/* * Copyright (c) 1999-2000, Eric Moon. * All rights reserved. * * 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. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR 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. */ // ObservableLooper.cpp #include "ObservableLooper.h" #include <Debug.h> #include <MessageRunner.h> __USE_CORTEX_NAMESPACE // ---------------------------------------------------------------- // // *** deletion // ---------------------------------------------------------------- // // clients must call release() rather than deleting, // to ensure that all observers are notified of the // object's demise. if the object has already been // released, return an error. status_t ObservableLooper::release() { // +++++ what if I'm not running? // +++++ is a lock necessary? if(isReleased()) return B_NOT_ALLOWED; // send request through proper channels BMessenger(this).SendMessage(B_QUIT_REQUESTED); return B_OK; } // ---------------------------------------------------------------- // // *** ctor/dtor // ---------------------------------------------------------------- // ObservableLooper::~ObservableLooper() { if(CountTargets()) { PRINT(( "*** ~ObservableLooper() '%s': %" B_PRId32 " observers remain\n", Name(), CountTargets())); } if(m_executioner) delete m_executioner; } ObservableLooper::ObservableLooper( const char* name, int32 priority, int32 portCapacity, bigtime_t quitTimeout) : BLooper(name, priority, portCapacity), m_quitTimeout(quitTimeout), m_executioner(0), m_quitting(false) {} ObservableLooper::ObservableLooper( BMessage* archive) : BLooper(archive), m_quitTimeout(B_INFINITE_TIMEOUT), m_executioner(0), m_quitting(false) { archive->FindInt64("quitTimeout", (int64*)&m_quitTimeout); } // ---------------------------------------------------------------- // // *** accessors // ---------------------------------------------------------------- // bool ObservableLooper::isReleased() const { return m_quitting; } // ---------------------------------------------------------------- // // *** hooks // ---------------------------------------------------------------- // // sends M_OBSERVER_ADDED to the newly-added observer void ObservableLooper::observerAdded( const BMessenger& observer) { BMessage m(M_OBSERVER_ADDED); m.AddMessenger("target", BMessenger(this)); observer.SendMessage(&m); } // sends M_OBSERVER_REMOVED to the newly-removed observer void ObservableLooper::observerRemoved( const BMessenger& observer) { BMessage m(M_OBSERVER_REMOVED); m.AddMessenger("target", BMessenger(this)); observer.SendMessage(&m); } // ---------------------------------------------------------------- // // *** internal operations // ---------------------------------------------------------------- // status_t ObservableLooper::notify( BMessage* message) { ASSERT(IsLocked()); return Invoke(message); } // sends M_RELEASE_OBSERVABLE void ObservableLooper::notifyRelease() { BMessage m(M_RELEASE_OBSERVABLE); m.AddMessenger("target", BMessenger(this)); notify(&m); } // ---------------------------------------------------------------- // // *** BLooper // ---------------------------------------------------------------- // void ObservableLooper::Quit() { ASSERT(IsLocked()); if(QuitRequested()) { releaseComplete(); _inherited::Quit(); } else Unlock(); } bool ObservableLooper::QuitRequested() { if(CountTargets()) { if(!m_quitting) { m_quitting = true; // no release request yet sent notifyRelease(); if(m_quitTimeout != B_INFINITE_TIMEOUT) { // Initiate a timer to force quit -- if an observer // has died, it shouldn't take me down with it. ASSERT(!m_executioner); m_executioner = new BMessageRunner( BMessenger(this), new BMessage(M_KILL_OBSERVABLE), m_quitTimeout, 1); } } // targets remain, so don't quit. return false; } // okay to quit return true; } // ---------------------------------------------------------------- // // *** BHandler // ---------------------------------------------------------------- // void ObservableLooper::MessageReceived( BMessage* message) { // PRINT(( // "### ObservableLooper::MessageReceived()\n")); // message->PrintToStream(); switch(message->what) { case M_ADD_OBSERVER: _handleAddObserver(message); break; case M_REMOVE_OBSERVER: _handleRemoveObserver(message); break; case M_KILL_OBSERVABLE: releaseComplete(); BLooper::Quit(); break; default: _inherited::MessageReceived(message); } } // ---------------------------------------------------------------- // // *** BArchivable // ---------------------------------------------------------------- // status_t ObservableLooper::Archive( BMessage* archive, bool deep) const { ASSERT(IsLocked()); // can't archive an object in limbo if(m_quitting) return B_NOT_ALLOWED; status_t err = _inherited::Archive(archive, deep); if(err < B_OK) return err; archive->AddInt64("quitTimeout", m_quitTimeout); return B_OK; } // ---------------------------------------------------------------- // // implementation // ---------------------------------------------------------------- // void ObservableLooper::_handleAddObserver( BMessage* message) { BMessage reply; BMessenger observer; status_t err = message->FindMessenger( "observer", &observer); if(err < B_OK) { PRINT(( "* ObservableLooper::_handleAddObserver(): no observer specified!\n")); // send reply? +++++ return; } // at this point, a reply of some sort will be sent reply.AddMessenger("target", BMessenger(this)); reply.AddMessenger("observer", observer); if(m_quitting) { // already quitting reply.what = M_BAD_TARGET; } else if(IndexOfTarget(observer.Target(0)) != -1) { // observer already added reply.what = M_BAD_OBSERVER; } else { // add it err = AddTarget(observer.Target(0)); ASSERT(err == B_OK); reply.what = M_OBSERVER_ADDED; } // send reply message->SendReply(&reply); // call hook observerAdded(observer); } void ObservableLooper::_handleRemoveObserver( BMessage* message) { // PRINT(("ObservableLooper::_handleRemoveObserver():\n" // " %ld targets\n", CountTargets())); BMessage reply; BMessenger observer; status_t err = message->FindMessenger( "observer", &observer); if(err < B_OK) { PRINT(( "* ObservableLooper::_handleRemoveObserver(): no observer specified!\n")); // send reply? +++++ return; } // at this point, a reply of some sort will be sent reply.AddMessenger("target", BMessenger(this)); reply.AddMessenger("observer", observer); int32 index = IndexOfTarget(observer.Target(0)); if(index == -1) { reply.what = M_BAD_OBSERVER; } else { RemoveTarget(index); reply.what = M_OBSERVER_REMOVED; } message->SendReply(&reply); // call hook observerRemoved(observer); // time to shut down? if(m_quitting && !CountTargets()) { releaseComplete(); BLooper::Quit(); } } // END -- ObservableLooper.cpp --
