there can be excluded. In FIG. 3, information indicated by white circles is dumped, and information indicated by shaded circles is not dumped. Even if the information is referenced from the non-dump target stack frame (for example, # 0), the information can be output to the core file 151 as long as the information can be referred to from the dump target stack frame (for example, # 1).

  Information that can be referred to from the stack frame includes not only information held by the stack frame but also information referred to by the information. Therefore, the acquisition unit 13 traces information from the stack frame and outputs it to the core file 151. Specifically, when a variable has another variable, another variable is also output to the core file 151. When the other variable has another variable, another variable is also output to the core file 151. . Information reference relationships are also output to the core file 151.

  FIG. 4 is a functional block diagram illustrating the configuration of the core file acquisition apparatus according to the second embodiment. A core file acquisition apparatus 100 shown in FIG. 1 includes a JVM (Java Virtual Machine) 110, a failure detection unit 120, a core file acquisition unit 130, and a dump target determination unit 140, and is connected to the secondary storage device 150.

  The JVM 110 is a virtual machine that executes a program 111 written in the Java (registered trademark) language. When a failure occurs in the program 111, a failure occurrence notification is transmitted to the failure detection unit 120. Failure detection can be realized by describing a failure occurrence notification transmission function in a catch clause, which is an exception catch instruction of Java, for example. It can also be realized by determining an abnormality of the variable value as a failure using an if statement and transmitting a failure occurrence notification. In addition, there are a method of detecting a case where a certain condition is satisfied using aspect orientation as a failure, and a method of detecting a failure using Byte Code Instrumentation (BCI).

  When receiving the failure occurrence notification, the failure detection unit 120 issues a core file acquisition request to the core file acquisition unit 130 and issues an initialization request to the dump target determination unit 140.

  The core file acquisition unit 130 connects to the program 111 via the JVM 110 in response to the core file acquisition request from the failure detection unit 120, and inquires of the dump target determination unit 140 whether or not the dump target is a stack frame unit. Information that can be referred to is acquired from the stack frame determined to be dumped and output to the core file 151. When a plurality of threads are executed by the program 111, an inquiry is made as to whether or not all stack frames of all threads are to be dumped. The core file acquisition unit 130 acquires stack frame execution position information (package name, source file name, line number in the source file, class name, method name, etc.), and passes the execution position information to the dump target determination unit 140. To inquire whether the stack frame is a dump target.

  In the present embodiment, JDI (Java Debug Interface) is used as a method of connecting to the program 111. If the program is written in the Java language, JVMDI (Java Virtual Machine Debug Interface) and JDWP (Java Debug Wire Protocol) can also be used. If the program is written in C language, the ptrace system call or gdb created using ptrace can be used.

  The dump target determination unit 140 determines whether the stack frame specified by the core file acquisition unit 130 is a dump target. In this embodiment, when the class name of the execution position information of the stack frame includes a part of the class name described in the setting file 152, the stack frame is determined not to be dumped. That is, when the class name of the execution position information of the stack frame does not include a part of the class name described in the setting file 152, the stack frame becomes a dump target. Note that a package name, a source file name, a line number in the source file, or a method name may be used as a determination condition for determining whether or not to dump. Of course, it is possible to use a regular expression as a judgment condition for dumping, or to use a line number size relationship.

  The dump target determination unit 140 reads the setting file 152 from the secondary storage device 150 in response to the initialization request from the failure detection unit 120 and loads it into the memory included in the dump target determination unit 140.

  The secondary storage device 150 stores the setting file 152 in which the determination condition for dumping is described, and stores the information output by the core file acquisition unit 130 as the core file 151.

  Next, a processing flow of the core file acquisition apparatus 100 will be described. FIG. 5 is a flowchart showing the processing flow of the core file acquisition apparatus 100 in the present embodiment.

  First, when the failure detection unit 120 receives a failure occurrence notification and detects a failure of the program 111, the failure detection unit 120 issues a core file acquisition request to the core file acquisition unit 130 and also initializes to the dump target determination unit 140. Issue an activation request (step S101). The dump target determination unit 140 reads the dump target determination condition of the setting file 152 from the secondary storage device 150 in response to the initialization request.

  When the core file acquisition unit 130 receives the core file acquisition request, the core file acquisition unit 130 attaches to the program 111 via the API of the debugger (step S102). After attaching to the program 111, the core file acquisition unit 130 stops the operation of the program 111, enumerates all the threads of the program 111 using the JDI VirtualMachine.allThreads () method, and performs the following processing for each thread. .

  The core file acquisition unit 130 acquires the thread ID of the target thread, the thread name, the monitor acquisition waiting object, and the object list holding the monitor, and outputs them as dump information to the core file 151 of the secondary storage device 150 ( Step S103). All information about threads can be acquired by JDI API. The core file acquisition unit 130 enumerates all stack frames for the target thread using the ThreadReference.frames () method of JDI, and performs the following processing for each stack frame.

