pthread_mutex_unlock(&mutex); pthread_cond_signal(&cond); } pthread_exit(0); } void*printOddNum(void*arg) { while(count<MAX) { pthread_mutex_lock(&mutex); while(count % 2 != 1) { pthread_cond_wait(&cond, &mutex)
Mutual exclusion locks, or C locks, are one of the fundamental components of any Linux system. A C lock, also known as a mutex, is a data structure used by a process to temporarily stop other processes from accessing a shared resource, thus ensuring that exclusive access is given to the ...
(单纯的替换mutex->spinlock好像会报编译错误。另外,顺便问下,把mutex换成spinlock在Singleton模式下会有比较大的性能提升么?(目测不会。。。= =。。我的代码如下:#ifndef SINGLETON #define SINGLETON class CSingleton { public: static CSingleton* getInstance() { if(!uniqueInstance) { pthread_mutex_lock(&...
std::lock_guard lck{mtx}; std::shared_lock lck{mtx}; Contributor ray6080 Nov 21, 2024 I don't think shared_lock is safe here, as the func can modify entires. One option is to change func signature to take in const CatalogEntry& instead of CatalogEntry*, or we should fall bac...
A mutex lock must not be reinitialized or destroyed while other threads might be using it. Program failure will result if either action is not done correctly. If a mutex is reinitialized or destroyed, the application must be sure the mutex is not currently in use....
generic_lock() ; fs.set_safe_flag(stream_MT::unsafe_object) ; ... do various i/o operations generic_unlock() ; where thegeneric_lockandgeneric_unlockfunctions can be any synchronization mechanism that uses such primitives as mutex, semaphores, or reader/writer locks. ...
However, they also increase the difficulty of deadlock detection, since detection methods have to consider deadlocks caused by different mechanisms and their attributes. Traditional deadlock detection techniques are for deadlocks that involve a few types of synchronization mechanisms, typically mutex only....
(kernel/cpu.c) for an example. However, if that is not feasible, and grabbing 'pm_mutex' is deemed necessary, it is strongly discouraged to directly call mutex_[un]lock(&pm_mutex) since that could lead to freezing failures, because if the suspend/hibernate code successfully acquired the ...
int mutex_trylock(mutex *m) { /* Try to take the lock, if is currently unlocked */ unsigned c = cmpxchg(m, 0, 1); if (!c) return 0; return EBUSY; } However, the above is a little faster in most cases than the algorithm shown in the "Futexes are Tricky" tutorial. Here, we...
Transaction Lock _txlock immediate deferred exclusive Specify locking behavior for transactions. Writable Schema _writable_schema Boolean When this pragma is on, the SQLITE_MASTER tables in which database can be changed using ordinary UPDATE, INSERT, and DELETE statements. Warning: misuse of this pra...