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/*
* Semaphore
* (C) 2013 Joel Low
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/internal/semaphore.h>
#if defined(BOTAN_TARGET_OS_HAS_THREADS)
// 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)
{
lock_guard_type<mutex_type> lock(m_mutex);
++m_value;
if(m_value <= 0)
{
++m_wakeups;
m_cond.notify_one();
}
}
}
void Semaphore::acquire()
{
std::unique_lock<mutex_type> lock(m_mutex);
--m_value;
if(m_value < 0)
{
m_cond.wait(lock, [this] { return m_wakeups > 0; });
--m_wakeups;
}
}
}
#endif
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