Changeset 181469 in webkit

Timestamp:

Mar 12, 2015 8:02:16 PM (9 years ago)

Author:

mark.lam@apple.com

Message:

Change the DFG crashLock to use std::atomic.
<​https://webkit.org/b/142649>

Reviewed by Filip Pizlo.

• dfg/DFGCommon.cpp:

(JSC::DFG::startCrashing):
(JSC::DFG::isCrashing):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGCommon.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-03-12  Mark Lam  <mark.lam@apple.com>
+
+        Change the DFG crashLock to use std::atomic.
+        <https://webkit.org/b/142649>
+
+        Reviewed by Filip Pizlo.
+
+        * dfg/DFGCommon.cpp:
+        (JSC::DFG::startCrashing):
+        (JSC::DFG::isCrashing):
+
 2015-03-12  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGCommon.cpp

@@ -35 +35 @@
 namespace JSC { namespace DFG {
 
-static unsigned crashLock;
+static std::atomic<unsigned> crashLock;
 
 void startCrashing()
 {
-#if ENABLE(COMPARE_AND_SWAP)
-    while (!WTF::weakCompareAndSwap(&crashLock, 0, 1))
+    unsigned expected = 0;
+    while (!crashLock.compare_exchange_weak(expected, 1, std::memory_order_acquire)) {
         std::this_thread::yield();
-#else
-    crashLock = 1;
-#endif
+        expected = 0;
+    }
 }
 
 bool isCrashing()
 {
-    return !!crashLock;
+    return !!crashLock.load(std::memory_order_acquire);
 }