|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Member functions | ||||
| Locking | ||||
recursive_mutex::try_lock | ||||
| Native handle | ||||
bool try_lock()noexcept; | (since C++11) | |
Tries to lock the mutex. Returns immediately. On successful lock acquisition returnstrue, otherwise returnsfalse.
This function is allowed to fail spuriously and returnfalse even if the mutex is not currently locked by any other thread.
A thread may calltry_lock on a recursive mutex repeatedly. Successful calls totry_lock increment the ownership count: the mutex will only be released after the thread makes a matching number of calls tounlock.
The maximum number of levels of ownership is unspecified. A call totry_lock will returnfalse if this number is exceeded.
Priorunlock() operation on the same mutexsynchronizes-with (as defined instd::memory_order) this operation if it returnstrue. Note that priorlock() does not synchronize with this operation if it returnsfalse.
Contents |
(none)
true if the lock was acquired successfully, otherwisefalse.
Throws nothing.
#include <iostream>#include <mutex> int main(){std::recursive_mutex test;if(test.try_lock()){std::cout<<"lock acquired\n"; test.unlock();}elsestd::cout<<"lock not acquired\n"; test.lock();// non-recursive mutex would return false from try_lock nowif(test.try_lock()){std::cout<<"lock acquired\n"; test.unlock();}elsestd::cout<<"lock not acquired\n"; test.unlock();}
Output:
lock acquiredlock acquired
| locks the mutex, blocks if the mutex is not available (public member function)[edit] | |
| unlocks the mutex (public member function)[edit] | |
C documentation formtx_trylock | |
