LCOV - code coverage report
Current view: directory - widget/xpwidgets - nsBaseAppShell.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 145 75 51.7 %
Date: 2012-06-02 Functions: 22 14 63.6 %

       1                 : /* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Widget code.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is Google Inc.
      18                 :  * Portions created by the Initial Developer are Copyright (C) 2006
      19                 :  * the Initial Developer. All Rights Reserved.
      20                 :  *
      21                 :  * Contributor(s):
      22                 :  *   Darin Fisher <darin@meer.net> (original author)
      23                 :  *   Mats Palmgren <mats.palmgren@bredband.net>
      24                 :  *
      25                 :  * Alternatively, the contents of this file may be used under the terms of
      26                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      27                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      28                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      29                 :  * of those above. If you wish to allow use of your version of this file only
      30                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      31                 :  * use your version of this file under the terms of the MPL, indicate your
      32                 :  * decision by deleting the provisions above and replace them with the notice
      33                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      34                 :  * the provisions above, a recipient may use your version of this file under
      35                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      36                 :  *
      37                 :  * ***** END LICENSE BLOCK ***** */
      38                 : 
      39                 : #include "base/message_loop.h"
      40                 : 
      41                 : #include "nsBaseAppShell.h"
      42                 : #include "nsThreadUtils.h"
      43                 : #include "nsIObserverService.h"
      44                 : #include "nsServiceManagerUtils.h"
      45                 : #include "mozilla/Services.h"
      46                 : 
      47                 : // When processing the next thread event, the appshell may process native
      48                 : // events (if not in performance mode), which can result in suppressing the
      49                 : // next thread event for at most this many ticks:
      50                 : #define THREAD_EVENT_STARVATION_LIMIT PR_MillisecondsToInterval(20)
      51                 : 
      52         1180423 : NS_IMPL_THREADSAFE_ISUPPORTS3(nsBaseAppShell, nsIAppShell, nsIThreadObserver,
      53                 :                               nsIObserver)
      54                 : 
      55            1387 : nsBaseAppShell::nsBaseAppShell()
      56                 :   : mSuspendNativeCount(0)
      57                 :   , mEventloopNestingLevel(0)
      58                 :   , mBlockedWait(nsnull)
      59                 :   , mFavorPerf(0)
      60                 :   , mNativeEventPending(0)
      61                 :   , mStarvationDelay(0)
      62                 :   , mSwitchTime(0)
      63                 :   , mLastNativeEventTime(0)
      64                 :   , mEventloopNestingState(eEventloopNone)
      65                 :   , mRunning(false)
      66                 :   , mExiting(false)
      67            1387 :   , mBlockNativeEvent(false)
      68                 : {
      69            1387 : }
      70                 : 
      71            2774 : nsBaseAppShell::~nsBaseAppShell()
      72                 : {
      73            1387 :   NS_ASSERTION(mSyncSections.Count() == 0, "Must have run all sync sections");
      74            2774 : }
      75                 : 
      76                 : nsresult
      77            1387 : nsBaseAppShell::Init()
      78                 : {
      79                 :   // Configure ourselves as an observer for the current thread:
      80                 : 
      81                 :   nsCOMPtr<nsIThreadInternal> threadInt =
      82            2774 :       do_QueryInterface(NS_GetCurrentThread());
      83            1387 :   NS_ENSURE_STATE(threadInt);
      84                 : 
      85            1387 :   threadInt->SetObserver(this);
      86                 : 
      87                 :   nsCOMPtr<nsIObserverService> obsSvc =
      88            2774 :     mozilla::services::GetObserverService();
      89            1387 :   if (obsSvc)
      90            1387 :     obsSvc->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
      91            1387 :   return NS_OK;
      92                 : }
      93                 : 
      94                 : // Called by nsAppShell's native event callback
      95                 : void
      96           81592 : nsBaseAppShell::NativeEventCallback()
      97                 : {
      98           81592 :   PRInt32 hasPending = PR_ATOMIC_SET(&mNativeEventPending, 0);
      99           81592 :   if (hasPending == 0)
     100               0 :     return;
     101                 : 
     102                 :   // If DoProcessNextNativeEvent is on the stack, then we assume that we can
     103                 :   // just unwind and let nsThread::ProcessNextEvent process the next event.
     104                 :   // However, if we are called from a nested native event loop (maybe via some
     105                 :   // plug-in or library function), then go ahead and process Gecko events now.
     106           81592 :   if (mEventloopNestingState == eEventloopXPCOM) {
     107           81592 :     mEventloopNestingState = eEventloopOther;
     108                 :     // XXX there is a tiny risk we will never get a new NativeEventCallback,
     109                 :     // XXX see discussion in bug 389931.
