1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/threads/nsTimerImpl.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,759 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "nsTimerImpl.h"
1.11 +#include "TimerThread.h"
1.12 +#include "nsAutoPtr.h"
1.13 +#include "nsThreadManager.h"
1.14 +#include "nsThreadUtils.h"
1.15 +#include "plarena.h"
1.16 +#include "pratom.h"
1.17 +#include "GeckoProfiler.h"
1.18 +#include "mozilla/Atomics.h"
1.19 +
1.20 +using mozilla::Atomic;
1.21 +using mozilla::TimeDuration;
1.22 +using mozilla::TimeStamp;
1.23 +
1.24 +static Atomic<int32_t> gGenerator;
1.25 +static TimerThread* gThread = nullptr;
1.26 +
1.27 +#ifdef DEBUG_TIMERS
1.28 +
1.29 +PRLogModuleInfo*
1.30 +GetTimerLog()
1.31 +{
1.32 + static PRLogModuleInfo *sLog;
1.33 + if (!sLog)
1.34 + sLog = PR_NewLogModule("nsTimerImpl");
1.35 + return sLog;
1.36 +}
1.37 +
1.38 +#include <math.h>
1.39 +
1.40 +double nsTimerImpl::sDeltaSumSquared = 0;
1.41 +double nsTimerImpl::sDeltaSum = 0;
1.42 +double nsTimerImpl::sDeltaNum = 0;
1.43 +
1.44 +static void
1.45 +myNS_MeanAndStdDev(double n, double sumOfValues, double sumOfSquaredValues,
1.46 + double *meanResult, double *stdDevResult)
1.47 +{
1.48 + double mean = 0.0, var = 0.0, stdDev = 0.0;
1.49 + if (n > 0.0 && sumOfValues >= 0) {
1.50 + mean = sumOfValues / n;
1.51 + double temp = (n * sumOfSquaredValues) - (sumOfValues * sumOfValues);
1.52 + if (temp < 0.0 || n <= 1)
1.53 + var = 0.0;
1.54 + else
1.55 + var = temp / (n * (n - 1));
1.56 + // for some reason, Windows says sqrt(0.0) is "-1.#J" (?!) so do this:
1.57 + stdDev = var != 0.0 ? sqrt(var) : 0.0;
1.58 + }
1.59 + *meanResult = mean;
1.60 + *stdDevResult = stdDev;
1.61 +}
1.62 +#endif
1.63 +
1.64 +namespace {
1.65 +
1.66 +// TimerEventAllocator is a thread-safe allocator used only for nsTimerEvents.
1.67 +// It's needed to avoid contention over the default allocator lock when
1.68 +// firing timer events (see bug 733277). The thread-safety is required because
1.69 +// nsTimerEvent objects are allocated on the timer thread, and freed on another
1.70 +// thread. Because TimerEventAllocator has its own lock, contention over that
1.71 +// lock is limited to the allocation and deallocation of nsTimerEvent objects.
1.72 +//
1.73 +// Because this allocator is layered over PLArenaPool, it never shrinks -- even
1.74 +// "freed" nsTimerEvents aren't truly freed, they're just put onto a free-list
1.75 +// for later recycling. So the amount of memory consumed will always be equal
1.76 +// to the high-water mark consumption. But nsTimerEvents are small and it's
1.77 +// unusual to have more than a few hundred of them, so this shouldn't be a
1.78 +// problem in practice.
