DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (409f3966645a)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986
/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * Runs the main native Cocoa run loop, interrupting it as needed to process
 * Gecko events.
 */

#import <Cocoa/Cocoa.h>

#include "CustomCocoaEvents.h"
#include "mozilla/WidgetTraceEvent.h"
#include "nsAppShell.h"
#include "nsCOMPtr.h"
#include "nsIFile.h"
#include "nsDirectoryServiceDefs.h"
#include "nsString.h"
#include "nsIRollupListener.h"
#include "nsIWidget.h"
#include "nsThreadUtils.h"
#include "nsIWindowMediator.h"
#include "nsServiceManagerUtils.h"
#include "nsIInterfaceRequestor.h"
#include "nsIWebBrowserChrome.h"
#include "nsObjCExceptions.h"
#include "nsCocoaFeatures.h"
#include "nsCocoaUtils.h"
#include "nsChildView.h"
#include "nsToolkit.h"
#include "TextInputHandler.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "GeckoProfiler.h"
#include "ScreenHelperCocoa.h"
#include "mozilla/Hal.h"
#include "mozilla/widget/ScreenManager.h"
#include "HeadlessScreenHelper.h"
#include "pratom.h"
#if !defined(RELEASE_OR_BETA) || defined(DEBUG)
#include "nsSandboxViolationSink.h"
#endif

#include <IOKit/pwr_mgt/IOPMLib.h>
#include "nsIDOMWakeLockListener.h"
#include "nsIPowerManagerService.h"

using namespace mozilla::widget;

#define WAKE_LOCK_LOG(...) MOZ_LOG(gMacWakeLockLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
static mozilla::LazyLogModule gMacWakeLockLog("MacWakeLock");

// A wake lock listener that disables screen saver when requested by
// Gecko. For example when we're playing video in a foreground tab we
// don't want the screen saver to turn on.

class MacWakeLockListener final : public nsIDOMMozWakeLockListener {
public:
  NS_DECL_ISUPPORTS;

private:
  ~MacWakeLockListener() {}

  IOPMAssertionID mAssertionNoDisplaySleepID = kIOPMNullAssertionID;
  IOPMAssertionID mAssertionNoIdleSleepID = kIOPMNullAssertionID;

  NS_IMETHOD Callback(const nsAString& aTopic, const nsAString& aState) override {
    if (!aTopic.EqualsASCII("screen") &&
        !aTopic.EqualsASCII("audio-playing") &&
        !aTopic.EqualsASCII("video-playing")) {
      return NS_OK;
    }

    // we should still hold the lock for background audio.
    if (aTopic.EqualsASCII("audio-playing") &&
        aState.EqualsASCII("locked-background")) {
      WAKE_LOCK_LOG("keep audio playing even in background");
      return NS_OK;
    }

    bool shouldKeepDisplayOn = aTopic.EqualsASCII("screen") ||
                               aTopic.EqualsASCII("video-playing");
    CFStringRef assertionType = shouldKeepDisplayOn ?
      kIOPMAssertionTypeNoDisplaySleep : kIOPMAssertionTypeNoIdleSleep;
    IOPMAssertionID& assertionId = shouldKeepDisplayOn ?
      mAssertionNoDisplaySleepID : mAssertionNoIdleSleepID;

    // Note the wake lock code ensures that we're not sent duplicate
    // "locked-foreground" notifications when multiple wake locks are held.
    if (aState.EqualsASCII("locked-foreground")) {
      if (assertionId != kIOPMNullAssertionID) {
        WAKE_LOCK_LOG("already has a lock");
        return NS_OK;
      }
      // Prevent screen saver.
      CFStringRef cf_topic =
        ::CFStringCreateWithCharacters(kCFAllocatorDefault,
                                       reinterpret_cast<const UniChar*>
                                         (aTopic.Data()),
                                       aTopic.Length());
      IOReturn success =
        ::IOPMAssertionCreateWithName(assertionType,
                                      kIOPMAssertionLevelOn,
                                      cf_topic,
                                      &assertionId);
      CFRelease(cf_topic);
      if (success != kIOReturnSuccess) {
        WAKE_LOCK_LOG("failed to disable screensaver");
      }
      WAKE_LOCK_LOG("create screensaver");
    } else {
      // Re-enable screen saver.
      if (assertionId != kIOPMNullAssertionID) {
        IOReturn result = ::IOPMAssertionRelease(assertionId);
        if (result != kIOReturnSuccess) {
          WAKE_LOCK_LOG("failed to release screensaver");
        }
        WAKE_LOCK_LOG("Release screensaver");
        assertionId = kIOPMNullAssertionID;
      }
    }
    return NS_OK;
  }
}; // MacWakeLockListener

