C++ named requirements: SharedLockable (since C++14)
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C++
C++ named requirements
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The SharedLockable requirements describe the minimal characteristics of types that provide shared blocking semantics for execution agents (i.e. threads).
Contents |
[edit] Requirements
For type L to be SharedLockable, the following conditions have to be satisfied for an object m of type L:
| Expression | Preconditions | Effects | Return value |
|---|---|---|---|
| m.lock_shared() | Blocks until a lock can be obtained for the current execution agent (thread, process, task). If an exception is thrown, no lock is obtained. | ||
| m.try_lock_shared() | Attempts to obtain a lock for the current execution agent (thread, process, task) without blocking. If an exception is thrown, no lock is obtained. | true if the lock was obtained, false otherwise | |
| m.unlock_shared() | The current execution agent holds a shared lock on m.
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Releases the shared lock held by the execution agent.
Throws no exceptions. |
[edit] Shared locks
A lock on an object is said to be shared lock if it is acquired by a call to lock_shared, try_lock_shared, try_lock_shared_for, or try_lock_shared_until member function.
[edit] Standard library
The following standard library types satisfy SharedLockable requirements:
| (C++17) |
provides shared mutual exclusion facility (class) [edit] |
| (C++14) |
provides shared mutual exclusion facility and implements locking with a timeout (class) [edit] |
