Linux / POSIX 线程pthread里几个关键机制cleanup push/pop、线程取消pthread_cancel、线程退出pthread_exit之间的关系。一、pthread_cleanup_push / pop 是什么它们是线程“清理栈”cleanup handler stack机制。1. 作用当线程被取消pthread_cancel或者调用 pthread_exit或者正常执行 pop 释放都会自动执行“清理函数”比如释放锁释放内存关闭文件2. 基本形式pthread_cleanup_push(void (*routine)(void *), void *arg); pthread_cleanup_pop(int execute);3. 典型用法void cleanup(void *arg) { printf(cleanup: %s\n, (char*)arg); } void* thread_func(void* arg) { pthread_cleanup_push(cleanup, resource A); printf(thread running\n); pthread_cleanup_pop(1); // 1 立即执行 cleanup return NULL; }4.一个综合例子最能说明问题#include pthread.h #include stdio.h #include unistd.h pthread_mutex_t lock PTHREAD_MUTEX_INITIALIZER; void cleanup(void* arg) { pthread_mutex_unlock((pthread_mutex_t*)arg); printf(cleanup: unlock mutex\n); } void* thread_func(void* arg) { pthread_mutex_lock(lock); pthread_cleanup_push(cleanup, lock); printf(thread running\n); sleep(10); // 这里是取消点 pthread_cleanup_pop(1); return NULL; } int main() { pthread_t tid; pthread_create(tid, NULL, thread_func, NULL); sleep(1); pthread_cancel(tid); pthread_join(tid, NULL); return 0; }
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