1.79 +
1.80 +class TimerEventAllocator
1.81 +{
1.82 +private:
1.83 + struct FreeEntry {
1.84 + FreeEntry* mNext;
1.85 + };
1.86 +
1.87 + PLArenaPool mPool;
1.88 + FreeEntry* mFirstFree;
1.89 + mozilla::Monitor mMonitor;
1.90 +
1.91 +public:
1.92 + TimerEventAllocator()
1.93 + : mFirstFree(nullptr),
1.94 + mMonitor("TimerEventAllocator")
1.95 + {
1.96 + PL_InitArenaPool(&mPool, "TimerEventPool", 4096, /* align = */ 0);
1.97 + }
1.98 +
1.99 + ~TimerEventAllocator()
1.100 + {
1.101 + PL_FinishArenaPool(&mPool);
1.102 + }
1.103 +
1.104 + void* Alloc(size_t aSize);
1.105 + void Free(void* aPtr);
1.106 +};
1.107 +
1.108 +} // anonymous namespace
1.109 +
1.110 +class nsTimerEvent : public nsRunnable {
1.111 +public:
1.112 + NS_IMETHOD Run();
1.113 +
1.114 + nsTimerEvent()
1.115 + : mTimer()
1.116 + , mGeneration(0)
1.117 + {
1.118 + MOZ_COUNT_CTOR(nsTimerEvent);
1.119 +
1.120 + MOZ_ASSERT(gThread->IsOnTimerThread(),
1.121 + "nsTimer must always be allocated on the timer thread");
1.122 +
1.123 + sAllocatorUsers++;
1.124 + }
1.125 +
1.126 +#ifdef DEBUG_TIMERS
1.127 + TimeStamp mInitTime;
1.128 +#endif
1.129 +
1.130 + static void Init();
1.131 + static void Shutdown();
1.132 + static void DeleteAllocatorIfNeeded();
1.133 +
1.134 + static void* operator new(size_t size) CPP_THROW_NEW {
1.135 + return sAllocator->Alloc(size);
1.136 + }
1.137 + void operator delete(void* p) {
1.138 + sAllocator->Free(p);
1.139 + DeleteAllocatorIfNeeded();
1.140 + }
1.141 +
1.142 + already_AddRefed<nsTimerImpl> ForgetTimer()
1.143 + {
1.144 + return mTimer.forget();
1.145 + }
1.146 +
1.147 + void SetTimer(already_AddRefed<nsTimerImpl> aTimer)
1.148 + {
1.149 + mTimer = aTimer;
1.150 + mGeneration = mTimer->GetGeneration();
1.151 + }
1.152 +
1.153 +private:
1.154 + ~nsTimerEvent() {
1.155 + MOZ_COUNT_DTOR(nsTimerEvent);
1.156 +
1.157 + MOZ_ASSERT(!sCanDeleteAllocator || sAllocatorUsers > 0,
1.158 + "This will result in us attempting to deallocate the nsTimerEvent allocator twice");
1.159 + sAllocatorUsers--;
1.160 + }
1.161 +
1.162 + nsRefPtr<nsTimerImpl> mTimer;
1.163 + int32_t mGeneration;
1.164 +
1.165 + static TimerEventAllocator* sAllocator;
1.166 + static Atomic<int32_t> sAllocatorUsers;
1.167 + static bool sCanDeleteAllocator;
1.168 +};
1.169 +
1.170 +TimerEventAllocator* nsTimerEvent::sAllocator = nullptr;
1.171 +Atomic<int32_t> nsTimerEvent::sAllocatorUsers;
1.172 +bool nsTimerEvent::sCanDeleteAllocator = false;
1.173 +
1.174 +namespace {
1.175 +
1.176 +void* TimerEventAllocator::Alloc(size_t aSize)
1.177 +{
1.178 + MOZ_ASSERT(aSize == sizeof(nsTimerEvent));
1.179 +
1.180 + mozilla::MonitorAutoLock lock(mMonitor);
1.181 +
1.182 + void* p;
1.183 + if (mFirstFree) {
1.184 + p = mFirstFree;
1.185 + mFirstFree = mFirstFree->mNext;
1.186 + }
1.187 + else {
1.188 + PL_ARENA_ALLOCATE(p, &mPool, aSize);
1.189 + if (!p)
1.190 + return nullptr;
1.191 + }
1.192 +
1.193 + return p;
1.194 +}
1.195 +
1.196 +void TimerEventAllocator::Free(void* aPtr)
1.197 +{
1.198 + mozilla::MonitorAutoLock lock(mMonitor);
1.199 +
1.200 + FreeEntry* entry = reinterpret_cast<FreeEntry*>(aPtr);
1.201 +
1.202 + entry->mNext = mFirstFree;
1.203 + mFirstFree = entry;
1.204 +}
1.205 +
1.206 +} // anonymous namespace
1.207 +
1.208 +NS_IMPL_QUERY_INTERFACE(nsTimerImpl, nsITimer)
1.209 +NS_IMPL_ADDREF(nsTimerImpl)
1.210 +
1.211 +NS_IMETHODIMP_(MozExternalRefCountType) nsTimerImpl::Release(void)
1.212 +{
1.213 + nsrefcnt count;
1.214 +
1.215 + MOZ_ASSERT(int32_t(mRefCnt) > 0, "dup release");
1.216 + count = --mRefCnt;
1.217 + NS_LOG_RELEASE(this, count, "nsTimerImpl");
1.218 + if (count == 0) {
1.219 + mRefCnt = 1; /* stabilize */
1.220 +
1.221 + /* enable this to find non-threadsafe destructors: */
1.222 + /* NS_ASSERT_OWNINGTHREAD(nsTimerImpl); */
1.223 + delete this;
1.224 + return 0;
1.225 + }
1.226 +
1.227 + // If only one reference remains, and mArmed is set, then the ref must be
1.228 + // from the TimerThread::mTimers array, so we Cancel this timer to remove
1.229 + // the mTimers element, and return 0 if Cancel in fact disarmed the timer.
