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// 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.
#import "base/message_loop/message_pump_mac.h"
#import <Foundation/Foundation.h>
#include <limits>
#include <memory>
#include "base/auto_reset.h"
#include "base/logging.h"
#include "base/mac/call_with_eh_frame.h"
#include "base/mac/scoped_cftyperef.h"
#include "base/macros.h"
#include "base/message_loop/timer_slack.h"
#include "base/run_loop.h"
#include "base/time/time.h"
#include "build_config.h"
#if !defined(OS_IOS)
#import <AppKit/AppKit.h>
#endif // !defined(OS_IOS)
namespace base {
const CFStringRef kMessageLoopExclusiveRunLoopMode =
CFSTR("kMessageLoopExclusiveRunLoopMode");
namespace {
// Mask that determines which modes to use.
enum { kCommonModeMask = 0x1, kAllModesMask = 0xf };
// Modes to use for MessagePumpNSApplication that are considered "safe".
// Currently just common and exclusive modes. Ideally, messages would be pumped
// in all modes, but that interacts badly with app modal dialogs (e.g. NSAlert).
enum { kNSApplicationModalSafeModeMask = 0x3 };
void NoOp(void* info) {
}
constexpr CFTimeInterval kCFTimeIntervalMax =
std::numeric_limits<CFTimeInterval>::max();
#if !defined(OS_IOS)
// Set to true if MessagePumpMac::Create() is called before NSApp is
// initialized. Only accessed from the main thread.
bool g_not_using_cr_app = false;
// The MessagePump controlling [NSApp run].
MessagePumpNSApplication* g_app_pump;
// Various CoreFoundation definitions.
typedef struct __CFRuntimeBase {
uintptr_t _cfisa;
uint8_t _cfinfo[4];
uint32_t _rc;
} CFRuntimeBase;
#if defined(__BIG_ENDIAN__)
#define __CF_BIG_ENDIAN__ 1
#define __CF_LITTLE_ENDIAN__ 0
#endif
#if defined(__LITTLE_ENDIAN__)
#define __CF_LITTLE_ENDIAN__ 1
#define __CF_BIG_ENDIAN__ 0
#endif
#define CF_INFO_BITS (!!(__CF_BIG_ENDIAN__)*3)
#define __CFBitfieldMask(N1, N2) \
((((UInt32)~0UL) << (31UL - (N1) + (N2))) >> (31UL - N1))
#define __CFBitfieldSetValue(V, N1, N2, X) \
((V) = ((V) & ~__CFBitfieldMask(N1, N2)) | \
(((X) << (N2)) & __CFBitfieldMask(N1, N2)))
// Marking timers as invalid at the right time by flipping their valid bit helps
// significantly reduce power use (see the explanation in
// RunDelayedWorkTimer()), however there is no public API for doing so.
// CFRuntime.h states that CFRuntimeBase can change from release to release
// and should not be accessed directly. The last known change of this struct
// occurred in 2008 in CF-476 / 10.5; unfortunately the source for 10.11 and
// 10.12 is not available for inspection at this time.
// CanInvalidateCFRunLoopTimers() will at least prevent us from invalidating
// timers if this function starts flipping the wrong bit on a future OS release.
void __ChromeCFRunLoopTimerSetValid(CFRunLoopTimerRef timer, bool valid) {
__CFBitfieldSetValue(((CFRuntimeBase*)timer)->_cfinfo[CF_INFO_BITS], 3, 3,
valid);
}
#endif // !defined(OS_IOS)
} // namespace
// A scoper for autorelease pools created from message pump run loops.
// Avoids dirtying up the ScopedNSAutoreleasePool interface for the rare
// case where an autorelease pool needs to be passed in.