// defined in nsCocoaWindow.mm
extern int32_t             gXULModalLevel;

static bool gAppShellMethodsSwizzled = false;

@implementation GeckoNSApplication

- (void)sendEvent:(NSEvent *)anEvent
{
  // Mark this function as non-idle because it's one of the exit points from
  // the event loop (running inside of -[GeckoNSApplication nextEventMatchingMask:...])
  // into non-idle code. So we basically unset the IDLE category from the inside.
  AUTO_PROFILER_LABEL("-[GeckoNSApplication sendEvent:]", OTHER);

  mozilla::BackgroundHangMonitor().NotifyActivity();

  if ([anEvent type] == NSApplicationDefined &&
      [anEvent subtype] == kEventSubtypeTrace) {
    mozilla::SignalTracerThread();
    return;
  }
  [super sendEvent:anEvent];
}

#if defined(MAC_OS_X_VERSION_10_12) && \
    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_12 && \
    __LP64__
// 10.12 changed `mask` to NSEventMask (unsigned long long) for x86_64 builds.
- (NSEvent*)nextEventMatchingMask:(NSEventMask)mask
#else
- (NSEvent*)nextEventMatchingMask:(NSUInteger)mask
#endif
                        untilDate:(NSDate*)expiration
                           inMode:(NSString*)mode
                          dequeue:(BOOL)flag
{
  // When we're waiting in the event loop, this is the last function under our
  // control that's on the stack, so this is the function that we mark with the
  // IDLE category.
  // However, when we're processing an event or when our CFRunLoopSource runs,
  // this function is still on the stack - "the event loop calls us". So we
  // need to mark functions that enter non-idle code with a different profiler
  // category, usually OTHER. This gives the profiler a rough approximation of
  // idleness but isn't perfect. For example, sometimes there's some Cocoa-
  // internal activity that's triggered from the event loop, and we'll
  // misidentify the stacks for that activity as idle because there's no Gecko
  // code on the stack that can change the stack's category to something
  // non-idle.
  AUTO_PROFILER_LABEL("-[GeckoNSApplication nextEventMatchingMask:untilDate:inMode:dequeue:]", IDLE);

  if (expiration) {
    mozilla::BackgroundHangMonitor().NotifyWait();
  }
  NSEvent* nextEvent = [super nextEventMatchingMask:mask
                        untilDate:expiration inMode:mode dequeue:flag];
  if (expiration) {
    mozilla::BackgroundHangMonitor().NotifyActivity();
  }
  return nextEvent;
}

@end

// AppShellDelegate
//
// Cocoa bridge class.  An object of this class is registered to receive
// notifications.
//
@interface AppShellDelegate : NSObject
{
  @private
    nsAppShell* mAppShell;
}

- (id)initWithAppShell:(nsAppShell*)aAppShell;
- (void)applicationWillTerminate:(NSNotification*)aNotification;
- (void)beginMenuTracking:(NSNotification*)aNotification;
@end

// nsAppShell implementation

NS_IMETHODIMP
nsAppShell::ResumeNative(void)
{
  nsresult retval = nsBaseAppShell::ResumeNative();
  if (NS_SUCCEEDED(retval) && (mSuspendNativeCount == 0) &&
      mSkippedNativeCallback)
  {
    mSkippedNativeCallback = false;
    ScheduleNativeEventCallback();
  }
  return retval;
}

nsAppShell::nsAppShell()
: mAutoreleasePools(nullptr)
, mDelegate(nullptr)
, mCFRunLoop(NULL)
, mCFRunLoopSource(NULL)
, mRunningEventLoop(false)
, mStarted(false)
, mTerminated(false)
, mSkippedNativeCallback(false)
, mNativeEventCallbackDepth(0)
, mNativeEventScheduledDepth(0)
{
  // A Cocoa event loop is running here if (and only if) we've been embedded
  // by a Cocoa app.
  mRunningCocoaEmbedded = [NSApp isRunning] ? true : false;
}

nsAppShell::~nsAppShell()
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  hal::Shutdown();

  if (mCFRunLoop) {
    if (mCFRunLoopSource) {
      ::CFRunLoopRemoveSource(mCFRunLoop, mCFRunLoopSource,
                              kCFRunLoopCommonModes);
      ::CFRelease(mCFRunLoopSource);
    }
    ::CFRelease(mCFRunLoop);
  }

  if (mAutoreleasePools) {
    NS_ASSERTION(::CFArrayGetCount(mAutoreleasePools) == 0,
                 "nsAppShell destroyed without popping all autorelease pools");
    ::CFRelease(mAutoreleasePools);
  }

