From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- xpcom/threads/PerformanceCounter.h | 139 +++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 xpcom/threads/PerformanceCounter.h (limited to 'xpcom/threads/PerformanceCounter.h') diff --git a/xpcom/threads/PerformanceCounter.h b/xpcom/threads/PerformanceCounter.h new file mode 100644 index 0000000000..4181320e10 --- /dev/null +++ b/xpcom/threads/PerformanceCounter.h @@ -0,0 +1,139 @@ +/* -*- 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/. */ + +#ifndef mozilla_PerformanceCounter_h +#define mozilla_PerformanceCounter_h + +#include "mozilla/Array.h" +#include "mozilla/Atomics.h" +#include "mozilla/TaskCategory.h" +#include "nsISupportsImpl.h" +#include "nsString.h" + +namespace mozilla { + +/* + * The DispatchCategory class is used to fake the inheritance + * of the TaskCategory enum so we can extend it to hold + * one more value corresponding to the category + * we use when a worker dispatches a call. + * + */ +class DispatchCategory final { + public: + explicit DispatchCategory(uint32_t aValue) : mValue(aValue) { + // Since DispatchCategory is adding one single value to the + // TaskCategory enum, we can check here that the value is + // the next index e.g. TaskCategory::Count + MOZ_ASSERT(aValue == (uint32_t)TaskCategory::Count); + } + + constexpr explicit DispatchCategory(TaskCategory aValue) + : mValue((uint32_t)aValue) {} + + uint32_t GetValue() const { return mValue; } + + static const DispatchCategory Worker; + + private: + uint32_t mValue; +}; + +typedef Array, (uint32_t)TaskCategory::Count + 1> + DispatchCounter; + +// PerformanceCounter is a class that can be used to keep track of +// runnable execution times and dispatch counts. +// +// - runnable execution time: time spent in a runnable when called +// in nsThread::ProcessNextEvent (not counting recursive calls) +// - dispatch counts: number of times a tracked runnable is dispatched +// in nsThread. Useful to measure the activity of a tab or worker. +// +// The PerformanceCounter class is currently instantiated in DocGroup +// and WorkerPrivate in order to count how many scheduler dispatches +// are done through them, and how long the execution lasts. +// +// The execution time is calculated by the nsThread class (and its +// inherited WorkerThread class) in its ProcessNextEvent method. +// +// For each processed runnable, nsThread will reach out the +// PerformanceCounter attached to the runnable via its DocGroup +// or WorkerPrivate and call IncrementExecutionDuration() +// +// Notice that the execution duration counting takes into account +// recursivity. If an event triggers a recursive call to +// nsThread::ProcessNextEVent, the counter will discard the time +// spent in sub events. +class PerformanceCounter final { + public: + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(PerformanceCounter) + + explicit PerformanceCounter(const nsACString& aName); + + /** + * This is called everytime a runnable is dispatched. + * + * aCategory can be used to distinguish counts per TaskCategory + * + * Note that an overflow will simply reset the counter. + */ + void IncrementDispatchCounter(DispatchCategory aCategory); + + /** + * This is called via nsThread::ProcessNextEvent to measure runnable + * execution duration. + * + * Note that an overflow will simply reset the counter. + */ + void IncrementExecutionDuration(uint32_t aMicroseconds); + + /** + * Returns a category/counter array of all dispatches. + */ + const DispatchCounter& GetDispatchCounter() const; + + /** + * Returns the total execution duration. + */ + uint64_t GetExecutionDuration() const; + + /** + * Returns the number of dispatches per TaskCategory. + */ + uint32_t GetDispatchCount(DispatchCategory aCategory) const; + + /** + * Returns the total number of dispatches. + */ + uint64_t GetTotalDispatchCount() const; + + /** + * Returns the unique id for the instance. + * + * Used to distinguish instances since the lifespan of + * a PerformanceCounter can be shorter than the + * host it's tracking. That leads to edge cases + * where a counter appears to have values that go + * backwards. Having this id let the consumers + * detect that they are dealing with a new counter + * when it happens. + */ + uint64_t GetID() const; + + private: + ~PerformanceCounter() = default; + + Atomic mExecutionDuration; + Atomic mTotalDispatchCount; + DispatchCounter mDispatchCounter; + nsCString mName; + const uint64_t mID; +}; + +} // namespace mozilla + +#endif // mozilla_PerformanceCounter_h -- cgit v1.2.3