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