  [mDelegate release];

  NS_OBJC_END_TRY_ABORT_BLOCK
}

NS_IMPL_ISUPPORTS(MacWakeLockListener, nsIDOMMozWakeLockListener)
mozilla::StaticRefPtr<MacWakeLockListener> sWakeLockListener;

static void
AddScreenWakeLockListener()
{
  nsCOMPtr<nsIPowerManagerService> sPowerManagerService = do_GetService(
                                                          POWERMANAGERSERVICE_CONTRACTID);
  if (sPowerManagerService) {
    sWakeLockListener = new MacWakeLockListener();
    sPowerManagerService->AddWakeLockListener(sWakeLockListener);
  } else {
    NS_WARNING("Failed to retrieve PowerManagerService, wakelocks will be broken!");
  }
}

static void
RemoveScreenWakeLockListener()
{
  nsCOMPtr<nsIPowerManagerService> sPowerManagerService = do_GetService(
                                                          POWERMANAGERSERVICE_CONTRACTID);
  if (sPowerManagerService) {
    sPowerManagerService->RemoveWakeLockListener(sWakeLockListener);
    sPowerManagerService = nullptr;
    sWakeLockListener = nullptr;
  }
}

// An undocumented CoreGraphics framework method, present in the same form
// since at least OS X 10.5.
extern "C" CGError CGSSetDebugOptions(int options);

// Init
//
// Loads the nib (see bug 316076c21) and sets up the CFRunLoopSource used to
// interrupt the main native run loop.
//
// public
nsresult
nsAppShell::Init()
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;

  // No event loop is running yet (unless an embedding app that uses
  // NSApplicationMain() is running).
  NSAutoreleasePool* localPool = [[NSAutoreleasePool alloc] init];

  // mAutoreleasePools is used as a stack of NSAutoreleasePool objects created
  // by |this|.  CFArray is used instead of NSArray because NSArray wants to
  // retain each object you add to it, and you can't retain an
  // NSAutoreleasePool.
  mAutoreleasePools = ::CFArrayCreateMutable(nullptr, 0, nullptr);
  NS_ENSURE_STATE(mAutoreleasePools);

  // Get the path of the nib file, which lives in the GRE location
  nsCOMPtr<nsIFile> nibFile;
  nsresult rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(nibFile));
  NS_ENSURE_SUCCESS(rv, rv);

  nibFile->AppendNative(NS_LITERAL_CSTRING("res"));
  nibFile->AppendNative(NS_LITERAL_CSTRING("MainMenu.nib"));

  nsAutoCString nibPath;
  rv = nibFile->GetNativePath(nibPath);
  NS_ENSURE_SUCCESS(rv, rv);

  // This call initializes NSApplication unless:
  // 1) we're using xre -- NSApp's already been initialized by
  //    MacApplicationDelegate.mm's EnsureUseCocoaDockAPI().
  // 2) an embedding app that uses NSApplicationMain() is running -- NSApp's
  //    already been initialized and its main run loop is already running.
  [NSBundle loadNibFile:
                     [NSString stringWithUTF8String:(const char*)nibPath.get()]
      externalNameTable:
           [NSDictionary dictionaryWithObject:[GeckoNSApplication sharedApplication]
                                       forKey:@"NSOwner"]
               withZone:NSDefaultMallocZone()];

  mDelegate = [[AppShellDelegate alloc] initWithAppShell:this];
  NS_ENSURE_STATE(mDelegate);

  // Add a CFRunLoopSource to the main native run loop.  The source is
  // responsible for interrupting the run loop when Gecko events are ready.

  mCFRunLoop = [[NSRunLoop currentRunLoop] getCFRunLoop];
  NS_ENSURE_STATE(mCFRunLoop);
  ::CFRetain(mCFRunLoop);

  CFRunLoopSourceContext context;
  bzero(&context, sizeof(context));
  // context.version = 0;
  context.info = this;
  context.perform = ProcessGeckoEvents;

  mCFRunLoopSource = ::CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &context);
  NS_ENSURE_STATE(mCFRunLoopSource);

