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Difference between revisions of "cpp/thread/shared lock"

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===[[cpp/thread/shared_lock/deduction_guides|Deduction guides]]{{mark since c++17}}===
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===Possible implementation===
 
===Possible implementation===

Revision as of 08:45, 12 April 2017

 
 
Concurrency support library
Threads
(C++11)
(C++20)
this_thread namespace
(C++11)
(C++11)
(C++11)
Cooperative cancellation
Mutual exclusion
(C++11)
Generic lock management
(C++11)
(C++11)
shared_lock
(C++14)
(C++11)
(C++11)
(C++11)
Condition variables
(C++11)
Semaphores
Latches and Barriers
(C++20)
(C++20)
Futures
(C++11)
(C++11)
(C++11)
(C++11)
Safe Reclamation
(C++26)
Hazard Pointers
Atomic types
(C++11)
(C++20)
Initialization of atomic types
(C++11)(deprecated in C++20)
(C++11)(deprecated in C++20)
Memory ordering
Free functions for atomic operations
Free functions for atomic flags
 
 
Defined in header <shared_mutex>
template< class Mutex >
class shared_lock;
(since C++14)

The class shared_lock is a general-purpose shared mutex ownership wrapper allowing deferred locking, timed locking and transfer of lock ownership. Locking a shared_lock locks the associated shared mutex in shared mode (to lock it in exclusive mode, std::unique_lock can be used)

The shared_lock class is movable, but not copyable -- it meets the requirements of Template:concept and Template:concept but not of Template:concept or Template:concept.

In order to wait in a shared mutex in shared ownership mode, std::condition_variable_any can be used (std::condition_variable requires std::unique_lock and so can only wait in unique ownership mode)

Contents

Template parameters

Mutex - the type of the shared mutex to lock. The type must meet the Template:concept requirements

Member types

Type Definition
mutex_type Mutex

Member functions

constructs a shared_lock, optionally locking the supplied mutex
(public member function) [edit]
unlocks the associated mutex
(public member function) [edit]
unlocks the mutex, if owned, and acquires ownership of another
(public member function) [edit]
Shared locking
locks the associated mutex
(public member function) [edit]
tries to lock the associated mutex
(public member function) [edit]
tries to lock the associated mutex, for the specified duration
(public member function) [edit]
tries to lock the associated mutex, until a specified time point
(public member function) [edit]
unlocks the associated mutex
(public member function) [edit]
Modifiers
swaps the data members with another shared_lock
(public member function) [edit]
disassociates the mutex without unlocking
(public member function) [edit]
Observers
returns a pointer to the associated mutex
(public member function) [edit]
tests whether the lock owns its associated mutex
(public member function) [edit]
tests whether the lock owns its associated mutex
(public member function) [edit]

Non-member functions

specializes the std::swap algorithm
(function template) [edit]

Deduction guides(since C++17)