class MessagePumpScopedAutoreleasePool {
public:
explicit MessagePumpScopedAutoreleasePool(MessagePumpCFRunLoopBase* pump) :
pool_(pump->CreateAutoreleasePool()) {
}
~MessagePumpScopedAutoreleasePool() {
[pool_ drain];
}
private:
NSAutoreleasePool* pool_;
DISALLOW_COPY_AND_ASSIGN(MessagePumpScopedAutoreleasePool);
};
class MessagePumpCFRunLoopBase::ScopedModeEnabler {
public:
ScopedModeEnabler(MessagePumpCFRunLoopBase* owner, int mode_index)
: owner_(owner), mode_index_(mode_index) {
CFRunLoopRef loop = owner_->run_loop_;
CFRunLoopAddTimer(loop, owner_->delayed_work_timer_, mode());
CFRunLoopAddSource(loop, owner_->work_source_, mode());
CFRunLoopAddSource(loop, owner_->idle_work_source_, mode());
CFRunLoopAddSource(loop, owner_->nesting_deferred_work_source_, mode());
CFRunLoopAddObserver(loop, owner_->pre_wait_observer_, mode());
CFRunLoopAddObserver(loop, owner_->pre_source_observer_, mode());
CFRunLoopAddObserver(loop, owner_->enter_exit_observer_, mode());
}
~ScopedModeEnabler() {
CFRunLoopRef loop = owner_->run_loop_;
CFRunLoopRemoveObserver(loop, owner_->enter_exit_observer_, mode());
CFRunLoopRemoveObserver(loop, owner_->pre_source_observer_, mode());
CFRunLoopRemoveObserver(loop, owner_->pre_wait_observer_, mode());
CFRunLoopRemoveSource(loop, owner_->nesting_deferred_work_source_, mode());
CFRunLoopRemoveSource(loop, owner_->idle_work_source_, mode());
CFRunLoopRemoveSource(loop, owner_->work_source_, mode());
CFRunLoopRemoveTimer(loop, owner_->delayed_work_timer_, mode());
}
// This function knows about the AppKit RunLoop modes observed to potentially
// run tasks posted to Chrome's main thread task runner. Some are internal to
// AppKit but must be observed to keep Chrome's UI responsive. Others that may
// be interesting, but are not watched:
// - com.apple.hitoolbox.windows.transitionmode
// - com.apple.hitoolbox.windows.flushmode
const CFStringRef& mode() const {
static const CFStringRef modes[] = {
// The standard Core Foundation "common modes" constant. Must always be
// first in this list to match the value of kCommonModeMask.
kCFRunLoopCommonModes,
// Mode that only sees Chrome work sources.
kMessageLoopExclusiveRunLoopMode,
// Process work when NSMenus are fading out.
CFSTR("com.apple.hitoolbox.windows.windowfadingmode"),
// Process work when AppKit is highlighting an item on the main menubar.
CFSTR("NSUnhighlightMenuRunLoopMode"),
};
static_assert(arraysize(modes) == kNumModes, "mode size mismatch");
static_assert((1 << kNumModes) - 1 == kAllModesMask,
"kAllModesMask not large enough");
return modes[mode_index_];
}
private:
MessagePumpCFRunLoopBase* const owner_; // Weak. Owns this.
const int mode_index_;
DISALLOW_COPY_AND_ASSIGN(ScopedModeEnabler);
};
// Must be called on the run loop thread.
void MessagePumpCFRunLoopBase::Run(Delegate* delegate) {
// nesting_level_ will be incremented in EnterExitRunLoop, so set
// run_nesting_level_ accordingly.
int last_run_nesting_level = run_nesting_level_;
run_nesting_level_ = nesting_level_ + 1;
Delegate* last_delegate = delegate_;
SetDelegate(delegate);
DoRun(delegate);
// Restore the previous state of the object.
SetDelegate(last_delegate);
run_nesting_level_ = last_run_nesting_level;
}
// May be called on any thread.
void MessagePumpCFRunLoopBase::ScheduleWork() {
CFRunLoopSourceSignal(work_source_);
CFRunLoopWakeUp(run_loop_);
}
// Must be called on the run loop thread.
void MessagePumpCFRunLoopBase::ScheduleDelayedWork(
const TimeTicks& delayed_work_time) {
TimeDelta delta = delayed_work_time - TimeTicks::Now();
delayed_work_fire_time_ = CFAbsoluteTimeGetCurrent() + delta.InSecondsF();
// Flip the timer's validation bit just before setting the new fire time. Do
// this now because CFRunLoopTimerSetNextFireDate() likely checks the validity
// of a timer before proceeding to set its fire date. Making the timer valid
// now won't have any side effects (such as a premature firing of the timer)
// because we're only flipping a bit.
//
// Please see the comment in RunDelayedWorkTimer() for more info on the whys
// of invalidation.
