PeerStreamer

/*

 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of Libav.

 *

 * Libav is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * Libav 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

//#define DEBUG

#include "avcodec.h"

#include "thread.h"

#define WIN32_LEAN_AND_MEAN

#include <windows.h>

#include <process.h>

typedef struct ThreadContext{

    AVCodecContext *avctx;

    HANDLE thread;

    HANDLE work_sem;

    HANDLE job_sem;

    HANDLE done_sem;

    int (*func)(AVCodecContext *c, void *arg);

    int (*func2)(AVCodecContext *c, void *arg, int, int);

    void *arg;

    int argsize;

    int *jobnr;

    int *ret;

    int threadnr;

}ThreadContext;

static unsigned WINAPI attribute_align_arg thread_func(void *v){

    ThreadContext *c= v;

    for(;;){

        int ret, jobnr;

//printf("thread_func %X enter wait\n", (int)v); fflush(stdout);

        WaitForSingleObject(c->work_sem, INFINITE);

        // avoid trying to access jobnr if we should quit

        if (!c->func && !c->func2)

            break;

        WaitForSingleObject(c->job_sem, INFINITE);

        jobnr = (*c->jobnr)++;

        ReleaseSemaphore(c->job_sem, 1, 0);

//printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);

        if(c->func)

            ret= c->func(c->avctx, (uint8_t *)c->arg + jobnr*c->argsize);

        else

            ret= c->func2(c->avctx, c->arg, jobnr, c->threadnr);

        if (c->ret)

            c->ret[jobnr] = ret;

//printf("thread_func %X signal complete\n", (int)v); fflush(stdout);

        ReleaseSemaphore(c->done_sem, 1, 0);

    }

    return 0;

}

/**

 * Free what has been allocated by ff_thread_init().

 * Must be called after decoding has finished, especially do not call while avcodec_thread_execute() is running.

 */

void ff_thread_free(AVCodecContext *s){

    ThreadContext *c= s->thread_opaque;

    int i;

    for(i=0; i<s->thread_count; i++){

        c[i].func= NULL;

        c[i].func2= NULL;

    }

    ReleaseSemaphore(c[0].work_sem, s->thread_count, 0);

    for(i=0; i<s->thread_count; i++){

        WaitForSingleObject(c[i].thread, INFINITE);

        if(c[i].thread)   CloseHandle(c[i].thread);

    }

    if(c[0].work_sem) CloseHandle(c[0].work_sem);

    if(c[0].job_sem)  CloseHandle(c[0].job_sem);

    if(c[0].done_sem) CloseHandle(c[0].done_sem);

    av_freep(&s->thread_opaque);

}

static int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){

    ThreadContext *c= s->thread_opaque;

    int i;

    int jobnr = 0;

    assert(s == c->avctx);

    /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */

    for(i=0; i<s->thread_count; i++){

        c[i].arg= arg;

        c[i].argsize= size;

        c[i].func= func;

        c[i].ret= ret;

        c[i].jobnr = &jobnr;

    }

    ReleaseSemaphore(c[0].work_sem, count, 0);

    for(i=0; i<count; i++)

        WaitForSingleObject(c[0].done_sem, INFINITE);

    return 0;

}

static int avcodec_thread_execute2(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count){

    ThreadContext *c= s->thread_opaque;

    int i;

    for(i=0; i<s->thread_count; i++)

        c[i].func2 = func;

    avcodec_thread_execute(s, NULL, arg, ret, count, 0);

}

int ff_thread_init(AVCodecContext *s){

    int i;

    ThreadContext *c;

    uint32_t threadid;

    if(!(s->thread_type & FF_THREAD_SLICE)){

        av_log(s, AV_LOG_WARNING, "The requested thread algorithm is not supported with this thread library.\n");

        return 0;

    }

    s->active_thread_type= FF_THREAD_SLICE;

    if (s->thread_count <= 1)

        return 0;

    assert(!s->thread_opaque);

    c= av_mallocz(sizeof(ThreadContext)*s->thread_count);

    s->thread_opaque= c;

    if(!(c[0].work_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))

        goto fail;

    if(!(c[0].job_sem  = CreateSemaphore(NULL, 1, 1, NULL)))

        goto fail;

    if(!(c[0].done_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))

        goto fail;

    for(i=0; i<s->thread_count; i++){

//printf("init semaphors %d\n", i); fflush(stdout);

        c[i].avctx= s;

        c[i].work_sem = c[0].work_sem;

        c[i].job_sem  = c[0].job_sem;

        c[i].done_sem = c[0].done_sem;

        c[i].threadnr = i;

//printf("create thread %d\n", i); fflush(stdout);

        c[i].thread = (HANDLE)_beginthreadex(NULL, 0, thread_func, &c[i], 0, &threadid );

        if( !c[i].thread ) goto fail;

    }

//printf("init done\n"); fflush(stdout);

    s->execute= avcodec_thread_execute;

    s->execute2= avcodec_thread_execute2;

    return 0;

fail:

    ff_thread_free(s);

    return -1;

}