[vlc-devel] [PATCH 2/4] threads: use an atomic_uint for VLC_CANCEL_ADDR_SET/CLEAR

[Steve Lhomme]

That's what the caller expects as the default storage format for these variables.
---
 include/vlc_threads.h |  4 ++--
 src/android/thread.c  |  8 ++++----
 src/misc/threads.c    | 25 +++++++++++++++----------
 src/win32/thread.c    |  6 +++---
 4 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/include/vlc_threads.h b/include/vlc_threads.h
index 341ee97271e..f30f0699e37 100644
--- a/include/vlc_threads.h
+++ b/include/vlc_threads.h
@@ -1028,8 +1028,8 @@ enum
 {
     VLC_CLEANUP_PUSH,
     VLC_CLEANUP_POP,
-    VLC_CANCEL_ADDR_SET,
-    VLC_CANCEL_ADDR_CLEAR,
+    VLC_CANCEL_ADDR_SET,   /* atomic_uint* or equivalent size */
+    VLC_CANCEL_ADDR_CLEAR, /* atomic_uint* or equivalent size */
 };
 
 #if defined (LIBVLC_USE_PTHREAD_CLEANUP)
diff --git a/src/android/thread.c b/src/android/thread.c
index ca715418d41..5e26d5566ac 100644
--- a/src/android/thread.c
+++ b/src/android/thread.c
@@ -139,7 +139,7 @@ struct vlc_thread
 
     struct
     {
-        void *addr; /// Non-null if waiting on futex
+        atomic_uint *addr; /// Non-null if waiting on futex
         vlc_mutex_t lock ; /// Protects futex address
     } wait;
 
@@ -284,7 +284,7 @@ int vlc_set_priority (vlc_thread_t th, int priority)
 
 void vlc_cancel (vlc_thread_t thread_id)
 {
-    atomic_int *addr;
+    atomic_uint *addr;
 
     atomic_store(&thread_id->killed, true);
 
@@ -341,7 +341,7 @@ void vlc_control_cancel(int cmd, ...)
     {
         case VLC_CANCEL_ADDR_SET:
         {
-            void *addr = va_arg(ap, void *);
+            atomic_uint *addr = va_arg(ap, atomic_uint *);
 
             vlc_mutex_lock(&th->wait.lock);
             assert(th->wait.addr == NULL);
@@ -352,7 +352,7 @@ void vlc_control_cancel(int cmd, ...)
 
         case VLC_CANCEL_ADDR_CLEAR:
         {
-            void *addr = va_arg(ap, void *);
+            atomic_uint *addr = va_arg(ap, atomic_uint *);
 
             vlc_mutex_lock(&th->wait.lock);
             assert(th->wait.addr == addr);
diff --git a/src/misc/threads.c b/src/misc/threads.c
index e6b993c4408..18855e85bd4 100644
--- a/src/misc/threads.c
+++ b/src/misc/threads.c
@@ -149,27 +149,32 @@ bool vlc_mutex_marked(const vlc_mutex_t *mutex)
 #if defined(LIBVLC_NEED_SLEEP) || defined(LIBVLC_NEED_CONDVAR)
 #include <stdatomic.h>
 
-static inline void vlc_cancel_addr_set(void *addr)
+static inline void vlc_cancel_addr_set(atomic_uint *addr)
 {
     vlc_control_cancel(VLC_CANCEL_ADDR_SET, addr);
 }
 
-static inline void vlc_cancel_addr_clear(void *addr)
+static inline void vlc_cancel_addr_clear(atomic_uint *addr)
 {
     vlc_control_cancel(VLC_CANCEL_ADDR_CLEAR, addr);
 }
 
-static void vlc_cancel_addr_prepare(void *addr)
+static inline void do_vlc_cancel_addr_clear(void *addr)
+{
+    vlc_cancel_addr_clear(addr);
+}
+
+static void vlc_cancel_addr_prepare(atomic_uint *addr)
 {
     /* Let thread subsystem on address to broadcast for cancellation */
     vlc_cancel_addr_set(addr);
-    vlc_cleanup_push(vlc_cancel_addr_clear, addr);
+    vlc_cleanup_push(do_vlc_cancel_addr_clear, addr);
     /* Check if cancellation was pending before vlc_cancel_addr_set() */
     vlc_testcancel();
     vlc_cleanup_pop();
 }
 
-static void vlc_cancel_addr_finish(void *addr)
+static void vlc_cancel_addr_finish(atomic_uint *addr)
 {
     vlc_cancel_addr_clear(addr);
     /* Act on cancellation as potential wake-up source */
@@ -181,7 +186,7 @@ static void vlc_cancel_addr_finish(void *addr)
 void (vlc_tick_wait)(vlc_tick_t deadline)
 {
     vlc_tick_t delay;
-    atomic_int value = ATOMIC_VAR_INIT(0);
+    atomic_uint value = ATOMIC_VAR_INIT(0);
 
     vlc_cancel_addr_prepare(&value);
 
@@ -268,13 +273,13 @@ void vlc_cond_wait(vlc_cond_t *cond, vlc_mutex_t *mutex)
             value++;
     }
 
-    vlc_cancel_addr_prepare(&cond->value);
+    vlc_cancel_addr_prepare(vlc_cond_value(cond));
     vlc_mutex_unlock(mutex);
 
     vlc_atomic_wait(&cond->value, value);
 
     vlc_mutex_lock(mutex);
-    vlc_cancel_addr_finish(&cond->value);
+    vlc_cancel_addr_finish(vlc_cond_value(cond));
 }
 
 static int vlc_cond_wait_delay(vlc_cond_t *cond, vlc_mutex_t *mutex,
@@ -291,7 +296,7 @@ static int vlc_cond_wait_delay(vlc_cond_t *cond, vlc_mutex_t *mutex,
             value++;
     }
 
-    vlc_cancel_addr_prepare(&cond->value);
+    vlc_cancel_addr_prepare(vlc_cond_value(cond));
     vlc_mutex_unlock(mutex);
 
     if (delay > 0)
@@ -300,7 +305,7 @@ static int vlc_cond_wait_delay(vlc_cond_t *cond, vlc_mutex_t *mutex,
         value = 0;
 
     vlc_mutex_lock(mutex);
-    vlc_cancel_addr_finish(&cond->value);
+    vlc_cancel_addr_finish(vlc_cond_value(cond));
 
     return value ? 0 : ETIMEDOUT;
 }
diff --git a/src/win32/thread.c b/src/win32/thread.c
index 6af2eb83852..069c83dbd3a 100644
--- a/src/win32/thread.c
+++ b/src/win32/thread.c
@@ -65,7 +65,7 @@ struct vlc_thread
 
     struct
     {
-        atomic_int      *addr;
+        atomic_uint      *addr;
         CRITICAL_SECTION lock;
     } wait;
 };
@@ -669,7 +669,7 @@ void vlc_control_cancel (int cmd, ...)
 
         case VLC_CANCEL_ADDR_SET:
         {
-            void *addr = va_arg(ap, void *);
+            atomic_uint *addr = va_arg(ap, atomic_uint *);
 
             EnterCriticalSection(&th->wait.lock);
             assert(th->wait.addr == NULL);
@@ -680,7 +680,7 @@ void vlc_control_cancel (int cmd, ...)
 
         case VLC_CANCEL_ADDR_CLEAR:
         {
-            void *addr = va_arg(ap, void *);
+            atomic_uint *addr = va_arg(ap, atomic_uint *);
 
             EnterCriticalSection(&th->wait.lock);
             assert(th->wait.addr == addr);
-- 
2.17.1