1.230 + //
1.231 + // We use an inlined version of nsTimerImpl::Cancel here to check for the
1.232 + // NS_ERROR_NOT_AVAILABLE code returned by gThread->RemoveTimer when this
1.233 + // timer is not found in the mTimers array -- i.e., when the timer was not
1.234 + // in fact armed once we acquired TimerThread::mLock, in spite of mArmed
1.235 + // being true here. That can happen if the armed timer is being fired by
1.236 + // TimerThread::Run as we race and test mArmed just before it is cleared by
1.237 + // the timer thread. If the RemoveTimer call below doesn't find this timer
1.238 + // in the mTimers array, then the last ref to this timer is held manually
1.239 + // and temporarily by the TimerThread, so we should fall through to the
1.240 + // final return and return 1, not 0.
1.241 + //
1.242 + // The original version of this thread-based timer code kept weak refs from
1.243 + // TimerThread::mTimers, removing this timer's weak ref in the destructor,
1.244 + // but that leads to double-destructions in the race described above, and
1.245 + // adding mArmed doesn't help, because destructors can't be deferred, once
1.246 + // begun. But by combining reference-counting and a specialized Release
1.247 + // method with "is this timer still in the mTimers array once we acquire
1.248 + // the TimerThread's lock" testing, we defer destruction until we're sure
1.249 + // that only one thread has its hot little hands on this timer.
1.250 + //
1.251 + // Note that both approaches preclude a timer creator, and everyone else
1.252 + // except the TimerThread who might have a strong ref, from dropping all
1.253 + // their strong refs without implicitly canceling the timer. Timers need
1.254 + // non-mTimers-element strong refs to stay alive.
1.255 +
1.256 + if (count == 1 && mArmed) {
1.257 + mCanceled = true;
1.258 +
1.259 + MOZ_ASSERT(gThread, "Armed timer exists after the thread timer stopped.");
1.260 + if (NS_SUCCEEDED(gThread->RemoveTimer(this)))
1.261 + return 0;
1.262 + }
1.263 +
1.264 + return count;
1.265 +}
1.266 +
1.267 +nsTimerImpl::nsTimerImpl() :
1.268 + mClosure(nullptr),
1.269 + mCallbackType(CALLBACK_TYPE_UNKNOWN),
1.270 + mFiring(false),
1.271 + mArmed(false),
1.272 + mCanceled(false),
1.273 + mGeneration(0),
1.274 + mDelay(0)
1.275 +{
1.276 + // XXXbsmedberg: shouldn't this be in Init()?
