threads.c

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/*
 *
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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.
 *
 * The Original Code is Copyright (C) 2006 Blender Foundation
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <errno.h>
#include <string.h>

#include "MEM_guardedalloc.h"


#include "BLI_blenlib.h"
#include "BLI_gsqueue.h"
#include "BLI_threads.h"

#include "PIL_time.h"

/* for checking system threads - BLI_system_thread_count */
#ifdef WIN32
#include "windows.h"
#include <sys/timeb.h>
#elif defined(__APPLE__)
#include <sys/types.h>
#include <sys/sysctl.h>
#else
#include <unistd.h> 
#include <sys/time.h>
#endif

#if defined(__APPLE__) && (PARALLEL == 1) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 2)
/* ************** libgomp (Apple gcc 4.2.1) TLS bug workaround *************** */
extern pthread_key_t gomp_tls_key;
static void *thread_tls_data;
#endif

/* ********** basic thread control API ************ 

Many thread cases have an X amount of jobs, and only an Y amount of
threads are useful (typically amount of cpus)

This code can be used to start a maximum amount of 'thread slots', which
then can be filled in a loop with an idle timer. 

A sample loop can look like this (pseudo c);

    ListBase lb;
    int maxthreads= 2;
    int cont= 1;

    BLI_init_threads(&lb, do_something_func, maxthreads);

    while(cont) {
        if(BLI_available_threads(&lb) && !(escape loop event)) {
            // get new job (data pointer)
            // tag job 'processed 
            BLI_insert_thread(&lb, job);
        }
        else PIL_sleep_ms(50);
        
        // find if a job is ready, this the do_something_func() should write in job somewhere
        cont= 0;
        for(go over all jobs)
            if(job is ready) {
                if(job was not removed) {
                    BLI_remove_thread(&lb, job);
                }
            }
            else cont= 1;
        }
        // conditions to exit loop 
        if(if escape loop event) {
            if(BLI_available_threadslots(&lb)==maxthreads)
                break;
        }
    }

    BLI_end_threads(&lb);

 ************************************************ */
static pthread_mutex_t _malloc_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _image_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _preview_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _viewer_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _custom1_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _rcache_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _opengl_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _nodes_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t _movieclip_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_t mainid;
static int thread_levels= 0;    /* threads can be invoked inside threads */

/* just a max for security reasons */
#define RE_MAX_THREAD BLENDER_MAX_THREADS

typedef struct ThreadSlot {
    struct ThreadSlot *next, *prev;
    void *(*do_thread)(void *);
    void *callerdata;
    pthread_t pthread;
    int avail;
} ThreadSlot;

static void BLI_lock_malloc_thread(void)
{
    pthread_mutex_lock(&_malloc_lock);
}

static void BLI_unlock_malloc_thread(void)
{
    pthread_mutex_unlock(&_malloc_lock);
}

void BLI_threadapi_init(void)
{
    mainid = pthread_self();
}

/* tot = 0 only initializes malloc mutex in a safe way (see sequence.c)
   problem otherwise: scene render will kill of the mutex!
*/

void BLI_init_threads(ListBase *threadbase, void *(*do_thread)(void *), int tot)
{
    int a;

    if(threadbase != NULL && tot > 0) {
        threadbase->first= threadbase->last= NULL;
    
        if(tot>RE_MAX_THREAD) tot= RE_MAX_THREAD;
        else if(tot<1) tot= 1;
    
        for(a=0; a<tot; a++) {
            ThreadSlot *tslot= MEM_callocN(sizeof(ThreadSlot), "threadslot");
            BLI_addtail(threadbase, tslot);
            tslot->do_thread= do_thread;
            tslot->avail= 1;
        }
    }
    
    if(thread_levels == 0) {
        MEM_set_lock_callback(BLI_lock_malloc_thread, BLI_unlock_malloc_thread);

#if defined(__APPLE__) && (PARALLEL == 1) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 2)
        /* workaround for Apple gcc 4.2.1 omp vs background thread bug,
           we copy gomp thread local storage pointer to setting it again
           inside the thread that we start */
        thread_tls_data = pthread_getspecific(gomp_tls_key);
#endif
    }

    thread_levels++;
}

/* amount of available threads */
int BLI_available_threads(ListBase *threadbase)
{
    ThreadSlot *tslot;
    int counter=0;
    
    for(tslot= threadbase->first; tslot; tslot= tslot->next) {
        if(tslot->avail)
            counter++;
    }
    return counter;
}