ChromeCFRunLoopTimerSetValid(delayed_work_timer_, true);
CFRunLoopTimerSetNextFireDate(delayed_work_timer_, delayed_work_fire_time_);
if (timer_slack_ == TIMER_SLACK_MAXIMUM) {
CFRunLoopTimerSetTolerance(delayed_work_timer_, delta.InSecondsF() * 0.5);
} else {
CFRunLoopTimerSetTolerance(delayed_work_timer_, 0);
}
}
void MessagePumpCFRunLoopBase::SetTimerSlack(TimerSlack timer_slack) {
timer_slack_ = timer_slack;
}
// Must be called on the run loop thread.
MessagePumpCFRunLoopBase::MessagePumpCFRunLoopBase(int initial_mode_mask)
: delegate_(NULL),
delayed_work_fire_time_(kCFTimeIntervalMax),
timer_slack_(base::TIMER_SLACK_NONE),
nesting_level_(0),
run_nesting_level_(0),
deepest_nesting_level_(0),
delegateless_work_(false),
delegateless_idle_work_(false) {
run_loop_ = CFRunLoopGetCurrent();
CFRetain(run_loop_);
// Set a repeating timer with a preposterous firing time and interval. The
// timer will effectively never fire as-is. The firing time will be adjusted
// as needed when ScheduleDelayedWork is called.
CFRunLoopTimerContext timer_context = CFRunLoopTimerContext();
timer_context.info = this;
delayed_work_timer_ = CFRunLoopTimerCreate(NULL, // allocator
kCFTimeIntervalMax, // fire time
kCFTimeIntervalMax, // interval
0, // flags
0, // priority
RunDelayedWorkTimer,
&timer_context);
CFRunLoopSourceContext source_context = CFRunLoopSourceContext();
source_context.info = this;
source_context.perform = RunWorkSource;
work_source_ = CFRunLoopSourceCreate(NULL, // allocator
1, // priority
&source_context);
source_context.perform = RunIdleWorkSource;
idle_work_source_ = CFRunLoopSourceCreate(NULL, // allocator
2, // priority
&source_context);
source_context.perform = RunNestingDeferredWorkSource;
nesting_deferred_work_source_ = CFRunLoopSourceCreate(NULL, // allocator
0, // priority
&source_context);
CFRunLoopObserverContext observer_context = CFRunLoopObserverContext();
observer_context.info = this;
pre_wait_observer_ = CFRunLoopObserverCreate(NULL, // allocator
kCFRunLoopBeforeWaiting,
true, // repeat
0, // priority
PreWaitObserver,
&observer_context);
pre_source_observer_ = CFRunLoopObserverCreate(NULL, // allocator
kCFRunLoopBeforeSources,
true, // repeat
0, // priority
PreSourceObserver,
&observer_context);
enter_exit_observer_ = CFRunLoopObserverCreate(NULL, // allocator
kCFRunLoopEntry |
kCFRunLoopExit,
true, // repeat
0, // priority
EnterExitObserver,
&observer_context);
SetModeMask(initial_mode_mask);
}
// Ideally called on the run loop thread. If other run loops were running
// lower on the run loop thread's stack when this object was created, the
// same number of run loops must be running when this object is destroyed.
MessagePumpCFRunLoopBase::~MessagePumpCFRunLoopBase() {
SetModeMask(0);
CFRelease(enter_exit_observer_);
CFRelease(pre_source_observer_);
CFRelease(pre_wait_observer_);
CFRelease(nesting_deferred_work_source_);
CFRelease(idle_work_source_);
CFRelease(work_source_);
CFRelease(delayed_work_timer_);
CFRelease(run_loop_);
}
void MessagePumpCFRunLoopBase::SetDelegate(Delegate* delegate) {
delegate_ = delegate;
if (delegate) {
// If any work showed up but could not be dispatched for want of a
// delegate, set it up for dispatch again now that a delegate is
// available.
if (delegateless_work_) {
CFRunLoopSourceSignal(work_source_);
delegateless_work_ = false;
}
if (delegateless_idle_work_) {
CFRunLoopSourceSignal(idle_work_source_);
delegateless_idle_work_ = false;
}
}
}
// Base version returns a standard NSAutoreleasePool.