  The core file acquisition unit 130 acquires stack frame execution position information (package name, source file name, line number in the source file, class name, method name), and uses the core file of the secondary storage device 150 as stack frame information. 151 (step S104). In this embodiment, the acquired execution position information is output to the core file 151 regardless of whether or not the stack frame is a dump target.

  When the core file acquisition unit 130 passes the execution position information to the dump target determination unit 140, the dump target determination unit 140 compares the execution position information with the dump target determination condition to determine whether the stack frame is a dump target. (Step S105). If the stack frame is not a dump target, the process proceeds to step S110 to process the next stack frame.

  When the stack frame is a dump target, the core file acquisition unit 130 uses JDI's StackFrame.visibleVariables () method to enumerate all the variables held by the stack frame, and among the enumerated variables, core type variables are listed. It outputs to the file 151 (step S106). A primitive variable is a variable that has an integer value, a floating-point value, or a character value as a value and does not have other variables as values. On the other hand, object type variables exist as variables other than primitive type variables. An object type variable is a variable having another variable such as a primitive type variable or another object type variable.

  Subsequently, among the enumerated variables, the object ID, type name, and character string expression value of the object type variable are output to the core file 151 as object information (step S107). Information on the object type variable is acquired by the JDI ObjectReference.uniqueID () method, ObjectReference.referenceType (). Name () method, and ObjectReference.toString () method.

  Then, using JDI's StackFrame.visibleVariables () method, all member variables held by the object type variable are enumerated, and among the enumerated variables, the primitive type variable is output to the core file 151 (step S108). If an object type variable exists as a member variable (step S109), the processing after step S107 is recursively executed on the object type variable.

  When all the variables that can be traced from the stack frame have been output, it is determined whether or not all the stack frames have been processed (step S110). If there is a stack frame that has not yet been processed, the process returns to step S104.

  If all the stack frames have been processed, it is determined whether all threads have been processed (step S111). If there is a thread that has not yet been processed, the process returns to step S103. When all the threads have been processed, the processing of the core file acquisition apparatus 100 ends.

  In addition, each part with which the core file acquisition apparatus shown in Example 1, 2 is comprised is comprised by the computer provided with the arithmetic processing unit, the memory | storage device, memory, etc., and the process of each part may be performed by a program. . This program is stored in a storage device included in the core file acquisition device, and can be recorded on a recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, or provided through a network. In addition, the configuration of the core file acquisition apparatus of each embodiment is an example, and each unit may be configured by a separate computer.

  As described above, all stack frames are listed, whether or not each stack frame is a dump target, and only information that can be referenced from the stack frame determined to be dumped is output to the core file. It becomes possible to reduce the size of the core file and shorten the core dump time. Since it is possible to specify the necessity of dumping in units of stack frames, for example, by excluding stack frames such as external libraries, that is, stack frames such as libraries that are relatively likely to fail are targeted for dumping. As a result, it is possible to reduce the size of the core file while leaving all the information necessary for analyzing the failure of the program.

DESCRIPTION OF SYMBOLS 1 ... Core file acquisition apparatus 11 ... Execution part 12 ... Detection part 13 ... Acquisition part 14 ... Determination part 15 ... Storage part 100 ... Core file acquisition apparatus 110 ... JVM
DESCRIPTION OF SYMBOLS 111 ... Program 120 ... Failure detection part 130 ... Core file acquisition part 140 ... Dump object determination part 150 ... Secondary storage device 151 ... Core file 152 ... Setting file

Claims (5)

Execution means for executing the program;
Detecting means for detecting a failure of the program;
An acquisition means for acquiring execution position information of each stack frame from the execution means when the detection means detects a failure of the program;
Storage means for storing setting information describing the dump target determination condition;
For each stack frame, the execution position information of the stack frame is compared with the dump target determination condition described in the setting information read from the storage unit to determine whether the stack frame is a dump target. A determination means;
Output means for acquiring information that can be referred to from the stack frame determined by the determination means to be dumped from the execution means and outputting the information to a core file;
A core file acquisition apparatus comprising:   2. The core file acquisition apparatus according to claim 1, wherein the determination unit reads the setting information from the storage unit when the detection unit detects a failure of the program. Detecting a failure of a program executed by the execution means;
Obtaining execution position information of each stack frame from the execution means when a failure of the program is detected;
Reading the setting information from the storage means storing the setting information describing the dump target determination condition;
For each stack frame, comparing execution position information of the stack frame with the dump target determination condition to determine whether the stack frame is a dump target; and
Obtaining from the execution means information that can be referred to from the stack frame determined to be a dump target, and outputting to the core file;
A core file acquisition method characterized by comprising:   4. The core file acquisition method according to claim 3, wherein the setting information is read from the storage means when a failure of the program is detected.   The core file acquisition program for functioning a computer as each means which comprises the core file acquisition apparatus of Claim 1 or 2.

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