Research On Deadlock Avoiding Technology Based On The Future Lockset

With the development of computers, the scale of software is expanding, it also increases the complexity of the program. concurrent execution has become a common way to improve program efficiency, but procedural issues are raised by the concurrent program has become increasingly serious. Deadlock is a typical problem in which concurrent program, is also a major problem of concurrent software security implications. Deadlock will lead to the termination of the program, can not run properly or even cause the system to crash, cause unnecessary losses. At the same time, because the deadlock running state space is too large, it is difficult to reproduce and correction of software problems to become one of the problems in the field and, therefore, how to effectively detect and avoid deadlocks, improve software reliability and security, has become an urgent problem.Currently, most of the current deadlock avoidance method is based on dynamic analysis. The way is that hijacking lock operation or using the rollback encountered a deadlock during the execution of the relevant program. Dynamic analysis of deadlock avoiding may affect the implementation of the efficiency of the program or even directly lead to the error results of a program.To address this problem, this paper studies on the deadlock avoidance method that combine static analysis and dynamic analysis and proposes a deadlock avoidance method based on future lock sets. The main idea is based on information of static instrumentation intelligent distinction may be the key area of the deadlock, and make them serialization to avoid deadlock. Specific completed the following work:First of all, based on the analysis Clang compiler front-end and the cause of the deadlock, this paper studied the deadlock avoidance program instrumentation method and proposed a deadlock avoidance method based on future lock set.Then, according to the previous calculation of the instrumentation information to complete the next lock set, determine whether to execute the lock operation, establish global lock distribution diagram, etc, for avoiding deadlocks logic, and to ensure that the process of interception is atomic operation.Finally, We design and implementation of a prototype system Flider, a deadlock to dodge ability deaklock avoidance efficiency and tools of extensibility of the system was tested, the test results show that the method can improve the ability to avoid deadlock, and the impact on the efficiency of the source is small.