c++实现互斥锁
typedef struct __lock_t
{
int flag;
} lock_t;
int TestAndSet(int *ptr, int new) { int old = *ptr; *ptr = new; return old; }
void init(lock_t *mutex) { // 0: lock is available // 1: lock is held mutex->flag = 0; }
void lock(lock_t *mutex) { while (mutex->flag == 1) { // Test the flag. ; // Wait the lock mutex->flag = 1; // Set the lock, i.e. start to hold lock } }
void unlock(lock_t * mutex) { mutex->flag = 0; }
int TestAndSet(int *ptr, int new) { int old = *ptr; *ptr = new; return old; }
void init(lock_t *mutex) { // 0: lock is available // 1: lock is held mutex->flag = 0; }
void lock(lock_t *mutex) { while (mutex->flag == 1) { // Test the flag. ; // Wait the lock mutex->flag = 1; // Set the lock, i.e. start to hold lock } }
void unlock(lock_t * mutex) { mutex->flag = 0; }