[FFmpeg-devel] [PATCH 1/3] avutil/log: add AV_LOG_ASYNC

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavutil/log.c |    7 +++++--
 libavutil/log.h |    6 ++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/libavutil/log.c b/libavutil/log.c
index a0bb5e4..e40ffa4 100644
--- a/libavutil/log.c
+++ b/libavutil/log.c
@@ -247,11 +247,13 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
     char line[LINE_SZ];
     static int is_atty;
     int type[2];
+    int use_lock = !(flags & AV_LOG_ASYNC);
 
     if (level > av_log_level)
         return;
 #if HAVE_PTHREADS
-    pthread_mutex_lock(&mutex);
+    if (use_lock)
+        pthread_mutex_lock(&mutex);
 #endif
 
     format_line(ptr, level, fmt, vl, part, &print_prefix, type);
@@ -283,7 +285,8 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
 end:
     av_bprint_finalize(part+2, NULL);
 #if HAVE_PTHREADS
-    pthread_mutex_unlock(&mutex);
+    if (use_lock)
+        pthread_mutex_unlock(&mutex);
 #endif
 }
 
diff --git a/libavutil/log.h b/libavutil/log.h
index f16e382..b8ea759 100644
--- a/libavutil/log.h
+++ b/libavutil/log.h
@@ -311,6 +311,12 @@ void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
  * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
  */
 #define AV_LOG_SKIP_REPEATED 1
+/**
+ * Do not thread synchronization.
+ * This allows av_log() to be used from a signal handler but may lead to
+ * garbled output.
+ */
+#define AV_LOG_ASYNC 0x1000
 void av_log_set_flags(int arg);
 
 /**
-- 
1.7.9.5