Changeset 48412 in webkit for trunk/JavaScriptCore/wtf/ThreadSpecific.h

Timestamp:

Sep 16, 2009, 6:18:55 AM (16 years ago)

Author:

[email protected]

Message:

2009-09-16 Zoltan Herczeg <​[email protected]>

Reviewed by Simon Hausmann.

[Qt] Fix wtf/ThreadSpecific.h under Qt to free thread local objects.
​https://bugs.webkit.org/show_bug.cgi?id=29295

This is an important fix when JavaScript workers are in use, since
unfreed ThreadGlobalDatas leak a big amount of memory (50-100k each).
QThreadStorage calls the destructor of a given object, which is the
ThreadSpecific::Data. Unlike pthread, Qt is object oriented, and does
not support the calling of a static utility function when the thread
is about to close. In this patch we call the ThreadSpecific::destroy()
utility function from the destructor of ThreadSpecific::Data. Moreover,
since Qt resets all thread local values to 0 before the calling of the
appropriate destructors, we set back the pointer to its original value.
This is necessary because the get() method of the ThreadSpecific
object may be called during the exuction of the destructor.

• wtf/ThreadSpecific.h: (WTF::ThreadSpecific::Data::~Data): (WTF::::~ThreadSpecific): (WTF::::set): (WTF::::destroy):

File:

• trunk/JavaScriptCore/wtf/ThreadSpecific.h (modified) (6 diffs)

trunk/JavaScriptCore/wtf/ThreadSpecific.h

@@ -80 +80 @@
     struct Data : Noncopyable {
         Data(T* value, ThreadSpecific<T>* owner) : value(value), owner(owner) {}
+#if PLATFORM(QT)
+        ~Data() { owner->destroy(this); }
+#endif
 
         T* value;
         ThreadSpecific<T>* owner;
-#if !USE(PTHREADS)
+#if !USE(PTHREADS) && !PLATFORM(QT)
         void (*destructor)(void*);
 #endif
@@ -137 +140 @@
 inline ThreadSpecific<T>::~ThreadSpecific()
 {
-    Data* data = static_cast<Data*>(m_key.localData());
-    if (data)
-        data->destructor(data);
+    // Does not invoke destructor functions. QThreadStorage will do it
 }
 
@@ -154 +155 @@
     ASSERT(!get());
     Data* data = new Data(ptr, this);
-    data->destructor = &ThreadSpecific<T>::destroy;
     m_key.setLocalData(data);
 }
@@ -219 +219 @@
     pthread_setspecific(data->owner->m_key, ptr);
 #endif
-    
+#if PLATFORM(QT)
+    // See comment as above
+    data->owner->m_key.setLocalData(data);
+#endif
+
     data->value->~T();
     fastFree(data->value);
@@ -226 +230 @@
     pthread_setspecific(data->owner->m_key, 0);
 #elif PLATFORM(QT)
-    data->owner->m_key.setLocalData(0);
+    // Do nothing here
 #elif PLATFORM(WIN_OS)
     TlsSetValue(tlsKeys()[data->owner->m_index], 0);
@@ -233 +237 @@
 #endif
 
+#if !PLATFORM(QT)
     delete data;
+#endif
 }