[vlc-commits] threads: use an atomic_uint for vlc_cancel_addr_set/clear

[Steve Lhomme]

vlc | branch: master | Steve Lhomme <robux4 at ycbcr.xyz> | Fri Feb  7 15:00:52 2020 +0100| [c18c1fa12bf7f5747f90f90c5929a7162ef60482] | committer: Steve Lhomme

threads: use an atomic_uint for vlc_cancel_addr_set/clear

That's what the caller expects as the default storage format for these variables.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=c18c1fa12bf7f5747f90f90c5929a7162ef60482
---

 include/vlc_threads.h | 10 +++++++---
 src/android/thread.c  |  8 ++++----
 src/misc/threads.c    | 21 +++++++++++++--------
 src/win32/thread.c    |  6 +++---
 4 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/include/vlc_threads.h b/include/vlc_threads.h
index 0025ca7ea7..1598c9c804 100644
--- a/include/vlc_threads.h
+++ b/include/vlc_threads.h
@@ -351,6 +351,10 @@ typedef struct vlc_timer *vlc_timer_t;
 #endif
 
 #ifdef LIBVLC_NEED_CONDVAR
+#ifndef __cplusplus
+#include <stdatomic.h>
+#endif
+
 typedef struct
 {
     unsigned value;
@@ -1098,9 +1102,9 @@ static inline void vlc_cleanup_lock (void *lock)
 }
 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 
-#if defined(LIBVLC_NEED_CONDVAR)
-void vlc_cancel_addr_set(void *addr);
-void vlc_cancel_addr_clear(void *addr);
+#if defined(LIBVLC_NEED_CONDVAR) && !defined(__cplusplus)
+void vlc_cancel_addr_set(atomic_uint *addr);
+void vlc_cancel_addr_clear(atomic_uint *addr);
 #endif
 
 #ifdef __cplusplus
diff --git a/src/android/thread.c b/src/android/thread.c
index c213e237ea..26723d5672 100644
--- a/src/android/thread.c
+++ b/src/android/thread.c
@@ -140,7 +140,7 @@ 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;
 
@@ -285,7 +285,7 @@ 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);
 
@@ -335,7 +335,7 @@ noreturn void vlc_control_cancel (int cmd, ...)
     vlc_assert_unreachable ();
 }
 
-void vlc_cancel_addr_set(void *addr)
+void vlc_cancel_addr_set(atomic_uint *addr)
 {
     vlc_thread_t th = vlc_thread_self();
     if (th == NULL)
@@ -347,7 +347,7 @@ void vlc_cancel_addr_set(void *addr)
     vlc_mutex_unlock(&th->wait.lock);
 }
 
-void vlc_cancel_addr_clear(void *addr)
+void vlc_cancel_addr_clear(atomic_uint *addr)
 {
     vlc_thread_t th = vlc_thread_self();
     if (th == NULL)
diff --git a/src/misc/threads.c b/src/misc/threads.c
index 501a17ac9b..b40348ca90 100644
--- a/src/misc/threads.c
+++ b/src/misc/threads.c
@@ -149,17 +149,22 @@ bool vlc_mutex_marked(const vlc_mutex_t *mutex)
 #if defined(LIBVLC_NEED_SLEEP) || defined(LIBVLC_NEED_CONDVAR)
 #include <stdatomic.h>
 
-static void vlc_cancel_addr_prepare(void *addr)
+static 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 */
@@ -171,7 +176,7 @@ 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);
 
@@ -258,13 +263,13 @@ 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,
@@ -281,7 +286,7 @@ 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)
@@ -290,7 +295,7 @@ 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 23f9c0afe5..994bd1631b 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;
 };
@@ -670,7 +670,7 @@ void vlc_control_cancel (int cmd, ...)
     va_end (ap);
 }
 
-void vlc_cancel_addr_set(void *addr)
+void vlc_cancel_addr_set(atomic_uint *addr)
 {
     struct vlc_thread *th = vlc_thread_self();
     if (th == NULL)
@@ -682,7 +682,7 @@ void vlc_cancel_addr_set(void *addr)
     LeaveCriticalSection(&th->wait.lock);
 }
 
-void vlc_cancel_addr_clear(void *addr)
+void vlc_cancel_addr_clear(atomic_uint *addr)
 {
     struct vlc_thread *th = vlc_thread_self();
     if (th == NULL)