1 files changed, 658 insertions, 0 deletions
diff --git a/xpcom/threads/nsTimerImpl.cpp b/xpcom/threads/nsTimerImpl.cpp
new file mode 100644
index 0000000000..bc2d338e0f
--- /dev/null
+++ b/xpcom/threads/nsTimerImpl.cpp
@@ -0,0 +1,658 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "nsTimerImpl.h"
+#include "TimerThread.h"
+#include "nsAutoPtr.h"
+#include "nsThreadManager.h"
+#include "nsThreadUtils.h"
+#include "pratom.h"
+#include "GeckoProfiler.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/IntegerPrintfMacros.h"
+#include "mozilla/Logging.h"
+#ifdef MOZ_TASK_TRACER
+#include "GeckoTaskTracerImpl.h"
+using namespace mozilla::tasktracer;
+#endif
+
+#ifdef XP_WIN
+#include <process.h>
+#ifndef getpid
+#define getpid _getpid
+#endif
+#else
+#include <unistd.h>
+#endif
+
+using mozilla::Atomic;
+using mozilla::LogLevel;
+using mozilla::TimeDuration;
+using mozilla::TimeStamp;
+
+static TimerThread*     gThread = nullptr;
+
+// This module prints info about the precision of timers.
+static mozilla::LazyLogModule sTimerLog("nsTimerImpl");
+
+mozilla::LogModule*
+GetTimerLog()
+{
+  return sTimerLog;
+}
+
+// This module prints info about which timers are firing, which is useful for
+// wakeups for the purposes of power profiling. Set the following environment
+// variable before starting the browser.
+//
+//   MOZ_LOG=TimerFirings:4
+//
+// Then a line will be printed for every timer that fires. The name used for a
+// |Callback::Type::Function| timer depends on the circumstances.
+//
+// - If it was explicitly named (e.g. it was initialized with
+//   InitWithNamedFuncCallback()) then that explicit name will be shown.
+//
+// - Otherwise, if we are on a platform that supports function name lookup
+//   (Mac or Linux) then the looked-up name will be shown with a
+//   "[from dladdr]" annotation. On Mac the looked-up name will be immediately
+//   useful. On Linux it'll need post-processing with
+//   tools/rb/fix_linux_stack.py.
+//
+// - Otherwise, no name will be printed. If many timers hit this case then
+//   you'll need to re-run the workload on a Mac to find out which timers they
+//   are, and then give them explicit names.
+//
+// If you redirect this output to a file called "out", you can then
+// post-process it with a command something like the following.
+//
+//   cat out | grep timer | sort | uniq -c | sort -r -n
+//
+// This will show how often each unique line appears, with the most common ones
+// first.
+//
+// More detailed docs are here:
+// https://developer.mozilla.org/en-US/docs/Mozilla/Performance/TimerFirings_logging
+//
+static mozilla::LazyLogModule sTimerFiringsLog("TimerFirings");
+
+mozilla::LogModule*
+GetTimerFiringsLog()
+{
+  return sTimerFiringsLog;
+}
+
+#include <math.h>
+
+double nsTimerImpl::sDeltaSumSquared = 0;
+double nsTimerImpl::sDeltaSum = 0;
+double nsTimerImpl::sDeltaNum = 0;
+
+static void
+myNS_MeanAndStdDev(double n, double sumOfValues, double sumOfSquaredValues,
+                   double* meanResult, double* stdDevResult)
+{
+  double mean = 0.0, var = 0.0, stdDev = 0.0;
+  if (n > 0.0 && sumOfValues >= 0) {
+    mean = sumOfValues / n;
+    double temp = (n * sumOfSquaredValues) - (sumOfValues * sumOfValues);
+    if (temp < 0.0 || n <= 1) {
+      var = 0.0;
+    } else {
+      var = temp / (n * (n - 1));
+    }
+    // for some reason, Windows says sqrt(0.0) is "-1.#J" (?!) so do this:
+    stdDev = var != 0.0 ? sqrt(var) : 0.0;
+  }
+  *meanResult = mean;
+  *stdDevResult = stdDev;
+}
+
+NS_IMPL_QUERY_INTERFACE(nsTimer, nsITimer)
+NS_IMPL_ADDREF(nsTimer)
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsTimer::Release(void)
+{
+  nsrefcnt count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "nsTimer");
+
+  if (count == 1) {
+    // Last ref, held by nsTimerImpl. Make sure the cycle is broken.