  ::CFRunLoopAddSource(mCFRunLoop, mCFRunLoopSource, kCFRunLoopCommonModes);

  hal::Init();

  if (XRE_IsParentProcess()) {
    ScreenManager& screenManager = ScreenManager::GetSingleton();

    if (gfxPlatform::IsHeadless()) {
      screenManager.SetHelper(mozilla::MakeUnique<HeadlessScreenHelper>());
    } else {
      screenManager.SetHelper(mozilla::MakeUnique<ScreenHelperCocoa>());
    }
  }

  rv = nsBaseAppShell::Init();

  if (!gAppShellMethodsSwizzled) {
    // We should only replace the original terminate: method if we're not
    // running in a Cocoa embedder. See bug 604901.
    if (!mRunningCocoaEmbedded) {
      nsToolkit::SwizzleMethods([NSApplication class], @selector(terminate:),
                                @selector(nsAppShell_NSApplication_terminate:));
    }
    gAppShellMethodsSwizzled = true;
  }

  // The bug that this works around was introduced in OS X 10.10.0
  // and fixed in OS X 10.10.2. Order these version checks so as
  // few as possible will actually end up running.
  if (nsCocoaFeatures::OSXVersionMinor() == 10 &&
      nsCocoaFeatures::OSXVersionBugFix() < 2 &&
      nsCocoaFeatures::OSXVersionMajor() == 10) {
    // Explicitly turn off CGEvent logging.  This works around bug 1092855.
    // If there are already CGEvents in the log, turning off logging also
    // causes those events to be written to disk.  But at this point no
    // CGEvents have yet been processed.  CGEvents are events (usually
    // input events) pulled from the WindowServer.  An option of 0x80000008
    // turns on CGEvent logging.
    CGSSetDebugOptions(0x80000007);
  }

#if !defined(RELEASE_OR_BETA) || defined(DEBUG)
  if (Preferences::GetBool("security.sandbox.mac.track.violations", false)) {
    nsSandboxViolationSink::Start();
  }
#endif

  [localPool release];

  return rv;

  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
}

// ProcessGeckoEvents
//
// The "perform" target of mCFRunLoop, called when mCFRunLoopSource is
// signalled from ScheduleNativeEventCallback.
//
// Arrange for Gecko events to be processed on demand (in response to a call
// to ScheduleNativeEventCallback(), if processing of Gecko events via "native
// methods" hasn't been suspended).  This happens in NativeEventCallback().
//
// protected static
void
nsAppShell::ProcessGeckoEvents(void* aInfo)
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
  AUTO_PROFILER_LABEL("nsAppShell::ProcessGeckoEvents", OTHER);

  nsAppShell* self = static_cast<nsAppShell*> (aInfo);

  if (self->mRunningEventLoop) {
    self->mRunningEventLoop = false;

    // The run loop may be sleeping -- [NSRunLoop runMode:...]
    // won't return until it's given a reason to wake up.  Awaken it by
    // posting a bogus event.  There's no need to make the event
    // presentable.
    //
    // But _don't_ set windowNumber to '-1' -- that can lead to nasty
    // weirdness like bmo bug 397039 (a crash in [NSApp sendEvent:] on one of
    // these fake events, because the -1 has gotten changed into the number
    // of an actual NSWindow object, and that NSWindow object has just been
    // destroyed).  Setting windowNumber to '0' seems to work fine -- this
    // seems to prevent the OS from ever trying to associate our bogus event
    // with a particular NSWindow object.
    [NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined
                                        location:NSMakePoint(0,0)
                                   modifierFlags:0
                                       timestamp:0
                                    windowNumber:0
                                         context:NULL
                                         subtype:kEventSubtypeNone
                                           data1:0
                                           data2:0]
             atStart:NO];
  }

  if (self->mSuspendNativeCount <= 0) {
    ++self->mNativeEventCallbackDepth;
    self->NativeEventCallback();
    --self->mNativeEventCallbackDepth;
  } else {
    self->mSkippedNativeCallback = true;
  }

  // Still needed to avoid crashes on quit in most Mochitests.
  [NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined
                                      location:NSMakePoint(0,0)
                                 modifierFlags:0
                                     timestamp:0
                                  windowNumber:0
                                       context:NULL
                                       subtype:kEventSubtypeNone
                                         data1:0
                                         data2:0]
           atStart:NO];