     110           81592 :     return;
     111                 :   }
     112                 : 
     113                 :   // nsBaseAppShell::Run is not being used to pump events, so this may be
     114                 :   // our only opportunity to process pending gecko events.
     115                 : 
     116               0 :   nsIThread *thread = NS_GetCurrentThread();
     117               0 :   bool prevBlockNativeEvent = mBlockNativeEvent;
     118               0 :   if (mEventloopNestingState == eEventloopOther) {
     119               0 :     if (!NS_HasPendingEvents(thread))
     120               0 :       return;
     121                 :     // We're in a nested native event loop and have some gecko events to
     122                 :     // process.  While doing that we block processing native events from the
     123                 :     // appshell - instead, we want to get back to the nested native event
     124                 :     // loop ASAP (bug 420148).
     125               0 :     mBlockNativeEvent = true;
     126                 :   }
     127                 : 
     128               0 :   ++mEventloopNestingLevel;
     129               0 :   EventloopNestingState prevVal = mEventloopNestingState;
     130               0 :   NS_ProcessPendingEvents(thread, THREAD_EVENT_STARVATION_LIMIT);
     131               0 :   mProcessedGeckoEvents = true;
     132               0 :   mEventloopNestingState = prevVal;
     133               0 :   mBlockNativeEvent = prevBlockNativeEvent;
     134                 : 
     135                 :   // Continue processing pending events later (we don't want to starve the
     136                 :   // embedders event loop).
     137               0 :   if (NS_HasPendingEvents(thread))
     138               0 :     DoProcessMoreGeckoEvents();
     139                 : 
     140               0 :   --mEventloopNestingLevel;
     141                 : }
     142                 : 
     143                 : // Note, this is currently overidden on windows, see comments in nsAppShell for
     144                 : // details. 
     145                 : void
     146               0 : nsBaseAppShell::DoProcessMoreGeckoEvents()
     147                 : {
     148               0 :   OnDispatchedEvent(nsnull);
     149               0 : }
     150                 : 
     151                 : 
     152                 : // Main thread via OnProcessNextEvent below
     153                 : bool
     154          271073 : nsBaseAppShell::DoProcessNextNativeEvent(bool mayWait)
     155                 : {
     156                 :   // The next native event to be processed may trigger our NativeEventCallback,
     157                 :   // in which case we do not want it to process any thread events since we'll
     158                 :   // do that when this function returns.
     159                 :   //
     160                 :   // If the next native event is not our NativeEventCallback, then we may end
     161                 :   // up recursing into this function.
     162                 :   //
     163                 :   // However, if the next native event is not our NativeEventCallback, but it
     164                 :   // results in another native event loop, then our NativeEventCallback could
     165                 :   // fire and it will see mEventloopNestingState as eEventloopOther.
     166                 :   //
     167          271073 :   EventloopNestingState prevVal = mEventloopNestingState;
     168          271073 :   mEventloopNestingState = eEventloopXPCOM;
     169                 : 
     170          271073 :   ++mEventloopNestingLevel;
     171          271073 :   bool result = ProcessNextNativeEvent(mayWait);
     172          271073 :   --mEventloopNestingLevel;
     173                 : 
     174          271073 :   mEventloopNestingState = prevVal;
     175          271073 :   return result;
     176                 : }
     177                 : 
     178                 : //-------------------------------------------------------------------------
     179                 : // nsIAppShell methods:
     180                 : 
     181                 : NS_IMETHODIMP
     182               0 : nsBaseAppShell::Run(void)
     183                 : {
     184               0 :   NS_ENSURE_STATE(!mRunning);  // should not call Run twice
     185               0 :   mRunning = true;
     186                 : 
     187               0 :   nsIThread *thread = NS_GetCurrentThread();
     188                 : 
     189               0 :   MessageLoop::current()->Run();
     190                 : 
     191               0 :   NS_ProcessPendingEvents(thread);
     192                 : 
     193               0 :   mRunning = false;
     194               0 :   return NS_OK;
     195                 : }
     196                 : 
     197                 : NS_IMETHODIMP
     198            1387 : nsBaseAppShell::Exit(void)
     199                 : {
     200            1387 :   if (mRunning && !mExiting) {
     201               0 :     MessageLoop::current()->Quit();
