PPAPI: Implement synchronous postMessage

ppapi/c/ppb_messaging.h

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-/* From ppb_messaging.idl modified Mon Jun  2 11:00:28 2014. */
+/* From ppb_messaging.idl modified Fri Jun 13 15:28:26 2014. */
 
 #ifndef PPAPI_C_PPB_MESSAGING_H_
 #define PPAPI_C_PPB_MESSAGING_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
@@ skipping 76 matching lines @@
    *                                                    sizeof(hello_world));
    *  ppb_messaging_interface->PostMessage(instance, hello_var); // Copies var.
    *  ppb_var_interface->Release(hello_var);
    *
    * @endcode
    *
    * The browser will pop-up an alert saying "Hello world!"
    */
   void (*PostMessage)(PP_Instance instance, struct PP_Var message);
   /**
-   * <strong>Note:</strong> This function is not yet implemented. Please use
-   * PPB_Messaging_1_0.
-   *
    * Registers a handler for receiving messages from JavaScript. If a handler
    * is registered this way, it will replace PPP_Messaging, and all messages
    * sent from JavaScript via postMessage and postMessageAndAwaitResponse will
    * be dispatched to <code>handler</code>.
    *
    * The function calls will be dispatched via <code>message_loop</code>. This
    * means that the functions will be invoked on the thread to which
    * <code>message_loop</code> is attached, when <code>message_loop</code> is
    * run. It is illegal to pass the main thread message loop;
    * RegisterMessageHandler will return PP_ERROR_WRONG_THREAD in that case.
+   * If you quit <code>message_loop</code> before calling Unregister(),
+   * the browser will not be able to call functions in the plugin's message
+   * handler any more. That could mean missing some messages or could cause a
+   * leak if you depend on Destroy() to free hander data. So you should,
+   * whenever possible, Unregister() the handler prior to quitting its event
+   * loop.
    *
    * Attempting to register a message handler when one is already registered
    * will cause the current MessageHandler to be unregistered and replaced. In
    * that case, no messages will be sent to the "default" message handler
    * (PPP_Messaging). Messages will stop arriving at the prior message handler
    * and will begin to be dispatched at the new message handler.
    *
    * @param[in] instance A <code>PP_Instance</code> identifying one instance
    * of a module.
    * @param[in] user_data A pointer the plugin may choose to use when handling
    * calls to functions within PPP_MessageHandler. The browser will pass this
    * same pointer when invoking functions within PPP_MessageHandler.
    * @param[in] handler The plugin-provided set of functions for handling
    * messages.
    * @param[in] message_loop Represents the message loop on which
    * PPP_MessageHandler functions should be invoked.
    * @return PP_OK on success, or an error from pp_errors.h.
    */
   int32_t (*RegisterMessageHandler)(
       PP_Instance instance,
       void* user_data,
       const struct PPP_MessageHandler_0_1* handler,
       PP_Resource message_loop);
   /**
-   * <strong>Note:</strong> This function is not yet implemented. Please use
-   * PPB_Messaging_1_0.
-   *
    * Unregisters the current message handler for <code>instance</code> if one
    * is registered. After this call, the message handler (if one was
    * registered) will have "Destroy" called on it and will receive no further
    * messages after that point. After that point, all messages sent from
    * JavaScript using postMessage() will be dispatched to PPP_Messaging (if
    * the plugin supports PPP_MESSAGING_INTERFACE). Attempts to call
    * postMessageAndAwaitResponse() from JavaScript will fail.
    *
    * Attempting to unregister a message handler when none is registered has no
    * effect.
    *
    * @param[in] instance A <code>PP_Instance</code> identifying one instance
    * of a module.
    */
   void (*UnregisterMessageHandler)(PP_Instance instance);
 };
 
 struct PPB_Messaging_1_0 {
   void (*PostMessage)(PP_Instance instance, struct PP_Var message);
 };
 
 typedef struct PPB_Messaging_1_0 PPB_Messaging;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPB_MESSAGING_H_ */