1.277 + mEventTarget = static_cast<nsIEventTarget*>(NS_GetCurrentThread());
1.278 +
1.279 + mCallback.c = nullptr;
1.280 +}
1.281 +
1.282 +nsTimerImpl::~nsTimerImpl()
1.283 +{
1.284 + ReleaseCallback();
1.285 +}
1.286 +
1.287 +//static
1.288 +nsresult
1.289 +nsTimerImpl::Startup()
1.290 +{
1.291 + nsresult rv;
1.292 +
1.293 + nsTimerEvent::Init();
1.294 +
1.295 + gThread = new TimerThread();
1.296 + if (!gThread) return NS_ERROR_OUT_OF_MEMORY;
1.297 +
1.298 + NS_ADDREF(gThread);
1.299 + rv = gThread->InitLocks();
1.300 +
1.301 + if (NS_FAILED(rv)) {
1.302 + NS_RELEASE(gThread);
1.303 + }
1.304 +
1.305 + return rv;
1.306 +}
1.307 +
1.308 +void nsTimerImpl::Shutdown()
1.309 +{
1.310 +#ifdef DEBUG_TIMERS
1.311 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.312 + double mean = 0, stddev = 0;
1.313 + myNS_MeanAndStdDev(sDeltaNum, sDeltaSum, sDeltaSumSquared, &mean, &stddev);
1.314 +
1.315 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("sDeltaNum = %f, sDeltaSum = %f, sDeltaSumSquared = %f\n", sDeltaNum, sDeltaSum, sDeltaSumSquared));
1.316 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("mean: %fms, stddev: %fms\n", mean, stddev));
1.317 + }
1.318 +#endif
1.319 +
1.320 + if (!gThread)
1.321 + return;
1.322 +
1.323 + gThread->Shutdown();
1.324 + NS_RELEASE(gThread);
1.325 +
1.326 + nsTimerEvent::Shutdown();
1.327 +}
1.328 +
1.329 +
1.330 +nsresult nsTimerImpl::InitCommon(uint32_t aType, uint32_t aDelay)
1.331 +{
1.332 + nsresult rv;
1.333 +
1.334 + if (NS_WARN_IF(!gThread))
1.335 + return NS_ERROR_NOT_INITIALIZED;
1.336 + if (!mEventTarget) {
1.337 + NS_ERROR("mEventTarget is NULL");
1.338 + return NS_ERROR_NOT_INITIALIZED;
1.339 + }
1.340 +
1.341 + rv = gThread->Init();
1.342 + if (NS_WARN_IF(NS_FAILED(rv)))
1.343 + return rv;
1.344 +
1.345 + /**
1.346 + * In case of re-Init, both with and without a preceding Cancel, clear the
1.347 + * mCanceled flag and assign a new mGeneration. But first, remove any armed
1.348 + * timer from the timer thread's list.
1.349 + *
1.350 + * If we are racing with the timer thread to remove this timer and we lose,
1.351 + * the RemoveTimer call made here will fail to find this timer in the timer
1.352 + * thread's list, and will return false harmlessly. We test mArmed here to
1.353 + * avoid the small overhead in RemoveTimer of locking the timer thread and
1.354 + * checking its list for this timer. It's safe to test mArmed even though
1.355 + * it might be cleared on another thread in the next cycle (or even already
1.356 + * be cleared by another CPU whose store hasn't reached our CPU's cache),
1.357 + * because RemoveTimer is idempotent.
1.358 + */
1.359 + if (mArmed)
1.360 + gThread->RemoveTimer(this);
1.361 + mCanceled = false;
1.362 + mTimeout = TimeStamp();
1.363 + mGeneration = gGenerator++;
1.364 +
1.365 + mType = (uint8_t)aType;
1.366 + SetDelayInternal(aDelay);
1.367 +