  // Normally every call to ScheduleNativeEventCallback() results in
  // exactly one call to ProcessGeckoEvents().  So each Release() here
  // normally balances exactly one AddRef() in ScheduleNativeEventCallback().
  // But if Exit() is called just after ScheduleNativeEventCallback(), the
  // corresponding call to ProcessGeckoEvents() will never happen.  We check
  // for this possibility in two different places -- here and in Exit()
  // itself.  If we find here that Exit() has been called (that mTerminated
  // is true), it's because we've been called recursively, that Exit() was
  // called from self->NativeEventCallback() above, and that we're unwinding
  // the recursion.  In this case we'll never be called again, and we balance
  // here any extra calls to ScheduleNativeEventCallback().
  //
  // When ProcessGeckoEvents() is called recursively, it's because of a
  // call to ScheduleNativeEventCallback() from NativeEventCallback().  We
  // balance the "extra" AddRefs here (rather than always in Exit()) in order
  // to ensure that 'self' stays alive until the end of this method.  We also
  // make sure not to finish the balancing until all the recursion has been
  // unwound.
  if (self->mTerminated) {
    int32_t releaseCount = 0;
    if (self->mNativeEventScheduledDepth > self->mNativeEventCallbackDepth) {
      releaseCount = PR_ATOMIC_SET(&self->mNativeEventScheduledDepth,
                                   self->mNativeEventCallbackDepth);
    }
    while (releaseCount-- > self->mNativeEventCallbackDepth)
      self->Release();
  } else {
    // As best we can tell, every call to ProcessGeckoEvents() is triggered
    // by a call to ScheduleNativeEventCallback().  But we've seen a few
    // (non-reproducible) cases of double-frees that *might* have been caused
    // by spontaneous calls (from the OS) to ProcessGeckoEvents().  So we
    // deal with that possibility here.
    if (PR_ATOMIC_DECREMENT(&self->mNativeEventScheduledDepth) < 0) {
      PR_ATOMIC_SET(&self->mNativeEventScheduledDepth, 0);
      NS_WARNING("Spontaneous call to ProcessGeckoEvents()!");
    } else {
      self->Release();
    }
  }

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

// WillTerminate
//
// Called by the AppShellDelegate when an NSApplicationWillTerminate
// notification is posted.  After this method is called, native events should
// no longer be processed.  The NSApplicationWillTerminate notification is
// only posted when [NSApp terminate:] is called, which doesn't happen on a
// "normal" application quit.
//
// public
void
nsAppShell::WillTerminate()
{
  if (mTerminated)
    return;

  // Make sure that the nsAppExitEvent posted by nsAppStartup::Quit() (called
  // from [MacApplicationDelegate applicationShouldTerminate:]) gets run.
  NS_ProcessPendingEvents(NS_GetCurrentThread());

  mTerminated = true;
}

// ScheduleNativeEventCallback
//
// Called (possibly on a non-main thread) when Gecko has an event that
// needs to be processed.  The Gecko event needs to be processed on the
// main thread, so the native run loop must be interrupted.
//
// In nsBaseAppShell.cpp, the mNativeEventPending variable is used to
// ensure that ScheduleNativeEventCallback() is called no more than once
// per call to NativeEventCallback().  ProcessGeckoEvents() can skip its
// call to NativeEventCallback() if processing of Gecko events by native
// means is suspended (using nsIAppShell::SuspendNative()), which will
// suspend calls from nsBaseAppShell::OnDispatchedEvent() to
// ScheduleNativeEventCallback().  But when Gecko event processing by
// native means is resumed (in ResumeNative()), an extra call is made to
// ScheduleNativeEventCallback() (from ResumeNative()).  This triggers
// another call to ProcessGeckoEvents(), which calls NativeEventCallback(),
// and nsBaseAppShell::OnDispatchedEvent() resumes calling
// ScheduleNativeEventCallback().
//
// protected virtual
void
nsAppShell::ScheduleNativeEventCallback()
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  if (mTerminated)
    return;

  // Each AddRef() here is normally balanced by exactly one Release() in
  // ProcessGeckoEvents().  But there are exceptions, for which see
  // ProcessGeckoEvents() and Exit().
  NS_ADDREF_THIS();
  PR_ATOMIC_INCREMENT(&mNativeEventScheduledDepth);

  // This will invoke ProcessGeckoEvents on the main thread.
  ::CFRunLoopSourceSignal(mCFRunLoopSource);
  ::CFRunLoopWakeUp(mCFRunLoop);

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

// Undocumented Cocoa Event Manager function, present in the same form since
// at least OS X 10.6.
extern "C" EventAttributes GetEventAttributes(EventRef inEvent);

// ProcessNextNativeEvent
//
// If aMayWait is false, process a single native event.  If it is true, run
// the native run loop until stopped by ProcessGeckoEvents.
//
// Returns true if more events are waiting in the native event queue.
//
// protected virtual
bool
nsAppShell::ProcessNextNativeEvent(bool aMayWait)
{
  bool moreEvents = false;

  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  bool eventProcessed = false;
  NSString* currentMode = nil;

  if (mTerminated)
    return false;

  bool wasRunningEventLoop = mRunningEventLoop;
  mRunningEventLoop = aMayWait;
  NSDate* waitUntil = nil;
  if (aMayWait)
    waitUntil = [NSDate distantFuture];