+    // If there is a nsTimerEvent in a queue for this timer, the nsTimer will
+    // live until that event pops, otherwise the nsTimerImpl will go away and
+    // the nsTimer along with it.
+    mImpl->Cancel();
+    mImpl = nullptr;
+  } else if (count == 0) {
+    delete this;
+  }
+
+  return count;
+}
+
+nsTimerImpl::nsTimerImpl(nsITimer* aTimer) :
+  mGeneration(0),
+  mDelay(0),
+  mITimer(aTimer),
+  mMutex("nsTimerImpl::mMutex")
+{
+  // XXXbsmedberg: shouldn't this be in Init()?
+  mEventTarget = static_cast<nsIEventTarget*>(NS_GetCurrentThread());
+}
+
+//static
+nsresult
+nsTimerImpl::Startup()
+{
+  nsresult rv;
+
+  gThread = new TimerThread();
+
+  NS_ADDREF(gThread);
+  rv = gThread->InitLocks();
+
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(gThread);
+  }
+
+  return rv;
+}
+
+void
+nsTimerImpl::Shutdown()
+{
+  if (MOZ_LOG_TEST(GetTimerLog(), LogLevel::Debug)) {
+    double mean = 0, stddev = 0;
+    myNS_MeanAndStdDev(sDeltaNum, sDeltaSum, sDeltaSumSquared, &mean, &stddev);
+
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("sDeltaNum = %f, sDeltaSum = %f, sDeltaSumSquared = %f\n",
+            sDeltaNum, sDeltaSum, sDeltaSumSquared));
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("mean: %fms, stddev: %fms\n", mean, stddev));
+  }
+
+  if (!gThread) {
+    return;
+  }
+
+  gThread->Shutdown();
+  NS_RELEASE(gThread);
+}
+
+
+nsresult
+nsTimerImpl::InitCommon(uint32_t aDelay, uint32_t aType)
+{
+  mMutex.AssertCurrentThreadOwns();
+  nsresult rv;
+
+  if (NS_WARN_IF(!gThread)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  if (!mEventTarget) {
+    NS_ERROR("mEventTarget is NULL");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  rv = gThread->Init();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  gThread->RemoveTimer(this);
+  ++mGeneration;
+
+  mType = (uint8_t)aType;
+  mDelay = aDelay;
+  mTimeout = TimeStamp::Now() + TimeDuration::FromMilliseconds(mDelay);
+
+  return gThread->AddTimer(this);
+}
+
+nsresult
+nsTimerImpl::InitWithFuncCallbackCommon(nsTimerCallbackFunc aFunc,
+                                        void* aClosure,
+                                        uint32_t aDelay,
+                                        uint32_t aType,
+                                        Callback::Name aName)
+{
+  if (NS_WARN_IF(!aFunc)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  Callback cb; // Goes out of scope after the unlock, prevents deadlock
+  cb.mType = Callback::Type::Function;
+  cb.mCallback.c = aFunc;
+  cb.mClosure = aClosure;
+  cb.mName = aName;
+
+  MutexAutoLock lock(mMutex);
+  cb.swap(mCallback);
+
+  return InitCommon(aDelay, aType);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::InitWithFuncCallback(nsTimerCallbackFunc aFunc,
+                                  void* aClosure,
+                                  uint32_t aDelay,
+                                  uint32_t aType)
+{
+  Callback::Name name(Callback::Nothing);
+  return InitWithFuncCallbackCommon(aFunc, aClosure, aDelay, aType, name);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::InitWithNamedFuncCallback(nsTimerCallbackFunc aFunc,
+                                       void* aClosure,
+                                       uint32_t aDelay,
+                                       uint32_t aType,
+                                       const char* aNameString)
+{
+  Callback::Name name(aNameString);
+  return InitWithFuncCallbackCommon(aFunc, aClosure, aDelay, aType, name);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::InitWithNameableFuncCallback(nsTimerCallbackFunc aFunc,
+                                          void* aClosure,
+                                          uint32_t aDelay,
+                                          uint32_t aType,
+                                          nsTimerNameCallbackFunc aNameFunc)
+{
+  Callback::Name name(aNameFunc);