AutoreleasePoolType* MessagePumpCFRunLoopBase::CreateAutoreleasePool() {
return [[NSAutoreleasePool alloc] init];
}
void MessagePumpCFRunLoopBase::SetModeMask(int mode_mask) {
for (size_t i = 0; i < kNumModes; ++i) {
bool enable = mode_mask & (0x1 << i);
if (enable == !enabled_modes_[i]) {
enabled_modes_[i] =
enable ? std::make_unique<ScopedModeEnabler>(this, i) : nullptr;
}
}
}
int MessagePumpCFRunLoopBase::GetModeMask() const {
int mask = 0;
for (size_t i = 0; i < kNumModes; ++i)
mask |= enabled_modes_[i] ? (0x1 << i) : 0;
return mask;
}
#if !defined(OS_IOS)
// This function uses private API to modify a test timer's valid state and
// uses public API to confirm that the private API changed the correct bit.
// static
bool MessagePumpCFRunLoopBase::CanInvalidateCFRunLoopTimers() {
CFRunLoopTimerContext timer_context = CFRunLoopTimerContext();
timer_context.info = nullptr;
ScopedCFTypeRef<CFRunLoopTimerRef> test_timer(
CFRunLoopTimerCreate(NULL, // allocator
kCFTimeIntervalMax, // fire time
kCFTimeIntervalMax, // interval
0, // flags
0, // priority
nullptr, &timer_context));
// Should be valid from the start.
if (!CFRunLoopTimerIsValid(test_timer)) {
return false;
}
// Confirm that the private API can mark the timer invalid.
__ChromeCFRunLoopTimerSetValid(test_timer, false);
if (CFRunLoopTimerIsValid(test_timer)) {
return false;
}
// Confirm that the private API can mark the timer valid.
__ChromeCFRunLoopTimerSetValid(test_timer, true);
return CFRunLoopTimerIsValid(test_timer);
}
#endif // !defined(OS_IOS)
// static
void MessagePumpCFRunLoopBase::ChromeCFRunLoopTimerSetValid(
CFRunLoopTimerRef timer,
bool valid) {
#if !defined(OS_IOS)
static bool can_invalidate_timers = CanInvalidateCFRunLoopTimers();
if (can_invalidate_timers) {
__ChromeCFRunLoopTimerSetValid(timer, valid);
}
#endif // !defined(OS_IOS)
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::RunDelayedWorkTimer(CFRunLoopTimerRef timer,
void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
// The timer won't fire again until it's reset.
self->delayed_work_fire_time_ = kCFTimeIntervalMax;
// The message pump's timer needs to fire at changing and unpredictable
// intervals. Creating a new timer for each firing time is very expensive, so
// the message pump instead uses a repeating timer with a very large repeat
// rate. After each firing of the timer, the run loop sets the timer's next
// firing time to the distant future, essentially pausing the timer until the
// pump sets the next firing time. This is the solution recommended by Apple.
//
// It turns out, however, that scheduling timers is also quite expensive, and
// that every one of the message pump's timer firings incurs two
// reschedulings. The first rescheduling occurs in ScheduleDelayedWork(),
// which sets the desired next firing time. The second comes after exiting
// this method (the timer's callback method), when the run loop sets the
// timer's next firing time to far in the future.
//
// The code in __CFRunLoopDoTimer() inside CFRunLoop.c calls the timer's
// callback, confirms that the timer is valid, and then sets its future
// firing time based on its repeat frequency. Flipping the valid bit here
// causes the __CFRunLoopDoTimer() to skip setting the future firing time.
// Note that there's public API to invalidate a timer but it goes beyond
// flipping the valid bit, making the timer unusable in the future.
//
// ScheduleDelayedWork() flips the valid bit back just before setting the
// timer's new firing time.
ChromeCFRunLoopTimerSetValid(self->delayed_work_timer_, false);
// CFRunLoopTimers fire outside of the priority scheme for CFRunLoopSources.
// In order to establish the proper priority in which work and delayed work
// are processed one for one, the timer used to schedule delayed work must
// signal a CFRunLoopSource used to dispatch both work and delayed work.
