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Diffstat (limited to '')
-rw-r--r-- | comm/third_party/botan/src/lib/utils/thread_utils/semaphore.cpp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/thread_utils/semaphore.cpp b/comm/third_party/botan/src/lib/utils/thread_utils/semaphore.cpp new file mode 100644 index 0000000000..0858a013f2 --- /dev/null +++ b/comm/third_party/botan/src/lib/utils/thread_utils/semaphore.cpp @@ -0,0 +1,38 @@ +/* +* Semaphore +* (C) 2013 Joel Low +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/internal/semaphore.h> + +// Based on code by Pierre Gaston (http://p9as.blogspot.com/2012/06/c11-semaphores.html) + +namespace Botan { + +void Semaphore::release(size_t n) + { + for(size_t i = 0; i != n; ++i) + { + std::lock_guard<std::mutex> lock(m_mutex); + + if(m_value++ < 0) + { + ++m_wakeups; + m_cond.notify_one(); + } + } + } + +void Semaphore::acquire() + { + std::unique_lock<std::mutex> lock(m_mutex); + if(m_value-- <= 0) + { + m_cond.wait(lock, [this] { return m_wakeups > 0; }); + --m_wakeups; + } + } + +} |