Merge webkit.org at r54127 : Initial merge by git

Change-Id: Ib661abb595522f50ea406f72d3a0ce17f7193c82

1 files changed, 77 insertions, 0 deletions

diff --git a/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h b/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h
new file mode 100644
index 0000000..3af87a8
--- /dev/null
+++ b/JavaScriptCore/wtf/ThreadIdentifierDataPthreads.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2009 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+ * OWNER OR 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.
+ */
+
+#ifndef ThreadIdentifierDataPthreads_h
+#define ThreadIdentifierDataPthreads_h
+
+#include <wtf/Noncopyable.h>
+#include <wtf/Threading.h>
+
+namespace WTF {
+
+// Holds ThreadIdentifier in the thread-specific storage and employs pthreads-specific 2-pass destruction to reliably remove
+// ThreadIdentifier from threadMap. It assumes regular ThreadSpecific types don't use multiple-pass destruction.
+class ThreadIdentifierData : public Noncopyable {
+public:
+    ~ThreadIdentifierData();
+
+    // Creates and puts an instance of ThreadIdentifierData into thread-specific storage.
+    static void initialize(ThreadIdentifier identifier);
+
+    // Returns 0 if thread-specific storage was not initialized.
+    static ThreadIdentifier identifier();
+
+private:
+    ThreadIdentifierData(ThreadIdentifier identifier)
+        : m_identifier(identifier)
+        , m_isDestroyedOnce(false)
+    {
+    }
+
+    // This thread-specific destructor is called 2 times when thread terminates:
+    // - first, when all the other thread-specific destructors are called, it simply remembers it was 'destroyed once'
+    // and re-sets itself into the thread-specific slot to make Pthreads to call it again later.
+    // - second, after all thread-specific destructors were invoked, it gets called again - this time, we remove the
+    // ThreadIdentifier from the threadMap, completing the cleanup.
+    static void destruct(void* data);
+
+    static void initializeKeyOnceHelper();
+    static void initializeKeyOnce();
+
+    ThreadIdentifier m_identifier;
+    bool m_isDestroyedOnce;
+    static pthread_key_t m_key;
+};
+
+} // namespace WTF
+
+#endif // ThreadIdentifierDataPthreads_h
+
+