You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
131 lines
4.1 KiB
131 lines
4.1 KiB
/*
|
|
Copyright 2005-2014 Intel Corporation. All Rights Reserved.
|
|
|
|
This file is part of Threading Building Blocks.
|
|
|
|
Threading Building Blocks is free software; you can redistribute it
|
|
and/or modify it under the terms of the GNU General Public License
|
|
version 2 as published by the Free Software Foundation.
|
|
|
|
Threading Building Blocks is distributed in the hope that it will be
|
|
useful, but WITHOUT ANY WARRANTY; without even the implied warranty
|
|
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with Threading Building Blocks; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
As a special exception, you may use this file as part of a free software
|
|
library without restriction. Specifically, if other files instantiate
|
|
templates or use macros or inline functions from this file, or you compile
|
|
this file and link it with other files to produce an executable, this
|
|
file does not by itself cause the resulting executable to be covered by
|
|
the GNU General Public License. This exception does not however
|
|
invalidate any other reasons why the executable file might be covered by
|
|
the GNU General Public License.
|
|
*/
|
|
|
|
#ifndef __TBB_queuing_mutex_H
|
|
#define __TBB_queuing_mutex_H
|
|
|
|
#include "tbb_config.h"
|
|
|
|
#if !TBB_USE_EXCEPTIONS && _MSC_VER
|
|
// Suppress "C++ exception handler used, but unwind semantics are not enabled" warning in STL headers
|
|
#pragma warning (push)
|
|
#pragma warning (disable: 4530)
|
|
#endif
|
|
|
|
#include <cstring>
|
|
|
|
#if !TBB_USE_EXCEPTIONS && _MSC_VER
|
|
#pragma warning (pop)
|
|
#endif
|
|
|
|
#include "atomic.h"
|
|
#include "tbb_profiling.h"
|
|
|
|
namespace tbb {
|
|
|
|
//! Queuing mutex with local-only spinning.
|
|
/** @ingroup synchronization */
|
|
class queuing_mutex {
|
|
public:
|
|
//! Construct unacquired mutex.
|
|
queuing_mutex() {
|
|
q_tail = NULL;
|
|
#if TBB_USE_THREADING_TOOLS
|
|
internal_construct();
|
|
#endif
|
|
}
|
|
|
|
//! The scoped locking pattern
|
|
/** It helps to avoid the common problem of forgetting to release lock.
|
|
It also nicely provides the "node" for queuing locks. */
|
|
class scoped_lock: internal::no_copy {
|
|
//! Initialize fields to mean "no lock held".
|
|
void initialize() {
|
|
mutex = NULL;
|
|
#if TBB_USE_ASSERT
|
|
internal::poison_pointer(next);
|
|
#endif /* TBB_USE_ASSERT */
|
|
}
|
|
|
|
public:
|
|
//! Construct lock that has not acquired a mutex.
|
|
/** Equivalent to zero-initialization of *this. */
|
|
scoped_lock() {initialize();}
|
|
|
|
//! Acquire lock on given mutex.
|
|
scoped_lock( queuing_mutex& m ) {
|
|
initialize();
|
|
acquire(m);
|
|
}
|
|
|
|
//! Release lock (if lock is held).
|
|
~scoped_lock() {
|
|
if( mutex ) release();
|
|
}
|
|
|
|
//! Acquire lock on given mutex.
|
|
void __TBB_EXPORTED_METHOD acquire( queuing_mutex& m );
|
|
|
|
//! Acquire lock on given mutex if free (i.e. non-blocking)
|
|
bool __TBB_EXPORTED_METHOD try_acquire( queuing_mutex& m );
|
|
|
|
//! Release lock.
|
|
void __TBB_EXPORTED_METHOD release();
|
|
|
|
private:
|
|
//! The pointer to the mutex owned, or NULL if not holding a mutex.
|
|
queuing_mutex* mutex;
|
|
|
|
//! The pointer to the next competitor for a mutex
|
|
scoped_lock *next;
|
|
|
|
//! The local spin-wait variable
|
|
/** Inverted (0 - blocked, 1 - acquired the mutex) for the sake of
|
|
zero-initialization. Defining it as an entire word instead of
|
|
a byte seems to help performance slightly. */
|
|
uintptr_t going;
|
|
};
|
|
|
|
void __TBB_EXPORTED_METHOD internal_construct();
|
|
|
|
// Mutex traits
|
|
static const bool is_rw_mutex = false;
|
|
static const bool is_recursive_mutex = false;
|
|
static const bool is_fair_mutex = true;
|
|
|
|
private:
|
|
//! The last competitor requesting the lock
|
|
atomic<scoped_lock*> q_tail;
|
|
|
|
};
|
|
|
|
__TBB_DEFINE_PROFILING_SET_NAME(queuing_mutex)
|
|
|
|
} // namespace tbb
|
|
|
|
#endif /* __TBB_queuing_mutex_H */
|