1.368 + return gThread->AddTimer(this);
1.369 +}
1.370 +
1.371 +NS_IMETHODIMP nsTimerImpl::InitWithFuncCallback(nsTimerCallbackFunc aFunc,
1.372 + void *aClosure,
1.373 + uint32_t aDelay,
1.374 + uint32_t aType)
1.375 +{
1.376 + if (NS_WARN_IF(!aFunc))
1.377 + return NS_ERROR_INVALID_ARG;
1.378 +
1.379 + ReleaseCallback();
1.380 + mCallbackType = CALLBACK_TYPE_FUNC;
1.381 + mCallback.c = aFunc;
1.382 + mClosure = aClosure;
1.383 +
1.384 + return InitCommon(aType, aDelay);
1.385 +}
1.386 +
1.387 +NS_IMETHODIMP nsTimerImpl::InitWithCallback(nsITimerCallback *aCallback,
1.388 + uint32_t aDelay,
1.389 + uint32_t aType)
1.390 +{
1.391 + if (NS_WARN_IF(!aCallback))
1.392 + return NS_ERROR_INVALID_ARG;
1.393 +
1.394 + ReleaseCallback();
1.395 + mCallbackType = CALLBACK_TYPE_INTERFACE;
1.396 + mCallback.i = aCallback;
1.397 + NS_ADDREF(mCallback.i);
1.398 +
1.399 + return InitCommon(aType, aDelay);
1.400 +}
1.401 +
1.402 +NS_IMETHODIMP nsTimerImpl::Init(nsIObserver *aObserver,
1.403 + uint32_t aDelay,
1.404 + uint32_t aType)
1.405 +{
1.406 + if (NS_WARN_IF(!aObserver))
1.407 + return NS_ERROR_INVALID_ARG;
1.408 +
1.409 + ReleaseCallback();
1.410 + mCallbackType = CALLBACK_TYPE_OBSERVER;
1.411 + mCallback.o = aObserver;
1.412 + NS_ADDREF(mCallback.o);
1.413 +
1.414 + return InitCommon(aType, aDelay);
1.415 +}
1.416 +
1.417 +NS_IMETHODIMP nsTimerImpl::Cancel()
1.418 +{
1.419 + mCanceled = true;
1.420 +
1.421 + if (gThread)
1.422 + gThread->RemoveTimer(this);
1.423 +
1.424 + ReleaseCallback();
1.425 +
1.426 + return NS_OK;
1.427 +}
1.428 +
1.429 +NS_IMETHODIMP nsTimerImpl::SetDelay(uint32_t aDelay)
1.430 +{
1.431 + if (mCallbackType == CALLBACK_TYPE_UNKNOWN && mType == TYPE_ONE_SHOT) {
1.432 + // This may happen if someone tries to re-use a one-shot timer
1.433 + // by re-setting delay instead of reinitializing the timer.
1.434 + NS_ERROR("nsITimer->SetDelay() called when the "
1.435 + "one-shot timer is not set up.");
1.436 + return NS_ERROR_NOT_INITIALIZED;
1.437 + }
1.438 +
1.439 + // If we're already repeating precisely, update mTimeout now so that the
1.440 + // new delay takes effect in the future.
1.441 + if (!mTimeout.IsNull() && mType == TYPE_REPEATING_PRECISE)
1.442 + mTimeout = TimeStamp::Now();
1.443 +
1.444 + SetDelayInternal(aDelay);
1.445 +
1.446 + if (!mFiring && gThread)
1.447 + gThread->TimerDelayChanged(this);
1.448 +
1.449 + return NS_OK;
1.450 +}
1.451 +
1.452 +NS_IMETHODIMP nsTimerImpl::GetDelay(uint32_t* aDelay)
1.453 +{
1.454 + *aDelay = mDelay;
1.455 + return NS_OK;
1.456 +}
1.457 +
1.458 +NS_IMETHODIMP nsTimerImpl::SetType(uint32_t aType)
1.459 +{
1.460 + mType = (uint8_t)aType;
1.461 + // XXX if this is called, we should change the actual type.. this could effect
1.462 + // repeating timers. we need to ensure in Fire() that if mType has changed
1.463 + // during the callback that we don't end up with the timer in the queue twice.
