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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
commit0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
treea31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /xpcom/threads/IdlePeriodState.cpp
parentInitial commit. (diff)
downloadfirefox-esr-upstream/115.8.0esr.tar.xz
firefox-esr-upstream/115.8.0esr.zip
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/threads/IdlePeriodState.cpp')
-rw-r--r--xpcom/threads/IdlePeriodState.cpp255
1 files changed, 255 insertions, 0 deletions
diff --git a/xpcom/threads/IdlePeriodState.cpp b/xpcom/threads/IdlePeriodState.cpp
new file mode 100644
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+++ b/xpcom/threads/IdlePeriodState.cpp
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+/* -*- 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 "mozilla/AppShutdown.h"
+#include "mozilla/IdlePeriodState.h"
+#include "mozilla/StaticPrefs_idle_period.h"
+#include "mozilla/ipc/IdleSchedulerChild.h"
+#include "nsIIdlePeriod.h"
+#include "nsThreadManager.h"
+#include "nsThreadUtils.h"
+#include "nsXPCOM.h"
+#include "nsXULAppAPI.h"
+
+static uint64_t sIdleRequestCounter = 0;
+
+namespace mozilla {
+
+IdlePeriodState::IdlePeriodState(already_AddRefed<nsIIdlePeriod>&& aIdlePeriod)
+ : mIdlePeriod(aIdlePeriod) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+}
+
+IdlePeriodState::~IdlePeriodState() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ if (mIdleScheduler) {
+ mIdleScheduler->Disconnect();
+ }
+}
+
+size_t IdlePeriodState::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ size_t n = 0;
+ if (mIdlePeriod) {
+ n += aMallocSizeOf(mIdlePeriod);
+ }
+
+ return n;
+}
+
+void IdlePeriodState::FlagNotIdle() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+
+ EnsureIsActive();
+ if (mIdleToken && mIdleToken < TimeStamp::Now()) {
+ ClearIdleToken();
+ }
+}
+
+void IdlePeriodState::RanOutOfTasks(const MutexAutoUnlock& aProofOfUnlock) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ MOZ_ASSERT(!mHasPendingEventsPromisedIdleEvent);
+ EnsureIsPaused(aProofOfUnlock);
+ ClearIdleToken();
+}
+
+TimeStamp IdlePeriodState::GetIdleDeadlineInternal(
+ bool aIsPeek, const MutexAutoUnlock& aProofOfUnlock) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+
+ bool shuttingDown;
+ TimeStamp localIdleDeadline =
+ GetLocalIdleDeadline(shuttingDown, aProofOfUnlock);
+ if (!localIdleDeadline) {
+ if (!aIsPeek) {
+ EnsureIsPaused(aProofOfUnlock);
+ ClearIdleToken();
+ }
+ return TimeStamp();
+ }
+
+ TimeStamp idleDeadline =
+ mHasPendingEventsPromisedIdleEvent || shuttingDown
+ ? localIdleDeadline
+ : GetIdleToken(localIdleDeadline, aProofOfUnlock);
+ if (!idleDeadline) {
+ if (!aIsPeek) {
+ EnsureIsPaused(aProofOfUnlock);
+
+ // Don't call ClearIdleToken() here, since we may have a pending
+ // request already.
+ //
+ // RequestIdleToken can do all sorts of IPC stuff that might
+ // take mutexes. This is one reason why we need the
+ // MutexAutoUnlock reference!
+ RequestIdleToken(localIdleDeadline);
+ }
+ return TimeStamp();
+ }
+
+ if (!aIsPeek) {
+ EnsureIsActive();
+ }
+ return idleDeadline;
+}
+
+TimeStamp IdlePeriodState::GetLocalIdleDeadline(
+ bool& aShuttingDown, const MutexAutoUnlock& aProofOfUnlock) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ // If we are shutting down, we won't honor the idle period, and we will
+ // always process idle runnables. This will ensure that the idle queue
+ // gets exhausted at shutdown time to prevent intermittently leaking
+ // some runnables inside that queue and even worse potentially leaving
+ // some important cleanup work unfinished.
+ if (AppShutdown::IsInOrBeyond(ShutdownPhase::XPCOMShutdownThreads) ||
+ nsThreadManager::get().GetCurrentThread()->ShuttingDown()) {
+ aShuttingDown = true;
+ return TimeStamp::Now();
+ }
+
+ aShuttingDown = false;
+ TimeStamp idleDeadline;
+ // This GetIdlePeriodHint() call is the reason we need a MutexAutoUnlock here.