+  return InitWithFuncCallbackCommon(aFunc, aClosure, aDelay, aType, name);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::InitWithCallback(nsITimerCallback* aCallback,
+                              uint32_t aDelay,
+                              uint32_t aType)
+{
+  if (NS_WARN_IF(!aCallback)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  Callback cb; // Goes out of scope after the unlock, prevents deadlock
+  cb.mType = Callback::Type::Interface;
+  cb.mCallback.i = aCallback;
+  NS_ADDREF(cb.mCallback.i);
+
+  MutexAutoLock lock(mMutex);
+  cb.swap(mCallback);
+
+  return InitCommon(aDelay, aType);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::Init(nsIObserver* aObserver, uint32_t aDelay, uint32_t aType)
+{
+  if (NS_WARN_IF(!aObserver)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  Callback cb; // Goes out of scope after the unlock, prevents deadlock
+  cb.mType = Callback::Type::Observer;
+  cb.mCallback.o = aObserver;
+  NS_ADDREF(cb.mCallback.o);
+
+  MutexAutoLock lock(mMutex);
+  cb.swap(mCallback);
+
+  return InitCommon(aDelay, aType);
+}
+
+NS_IMETHODIMP
+nsTimerImpl::Cancel()
+{
+  Callback cb;
+
+  MutexAutoLock lock(mMutex);
+
+  if (gThread) {
+    gThread->RemoveTimer(this);
+  }
+
+  cb.swap(mCallback);
+  ++mGeneration;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTimerImpl::SetDelay(uint32_t aDelay)
+{
+  MutexAutoLock lock(mMutex);
+  if (GetCallback().mType == Callback::Type::Unknown && !IsRepeating()) {
+    // This may happen if someone tries to re-use a one-shot timer
+    // by re-setting delay instead of reinitializing the timer.
+    NS_ERROR("nsITimer->SetDelay() called when the "
+             "one-shot timer is not set up.");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  bool reAdd = false;
+  if (gThread) {
+    reAdd = NS_SUCCEEDED(gThread->RemoveTimer(this));
+  }
+
+  mDelay = aDelay;
+  mTimeout = TimeStamp::Now() + TimeDuration::FromMilliseconds(mDelay);
+
+  if (reAdd) {
+    gThread->AddTimer(this);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTimerImpl::GetDelay(uint32_t* aDelay)
+{
+  MutexAutoLock lock(mMutex);
+  *aDelay = mDelay;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTimerImpl::SetType(uint32_t aType)
+{
+  MutexAutoLock lock(mMutex);
+  mType = (uint8_t)aType;
+  // XXX if this is called, we should change the actual type.. this could effect
+  // repeating timers.  we need to ensure in Fire() that if mType has changed
+  // during the callback that we don't end up with the timer in the queue twice.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTimerImpl::GetType(uint32_t* aType)
+{
+  MutexAutoLock lock(mMutex);
+  *aType = mType;
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsTimerImpl::GetClosure(void** aClosure)
+{
+  MutexAutoLock lock(mMutex);
+  *aClosure = GetCallback().mClosure;
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsTimerImpl::GetCallback(nsITimerCallback** aCallback)
+{
+  MutexAutoLock lock(mMutex);
+  if (GetCallback().mType == Callback::Type::Interface) {
+    NS_IF_ADDREF(*aCallback = GetCallback().mCallback.i);
+  } else {
+    *aCallback = nullptr;
+  }
+
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsTimerImpl::GetTarget(nsIEventTarget** aTarget)
+{
+  MutexAutoLock lock(mMutex);
+  NS_IF_ADDREF(*aTarget = mEventTarget);
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsTimerImpl::SetTarget(nsIEventTarget* aTarget)
+{
+  MutexAutoLock lock(mMutex);
+  if (NS_WARN_IF(mCallback.mType != Callback::Type::Unknown)) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  if (aTarget) {
+    mEventTarget = aTarget;
+  } else {
+    mEventTarget = static_cast<nsIEventTarget*>(NS_GetCurrentThread());
+  }
+  return NS_OK;
+}
+
+
+void
+nsTimerImpl::Fire(int32_t aGeneration)
+{
+  uint8_t oldType;
+  uint32_t oldDelay;
+  TimeStamp oldTimeout;
+
+  {
+    // Don't fire callbacks or fiddle with refcounts when the mutex is locked.