/* returns thread number, for sample patterns or threadsafe tables */
int BLI_available_thread_index(ListBase *threadbase)
{
    ThreadSlot *tslot;
    int counter=0;
    
    for(tslot= threadbase->first; tslot; tslot= tslot->next, counter++) {
        if(tslot->avail)
            return counter;
    }
    return 0;
}

static void *tslot_thread_start(void *tslot_p)
{
    ThreadSlot *tslot= (ThreadSlot*)tslot_p;

#if defined(__APPLE__) && (PARALLEL == 1) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 2)
    /* workaround for Apple gcc 4.2.1 omp vs background thread bug,
       set gomp thread local storage pointer which was copied beforehand */
    pthread_setspecific (gomp_tls_key, thread_tls_data);
#endif

    return tslot->do_thread(tslot->callerdata);
}

int BLI_thread_is_main(void)
{
    return pthread_equal(pthread_self(), mainid);
}

void BLI_insert_thread(ListBase *threadbase, void *callerdata)
{
    ThreadSlot *tslot;
    
    for(tslot= threadbase->first; tslot; tslot= tslot->next) {
        if(tslot->avail) {
            tslot->avail= 0;
            tslot->callerdata= callerdata;
            pthread_create(&tslot->pthread, NULL, tslot_thread_start, tslot);
            return;
        }
    }
    printf("ERROR: could not insert thread slot\n");
}

void BLI_remove_thread(ListBase *threadbase, void *callerdata)
{
    ThreadSlot *tslot;
    
    for(tslot= threadbase->first; tslot; tslot= tslot->next) {
        if(tslot->callerdata==callerdata) {
            pthread_join(tslot->pthread, NULL);
            tslot->callerdata= NULL;
            tslot->avail= 1;
        }
    }
}

void BLI_remove_thread_index(ListBase *threadbase, int index)
{
    ThreadSlot *tslot;
    int counter=0;
    
    for(tslot = threadbase->first; tslot; tslot = tslot->next, counter++) {
        if (counter == index && tslot->avail == 0) {
            pthread_join(tslot->pthread, NULL);
            tslot->callerdata = NULL;
            tslot->avail = 1;
            break;
        }
    }
}

void BLI_remove_threads(ListBase *threadbase)
{
    ThreadSlot *tslot;
    
    for(tslot = threadbase->first; tslot; tslot = tslot->next) {
        if (tslot->avail == 0) {
            pthread_join(tslot->pthread, NULL);
            tslot->callerdata = NULL;
            tslot->avail = 1;
        }
    }
}

void BLI_end_threads(ListBase *threadbase)
{
    ThreadSlot *tslot;
    
    /* only needed if there's actually some stuff to end
     * this way we don't end up decrementing thread_levels on an empty threadbase 
     * */
    if (threadbase && threadbase->first != NULL) {
        for(tslot= threadbase->first; tslot; tslot= tslot->next) {
            if(tslot->avail==0) {
                pthread_join(tslot->pthread, NULL);
            }
        }
        BLI_freelistN(threadbase);
    }

    thread_levels--;
    if(thread_levels==0)
        MEM_set_lock_callback(NULL, NULL);
}

/* System Information */

/* how many threads are native on this system? */
int BLI_system_thread_count( void )
{
    int t;
#ifdef WIN32
    SYSTEM_INFO info;
    GetSystemInfo(&info);
    t = (int) info.dwNumberOfProcessors;
#else 
#   ifdef __APPLE__
    int mib[2];
    size_t len;
    
    mib[0] = CTL_HW;
    mib[1] = HW_NCPU;
    len = sizeof(t);
    sysctl(mib, 2, &t, &len, NULL, 0);
#   else
    t = (int)sysconf(_SC_NPROCESSORS_ONLN);
#   endif
#endif
    
    if (t>RE_MAX_THREAD)
        return RE_MAX_THREAD;
    if (t<1)
        return 1;
    
    return t;
}

/* Global Mutex Locks */

void BLI_lock_thread(int type)
{
    if (type==LOCK_IMAGE)
        pthread_mutex_lock(&_image_lock);
    else if (type==LOCK_PREVIEW)
        pthread_mutex_lock(&_preview_lock);
    else if (type==LOCK_VIEWER)
        pthread_mutex_lock(&_viewer_lock);
    else if (type==LOCK_CUSTOM1)
        pthread_mutex_lock(&_custom1_lock);
    else if (type==LOCK_RCACHE)
        pthread_mutex_lock(&_rcache_lock);
    else if (type==LOCK_OPENGL)
        pthread_mutex_lock(&_opengl_lock);
    else if (type==LOCK_NODES)
        pthread_mutex_lock(&_nodes_lock);
    else if (type==LOCK_MOVIECLIP)
        pthread_mutex_lock(&_movieclip_lock);
}