     202                 :   }
     203            1387 :   mExiting = true;
     204            1387 :   return NS_OK;
     205                 : }
     206                 : 
     207                 : NS_IMETHODIMP
     208               0 : nsBaseAppShell::FavorPerformanceHint(bool favorPerfOverStarvation,
     209                 :                                      PRUint32 starvationDelay)
     210                 : {
     211               0 :   mStarvationDelay = PR_MillisecondsToInterval(starvationDelay);
     212               0 :   if (favorPerfOverStarvation) {
     213               0 :     ++mFavorPerf;
     214                 :   } else {
     215               0 :     --mFavorPerf;
     216               0 :     mSwitchTime = PR_IntervalNow();
     217                 :   }
     218               0 :   return NS_OK;
     219                 : }
     220                 : 
     221                 : NS_IMETHODIMP
     222               0 : nsBaseAppShell::SuspendNative()
     223                 : {
     224               0 :   ++mSuspendNativeCount;
     225               0 :   return NS_OK;
     226                 : }
     227                 : 
     228                 : NS_IMETHODIMP
     229               0 : nsBaseAppShell::ResumeNative()
     230                 : {
     231               0 :   --mSuspendNativeCount;
     232               0 :   NS_ASSERTION(mSuspendNativeCount >= 0, "Unbalanced call to nsBaseAppShell::ResumeNative!");
     233               0 :   return NS_OK;
     234                 : }
     235                 : 
     236                 : NS_IMETHODIMP
     237               0 : nsBaseAppShell::GetEventloopNestingLevel(PRUint32* aNestingLevelResult)
     238                 : {
     239               0 :   NS_ENSURE_ARG_POINTER(aNestingLevelResult);
     240                 : 
     241               0 :   *aNestingLevelResult = mEventloopNestingLevel;
     242                 : 
     243               0 :   return NS_OK;
     244                 : }
     245                 : 
     246                 : //-------------------------------------------------------------------------
     247                 : // nsIThreadObserver methods:
     248                 : 
     249                 : // Called from any thread
     250                 : NS_IMETHODIMP
     251          162753 : nsBaseAppShell::OnDispatchedEvent(nsIThreadInternal *thr)
     252                 : {
     253          162753 :   if (mBlockNativeEvent)
     254               0 :     return NS_OK;
     255                 : 
     256          162753 :   PRInt32 lastVal = PR_ATOMIC_SET(&mNativeEventPending, 1);
     257          162753 :   if (lastVal == 1)
     258           81161 :     return NS_OK;
     259                 : 
     260                 :   // Returns on the main thread in NativeEventCallback above
     261           81592 :   ScheduleNativeEventCallback();
     262           81592 :   return NS_OK;
     263                 : }
     264                 : 
     265                 : // Called from the main thread
     266                 : NS_IMETHODIMP
     267          174261 : nsBaseAppShell::OnProcessNextEvent(nsIThreadInternal *thr, bool mayWait,
     268                 :                                    PRUint32 recursionDepth)
     269                 : {
     270          174261 :   if (mBlockNativeEvent) {
     271               0 :     if (!mayWait)
     272               0 :       return NS_OK;
     273                 :     // Hmm, we're in a nested native event loop and would like to get
     274                 :     // back to it ASAP, but it seems a gecko event has caused us to
     275                 :     // spin up a nested XPCOM event loop (eg. modal window), so we
     276                 :     // really must start processing native events here again.
     277               0 :     mBlockNativeEvent = false;
     278               0 :     if (NS_HasPendingEvents(thr))
     279               0 :       OnDispatchedEvent(thr); // in case we blocked it earlier
     280                 :   }
     281                 : 
     282          174261 :   PRIntervalTime start = PR_IntervalNow();
     283          174261 :   PRIntervalTime limit = THREAD_EVENT_STARVATION_LIMIT;
     284                 : 
     285                 :   // Unblock outer nested wait loop (below).
     286          174261 :   if (mBlockedWait)
     287               0 :     *mBlockedWait = false;
     288                 : 
     289          174261 :   bool *oldBlockedWait = mBlockedWait;
     290          174261 :   mBlockedWait = &mayWait;
     291                 : 
     292                 :   // When mayWait is true, we need to make sure that there is an event in the
     293                 :   // thread's event queue before we return.  Otherwise, the thread will block
     294                 :   // on its event queue waiting for an event.
     295          174261 :   bool needEvent = mayWait;
     296                 :   // Reset prior to invoking DoProcessNextNativeEvent which might cause
     297                 :   // NativeEventCallback to process gecko events.