+    // If some other thread Cancels/Inits after this, they're just too late.
+    MutexAutoLock lock(mMutex);
+    if (aGeneration != mGeneration) {
+      return;
+    }
+
+    mCallbackDuringFire.swap(mCallback);
+    oldType = mType;
+    oldDelay = mDelay;
+    oldTimeout = mTimeout;
+  }
+
+  PROFILER_LABEL("Timer", "Fire",
+                 js::ProfileEntry::Category::OTHER);
+
+  TimeStamp now = TimeStamp::Now();
+  if (MOZ_LOG_TEST(GetTimerLog(), LogLevel::Debug)) {
+    TimeDuration   delta = now - oldTimeout;
+    int32_t       d = delta.ToMilliseconds(); // delta in ms
+    sDeltaSum += abs(d);
+    sDeltaSumSquared += double(d) * double(d);
+    sDeltaNum++;
+
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("[this=%p] expected delay time %4ums\n", this, oldDelay));
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("[this=%p] actual delay time   %4dms\n", this, oldDelay + d));
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("[this=%p] (mType is %d)       -------\n", this, oldType));
+    MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+           ("[this=%p]     delta           %4dms\n", this, d));
+  }
+
+  if (MOZ_LOG_TEST(GetTimerFiringsLog(), LogLevel::Debug)) {
+    LogFiring(mCallbackDuringFire, oldType, oldDelay);
+  }
+
+  switch (mCallbackDuringFire.mType) {
+    case Callback::Type::Function:
+      mCallbackDuringFire.mCallback.c(mITimer, mCallbackDuringFire.mClosure);
+      break;
+    case Callback::Type::Interface:
+      mCallbackDuringFire.mCallback.i->Notify(mITimer);
+      break;
+    case Callback::Type::Observer:
+      mCallbackDuringFire.mCallback.o->Observe(mITimer, NS_TIMER_CALLBACK_TOPIC,
+                                               nullptr);
+      break;
+    default:
+      ;
+  }
+
+  Callback trash; // Swap into here to dispose of callback after the unlock
+  MutexAutoLock lock(mMutex);
+  if (aGeneration == mGeneration && IsRepeating()) {
+    // Repeating timer has not been re-init or canceled; reschedule
+    mCallbackDuringFire.swap(mCallback);
+    TimeDuration delay = TimeDuration::FromMilliseconds(mDelay);
+    if (mType == nsITimer::TYPE_REPEATING_SLACK) {
+      mTimeout = TimeStamp::Now() + delay;
+    } else {
+      mTimeout = mTimeout + delay;
+    }
+    if (gThread) {
+      gThread->AddTimer(this);
+    }
+  }
+
+  mCallbackDuringFire.swap(trash);
+
+  MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+         ("[this=%p] Took %fms to fire timer callback\n",
+          this, (TimeStamp::Now() - now).ToMilliseconds()));
+}
+
+#if defined(HAVE_DLADDR) && defined(HAVE___CXA_DEMANGLE)
+#define USE_DLADDR 1
+#endif
+
+#ifdef USE_DLADDR
+#include <cxxabi.h>
+#include <dlfcn.h>
+#endif
+
+// See the big comment above GetTimerFiringsLog() to understand this code.
