blender/intern/cycles/util/util_thread.h
Ton Roosendaal da376e0237 Cycles render engine, initial commit. This is the engine itself, blender modifications and build instructions will follow later.
Cycles uses code from some great open source projects, many thanks them:

* BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs":
http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/
* Open Shading Language for a large part of the shading system:
http://code.google.com/p/openshadinglanguage/
* Blender for procedural textures and a few other nodes.
* Approximate Catmull Clark subdivision from NVidia Mesh tools:
http://code.google.com/p/nvidia-mesh-tools/
* Sobol direction vectors from:
http://web.maths.unsw.edu.au/~fkuo/sobol/
* Film response functions from:
http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php
2011-04-27 11:58:34 +00:00

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/*
* Copyright 2011, Blender Foundation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __UTIL_THREAD_H__
#define __UTIL_THREAD_H__
#include <boost/thread.hpp>
#include <queue>
CCL_NAMESPACE_BEGIN
#if 0
/* Use STL for threading */
using std::thread;
using std::thread_mutex;
typedef std::lock_guard thread_scoped_lock;
using std::condition_variable;
#else
/* Use boost for threading */
using boost::thread;
typedef boost::mutex thread_mutex;
typedef boost::mutex::scoped_lock thread_scoped_lock;
typedef boost::condition_variable thread_condition_variable;
#endif
/* Thread Safe Queue to pass tasks from one thread to another. Tasks should be
* pushed into the queue, while the worker thread waits to pop the next task
* off the queue. Once all tasks are into the queue, calling stop() will stop
* the worker threads from waiting for more tasks once all tasks are done. */
template<typename T> class ThreadQueue
{
public:
ThreadQueue()
{
tot = 0;
tot_done = 0;
do_stop = false;
do_cancel = false;
}
/* Main thread functions */
/* push a task to be executed */
void push(const T& value)
{
thread_scoped_lock lock(queue_mutex);
queue.push(value);
tot++;
lock.unlock();
queue_cond.notify_one();
}
/* wait until all tasks are done */
void wait_done()
{
thread_scoped_lock lock(done_mutex);
while(tot_done != tot)
done_cond.wait(lock);
}
/* stop all worker threads */
void stop()
{
clear();
do_stop = true;
queue_cond.notify_all();
}
/* cancel all tasks, but keep worker threads running */
void cancel()
{
clear();
do_cancel = true;
wait_done();
do_cancel = false;
}
/* Worker thread functions
*
* while(queue.worker_wait_pop(task)) {
* for(..) {
* ... do work ...
*
* if(queue.worker_cancel())
* break;
* }
*
* queue.worker_done();
* }
*/
bool worker_wait_pop(T& value)
{
thread_scoped_lock lock(queue_mutex);
while(queue.empty() && !do_stop)
queue_cond.wait(lock);
if(queue.empty())
return false;
value = queue.front();
queue.pop();
return true;
}
void worker_done()
{
thread_scoped_lock lock(done_mutex);
tot_done++;
lock.unlock();
assert(tot_done <= tot);
done_cond.notify_all();
}
bool worker_cancel()
{
return do_cancel;
}
protected:
void clear()
{
thread_scoped_lock lock(queue_mutex);
while(!queue.empty()) {
thread_scoped_lock done_lock(done_mutex);
tot_done++;
done_lock.unlock();
queue.pop();
}
done_cond.notify_all();
}
std::queue<T> queue;
thread_mutex queue_mutex;
thread_mutex done_mutex;
thread_condition_variable queue_cond;
thread_condition_variable done_cond;
volatile bool do_stop;
volatile bool do_cancel;
volatile int tot, tot_done;
};
/* Thread Local Storage
*
* Boost implementation is a bit slow, and Mac OS X __thread is not supported
* but the pthreads implementation is optimized, so we use these macros. */
#ifdef __APPLE__
#define tls_ptr(type, name) \
pthread_key_t name
#define tls_set(name, value) \
pthread_setspecific(name, value)
#define tls_get(type, name) \
((type*)pthread_getspecific(name))
#define tls_create(type, name) \
pthread_key_create(&name, NULL)
#define tls_delete(type, name) \
pthread_key_delete(name);
#else
#ifdef __WIN32
#define __thread __declspec(thread)
#endif
#define tls_ptr(type, name) \
__thread type *name
#define tls_set(name, value) \
name = value
#define tls_get(type, name) \
name
#define tls_create(type, name)
#define tls_delete(type, name)
#endif
CCL_NAMESPACE_END
#endif /* __UTIL_THREAD_H__ */