1.464 + return NS_OK;
1.465 +}
1.466 +
1.467 +NS_IMETHODIMP nsTimerImpl::GetType(uint32_t* aType)
1.468 +{
1.469 + *aType = mType;
1.470 + return NS_OK;
1.471 +}
1.472 +
1.473 +
1.474 +NS_IMETHODIMP nsTimerImpl::GetClosure(void** aClosure)
1.475 +{
1.476 + *aClosure = mClosure;
1.477 + return NS_OK;
1.478 +}
1.479 +
1.480 +
1.481 +NS_IMETHODIMP nsTimerImpl::GetCallback(nsITimerCallback **aCallback)
1.482 +{
1.483 + if (mCallbackType == CALLBACK_TYPE_INTERFACE)
1.484 + NS_IF_ADDREF(*aCallback = mCallback.i);
1.485 + else if (mTimerCallbackWhileFiring)
1.486 + NS_ADDREF(*aCallback = mTimerCallbackWhileFiring);
1.487 + else
1.488 + *aCallback = nullptr;
1.489 +
1.490 + return NS_OK;
1.491 +}
1.492 +
1.493 +
1.494 +NS_IMETHODIMP nsTimerImpl::GetTarget(nsIEventTarget** aTarget)
1.495 +{
1.496 + NS_IF_ADDREF(*aTarget = mEventTarget);
1.497 + return NS_OK;
1.498 +}
1.499 +
1.500 +
1.501 +NS_IMETHODIMP nsTimerImpl::SetTarget(nsIEventTarget* aTarget)
1.502 +{
1.503 + if (NS_WARN_IF(mCallbackType != CALLBACK_TYPE_UNKNOWN))
1.504 + return NS_ERROR_ALREADY_INITIALIZED;
1.505 +
1.506 + if (aTarget)
1.507 + mEventTarget = aTarget;
1.508 + else
1.509 + mEventTarget = static_cast<nsIEventTarget*>(NS_GetCurrentThread());
1.510 + return NS_OK;
1.511 +}
1.512 +
1.513 +
1.514 +void nsTimerImpl::Fire()
1.515 +{
1.516 + if (mCanceled)
1.517 + return;
1.518 +
1.519 + PROFILER_LABEL("Timer", "Fire");
1.520 +
1.521 +#ifdef MOZ_TASK_TRACER
1.522 + mozilla::tasktracer::AutoRunFakeTracedTask runTracedTask(mTracedTask);
1.523 +#endif
1.524 +
1.525 +#ifdef DEBUG_TIMERS
1.526 + TimeStamp now = TimeStamp::Now();
1.527 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.528 + TimeDuration a = now - mStart; // actual delay in intervals
1.529 + TimeDuration b = TimeDuration::FromMilliseconds(mDelay); // expected delay in intervals
1.530 + TimeDuration delta = (a > b) ? a - b : b - a;
1.531 + uint32_t d = delta.ToMilliseconds(); // delta in ms
1.532 + sDeltaSum += d;
1.533 + sDeltaSumSquared += double(d) * double(d);
1.534 + sDeltaNum++;
1.535 +
1.536 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("[this=%p] expected delay time %4ums\n", this, mDelay));
1.537 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("[this=%p] actual delay time %fms\n", this, a.ToMilliseconds()));
1.538 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("[this=%p] (mType is %d) -------\n", this, mType));
1.539 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG, ("[this=%p] delta %4dms\n", this, (a > b) ? (int32_t)d : -(int32_t)d));
1.540 +
1.541 + mStart = mStart2;
1.542 + mStart2 = TimeStamp();
1.543 + }
1.544 +#endif
1.545 +
1.546 + TimeStamp timeout = mTimeout;
1.547 + if (IsRepeatingPrecisely()) {
1.548 + // Precise repeating timers advance mTimeout by mDelay without fail before
1.549 + // calling Fire().
1.550 + timeout -= TimeDuration::FromMilliseconds(mDelay);
1.551 + }
1.552 +
1.553 + if (mCallbackType == CALLBACK_TYPE_INTERFACE)
1.554 + mTimerCallbackWhileFiring = mCallback.i;
1.555 + mFiring = true;
1.556 +
1.557 + // Handle callbacks that re-init the timer, but avoid leaking.
1.558 + // See bug 330128.
1.559 + CallbackUnion callback = mCallback;
1.560 + unsigned callbackType = mCallbackType;
1.561 + if (callbackType == CALLBACK_TYPE_INTERFACE)
1.562 + NS_ADDREF(callback.i);
1.563 + else if (callbackType == CALLBACK_TYPE_OBSERVER)
1.564 + NS_ADDREF(callback.o);
1.565 + ReleaseCallback();
1.566 +
1.567 + switch (callbackType) {
1.568 + case CALLBACK_TYPE_FUNC:
1.569 + callback.c(this, mClosure);
1.570 + break;
1.571 + case CALLBACK_TYPE_INTERFACE:
1.572 + callback.i->Notify(this);
1.573 + break;
1.574 + case CALLBACK_TYPE_OBSERVER:
1.575 + callback.o->Observe(static_cast<nsITimer*>(this),
1.576 + NS_TIMER_CALLBACK_TOPIC,
1.577 + nullptr);
1.578 + break;
1.579 + default:;
1.580 + }
1.581 +
1.582 + // If the callback didn't re-init the timer, and it's not a one-shot timer,
1.583 + // restore the callback state.
