[libbluray-devel] maintain mutex lock order between register and player state

[joakim]

libbluray | branch: master | joakim <joakim at mefx.(none)> | Mon Feb  4 23:05:28 2013 +0100| [b0a7e5a941c1bfaaab1154735a36b4b520ec300c] | committer: hpi1

maintain mutex lock order between register and player state

bd_psr_write can trigger lock of bd mutex in a callback, which
can already be held by other thread waiting for psr mutex.

> http://git.videolan.org/gitweb.cgi/libbluray.git/?a=commit;h=b0a7e5a941c1bfaaab1154735a36b4b520ec300c
---

 src/libbluray/bdj/native/org_videolan_Libbluray.c |    6 +++++-
 src/libbluray/bluray.c                            |    2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/libbluray/bdj/native/org_videolan_Libbluray.c b/src/libbluray/bdj/native/org_videolan_Libbluray.c
index e4fbc9e..7802f97 100644
--- a/src/libbluray/bdj/native/org_videolan_Libbluray.c
+++ b/src/libbluray/bdj/native/org_videolan_Libbluray.c
@@ -26,6 +26,7 @@
 #include "libbluray/bluray.h"
 #include "libbluray/bluray_internal.h"
 
+#include "util/mutex.h"
 #include "util/strutl.h"
 #include "util/macro.h"
 #include "util/logging.h"
@@ -325,7 +326,10 @@ JNIEXPORT jint JNICALL Java_org_videolan_Libbluray_readGPRN(JNIEnv * env,
 JNIEXPORT jint JNICALL Java_org_videolan_Libbluray_writePSRN(JNIEnv * env,
         jclass cls, jlong np, jint num, jint value) {
     BDJAVA* bdj = (BDJAVA*)(intptr_t)np;
-    return bd_psr_write(bdj->reg, num, value);
+    bd_mutex_lock((BD_MUTEX*)bdj->bd);
+    int res = bd_psr_write(bdj->reg, num, value);
+    bd_mutex_unlock((BD_MUTEX*)bdj->bd);
+    return res;
 }
 
 JNIEXPORT jint JNICALL Java_org_videolan_Libbluray_readPSRN(JNIEnv * env,
diff --git a/src/libbluray/bluray.c b/src/libbluray/bluray.c
index 2452312..1e52181 100644
--- a/src/libbluray/bluray.c
+++ b/src/libbluray/bluray.c
@@ -109,7 +109,7 @@ typedef struct {
 
 struct bluray {
 
-    BD_MUTEX          mutex;  /* protect API function access to internal data */
+    BD_MUTEX          mutex;  /* protect API function access to internal data (must be first element in struct) */
 
     /* current disc */
     char             *device_path;