  NSRunLoop* currentRunLoop = [NSRunLoop currentRunLoop];

  EventQueueRef currentEventQueue = GetCurrentEventQueue();
  EventTargetRef eventDispatcherTarget = GetEventDispatcherTarget();

  if (aMayWait) {
    mozilla::BackgroundHangMonitor().NotifyWait();
  }

  // Only call -[NSApp sendEvent:] (and indirectly send user-input events to
  // Gecko) if aMayWait is true.  Tbis ensures most calls to -[NSApp
  // sendEvent:] happen under nsAppShell::Run(), at the lowest level of
  // recursion -- thereby making it less likely Gecko will process user-input
  // events in the wrong order or skip some of them.  It also avoids eating
  // too much CPU in nsBaseAppShell::OnProcessNextEvent() (which calls
  // us) -- thereby avoiding the starvation of nsIRunnable events in
  // nsThread::ProcessNextEvent().  For more information see bug 996848.
  do {
    // No autorelease pool is provided here, because OnProcessNextEvent
    // and AfterProcessNextEvent are responsible for maintaining it.
    NS_ASSERTION(mAutoreleasePools && ::CFArrayGetCount(mAutoreleasePools),
                 "No autorelease pool for native event");

    if (aMayWait) {
      currentMode = [currentRunLoop currentMode];
      if (!currentMode)
        currentMode = NSDefaultRunLoopMode;
      NSEvent *nextEvent = [NSApp nextEventMatchingMask:NSAnyEventMask
                                              untilDate:waitUntil
                                                 inMode:currentMode
                                                dequeue:YES];
      if (nextEvent) {
        mozilla::BackgroundHangMonitor().NotifyActivity();
        [NSApp sendEvent:nextEvent];
        eventProcessed = true;
      }
    } else {
      // AcquireFirstMatchingEventInQueue() doesn't spin the (native) event
      // loop, though it does queue up any newly available events from the
      // window server.
      EventRef currentEvent = AcquireFirstMatchingEventInQueue(currentEventQueue, 0, NULL,
                                                               kEventQueueOptionsNone);
      if (!currentEvent) {
        continue;
      }
      EventAttributes attrs = GetEventAttributes(currentEvent);
      UInt32 eventKind = GetEventKind(currentEvent);
      UInt32 eventClass = GetEventClass(currentEvent);
      bool osCocoaEvent =
        ((eventClass == 'appl') || (eventClass == kEventClassAppleEvent) ||
         ((eventClass == 'cgs ') && (eventKind != NSApplicationDefined)));
      // If attrs is kEventAttributeUserEvent or kEventAttributeMonitored
      // (i.e. a user input event), we shouldn't process it here while
      // aMayWait is false.  Likewise if currentEvent will eventually be
      // turned into an OS-defined Cocoa event, or otherwise needs AppKit
      // processing.  Doing otherwise risks doing too much work here, and
      // preventing the event from being properly processed by the AppKit
      // framework.
      if ((attrs != kEventAttributeNone) || osCocoaEvent) {
        // Since we can't process the next event here (while aMayWait is false),
        // we want moreEvents to be false on return.
        eventProcessed = false;
        // This call to ReleaseEvent() matches a call to RetainEvent() in
        // AcquireFirstMatchingEventInQueue() above.
        ReleaseEvent(currentEvent);
        break;
      }
      // This call to RetainEvent() matches a call to ReleaseEvent() in
      // RemoveEventFromQueue() below.
      RetainEvent(currentEvent);
      RemoveEventFromQueue(currentEventQueue, currentEvent);
      SendEventToEventTarget(currentEvent, eventDispatcherTarget);
      // This call to ReleaseEvent() matches a call to RetainEvent() in
      // AcquireFirstMatchingEventInQueue() above.
      ReleaseEvent(currentEvent);
      eventProcessed = true;
    }
  } while (mRunningEventLoop);

  if (eventProcessed) {
    moreEvents =
      (AcquireFirstMatchingEventInQueue(currentEventQueue, 0, NULL,
                                        kEventQueueOptionsNone) != NULL);
  }

  mRunningEventLoop = wasRunningEventLoop;