1.584 + if (mCallbackType == CALLBACK_TYPE_UNKNOWN &&
1.585 + mType != TYPE_ONE_SHOT && !mCanceled) {
1.586 + mCallback = callback;
1.587 + mCallbackType = callbackType;
1.588 + } else {
1.589 + // The timer was a one-shot, or the callback was reinitialized.
1.590 + if (callbackType == CALLBACK_TYPE_INTERFACE)
1.591 + NS_RELEASE(callback.i);
1.592 + else if (callbackType == CALLBACK_TYPE_OBSERVER)
1.593 + NS_RELEASE(callback.o);
1.594 + }
1.595 +
1.596 + mFiring = false;
1.597 + mTimerCallbackWhileFiring = nullptr;
1.598 +
1.599 +#ifdef DEBUG_TIMERS
1.600 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.601 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG,
1.602 + ("[this=%p] Took %fms to fire timer callback\n",
1.603 + this, (TimeStamp::Now() - now).ToMilliseconds()));
1.604 + }
1.605 +#endif
1.606 +
1.607 + // Reschedule repeating timers, except REPEATING_PRECISE which already did
1.608 + // that in PostTimerEvent, but make sure that we aren't armed already (which
1.609 + // can happen if the callback reinitialized the timer).
1.610 + if (IsRepeating() && mType != TYPE_REPEATING_PRECISE && !mArmed) {
1.611 + if (mType == TYPE_REPEATING_SLACK)
1.612 + SetDelayInternal(mDelay); // force mTimeout to be recomputed. For
1.613 + // REPEATING_PRECISE_CAN_SKIP timers this has
1.614 + // already happened.
1.615 + if (gThread)
1.616 + gThread->AddTimer(this);
1.617 + }
1.618 +}
1.619 +
1.620 +void nsTimerEvent::Init()
1.621 +{
1.622 + sAllocator = new TimerEventAllocator();
1.623 +}
1.624 +
1.625 +void nsTimerEvent::Shutdown()
1.626 +{
1.627 + sCanDeleteAllocator = true;
1.628 + DeleteAllocatorIfNeeded();
1.629 +}
1.630 +
1.631 +void nsTimerEvent::DeleteAllocatorIfNeeded()
1.632 +{
1.633 + if (sCanDeleteAllocator && sAllocatorUsers == 0) {
1.634 + delete sAllocator;
1.635 + sAllocator = nullptr;
1.636 + }
1.637 +}
1.638 +
1.639 +NS_IMETHODIMP nsTimerEvent::Run()
1.640 +{
1.641 + if (mGeneration != mTimer->GetGeneration())
1.642 + return NS_OK;
1.643 +
1.644 +#ifdef DEBUG_TIMERS
1.645 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.646 + TimeStamp now = TimeStamp::Now();
1.647 + PR_LOG(GetTimerLog(), PR_LOG_DEBUG,
1.648 + ("[this=%p] time between PostTimerEvent() and Fire(): %fms\n",
1.649 + this, (now - mInitTime).ToMilliseconds()));
1.650 + }
1.651 +#endif
1.652 +
1.653 + mTimer->Fire();
1.654 + // Since nsTimerImpl is not thread-safe, we should release |mTimer|
1.655 + // here in the target thread to avoid race condition. Otherwise,
1.656 + // ~nsTimerEvent() which calls nsTimerImpl::Release() could run in the
1.657 + // timer thread and result in race condition.
1.658 + mTimer = nullptr;
1.659 +
1.660 + return NS_OK;
1.661 +}
1.662 +
1.663 +already_AddRefed<nsTimerImpl>
1.664 +nsTimerImpl::PostTimerEvent(already_AddRefed<nsTimerImpl> aTimerRef)
1.665 +{
1.666 + nsRefPtr<nsTimerImpl> timer(aTimerRef);
1.667 + if (!timer->mEventTarget) {
1.668 + NS_ERROR("Attempt to post timer event to NULL event target");
1.669 + return timer.forget();
1.670 + }
1.671 +
1.672 + // XXX we may want to reuse this nsTimerEvent in the case of repeating timers.
