Changeset 91082 in webkit for trunk/Source/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h

Timestamp:

Jul 15, 2011, 11:49:24 AM (14 years ago)

Author:

[email protected]

Message:

currentThread is too slow!
​https://bugs.webkit.org/show_bug.cgi?id=64577

Reviewed by Darin Adler and Dmitry Titov.

The problem is that currentThread results in a pthread_once call which always takes a lock.
With this change, currentThread is 10% faster than isMainThread in release mode and only
5% slower than isMainThread in debug.

• wtf/ThreadIdentifierDataPthreads.cpp:

(WTF::ThreadIdentifierData::initializeOnce): Remove the pthread once stuff
which is no longer needed because this is called from initializeThreading().
(WTF::ThreadIdentifierData::identifier): Remove the initializeKeyOnce call because
intialization of the pthread key should already be done.
(WTF::ThreadIdentifierData::initialize): Ditto.

• wtf/ThreadIdentifierDataPthreads.h:
• wtf/ThreadingPthreads.cpp:

(WTF::initializeThreading): Acquire the pthread key here.

File:

• trunk/Source/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h

@@ -43 +43 @@
     ~ThreadIdentifierData();
 
+    // One time initialization for this class as a whole.
+    // This method must be called before initialize() and it is not thread-safe.
+    static void initializeOnce();
+
     // Creates and puts an instance of ThreadIdentifierData into thread-specific storage.
     static void initialize(ThreadIdentifier identifier);
@@ -63 +67 @@
     static void destruct(void* data);
 
-    static void initializeKeyOnceHelper();
-    static void initializeKeyOnce();
-
     ThreadIdentifier m_identifier;
     bool m_isDestroyedOnce;