--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/ThreadSpecific.h Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,347 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2009 Jian Li <jianli@chromium.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ * its contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Thread local storage is implemented by using either pthread API or Windows
+ * native API. There is subtle semantic discrepancy for the cleanup function
+ * implementation as noted below:
+ * @ In pthread implementation, the destructor function will be called
+ * repeatedly if there is still non-NULL value associated with the function.
+ * @ In Windows native implementation, the destructor function will be called
+ * only once.
+ * This semantic discrepancy does not impose any problem because nowhere in
+ * WebKit the repeated call bahavior is utilized.
+ */
+
+#ifndef WTF_ThreadSpecific_h
+#define WTF_ThreadSpecific_h
+
+#include <wtf/Noncopyable.h>
+
+#if USE(PTHREADS)
+#include <pthread.h>
+#elif PLATFORM(QT)
+#include <QThreadStorage>
+#elif PLATFORM(GTK)
+#include <glib.h>
+#elif OS(WINDOWS)
+#include <windows.h>
+#endif
+
+namespace WTF {
+
+#if !USE(PTHREADS) && !PLATFORM(QT) && !PLATFORM(GTK) && OS(WINDOWS)
+// ThreadSpecificThreadExit should be called each time when a thread is detached.
+// This is done automatically for threads created with WTF::createThread.
+void ThreadSpecificThreadExit();
+#endif
+
+template<typename T> class ThreadSpecific : public Noncopyable {
+public:
+ ThreadSpecific();
+ T* operator->();
+ operator T*();
+ T& operator*();
+ ~ThreadSpecific();
+
+private:
+#if !USE(PTHREADS) && !PLATFORM(QT) && !PLATFORM(GTK) && OS(WINDOWS)
+ friend void ThreadSpecificThreadExit();
+#endif
+
+ T* get();
+ void set(T*);
+ void static destroy(void* ptr);
+
+#if USE(PTHREADS) || PLATFORM(QT) || PLATFORM(GTK) || OS(WINDOWS)
+ 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) && !PLATFORM(QT) && !PLATFORM(GTK)
+ void (*destructor)(void*);
+#endif
+ };
+#endif
+
+#if ENABLE(SINGLE_THREADED)
+ T* m_value;
+#else
+#if USE(PTHREADS)
+ pthread_key_t m_key;
+#elif PLATFORM(QT)
+ QThreadStorage<Data*> m_key;
+#elif PLATFORM(GTK)
+ GStaticPrivate m_key;
+#elif OS(WINDOWS)
+ int m_index;
+#endif
+#endif
+};
+
+#if ENABLE(SINGLE_THREADED)
+template<typename T>
+inline ThreadSpecific<T>::ThreadSpecific()
+ : m_value(0)
+{
+}
+
+template<typename T>
+inline ThreadSpecific<T>::~ThreadSpecific()
+{
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::get()
+{
+ return m_value;
+}
+
+template<typename T>
+inline void ThreadSpecific<T>::set(T* ptr)
+{
+ ASSERT(!get());
+ m_value = ptr;
+}
+#else
+#if USE(PTHREADS)
+template<typename T>
+inline ThreadSpecific<T>::ThreadSpecific()
+{
+ int error = pthread_key_create(&m_key, destroy);
+ if (error)
+ CRASH();
+}
+
+template<typename T>
+inline ThreadSpecific<T>::~ThreadSpecific()
+{
+ pthread_key_delete(m_key); // Does not invoke destructor functions.
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::get()
+{
+ Data* data = static_cast<Data*>(pthread_getspecific(m_key));
+ return data ? data->value : 0;
+}
+
+template<typename T>
+inline void ThreadSpecific<T>::set(T* ptr)
+{
+ ASSERT(!get());
+ pthread_setspecific(m_key, new Data(ptr, this));
+}
+
+#elif PLATFORM(QT)
+
+template<typename T>
+inline ThreadSpecific<T>::ThreadSpecific()
+{
+}
+
+template<typename T>
+inline ThreadSpecific<T>::~ThreadSpecific()
+{
+ // Does not invoke destructor functions. QThreadStorage will do it
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::get()
+{
+ Data* data = static_cast<Data*>(m_key.localData());
+ return data ? data->value : 0;
+}
+
+template<typename T>
+inline void ThreadSpecific<T>::set(T* ptr)
+{
+ ASSERT(!get());
+ Data* data = new Data(ptr, this);
+ m_key.setLocalData(data);
+}
+
+#elif PLATFORM(GTK)
+
+template<typename T>
+inline ThreadSpecific<T>::ThreadSpecific()
+{
+ g_static_private_init(&m_key);
+}
+
+template<typename T>
+inline ThreadSpecific<T>::~ThreadSpecific()
+{
+ g_static_private_free(&m_key);
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::get()
+{
+ Data* data = static_cast<Data*>(g_static_private_get(&m_key));
+ return data ? data->value : 0;
+}
+
+template<typename T>
+inline void ThreadSpecific<T>::set(T* ptr)
+{
+ ASSERT(!get());
+ Data* data = new Data(ptr, this);
+ g_static_private_set(&m_key, data, destroy);
+}
+
+#elif OS(WINDOWS)
+
+// TLS_OUT_OF_INDEXES is not defined on WinCE.