1.673 +
1.674 + // Since TimerThread addref'd 'timer' for us, we don't need to addref here.
1.675 + // We will release either in ~nsTimerEvent(), or pass the reference back to
1.676 + // the caller. We need to copy the generation number from this timer into the
1.677 + // event, so we can avoid firing a timer that was re-initialized after being
1.678 + // canceled.
1.679 +
1.680 + // Note: We override operator new for this class, and the override is
1.681 + // fallible!
1.682 + nsRefPtr<nsTimerEvent> event = new nsTimerEvent;
1.683 + if (!event)
1.684 + return timer.forget();
1.685 +
1.686 +#ifdef DEBUG_TIMERS
1.687 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.688 + event->mInitTime = TimeStamp::Now();
1.689 + }
1.690 +#endif
1.691 +
1.692 + // If this is a repeating precise timer, we need to calculate the time for
1.693 + // the next timer to fire before we make the callback.
1.694 + if (timer->IsRepeatingPrecisely()) {
1.695 + timer->SetDelayInternal(timer->mDelay);
1.696 +
1.697 + // But only re-arm REPEATING_PRECISE timers.
1.698 + if (gThread && timer->mType == TYPE_REPEATING_PRECISE) {
1.699 + nsresult rv = gThread->AddTimer(timer);
1.700 + if (NS_FAILED(rv)) {
1.701 + return timer.forget();
1.702 + }
1.703 + }
1.704 + }
1.705 +
1.706 + nsIEventTarget* target = timer->mEventTarget;
1.707 + event->SetTimer(timer.forget());
1.708 +
1.709 + nsresult rv = target->Dispatch(event, NS_DISPATCH_NORMAL);
1.710 + if (NS_FAILED(rv)) {
1.711 + timer = event->ForgetTimer();
1.712 + if (gThread) {
1.713 + gThread->RemoveTimer(timer);
1.714 + }
1.715 + return timer.forget();
1.716 + }
1.717 +
1.718 + return nullptr;
1.719 +}
1.720 +
1.721 +void nsTimerImpl::SetDelayInternal(uint32_t aDelay)
1.722 +{
1.723 + TimeDuration delayInterval = TimeDuration::FromMilliseconds(aDelay);
1.724 +
1.725 + mDelay = aDelay;
1.726 +
1.727 + TimeStamp now = TimeStamp::Now();
1.728 + if (mTimeout.IsNull() || mType != TYPE_REPEATING_PRECISE)
1.729 + mTimeout = now;
1.730 +
1.731 + mTimeout += delayInterval;
1.732 +
1.733 +#ifdef DEBUG_TIMERS
1.734 + if (PR_LOG_TEST(GetTimerLog(), PR_LOG_DEBUG)) {
1.735 + if (mStart.IsNull())
1.736 + mStart = now;
1.737 + else
1.738 + mStart2 = now;
1.739 + }
1.740 +#endif
1.741 +}
1.742 +
1.743 +// NOT FOR PUBLIC CONSUMPTION!
1.744 +nsresult
1.745 +NS_NewTimer(nsITimer* *aResult, nsTimerCallbackFunc aCallback, void *aClosure,
1.746 + uint32_t aDelay, uint32_t aType)
1.747 +{
1.748 + nsTimerImpl* timer = new nsTimerImpl();
1.749 + if (timer == nullptr)
1.750 + return NS_ERROR_OUT_OF_MEMORY;
1.751 + NS_ADDREF(timer);
1.752 +
1.753 + nsresult rv = timer->InitWithFuncCallback(aCallback, aClosure,
1.754 + aDelay, aType);
1.755 + if (NS_FAILED(rv)) {
1.756 + NS_RELEASE(timer);
1.757 + return rv;
1.758 + }
1.759 +
1.760 + *aResult = timer;
1.761 + return NS_OK;
1.762 +}
