summaryrefslogtreecommitdiffstats
path: root/xpcom/threads/MainThreadIdlePeriod.cpp
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /xpcom/threads/MainThreadIdlePeriod.cpp
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/threads/MainThreadIdlePeriod.cpp')
-rw-r--r--xpcom/threads/MainThreadIdlePeriod.cpp77
1 files changed, 77 insertions, 0 deletions
diff --git a/xpcom/threads/MainThreadIdlePeriod.cpp b/xpcom/threads/MainThreadIdlePeriod.cpp
new file mode 100644
index 0000000000..805626dd67
--- /dev/null
+++ b/xpcom/threads/MainThreadIdlePeriod.cpp
@@ -0,0 +1,77 @@
+/* -*- 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 "MainThreadIdlePeriod.h"
+
+#include "mozilla/Maybe.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/StaticPrefs_idle_period.h"
+#include "mozilla/dom/Document.h"
+#include "VRManagerChild.h"
+#include "nsRefreshDriver.h"
+#include "nsThreadUtils.h"
+
+// The amount of idle time (milliseconds) reserved for a long idle period.
+static const double kLongIdlePeriodMS = 50.0;
+
+// The minimum amount of time (milliseconds) required for an idle period to be
+// scheduled on the main thread. N.B. layout.idle_period.time_limit adds
+// padding at the end of the idle period, which makes the point in time that we
+// expect to become busy again be:
+// now + idle_period.min + layout.idle_period.time_limit
+// or during page load
+// now + idle_period.during_page_load.min + layout.idle_period.time_limit
+
+static const uint32_t kMaxTimerThreadBound = 25; // Number of timers to check.
+
+namespace mozilla {
+
+NS_IMETHODIMP
+MainThreadIdlePeriod::GetIdlePeriodHint(TimeStamp* aIdleDeadline) {
+ MOZ_ASSERT(NS_IsMainThread());
+ MOZ_ASSERT(aIdleDeadline);
+
+ TimeStamp now = TimeStamp::Now();
+ TimeStamp currentGuess =
+ now + TimeDuration::FromMilliseconds(kLongIdlePeriodMS);
+
+ currentGuess = nsRefreshDriver::GetIdleDeadlineHint(
+ currentGuess, nsRefreshDriver::IdleCheck::AllVsyncListeners);
+ if (XRE_IsContentProcess()) {
+ currentGuess = gfx::VRManagerChild::GetIdleDeadlineHint(currentGuess);
+ }
+ currentGuess = NS_GetTimerDeadlineHintOnCurrentThread(currentGuess,
+ kMaxTimerThreadBound);
+
+ // If the idle period is too small, then just return a null time
+ // to indicate we are busy. Otherwise return the actual deadline.
+ double highRateMultiplier = nsRefreshDriver::HighRateMultiplier();
+ TimeDuration minIdlePeriod = TimeDuration::FromMilliseconds(
+ std::max(highRateMultiplier * StaticPrefs::idle_period_min(), 1.0));
+ bool busySoon = currentGuess.IsNull() ||
+ (now >= (currentGuess - minIdlePeriod)) ||
+ currentGuess < mLastIdleDeadline;
+
+ // During page load use higher minimum idle period.
+ if (!busySoon && XRE_IsContentProcess() &&
+ mozilla::dom::Document::HasRecentlyStartedForegroundLoads()) {
+ TimeDuration minIdlePeriod = TimeDuration::FromMilliseconds(std::max(
+ highRateMultiplier * StaticPrefs::idle_period_during_page_load_min(),
+ 1.0));
+ busySoon = (now >= (currentGuess - minIdlePeriod));
+ }
+
+ if (!busySoon) {
+ *aIdleDeadline = mLastIdleDeadline = currentGuess;
+ }
+
+ return NS_OK;
+}
+
+/* static */
+float MainThreadIdlePeriod::GetLongIdlePeriod() { return kLongIdlePeriodMS; }
+
+} // namespace mozilla