CFRunLoopSourceSignal(self->work_source_);
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::RunWorkSource(void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
base::mac::CallWithEHFrame(^{
self->RunWork();
});
}
// Called by MessagePumpCFRunLoopBase::RunWorkSource.
bool MessagePumpCFRunLoopBase::RunWork() {
if (!delegate_) {
// This point can be reached with a NULL delegate_ if Run is not on the
// stack but foreign code is spinning the CFRunLoop. Arrange to come back
// here when a delegate is available.
delegateless_work_ = true;
return false;
}
// The NSApplication-based run loop only drains the autorelease pool at each
// UI event (NSEvent). The autorelease pool is not drained for each
// CFRunLoopSource target that's run. Use a local pool for any autoreleased
// objects if the app is not currently handling a UI event to ensure they're
// released promptly even in the absence of UI events.
MessagePumpScopedAutoreleasePool autorelease_pool(this);
// Call DoWork and DoDelayedWork once, and if something was done, arrange to
// come back here again as long as the loop is still running.
bool did_work = delegate_->DoWork();
bool resignal_work_source = did_work;
TimeTicks next_time;
delegate_->DoDelayedWork(&next_time);
if (!did_work) {
// Determine whether there's more delayed work, and if so, if it needs to
// be done at some point in the future or if it's already time to do it.
// Only do these checks if did_work is false. If did_work is true, this
// function, and therefore any additional delayed work, will get another
// chance to run before the loop goes to sleep.
bool more_delayed_work = !next_time.is_null();
if (more_delayed_work) {
TimeDelta delay = next_time - TimeTicks::Now();
if (delay > TimeDelta()) {
// There's more delayed work to be done in the future.
ScheduleDelayedWork(next_time);
} else {
// There's more delayed work to be done, and its time is in the past.
// Arrange to come back here directly as long as the loop is still
// running.
resignal_work_source = true;
}
}
}
if (resignal_work_source) {
CFRunLoopSourceSignal(work_source_);
}
return resignal_work_source;
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::RunIdleWorkSource(void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
base::mac::CallWithEHFrame(^{
self->RunIdleWork();
});
}
// Called by MessagePumpCFRunLoopBase::RunIdleWorkSource.
bool MessagePumpCFRunLoopBase::RunIdleWork() {
if (!delegate_) {
// This point can be reached with a NULL delegate_ if Run is not on the
// stack but foreign code is spinning the CFRunLoop. Arrange to come back
// here when a delegate is available.
delegateless_idle_work_ = true;
return false;
}
// The NSApplication-based run loop only drains the autorelease pool at each
// UI event (NSEvent). The autorelease pool is not drained for each
// CFRunLoopSource target that's run. Use a local pool for any autoreleased
// objects if the app is not currently handling a UI event to ensure they're
// released promptly even in the absence of UI events.
MessagePumpScopedAutoreleasePool autorelease_pool(this);
// Call DoIdleWork once, and if something was done, arrange to come back here
// again as long as the loop is still running.
bool did_work = delegate_->DoIdleWork();
if (did_work) {
CFRunLoopSourceSignal(idle_work_source_);
}
return did_work;
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::RunNestingDeferredWorkSource(void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
base::mac::CallWithEHFrame(^{
self->RunNestingDeferredWork();
});
}
// Called by MessagePumpCFRunLoopBase::RunNestingDeferredWorkSource.
bool MessagePumpCFRunLoopBase::RunNestingDeferredWork() {
if (!delegate_) {
// This point can be reached with a NULL delegate_ if Run is not on the
// stack but foreign code is spinning the CFRunLoop. There's no sense in
// attempting to do any work or signalling the work sources because
// without a delegate, work is not possible.
return false;
}
// Immediately try work in priority order.
if (!RunWork()) {
if (!RunIdleWork()) {
return false;
}
} else {
// Work was done. Arrange for the loop to try non-nestable idle work on
// a subsequent pass.
CFRunLoopSourceSignal(idle_work_source_);
}
return true;
}
// Called before the run loop goes to sleep or exits, or processes sources.
void MessagePumpCFRunLoopBase::MaybeScheduleNestingDeferredWork() {
// deepest_nesting_level_ is set as run loops are entered. If the deepest
// level encountered is deeper than the current level, a nested loop
// (relative to the current level) ran since the last time nesting-deferred
// work was scheduled. When that situation is encountered, schedule
// nesting-deferred work in case any work was deferred because nested work
// was disallowed.
if (deepest_nesting_level_ > nesting_level_) {
deepest_nesting_level_ = nesting_level_;
CFRunLoopSourceSignal(nesting_deferred_work_source_);
}
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::PreWaitObserver(CFRunLoopObserverRef observer,
CFRunLoopActivity activity,
void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
base::mac::CallWithEHFrame(^{
// Attempt to do some idle work before going to sleep.