+ mIdlePeriod->GetIdlePeriodHint(&idleDeadline);
+
+ // If HasPendingEvents() has been called and it has returned true because of
+ // pending idle events, there is a risk that we may decide here that we aren't
+ // idle and return null, in which case HasPendingEvents() has effectively
+ // lied. Since we can't go back and fix the past, we have to adjust what we
+ // do here and forcefully pick the idle queue task here. Note that this means
+ // that we are choosing to run a task from the idle queue when we would
+ // normally decide that we aren't in an idle period, but this can only happen
+ // if we fall out of the idle period in between the call to HasPendingEvents()
+ // and here, which should hopefully be quite rare. We are effectively
+ // choosing to prioritize the sanity of our API semantics over the optimal
+ // scheduling.
+ if (!mHasPendingEventsPromisedIdleEvent &&
+ (!idleDeadline || idleDeadline < TimeStamp::Now())) {
+ return TimeStamp();
+ }
+ if (mHasPendingEventsPromisedIdleEvent && !idleDeadline) {
+ // If HasPendingEvents() has been called and it has returned true, but we're
+ // no longer in the idle period, we must return a valid timestamp to pretend
+ // that we are still in the idle period.
+ return TimeStamp::Now();
+ }
+ return idleDeadline;
+}
+
+TimeStamp IdlePeriodState::GetIdleToken(TimeStamp aLocalIdlePeriodHint,
+ const MutexAutoUnlock& aProofOfUnlock) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+
+ if (!ShouldGetIdleToken()) {
+ return aLocalIdlePeriodHint;
+ }
+
+ if (mIdleToken) {
+ TimeStamp now = TimeStamp::Now();
+ if (mIdleToken < now) {
+ ClearIdleToken();
+ return mIdleToken;
+ }
+ return mIdleToken < aLocalIdlePeriodHint ? mIdleToken
+ : aLocalIdlePeriodHint;
+ }
+ return TimeStamp();
+}
+
+void IdlePeriodState::RequestIdleToken(TimeStamp aLocalIdlePeriodHint) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ MOZ_ASSERT(!mActive);
+
+ if (!mIdleSchedulerInitialized) {
+ mIdleSchedulerInitialized = true;
+ if (ShouldGetIdleToken()) {
+ // For now cross-process idle scheduler is supported only on the main
+ // threads of the child processes.
+ mIdleScheduler = ipc::IdleSchedulerChild::GetMainThreadIdleScheduler();
+ if (mIdleScheduler) {
+ mIdleScheduler->Init(this);
+ }
+ }
+ }
+
+ if (mIdleScheduler && !mIdleRequestId) {
+ TimeStamp now = TimeStamp::Now();
+ if (aLocalIdlePeriodHint <= now) {
+ return;
+ }
+
+ mIdleRequestId = ++sIdleRequestCounter;
+ mIdleScheduler->SendRequestIdleTime(mIdleRequestId,
+ aLocalIdlePeriodHint - now);
+ }
+}
+
+void IdlePeriodState::SetIdleToken(uint64_t aId, TimeDuration aDuration) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+
+ // We check the request ID. It's possible that the server may be granting a
+ // an ealier request that the client has since cancelled and re-requested.
+ if (mIdleRequestId == aId) {
+ mIdleToken = TimeStamp::Now() + aDuration;
+ }
+}
+
+void IdlePeriodState::SetActive() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ MOZ_ASSERT(!mActive);
+ if (mIdleScheduler) {
+ mIdleScheduler->SetActive();
+ }
+ mActive = true;
+}
+
+void IdlePeriodState::SetPaused(const MutexAutoUnlock& aProofOfUnlock) {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+ MOZ_ASSERT(mActive);
+ if (mIdleScheduler && mIdleScheduler->SetPaused()) {
+ // We may have gotten a free cpu core for running idle tasks.
+ // We don't try to catch the case when there are prioritized processes
+ // running.
+
+ // This SendSchedule call is why we need the MutexAutoUnlock here, because
+ // IPC can do weird things with mutexes.
+ mIdleScheduler->SendSchedule();
+ }
+ mActive = false;
+}
+
+void IdlePeriodState::ClearIdleToken() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Why are we touching idle state off the main thread?");
+
+ if (mIdleRequestId) {
+ if (mIdleScheduler) {
+ // This SendIdleTimeUsed call is why we need to not be holding
+ // any locks here, because IPC can do weird things with mutexes.
+ // Ideally we'd have a MutexAutoUnlock& reference here, but some
+ // callers end up here while just not holding any locks at all.
+ mIdleScheduler->SendIdleTimeUsed(mIdleRequestId);
+ }
+ mIdleRequestId = 0;
+ mIdleToken = TimeStamp();
+ }
+}
+
+bool IdlePeriodState::ShouldGetIdleToken() {
+ return StaticPrefs::idle_period_cross_process_scheduling() &&
+ XRE_IsContentProcess();
+}
+} // namespace mozilla
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