ultimatepp/uppsrc/Core/src.tpp/Semaphore$en-us.tpp
cxl 7f4bf80baa MT docs
git-svn-id: svn://ultimatepp.org/upp/trunk@1021 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2009-03-29 14:26:07 +00:00

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topic "Semaphore";
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[{_}
[ {{10000@(113.42.0) [s0;%% [*@7;4 StaticSemaphore]]}}&]
[s3; &]
[s1;:Semaphore`:`:class: [@(0.0.255)3 class][3 _][*3 Semaphore]&]
[s2;%% Well known multithreading synchronization tool. In U`+`+,
it is primarily used to block and release thread execution. Semaphore
has an internal counter, initially initialized to zero. Wait
operation blocks thread execution as long as counter is zero,
then decreases it by one. Release operation increases counter
by 1.&]
[s3; &]
[ {{10000F(128)G(128)@1 [s0;%% [* Public Method List]]}}&]
[s3; &]
[s5;:Semaphore`:`:Wait`(`): [@(0.0.255) void]_[* Wait]()&]
[s2;%% If internal semaphore counter is zero, waits (blocks calling
thread) until some other thread increases this counter by 1 calling
the Release method. Before returning, decreases counter by 1.&]
[s3; &]
[s4; &]
[s5;:Semaphore`:`:Release`(`): [@(0.0.255) void]_[* Release]()&]
[s2;%% Increases internal counter by 1.&]
[s3; &]
[ {{10000F(128)G(128)@1 [s0;%% [* Constructor detail]]}}&]
[s3; &]
[s5;:Semaphore`:`:Semaphore`(`): [* Semaphore]()&]
[s2;%% Initializes internal counter to 0.&]
[s3; &]
[s0; &]
[ {{10000@(113.42.0) [s0;%% [*@7;4 StaticSemaphore]]}}&]
[s4; &]
[s1;:StaticSemaphore`:`:class: [@(0.0.255)3 class][3 _][*3 StaticSemaphore]&]
[s2;%% Variant of Semaphore that can be used as static or global
variable without the need of initialization `- it has no constructor
and correctly performs the first initialization when any of methods
is called. That avoids problems with initialization order or
multithreaded initialization issues.&]
[s3; &]
[ {{10000F(128)G(128)@1 [s0;%% [* Public Method List]]}}&]
[s3; &]
[s5;:StaticSemaphore`:`:Get`(`): [_^Semaphore^ Semaphore][@(0.0.255) `&]_[* Get]()&]
[s0; [* operator_Semaphore`&]()&]
[s2;%% Returns the Semaphore instance.&]
[s3;%% &]
[s4; &]
[s5;:StaticSemaphore`:`:Wait`(`): [@(0.0.255) void]_[* Wait]()&]
[s5;:StaticSemaphore`:`:Release`(`): [@(0.0.255) void]_[* Release]()&]
[s2;%% Call respective methods of Semaphore instance.&]
[s0; ]