self->RunIdleWork();
// The run loop is about to go to sleep. If any of the work done since it
// started or woke up resulted in a nested run loop running,
// nesting-deferred work may have accumulated. Schedule it for processing
// if appropriate.
self->MaybeScheduleNestingDeferredWork();
});
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::PreSourceObserver(CFRunLoopObserverRef observer,
CFRunLoopActivity activity,
void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
// The run loop has reached the top of the loop and is about to begin
// processing sources. If the last iteration of the loop at this nesting
// level did not sleep or exit, nesting-deferred work may have accumulated
// if a nested loop ran. Schedule nesting-deferred work for processing if
// appropriate.
base::mac::CallWithEHFrame(^{
self->MaybeScheduleNestingDeferredWork();
});
}
// Called from the run loop.
// static
void MessagePumpCFRunLoopBase::EnterExitObserver(CFRunLoopObserverRef observer,
CFRunLoopActivity activity,
void* info) {
MessagePumpCFRunLoopBase* self = static_cast<MessagePumpCFRunLoopBase*>(info);
switch (activity) {
case kCFRunLoopEntry:
++self->nesting_level_;
if (self->nesting_level_ > self->deepest_nesting_level_) {
self->deepest_nesting_level_ = self->nesting_level_;
}
break;
case kCFRunLoopExit:
// Not all run loops go to sleep. If a run loop is stopped before it
// goes to sleep due to a CFRunLoopStop call, or if the timeout passed
// to CFRunLoopRunInMode expires, the run loop may proceed directly from
// handling sources to exiting without any sleep. This most commonly
// occurs when CFRunLoopRunInMode is passed a timeout of 0, causing it
// to make a single pass through the loop and exit without sleep. Some
// native loops use CFRunLoop in this way. Because PreWaitObserver will
// not be called in these case, MaybeScheduleNestingDeferredWork needs
// to be called here, as the run loop exits.
//
// MaybeScheduleNestingDeferredWork consults self->nesting_level_
// to determine whether to schedule nesting-deferred work. It expects
// the nesting level to be set to the depth of the loop that is going
// to sleep or exiting. It must be called before decrementing the
// value so that the value still corresponds to the level of the exiting
// loop.
base::mac::CallWithEHFrame(^{
self->MaybeScheduleNestingDeferredWork();
});
--self->nesting_level_;
break;
default:
break;
}
base::mac::CallWithEHFrame(^{
self->EnterExitRunLoop(activity);
});
}
// Called by MessagePumpCFRunLoopBase::EnterExitRunLoop. The default
// implementation is a no-op.
void MessagePumpCFRunLoopBase::EnterExitRunLoop(CFRunLoopActivity activity) {
}
MessagePumpCFRunLoop::MessagePumpCFRunLoop()
: MessagePumpCFRunLoopBase(kCommonModeMask), quit_pending_(false) {}
MessagePumpCFRunLoop::~MessagePumpCFRunLoop() {}
// Called by MessagePumpCFRunLoopBase::DoRun. If other CFRunLoopRun loops were
// running lower on the run loop thread's stack when this object was created,
// the same number of CFRunLoopRun loops must be running for the outermost call
// to Run. Run/DoRun are reentrant after that point.
void MessagePumpCFRunLoop::DoRun(Delegate* delegate) {
// This is completely identical to calling CFRunLoopRun(), except autorelease
// pool management is introduced.
int result;
do {
MessagePumpScopedAutoreleasePool autorelease_pool(this);
result = CFRunLoopRunInMode(kCFRunLoopDefaultMode,
kCFTimeIntervalMax,
false);
} while (result != kCFRunLoopRunStopped && result != kCFRunLoopRunFinished);
}
// Must be called on the run loop thread.
void MessagePumpCFRunLoop::Quit() {
// Stop the innermost run loop managed by this MessagePumpCFRunLoop object.
if (nesting_level() == run_nesting_level()) {
// This object is running the innermost loop, just stop it.
CFRunLoopStop(run_loop());
} else {
// There's another loop running inside the loop managed by this object.