void BLI_unlock_thread(int type)
{
    if (type==LOCK_IMAGE)
        pthread_mutex_unlock(&_image_lock);
    else if (type==LOCK_PREVIEW)
        pthread_mutex_unlock(&_preview_lock);
    else if (type==LOCK_VIEWER)
        pthread_mutex_unlock(&_viewer_lock);
    else if(type==LOCK_CUSTOM1)
        pthread_mutex_unlock(&_custom1_lock);
    else if(type==LOCK_RCACHE)
        pthread_mutex_unlock(&_rcache_lock);
    else if(type==LOCK_OPENGL)
        pthread_mutex_unlock(&_opengl_lock);
    else if(type==LOCK_NODES)
        pthread_mutex_unlock(&_nodes_lock);
    else if(type==LOCK_MOVIECLIP)
        pthread_mutex_unlock(&_movieclip_lock);
}

/* Mutex Locks */

void BLI_mutex_init(ThreadMutex *mutex)
{
    pthread_mutex_init(mutex, NULL);
}

void BLI_mutex_lock(ThreadMutex *mutex)
{
    pthread_mutex_lock(mutex);
}

void BLI_mutex_unlock(ThreadMutex *mutex)
{
    pthread_mutex_unlock(mutex);
}

void BLI_mutex_end(ThreadMutex *mutex)
{
    pthread_mutex_destroy(mutex);
}

/* Read/Write Mutex Lock */

void BLI_rw_mutex_init(ThreadRWMutex *mutex)
{
    pthread_rwlock_init(mutex, NULL);
}

void BLI_rw_mutex_lock(ThreadRWMutex *mutex, int mode)
{
    if(mode == THREAD_LOCK_READ)
        pthread_rwlock_rdlock(mutex);
    else
        pthread_rwlock_wrlock(mutex);
}

void BLI_rw_mutex_unlock(ThreadRWMutex *mutex)
{
    pthread_rwlock_unlock(mutex);
}

void BLI_rw_mutex_end(ThreadRWMutex *mutex)
{
    pthread_rwlock_destroy(mutex);
}

/* ************************************************ */

typedef struct ThreadedWorker {
    ListBase threadbase;
    void *(*work_fnct)(void *);
    char     busy[RE_MAX_THREAD];
    int      total;
    int      sleep_time;
} ThreadedWorker;

typedef struct WorkParam {
    ThreadedWorker *worker;
    void *param;
    int   index;
} WorkParam;

static void *exec_work_fnct(void *v_param)
{
    WorkParam *p = (WorkParam*)v_param;
    void *value;
    
    value = p->worker->work_fnct(p->param);
    
    p->worker->busy[p->index] = 0;
    MEM_freeN(p);
    
    return value;
}

ThreadedWorker *BLI_create_worker(void *(*do_thread)(void *), int tot, int sleep_time)
{
    ThreadedWorker *worker;
    
    (void)sleep_time; /* unused */
    
    worker = MEM_callocN(sizeof(ThreadedWorker), "threadedworker");
    
    if (tot > RE_MAX_THREAD)
    {
        tot = RE_MAX_THREAD;
    }
    else if (tot < 1)
    {
        tot= 1;
    }
    
    worker->total = tot;
    worker->work_fnct = do_thread;
    
    BLI_init_threads(&worker->threadbase, exec_work_fnct, tot);
    
    return worker;
}

void BLI_end_worker(ThreadedWorker *worker)
{
    BLI_remove_threads(&worker->threadbase);
}

void BLI_destroy_worker(ThreadedWorker *worker)
{
    BLI_end_worker(worker);
    BLI_freelistN(&worker->threadbase);
    MEM_freeN(worker);
}

void BLI_insert_work(ThreadedWorker *worker, void *param)
{
    WorkParam *p = MEM_callocN(sizeof(WorkParam), "workparam");
    int index;
    
    if (BLI_available_threads(&worker->threadbase) == 0)
    {
        index = worker->total;
        while(index == worker->total)
        {
            PIL_sleep_ms(worker->sleep_time);
            
            for (index = 0; index < worker->total; index++)
            {
                if (worker->busy[index] == 0)
                {
                    BLI_remove_thread_index(&worker->threadbase, index);
                    break;
                }
            }
        }
    }
    else
    {
        index = BLI_available_thread_index(&worker->threadbase);
    }
    
    worker->busy[index] = 1;
    
    p->param = param;
    p->index = index;
    p->worker = worker;
    