+#ifndef TLS_OUT_OF_INDEXES
+#define TLS_OUT_OF_INDEXES 0xffffffff
+#endif
+
+// The maximum number of TLS keys that can be created. For simplification, we assume that:
+// 1) Once the instance of ThreadSpecific<> is created, it will not be destructed until the program dies.
+// 2) We do not need to hold many instances of ThreadSpecific<> data. This fixed number should be far enough.
+const int kMaxTlsKeySize = 256;
+
+long& tlsKeyCount();
+DWORD* tlsKeys();
+
+template<typename T>
+inline ThreadSpecific<T>::ThreadSpecific()
+ : m_index(-1)
+{
+ DWORD tlsKey = TlsAlloc();
+ if (tlsKey == TLS_OUT_OF_INDEXES)
+ CRASH();
+
+ m_index = InterlockedIncrement(&tlsKeyCount()) - 1;
+ if (m_index >= kMaxTlsKeySize)
+ CRASH();
+ tlsKeys()[m_index] = tlsKey;
+}
+
+template<typename T>
+inline ThreadSpecific<T>::~ThreadSpecific()
+{
+ // Does not invoke destructor functions. They will be called from ThreadSpecificThreadExit when the thread is detached.
+ TlsFree(tlsKeys()[m_index]);
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::get()
+{
+ Data* data = static_cast<Data*>(TlsGetValue(tlsKeys()[m_index]));
+ return data ? data->value : 0;
+}
+
+template<typename T>
+inline void ThreadSpecific<T>::set(T* ptr)
+{
+ ASSERT(!get());
+ Data* data = new Data(ptr, this);
+ data->destructor = &ThreadSpecific<T>::destroy;
+ TlsSetValue(tlsKeys()[m_index], data);
+}
+
+#else
+#error ThreadSpecific is not implemented for this platform.
+#endif
+#endif
+
+template<typename T>
+inline void ThreadSpecific<T>::destroy(void* ptr)
+{
+#if !ENABLE(SINGLE_THREADED)
+ Data* data = static_cast<Data*>(ptr);
+
+#if USE(PTHREADS)
+ // We want get() to keep working while data destructor works, because it can be called indirectly by the destructor.
+ // Some pthreads implementations zero out the pointer before calling destroy(), so we temporarily reset it.
+ pthread_setspecific(data->owner->m_key, ptr);
+#elif PLATFORM(GTK)
+ // See comment as above
+ g_static_private_set(&data->owner->m_key, data, 0);
+#endif
+#if PLATFORM(QT)
+ // See comment as above
+ data->owner->m_key.setLocalData(data);
+#endif
+
+ data->value->~T();
+ fastFree(data->value);
+
+#if USE(PTHREADS)
+ pthread_setspecific(data->owner->m_key, 0);
+#elif PLATFORM(QT)
+ // Do nothing here
+#elif PLATFORM(GTK)
+ g_static_private_set(&data->owner->m_key, 0, 0);
+#elif OS(WINDOWS)
+ TlsSetValue(tlsKeys()[data->owner->m_index], 0);
+#else
+#error ThreadSpecific is not implemented for this platform.
+#endif
+
+#if !PLATFORM(QT)
+ delete data;
+#endif
+#endif
+}
+
+template<typename T>
+inline ThreadSpecific<T>::operator T*()
+{
+ T* ptr = static_cast<T*>(get());
+ if (!ptr) {
+ // Set up thread-specific value's memory pointer before invoking constructor, in case any function it calls
+ // needs to access the value, to avoid recursion.
+ ptr = static_cast<T*>(fastZeroedMalloc(sizeof(T)));
+ set(ptr);
+ new (ptr) T;
+ }
+ return ptr;
+}
+
+template<typename T>
+inline T* ThreadSpecific<T>::operator->()
+{
+ return operator T*();
+}
+
+template<typename T>
+inline T& ThreadSpecific<T>::operator*()
+{
+ return *operator T*();
+}
+
+}
+
+#endif