// In other words, someone else called CFRunLoopRunInMode on the same
// thread, deeper on the stack than the deepest Run call. Don't preempt
// other run loops, just mark this object to quit the innermost Run as
// soon as the other inner loops not managed by Run are done.
quit_pending_ = true;
}
}
// Called by MessagePumpCFRunLoopBase::EnterExitObserver.
void MessagePumpCFRunLoop::EnterExitRunLoop(CFRunLoopActivity activity) {
if (activity == kCFRunLoopExit &&
nesting_level() == run_nesting_level() &&
quit_pending_) {
// Quit was called while loops other than those managed by this object
// were running further inside a run loop managed by this object. Now
// that all unmanaged inner run loops are gone, stop the loop running
// just inside Run.
CFRunLoopStop(run_loop());
quit_pending_ = false;
}
}
MessagePumpNSRunLoop::MessagePumpNSRunLoop()
: MessagePumpCFRunLoopBase(kCommonModeMask), keep_running_(true) {
CFRunLoopSourceContext source_context = CFRunLoopSourceContext();
source_context.perform = NoOp;
quit_source_ = CFRunLoopSourceCreate(NULL, // allocator
0, // priority
&source_context);
CFRunLoopAddSource(run_loop(), quit_source_, kCFRunLoopCommonModes);
}
MessagePumpNSRunLoop::~MessagePumpNSRunLoop() {
CFRunLoopRemoveSource(run_loop(), quit_source_, kCFRunLoopCommonModes);
CFRelease(quit_source_);
}
void MessagePumpNSRunLoop::DoRun(Delegate* delegate) {
AutoReset<bool> auto_reset_keep_running(&keep_running_, true);
while (keep_running_) {
// NSRunLoop manages autorelease pools itself.
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
beforeDate:[NSDate distantFuture]];
}
}
void MessagePumpNSRunLoop::Quit() {
keep_running_ = false;
CFRunLoopSourceSignal(quit_source_);
CFRunLoopWakeUp(run_loop());
}
#if defined(OS_IOS)
MessagePumpUIApplication::MessagePumpUIApplication()
: MessagePumpCFRunLoopBase(kCommonModeMask), run_loop_(NULL) {}
MessagePumpUIApplication::~MessagePumpUIApplication() {}
void MessagePumpUIApplication::DoRun(Delegate* delegate) {
NOTREACHED();
}
void MessagePumpUIApplication::Quit() {
NOTREACHED();
}
void MessagePumpUIApplication::Attach(Delegate* delegate) {
DCHECK(!run_loop_);
run_loop_ = new RunLoop();
CHECK(run_loop_->BeforeRun());
SetDelegate(delegate);
}
#else
ScopedPumpMessagesInPrivateModes::ScopedPumpMessagesInPrivateModes() {
DCHECK(g_app_pump);
DCHECK_EQ(kNSApplicationModalSafeModeMask, g_app_pump->GetModeMask());
// Pumping events in private runloop modes is known to interact badly with
// app modal windows like NSAlert.
if (![NSApp modalWindow])
g_app_pump->SetModeMask(kAllModesMask);
}
ScopedPumpMessagesInPrivateModes::~ScopedPumpMessagesInPrivateModes() {
DCHECK(g_app_pump);
g_app_pump->SetModeMask(kNSApplicationModalSafeModeMask);
}
int ScopedPumpMessagesInPrivateModes::GetModeMaskForTest() {
return g_app_pump ? g_app_pump->GetModeMask() : -1;
}
MessagePumpNSApplication::MessagePumpNSApplication()
: MessagePumpCFRunLoopBase(kNSApplicationModalSafeModeMask),
keep_running_(true),
running_own_loop_(false) {
DCHECK_EQ(nullptr, g_app_pump);
g_app_pump = this;
}
MessagePumpNSApplication::~MessagePumpNSApplication() {
DCHECK_EQ(this, g_app_pump);
g_app_pump = nullptr;
}
void MessagePumpNSApplication::DoRun(Delegate* delegate) {
AutoReset<bool> auto_reset_keep_running(&keep_running_, true);
bool last_running_own_loop_ = running_own_loop_;
// NSApp must be initialized by calling:
// [{some class which implements CrAppProtocol} sharedApplication]
// Most likely candidates are CrApplication or BrowserCrApplication.
// These can be initialized from C++ code by calling
// RegisterCrApp() or RegisterBrowserCrApp().
CHECK(NSApp);
if (![NSApp isRunning]) {
running_own_loop_ = false;
// NSApplication manages autorelease pools itself when run this way.
