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43 строки
789 B
ReStructuredText
43 строки
789 B
ReStructuredText
PR_WaitSemaphore
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================
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Returns the value of the environment variable.
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Syntax
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------
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.. code:: eval
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#include <pripcsem.h>
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NSPR_API(PRStatus) PR_WaitSemaphore(PRSem *sem);
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Parameter
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~~~~~~~~~
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The function has the following parameter:
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``sem``
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A pointer to a ``PRSem`` structure returned from a call to
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:ref:`PR_OpenSemaphore`.
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Returns
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~~~~~~~
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:ref:`PRStatus`
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Description
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-----------
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:ref:`PR_WaitSemaphore` tests the value of the semaphore. If the value of
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the semaphore is > 0, the value of the semaphore is decremented and the
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function returns. If the value of the semaphore is 0, the function
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blocks until the value becomes > 0, then the semaphore is decremented
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and the function returns.
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The "test and decrement" operation is performed atomically.
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