    BLI_insert_thread(&worker->threadbase, p);
}

/* ************************************************ */

struct ThreadQueue {
    GSQueue *queue;
    pthread_mutex_t mutex;
    pthread_cond_t cond;
    int nowait;
};

ThreadQueue *BLI_thread_queue_init(void)
{
    ThreadQueue *queue;

    queue= MEM_callocN(sizeof(ThreadQueue), "ThreadQueue");
    queue->queue= BLI_gsqueue_new(sizeof(void*));

    pthread_mutex_init(&queue->mutex, NULL);
    pthread_cond_init(&queue->cond, NULL);

    return queue;
}

void BLI_thread_queue_free(ThreadQueue *queue)
{
    pthread_cond_destroy(&queue->cond);
    pthread_mutex_destroy(&queue->mutex);

    BLI_gsqueue_free(queue->queue);

    MEM_freeN(queue);
}

void BLI_thread_queue_push(ThreadQueue *queue, void *work)
{
    pthread_mutex_lock(&queue->mutex);

    BLI_gsqueue_push(queue->queue, &work);

    /* signal threads waiting to pop */
    pthread_cond_signal(&queue->cond);
    pthread_mutex_unlock(&queue->mutex);
}

void *BLI_thread_queue_pop(ThreadQueue *queue)
{
    void *work= NULL;

    /* wait until there is work */
    pthread_mutex_lock(&queue->mutex);
    while(BLI_gsqueue_is_empty(queue->queue) && !queue->nowait)
        pthread_cond_wait(&queue->cond, &queue->mutex);

    /* if we have something, pop it */
    if(!BLI_gsqueue_is_empty(queue->queue))
        BLI_gsqueue_pop(queue->queue, &work);

    pthread_mutex_unlock(&queue->mutex);

    return work;
}

static void wait_timeout(struct timespec *timeout, int ms)
{
    ldiv_t div_result;
    long sec, usec, x;

#ifdef WIN32
    {
        struct _timeb now;
        _ftime(&now);
        sec = now.time;
        usec = now.millitm*1000; /* microsecond precision would be better */
    }
#else
    {
        struct timeval now;
        gettimeofday(&now, NULL);
        sec = now.tv_sec;
        usec = now.tv_usec;
    }
#endif

    /* add current time + millisecond offset */
    div_result = ldiv(ms, 1000);
    timeout->tv_sec = sec + div_result.quot;

    x = usec + (div_result.rem*1000);

    if (x >= 1000000) {
        timeout->tv_sec++;
        x -= 1000000;
    }

    timeout->tv_nsec = x*1000;
}

void *BLI_thread_queue_pop_timeout(ThreadQueue *queue, int ms)
{
    double t;
    void *work= NULL;
    struct timespec timeout;

    t= PIL_check_seconds_timer();
    wait_timeout(&timeout, ms);

    /* wait until there is work */
    pthread_mutex_lock(&queue->mutex);
    while(BLI_gsqueue_is_empty(queue->queue) && !queue->nowait) {
        if(pthread_cond_timedwait(&queue->cond, &queue->mutex, &timeout) == ETIMEDOUT)
            break;
        else if(PIL_check_seconds_timer() - t >= ms*0.001)
            break;
    }

    /* if we have something, pop it */
    if(!BLI_gsqueue_is_empty(queue->queue))
        BLI_gsqueue_pop(queue->queue, &work);

    pthread_mutex_unlock(&queue->mutex);

    return work;
}

int BLI_thread_queue_size(ThreadQueue *queue)
{
    int size;

    pthread_mutex_lock(&queue->mutex);
    size= BLI_gsqueue_size(queue->queue);
    pthread_mutex_unlock(&queue->mutex);

    return size;
}

void BLI_thread_queue_nowait(ThreadQueue *queue)
{
    pthread_mutex_lock(&queue->mutex);

    queue->nowait= 1;

    /* signal threads waiting to pop */
    pthread_cond_signal(&queue->cond);
    pthread_mutex_unlock(&queue->mutex);
}

void BLI_begin_threaded_malloc(void)
{
    if(thread_levels == 0) {
        MEM_set_lock_callback(BLI_lock_malloc_thread, BLI_unlock_malloc_thread);
    }
    thread_levels++;
}

void BLI_end_threaded_malloc(void)
{
    thread_levels--;
    if(thread_levels==0)
        MEM_set_lock_callback(NULL, NULL);
}