  NS_OBJC_END_TRY_ABORT_BLOCK;

  if (!moreEvents) {
    nsChildView::UpdateCurrentInputEventCount();
  }

  return moreEvents;
}

// Run
//
// Overrides the base class's Run() method to call [NSApp run] (which spins
// the native run loop until the application quits).  Since (unlike the base
// class's Run() method) we don't process any Gecko events here, they need
// to be processed elsewhere (in NativeEventCallback(), called from
// ProcessGeckoEvents()).
//
// Camino called [NSApp run] on its own (via NSApplicationMain()), and so
// didn't call nsAppShell::Run().
//
// public
NS_IMETHODIMP
nsAppShell::Run(void)
{
  NS_ASSERTION(!mStarted, "nsAppShell::Run() called multiple times");
  if (mStarted || mTerminated)
    return NS_OK;

  mStarted = true;

  if (XRE_IsParentProcess()) {
    AddScreenWakeLockListener();
  }

  // We use the native Gecko event loop in content processes.
  nsresult rv = NS_OK;
  if (XRE_UseNativeEventProcessing()) {
    NS_OBJC_TRY_ABORT([NSApp run]);
  } else {
    rv = nsBaseAppShell::Run();
  }

  if (XRE_IsParentProcess()) {
    RemoveScreenWakeLockListener();
  }

  return rv;
}

NS_IMETHODIMP
nsAppShell::Exit(void)
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;

  // This method is currently called more than once -- from (according to
  // mento) an nsAppExitEvent dispatched by nsAppStartup::Quit() and from an
  // XPCOM shutdown notification that nsBaseAppShell has registered to
  // receive.  So we need to ensure that multiple calls won't break anything.
  // But we should also complain about it (since it isn't quite kosher).
  if (mTerminated) {
    NS_WARNING("nsAppShell::Exit() called redundantly");
    return NS_OK;
  }

  mTerminated = true;

#if !defined(RELEASE_OR_BETA) || defined(DEBUG)
  nsSandboxViolationSink::Stop();
#endif

  // Quoting from Apple's doc on the [NSApplication stop:] method (from their
  // doc on the NSApplication class):  "If this method is invoked during a
  // modal event loop, it will break that loop but not the main event loop."
  // nsAppShell::Exit() shouldn't be called from a modal event loop.  So if
  // it is we complain about it (to users of debug builds) and call [NSApp
  // stop:] one extra time.  (I'm not sure if modal event loops can be nested
  // -- Apple's docs don't say one way or the other.  But the return value
  // of [NSApp _isRunningModal] doesn't change immediately after a call to
  // [NSApp stop:], so we have to assume that one extra call to [NSApp stop:]
  // will do the job.)
  BOOL cocoaModal = [NSApp _isRunningModal];
  NS_ASSERTION(!cocoaModal,
               "Don't call nsAppShell::Exit() from a modal event loop!");
  if (cocoaModal)
    [NSApp stop:nullptr];
  [NSApp stop:nullptr];

  // A call to Exit() just after a call to ScheduleNativeEventCallback()
  // prevents the (normally) matching call to ProcessGeckoEvents() from
  // happening.  If we've been called from ProcessGeckoEvents() (as usually
  // happens), we take care of it there.  But if we have an unbalanced call
  // to ScheduleNativeEventCallback() and ProcessGeckoEvents() isn't on the
  // stack, we need to take care of the problem here.
  if (!mNativeEventCallbackDepth && mNativeEventScheduledDepth) {
    int32_t releaseCount = PR_ATOMIC_SET(&mNativeEventScheduledDepth, 0);
    while (releaseCount-- > 0)
      NS_RELEASE_THIS();
  }

  return nsBaseAppShell::Exit();

  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
}

// OnProcessNextEvent
//
// This nsIThreadObserver method is called prior to processing an event.
// Set up an autorelease pool that will service any autoreleased Cocoa
// objects during this event.  This includes native events processed by
// ProcessNextNativeEvent.  The autorelease pool will be popped by
// AfterProcessNextEvent, it is important for these two methods to be
// tightly coupled.
//
// public
NS_IMETHODIMP
nsAppShell::OnProcessNextEvent(nsIThreadInternal *aThread, bool aMayWait)
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;

  NS_ASSERTION(mAutoreleasePools,
               "No stack on which to store autorelease pool");

  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  ::CFArrayAppendValue(mAutoreleasePools, pool);

  return nsBaseAppShell::OnProcessNextEvent(aThread, aMayWait);

  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
}

// AfterProcessNextEvent
//
// This nsIThreadObserver method is called after event processing is complete.
// The Cocoa implementation cleans up the autorelease pool create by the
// previous OnProcessNextEvent call.
//
// public
NS_IMETHODIMP
nsAppShell::AfterProcessNextEvent(nsIThreadInternal *aThread,
                                  bool aEventWasProcessed)
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;

  CFIndex count = ::CFArrayGetCount(mAutoreleasePools);

