libcruft-util/threads/semaphore_posix.cpp

73 lines
1.7 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
*/
#include "semaphore.hpp"
#include "debug.hpp"
#include "except.hpp"
using util::threads::semaphore;
///////////////////////////////////////////////////////////////////////////////
semaphore::semaphore (unsigned value)
{
auto err = sem_init (&m_id, false, value);
errno_error::try_code (err);
}
//-----------------------------------------------------------------------------
semaphore::~semaphore ()
{
auto err = sem_destroy (&m_id);
errno_error::try_code (err);
}
///////////////////////////////////////////////////////////////////////////////
void
semaphore::wait (void)
{
auto err = sem_wait (&m_id);
errno_error::try_code (err);
}
//-----------------------------------------------------------------------------
bool
semaphore::try_wait (void)
{
switch (auto err = sem_wait (&m_id)) {
case 0: return true;
case EAGAIN: return false;
default:
errno_error::throw_code (err);
}
unreachable ();
}
//-----------------------------------------------------------------------------
void
semaphore::post (void)
{
auto err = sem_post (&m_id);
errno_error::try_code (err);
}