Deadlock preventing apparatus, deadlock preventing method, and program

Patent metadata

Field	Value
Publication number	US-9323585-B2
Application number	US-201214117283-A
Country	US
Kind code	B2
Filing date	May 8, 2012
Priority date	May 12, 2011
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A deadlock preventing apparatus includes a deadlock detecting section 360 configured to detect a lock command causing a deadlock on a program code of application programs 120, 130 and an emergency processing section 180 configured to insert a new lock command and a new unlock command to the program code to encompass a part from a lock command place corresponding to the lock command detected by the deadlock detecting section 360 to an unlock command place.

First claim

I claim:

1. A deadlock preventing apparatus comprising:
a processor for executing an application program;
a memory in communication with the processor;
a deadlock-occurrence-position detecting section configured to detect a lock command causing a deadlock on a program code of the application program;
an emergency processing section configured to insert a new lock command and a new unlock command to the program code to encompass a part from a lock command place corresponding to the lock command detected by the deadlock-occurrence-position detecting section to an unlock command place;
a lock monitor configured to receive a lock request and an unlock request from the application program and manage a state of a lock;
a lock-management-table storing section for the lock monitor to manage the state of the lock;
a deadlock-management-table storing section in which the lock monitor records the state of the lock in order to detect the deadlock;
a deadlock-graph-matrix storing section configured to manage a history of the state of the lock and record a place where the lock is performed in the application program;
a lock-address-table storing section in which the lock monitor records a position where a lock request is issued on the program code; and
a deadlock-graph creating section configured to create the deadlock graph matrix referring to the deadlock management table and the lock address table,
wherein
the deadlock-occurrence-position detecting section detects, on the basis of the deadlock graph matrix, likelihood of deadlock occurrence, a position where the deadlock is likely to occur, and a position of the lock command on the program code likely to cause the deadlock.

2. The deadlock preventing apparatus according to claim 1 , wherein the deadlock-occurrence-position detecting section detects, on the basis of recording information of a state of lock by the application program, the lock command causing the deadlock.

3. The deadlock preventing apparatus according to claim 1 , further comprising a GUI for presenting the position detected by the deadlock-occurrence-position detecting section.

4. The deadlock preventing apparatus according to claim 1 , further comprising a GUI for presenting the likelihood of the deadlock occurrence and the position of the lock command on the program code likely to cause the deadlock detected by the deadlock-occurrence-position detecting section.

5. The deadlock preventing apparatus according to claim 1 , further comprising a probe inserting section configured to embed, in the application program, a probe for recording lock information in the deadlock management table and the lock address table when the application program is executed.

6. The deadlock preventing apparatus according to claim 1 , wherein:
the deadlock-graph-matrix storing section is configured to record a history of the lock command by the application program,
the lock-address-table storing section is configured to record the lock command place on the program code corresponding to the lock command by the application program, and
the emergency processing section acquires, referring to the lock address table, the lock command place corresponding to the lock command causing the deadlock detected on the basis of the deadlock graph matrix, searches through the program code and acquires the unlock command place corresponding to the lock command place, and inserts the new lock command and the new unlock command to the program code to encompass a part from the lock command place to the unlock command place.

7. A deadlock preventing method comprising:
storing a program code of the application program to a memory; and
executing, by a processor, the stored program code;
receiving a lock command of a lock on the program code of the application program;
recording the state of the lock;
managing the state of the lock;
recording a place where the lock is performed in the application program;
recording a position where the lock command is issued on the program code; and
detecting, on the basis of a history of the state of the lock, the place where the lock is performed in the application program, and the position where the lock command is issued on the program code, likelihood of deadlock occurrence, a position where a deadlock is likely to occur, and a position of the lock command on the program code likely to cause the deadlock, wherein the history comprises a deadlock-graph-matrix;
if the deadlock is detected, inserting a new lock command and a new unlock command to the program code to encompass a part from a lock command place corresponding to the lock command to an unlock command place.

Assignees

• Tonouchi Toshio
• Nec Corp

Inventors

• Tonouchi Toshio

Classifications

• G06F11/3604

  Analysis of software for verifying properties of programs (testing of software G06F11/3668) · CPC title

• G06F9/524 Primary

  Deadlock detection or avoidance · CPC title