Changes between Version 5 and Version 6 of ThreadCommunication

Timestamp:

Apr 19, 2011, 3:43:59 PM (15 years ago)

Author:

levin@chromium.org

Comment:

Added "case study" of converting code to using the new api.

ThreadCommunication

@@ -58 +58 @@
 '''Case study: File API from Workers'''
 
-TBD: In progress
+Here's an example of converting the move method from WebKit/chromium/src/WorkerFileSystemCallbacksBridge.cpp (http://trac.webkit.org/browser/trunk/Source/WebKit/chromium/src/WorkerFileSystemCallbacksBridge.cpp) to using this.
+
+The main changes are less code at the calling sites and less mechanics around carefully tracking the lifetime of each side.
+
+{{{
+class MainThreadFileSystemCallbacks : public WebFileSystemCallbacks {
+public:
+    // Callbacks are self-destructed and we always return leaked pointer here.
+    static MainThreadFileSystemCallbacks* createLeakedPtr(PassOwnPtr<ClassProxy> callbackProxy)
+    {
+        return adoptPtr(new MainThreadFileSystemCallbacks(callbackProxy)).leakPtr();
+    }
+
+    virtual void didSucceed()
+    {
+        m_callbackProxy->invoke(&didSucceedOnMainThread);
+        m_callbackProxy->done();
+        delete this;
+    }
+
+private:
+    MainThreadFileSystemCallbacks(PassOwnPtr<ClassProxy> callbackProxy)
+        : m_callbackProxy(callbackProxy)
+    {
+    }
+
+    OwnPtr<ClassProxy> m_callbackProxy;
+};
+
+void moveOnMainThread(PassOwnPtr<ClassProxy> callbackProxy, WebFileSystem* fileSystem, const String& sourcePath, const String& destinationPath, const String& mode)
+{
+    fileSystem->move(sourcePath, destinationPath, MainThreadFileSystemCallbacks::createLeakedPtr(callbackProxy));
+}
+
+void WorkerFileSystemCallbacks::stop()
+{
+    if (m_callbacksOnWorkerThread) {
+        m_callbacksOnWorkerThread->didFail(WebFileErrorAbort);
+        m_callbacksOnWorkerThread = 0;
+    }
+}
+
+void WorkerFileSystemCallbacks::postMoveToMainThread(WebFileSystem* fileSystem, const String& sourcePath, const String& destinationPath, const String& mode)
+{
+    OwnPtr<SyncWaiter> syncCall = mainThreadMessageLoop->invoke(&moveOnMainThread, getProxy(), fileSystem, sourcePath, destinationPath);
+    syncCall.wait();
+    stop();
+}
+}}}