  NS_ASSERTION(mAutoreleasePools && count,
               "Processed an event, but there's no autorelease pool?");

  const NSAutoreleasePool* pool = static_cast<const NSAutoreleasePool*>
    (::CFArrayGetValueAtIndex(mAutoreleasePools, count - 1));
  ::CFArrayRemoveValueAtIndex(mAutoreleasePools, count - 1);
  [pool release];

  return nsBaseAppShell::AfterProcessNextEvent(aThread, aEventWasProcessed);

  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
}


// AppShellDelegate implementation


@implementation AppShellDelegate
// initWithAppShell:
//
// Constructs the AppShellDelegate object
- (id)initWithAppShell:(nsAppShell*)aAppShell
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;

  if ((self = [self init])) {
    mAppShell = aAppShell;

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(applicationWillTerminate:)
                                                 name:NSApplicationWillTerminateNotification
                                               object:NSApp];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(applicationDidBecomeActive:)
                                                 name:NSApplicationDidBecomeActiveNotification
                                               object:NSApp];
    [[NSDistributedNotificationCenter defaultCenter] addObserver:self
                                                        selector:@selector(beginMenuTracking:)
                                                            name:@"com.apple.HIToolbox.beginMenuTrackingNotification"
                                                          object:nil];
  }

  return self;

  NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
}

- (void)dealloc
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  [[NSNotificationCenter defaultCenter] removeObserver:self];
  [[NSDistributedNotificationCenter defaultCenter] removeObserver:self];
  [super dealloc];

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

// applicationWillTerminate:
//
// Notify the nsAppShell that native event processing should be discontinued.
- (void)applicationWillTerminate:(NSNotification*)aNotification
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  mAppShell->WillTerminate();

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

// applicationDidBecomeActive
//
// Make sure TextInputHandler::sLastModifierState is updated when we become
// active (since we won't have received [ChildView flagsChanged:] messages
// while inactive).
- (void)applicationDidBecomeActive:(NSNotification*)aNotification
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  // [NSEvent modifierFlags] is valid on every kind of event, so we don't need
  // to worry about getting an NSInternalInconsistencyException here.
  NSEvent* currentEvent = [NSApp currentEvent];
  if (currentEvent) {
    TextInputHandler::sLastModifierState =
      [currentEvent modifierFlags] & NSDeviceIndependentModifierFlagsMask;
  }

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

// beginMenuTracking
//
// Roll up our context menu (if any) when some other app (or the OS) opens
// any sort of menu.  But make sure we don't do this for notifications we
// send ourselves (whose 'sender' will be @"org.mozilla.gecko.PopupWindow").
- (void)beginMenuTracking:(NSNotification*)aNotification
{
  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

  NSString *sender = [aNotification object];
  if (!sender || ![sender isEqualToString:@"org.mozilla.gecko.PopupWindow"]) {
    nsIRollupListener* rollupListener = nsBaseWidget::GetActiveRollupListener();
    nsCOMPtr<nsIWidget> rollupWidget = rollupListener->GetRollupWidget();
    if (rollupWidget)
      rollupListener->Rollup(0, true, nullptr, nullptr);
  }

  NS_OBJC_END_TRY_ABORT_BLOCK;
}

@end

// We hook terminate: in order to make OS-initiated termination work nicely
// with Gecko's shutdown sequence.  (Two ways to trigger OS-initiated
// termination:  1) Quit from the Dock menu; 2) Log out from (or shut down)
// your computer while the browser is active.)
@interface NSApplication (MethodSwizzling)
- (void)nsAppShell_NSApplication_terminate:(id)sender;
@end

@implementation NSApplication (MethodSwizzling)

// Called by the OS after [MacApplicationDelegate applicationShouldTerminate:]
// has returned NSTerminateNow.  This method "subclasses" and replaces the
// OS's original implementation.  The only thing the orginal method does which
// we need is that it posts NSApplicationWillTerminateNotification.  Everything
// else is unneeded (because it's handled elsewhere), or actively interferes
// with Gecko's shutdown sequence.  For example the original terminate: method
// causes the app to exit() inside [NSApp run] (called from nsAppShell::Run()
// above), which means that nothing runs after the call to nsAppStartup::Run()
// in XRE_Main(), which in particular means that ScopedXPCOMStartup's destructor
// and NS_ShutdownXPCOM() never get called.
- (void)nsAppShell_NSApplication_terminate:(id)sender
{
  [[NSNotificationCenter defaultCenter] postNotificationName:NSApplicationWillTerminateNotification
                                                      object:NSApp];
}

@end