[NSApp run];
} else {
running_own_loop_ = true;
NSDate* distant_future = [NSDate distantFuture];
while (keep_running_) {
MessagePumpScopedAutoreleasePool autorelease_pool(this);
NSEvent* event = [NSApp nextEventMatchingMask:NSAnyEventMask
untilDate:distant_future
inMode:NSDefaultRunLoopMode
dequeue:YES];
if (event) {
[NSApp sendEvent:event];
}
}
}
running_own_loop_ = last_running_own_loop_;
}
void MessagePumpNSApplication::Quit() {
if (!running_own_loop_) {
[[NSApplication sharedApplication] stop:nil];
} else {
keep_running_ = false;
}
// Send a fake event to wake the loop up.
[NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined
location:NSZeroPoint
modifierFlags:0
timestamp:0
windowNumber:0
context:NULL
subtype:0
data1:0
data2:0]
atStart:NO];
}
MessagePumpCrApplication::MessagePumpCrApplication() {
}
MessagePumpCrApplication::~MessagePumpCrApplication() {
}
// Prevents an autorelease pool from being created if the app is in the midst of
// handling a UI event because various parts of AppKit depend on objects that
// are created while handling a UI event to be autoreleased in the event loop.
// An example of this is NSWindowController. When a window with a window
// controller is closed it goes through a stack like this:
// (Several stack frames elided for clarity)
//
// #0 [NSWindowController autorelease]
// #1 DoAClose
// #2 MessagePumpCFRunLoopBase::DoWork()
// #3 [NSRunLoop run]
// #4 [NSButton performClick:]
// #5 [NSWindow sendEvent:]
// #6 [NSApp sendEvent:]
// #7 [NSApp run]
//
// -performClick: spins a nested run loop. If the pool created in DoWork was a
// standard NSAutoreleasePool, it would release the objects that were
// autoreleased into it once DoWork released it. This would cause the window
// controller, which autoreleased itself in frame #0, to release itself, and
// possibly free itself. Unfortunately this window controller controls the
// window in frame #5. When the stack is unwound to frame #5, the window would
// no longer exists and crashes may occur. Apple gets around this by never
// releasing the pool it creates in frame #4, and letting frame #7 clean it up
// when it cleans up the pool that wraps frame #7. When an autorelease pool is
// released it releases all other pools that were created after it on the
// autorelease pool stack.
//
// CrApplication is responsible for setting handlingSendEvent to true just
// before it sends the event through the event handling mechanism, and
// returning it to its previous value once the event has been sent.
AutoreleasePoolType* MessagePumpCrApplication::CreateAutoreleasePool() {
if (MessagePumpMac::IsHandlingSendEvent())
return nil;
return MessagePumpNSApplication::CreateAutoreleasePool();
}
// static
bool MessagePumpMac::UsingCrApp() {
DCHECK([NSThread isMainThread]);
// If NSApp is still not initialized, then the subclass used cannot
// be determined.
DCHECK(NSApp);
// The pump was created using MessagePumpNSApplication.
if (g_not_using_cr_app)
return false;
return [NSApp conformsToProtocol:@protocol(CrAppProtocol)];
}
// static
bool MessagePumpMac::IsHandlingSendEvent() {
DCHECK([NSApp conformsToProtocol:@protocol(CrAppProtocol)]);
NSObject<CrAppProtocol>* app = static_cast<NSObject<CrAppProtocol>*>(NSApp);
return [app isHandlingSendEvent];
}
#endif // !defined(OS_IOS)
// static
std::unique_ptr<MessagePump> MessagePumpMac::Create() {
if ([NSThread isMainThread]) {
#if defined(OS_IOS)
return std::make_unique<MessagePumpUIApplication>();
#else
if ([NSApp conformsToProtocol:@protocol(CrAppProtocol)])
return std::make_unique<MessagePumpCrApplication>();
// The main-thread MessagePump implementations REQUIRE an NSApp.
// Executables which have specific requirements for their
// NSApplication subclass should initialize appropriately before
// creating an event loop.
[NSApplication sharedApplication];
g_not_using_cr_app = true;
return std::make_unique<MessagePumpNSApplication>();
#endif
}
return std::make_unique<MessagePumpNSRunLoop>();
}
} // namespace base