     298          174261 :   mProcessedGeckoEvents = false;
     299                 : 
     300          174261 :   if (mFavorPerf <= 0 && start > mSwitchTime + mStarvationDelay) {
     301                 :     // Favor pending native events
     302          174261 :     PRIntervalTime now = start;
     303                 :     bool keepGoing;
     304          243747 :     do {
     305          243747 :       mLastNativeEventTime = now;
     306          243747 :       keepGoing = DoProcessNextNativeEvent(false);
     307          174261 :     } while (keepGoing && ((now = PR_IntervalNow()) - start) < limit);
     308                 :   } else {
     309                 :     // Avoid starving native events completely when in performance mode
     310               0 :     if (start - mLastNativeEventTime > limit) {
     311               0 :       mLastNativeEventTime = start;
     312               0 :       DoProcessNextNativeEvent(false);
     313                 :     }
     314                 :   }
     315                 : 
     316          362192 :   while (!NS_HasPendingEvents(thr) && !mProcessedGeckoEvents) {
     317                 :     // If we have been asked to exit from Run, then we should not wait for
     318                 :     // events to process.  Note that an inner nested event loop causes
     319                 :     // 'mayWait' to become false too, through 'mBlockedWait'.
     320           27326 :     if (mExiting)
     321           10319 :       mayWait = false;
     322                 : 
     323           27326 :     mLastNativeEventTime = PR_IntervalNow();
     324           27326 :     if (!DoProcessNextNativeEvent(mayWait) || !mayWait)
     325           13656 :       break;
     326                 :   }
     327                 : 
     328          174261 :   mBlockedWait = oldBlockedWait;
     329                 : 
     330                 :   // Make sure that the thread event queue does not block on its monitor, as
     331                 :   // it normally would do if it did not have any pending events.  To avoid
     332                 :   // that, we simply insert a dummy event into its queue during shutdown.
     333          174261 :   if (needEvent && !mExiting && !NS_HasPendingEvents(thr)) {  
     334               0 :     if (!mDummyEvent)
     335               0 :       mDummyEvent = new nsRunnable();
     336               0 :     thr->Dispatch(mDummyEvent, NS_DISPATCH_NORMAL);
     337                 :   }
     338                 : 
     339                 :   // We're about to run an event, so we're in a stable state. 
     340          174261 :   RunSyncSections();
     341                 : 
     342          174261 :   return NS_OK;
     343                 : }
     344                 : 
     345                 : void
     346          348522 : nsBaseAppShell::RunSyncSections()
     347                 : {
     348          348522 :   if (mSyncSections.Count() == 0) {
     349          348522 :     return;
     350                 :   }
     351                 :   // We've got synchronous sections awaiting a stable state. Run
     352                 :   // all the synchronous sections. Note that a synchronous section could
     353                 :   // add another synchronous section, so we don't remove elements from
     354                 :   // mSyncSections until all sections have been run, else we'll screw up
     355                 :   // our iteration.
     356               0 :   for (PRInt32 i = 0; i < mSyncSections.Count(); i++) {
     357               0 :     mSyncSections[i]->Run();
     358                 :   }
     359               0 :   mSyncSections.Clear();
     360                 : }
     361                 : 
     362                 : // Called from the main thread
     363                 : NS_IMETHODIMP
     364          174261 : nsBaseAppShell::AfterProcessNextEvent(nsIThreadInternal *thr,
     365                 :                                       PRUint32 recursionDepth)
     366                 : {
     367                 :   // We've just finished running an event, so we're in a stable state. 
     368          174261 :   RunSyncSections();
     369          174261 :   return NS_OK;
     370                 : }
     371                 : 
     372                 : NS_IMETHODIMP
     373            1387 : nsBaseAppShell::Observe(nsISupports *subject, const char *topic,
     374                 :                         const PRUnichar *data)
     375                 : {
     376            1387 :   NS_ASSERTION(!strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID), "oops");
     377            1387 :   Exit();
     378            1387 :   return NS_OK;
     379                 : }
     380                 : 
     381                 : NS_IMETHODIMP
     382               0 : nsBaseAppShell::RunInStableState(nsIRunnable* aRunnable)
     383                 : {
     384               0 :   NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
     385                 :   // Record the synchronous section, and run it with any others once
     386                 :   // we reach a stable state.
     387               0 :   mSyncSections.AppendObject(aRunnable);
     388                 : 
     389                 :   // Ensure we've got a pending event, else the callbacks will never run.
     390               0 :   nsIThread* thread = NS_GetCurrentThread(); 
     391               0 :   if (!NS_HasPendingEvents(thread) &&
     392               0 :        NS_FAILED(thread->Dispatch(new nsRunnable(), NS_DISPATCH_NORMAL)))
     393                 :   {
     394                 :     // Failed to dispatch dummy event to cause sync sections to run, thread
     395                 :     // is probably done processing events, just run the sync sections now.
     396               0 :     RunSyncSections();
     397                 :   }
     398               0 :   return NS_OK;
     399                 : }
     400                 : 

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