+void
+nsTimerImpl::LogFiring(const Callback& aCallback, uint8_t aType, uint32_t aDelay)
+{
+  const char* typeStr;
+  switch (aType) {
+    case nsITimer::TYPE_ONE_SHOT:                   typeStr = "ONE_SHOT"; break;
+    case nsITimer::TYPE_REPEATING_SLACK:            typeStr = "SLACK   "; break;
+    case nsITimer::TYPE_REPEATING_PRECISE:          /* fall through */
+    case nsITimer::TYPE_REPEATING_PRECISE_CAN_SKIP: typeStr = "PRECISE "; break;
+    default:                              MOZ_CRASH("bad type");
+  }
+
+  switch (aCallback.mType) {
+    case Callback::Type::Function: {
+      bool needToFreeName = false;
+      const char* annotation = "";
+      const char* name;
+      static const size_t buflen = 1024;
+      char buf[buflen];
+
+      if (aCallback.mName.is<Callback::NameString>()) {
+        name = aCallback.mName.as<Callback::NameString>();
+
+      } else if (aCallback.mName.is<Callback::NameFunc>()) {
+        aCallback.mName.as<Callback::NameFunc>()(
+            mITimer, aCallback.mClosure, buf, buflen);
+        name = buf;
+
+      } else {
+        MOZ_ASSERT(aCallback.mName.is<Callback::NameNothing>());
+#ifdef USE_DLADDR
+        annotation = "[from dladdr] ";
+
+        Dl_info info;
+        void* addr = reinterpret_cast<void*>(aCallback.mCallback.c);
+        if (dladdr(addr, &info) == 0) {
+          name = "???[dladdr: failed]";
+
+        } else if (info.dli_sname) {
+          int status;
+          name = abi::__cxa_demangle(info.dli_sname, nullptr, nullptr, &status);
+          if (status == 0) {
+            // Success. Because we didn't pass in a buffer to __cxa_demangle it
+            // allocates its own one with malloc() which we must free() later.
+            MOZ_ASSERT(name);
+            needToFreeName = true;
+          } else if (status == -1) {
+            name = "???[__cxa_demangle: OOM]";
+          } else if (status == -2) {
+            name = "???[__cxa_demangle: invalid mangled name]";
+          } else if (status == -3) {
+            name = "???[__cxa_demangle: invalid argument]";
+          } else {
+            name = "???[__cxa_demangle: unexpected status value]";
+          }
+
+        } else if (info.dli_fname) {
+          // The "#0: " prefix is necessary for fix_linux_stack.py to interpret
+          // this string as something to convert.
+          snprintf(buf, buflen, "#0: ???[%s +0x%" PRIxPTR "]\n",
+                   info.dli_fname, uintptr_t(addr) - uintptr_t(info.dli_fbase));
+          name = buf;
+
+        } else {
+          name = "???[dladdr: no symbol or shared object obtained]";
+        }
+#else
+        name = "???[dladdr is unimplemented or doesn't work well on this OS]";
+#endif
+      }
+
+      MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+              ("[%d]    fn timer (%s %5d ms): %s%s\n",
+               getpid(), typeStr, aDelay, annotation, name));
+
+      if (needToFreeName) {
+        free(const_cast<char*>(name));
+      }
+
+      break;
+    }
+
+    case Callback::Type::Interface: {
+      MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+              ("[%d] iface timer (%s %5d ms): %p\n",
+               getpid(), typeStr, aDelay, aCallback.mCallback.i));
+      break;
+    }
+
+    case Callback::Type::Observer: {
+      MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+              ("[%d]   obs timer (%s %5d ms): %p\n",
+               getpid(), typeStr, aDelay, aCallback.mCallback.o));
+      break;
+    }
+
+    case Callback::Type::Unknown:
+    default: {
+      MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+              ("[%d]   ??? timer (%s, %5d ms)\n",
+               getpid(), typeStr, aDelay));
+      break;
+    }
+  }
+}
+
+nsTimer::~nsTimer()
+{
+}
+
+size_t
+nsTimer::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+{
+  return aMallocSizeOf(this);
+}
+
+/* static */
+const nsTimerImpl::Callback::NameNothing nsTimerImpl::Callback::Nothing = 0;
+
+#ifdef MOZ_TASK_TRACER
+void
+nsTimerImpl::GetTLSTraceInfo()
+{
+  mTracedTask.GetTLSTraceInfo();
+}
+
+TracedTaskCommon
+nsTimerImpl::GetTracedTask()
+{
+  return mTracedTask;
+}
+
+#endif
+