w32threads by (Gildas Bazin <gbazin at altern dot org>)

Originally committed as revision 2803 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 134 insertions, 0 deletions

diff --git a/libavcodec/w32thread.c b/libavcodec/w32thread.c
new file mode 100644
index 0000000000..186e302dc8
--- /dev/null
+++ b/libavcodec/w32thread.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+//#define DEBUG
+
+#include "avcodec.h"
+#include "common.h"
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <process.h>
+
+typedef struct ThreadContext{
+    AVCodecContext *avctx;
+    HANDLE thread;
+    HANDLE work_sem;
+    HANDLE done_sem;
+    int (*func)(AVCodecContext *c, void *arg);
+    void *arg;
+    int ret;
+}ThreadContext;
+
+
+static unsigned __stdcall thread_func(void *v){
+    ThreadContext *c= v;
+
+    for(;;){
+//printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
+        WaitForSingleObject(c->work_sem, INFINITE);
+//printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
+        if(c->func)
+            c->ret= c->func(c->avctx, c->arg);
+        else
+            return 0;
+//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 avcodec_thread_init().
+ * must be called after decoding has finished, especially dont call while avcodec_thread_execute() is running
+ */
+void avcodec_thread_free(AVCodecContext *s){
+    ThreadContext *c= s->thread_opaque;
+    int i;
+
+    for(i=0; i<s->thread_count; i++){
+        
+        c[i].func= NULL;
+        ReleaseSemaphore(c[i].work_sem, 1, 0);
+        WaitForSingleObject(c[i].thread, INFINITE);
+        if(c[i].work_sem) CloseHandle(c[i].work_sem);
+        if(c[i].done_sem) CloseHandle(c[i].done_sem);
+    }
+
+    av_freep(&s->thread_opaque);
+}
+
+int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void **arg, int *ret, int count){
+    ThreadContext *c= s->thread_opaque;
+    int i;
+    
+    assert(s == c->avctx);
+    assert(count <= s->thread_count);
+    
+    /* 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<count; i++){
+        c[i].arg= arg[i];
+        c[i].func= func;
+        c[i].ret= 12345;
+
+        ReleaseSemaphore(c[i].work_sem, 1, 0);
+    }
+    for(i=0; i<count; i++){
+        WaitForSingleObject(c[i].done_sem, INFINITE);
+        
+        c[i].func= NULL;
+        if(ret) ret[i]= c[i].ret;
+    }
+    return 0;
+}
+
+int avcodec_thread_init(AVCodecContext *s, int thread_count){
+    int i;
+    ThreadContext *c;
+    uint32_t threadid;
+
+    s->thread_count= thread_count;
+
+    assert(!s->thread_opaque);
+    c= av_mallocz(sizeof(ThreadContext)*thread_count);
+    s->thread_opaque= c;
+    
+    for(i=0; i<thread_count; i++){
+//printf("init semaphors %d\n", i); fflush(stdout);
+        c[i].avctx= s;
+
+        if(!(c[i].work_sem = CreateSemaphore(NULL, 0, s->thread_count, NULL)))
+            goto fail;
+        if(!(c[i].done_sem = CreateSemaphore(NULL, 0, s->thread_count, NULL)))
+            goto fail;
+
+//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;
+
+    return 0;
+fail:
+    avcodec_thread_free(s);
+    return -1;
+}