Thread support library

< cpp
Revision as of 12:54, 5 January 2013 by Arbalest (Talk | contribs)

C++ includes built-in support for threads, mutual exclusion, condition variables, and futures.



Threads enable programs to execute across several processor cores.

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Defined in header <thread>
Functions managing the current thread
Defined in namespace this_thread

Mutual exclusion

Mutual exclusion algorithms prevent multiple threads from simultaneously accessing shared resources. This prevents data races and provides support for synchronization between threads.

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Defined in header <mutex>
Generic mutex management
Generic locking algorithms
Call once

Condition variables

A condition variable is a synchronization primitive that allows multiple threads to communicate with each other. It allows some number of threads to wait (possibly with a timeout) for notification from another thread that they may proceed. A condition variable is always associated with a mutex.

Defined in header <condition_variable>
provides a condition variable associated with a std::unique_lock
provides a condition variable associated with any lock type
schedules a call to notify_all to be invoked when this thread is completely finished
lists the possible results of timed waits on condition variables


The standard library provides facilities to obtain values that are returned and to catch exceptions that are thrown by asynchronous tasks (i.e. functions launched in separate threads). These values are communicated in a shared state, in which the asynchronous task may write its return value or store an exception, and which may be examined, waited for, and otherwise manipulated by other threads that hold instances of std::future or std::shared_future that reference that shared state.

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Defined in header <future>
Future errors