gecko-dev/toolkit/components/telemetry/ThreadHangStats.h

114 lines
3.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* 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_BackgroundHangTelemetry_h
#define mozilla_BackgroundHangTelemetry_h
#include "mozilla/Array.h"
#include "mozilla/Assertions.h"
#include "mozilla/Move.h"
#include "mozilla/Mutex.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Vector.h"
#include "nsString.h"
#include "prinrval.h"
namespace mozilla {
namespace Telemetry {
static const size_t kTimeHistogramBuckets = 8 * sizeof(PRIntervalTime);
/* TimeHistogram is an efficient histogram that puts time durations into
exponential (base 2) buckets; times are accepted in PRIntervalTime and
stored in milliseconds. */
class TimeHistogram : public mozilla::Array<uint32_t, kTimeHistogramBuckets>
{
public:
TimeHistogram()
{
mozilla::PodArrayZero(*this);
}
// Get minimum (inclusive) range of bucket in milliseconds
uint32_t GetBucketMin(size_t aBucket) const {
MOZ_ASSERT(aBucket < ArrayLength(*this));
return (1u << aBucket) & ~1u; // Bucket 0 starts at 0, not 1
}
// Get maximum (inclusive) range of bucket in milliseconds
uint32_t GetBucketMax(size_t aBucket) const {
MOZ_ASSERT(aBucket < ArrayLength(*this));
return (1u << (aBucket + 1u)) - 1u;
}
void Add(PRIntervalTime aTime);
};
/* A hang histogram consists of a stack associated with the
hang, along with a time histogram of the hang times. */
class HangHistogram : public TimeHistogram
{
public:
typedef mozilla::Vector<const char*, 8> Stack;
private:
static uint32_t GetHash(const Stack& aStack);
Stack mStack;
// Use a hash to speed comparisons
const uint32_t mHash;
public:
explicit HangHistogram(Stack&& aStack)
: mStack(mozilla::Move(aStack))
, mHash(GetHash(mStack))
{
}
HangHistogram(HangHistogram&& aOther)
: TimeHistogram(mozilla::Move(aOther))
, mStack(mozilla::Move(aOther.mStack))
, mHash(mozilla::Move(aOther.mHash))
{
}
bool operator==(const HangHistogram& aOther) const;
bool operator!=(const HangHistogram& aOther) const
{
return !operator==(aOther);
}
const Stack& GetStack() const {
return mStack;
}
};
/* Thread hang stats consist of
- thread name
- time histogram of all task run times
- hang histograms of individual hangs. */
class ThreadHangStats
{
private:
nsAutoCString mName;
public:
TimeHistogram mActivity;
mozilla::Vector<HangHistogram, 4> mHangs;
explicit ThreadHangStats(const char* aName)
: mName(aName)
{
}
ThreadHangStats(ThreadHangStats&& aOther)
: mName(mozilla::Move(aOther.mName))
, mActivity(mozilla::Move(aOther.mActivity))
, mHangs(mozilla::Move(aOther.mHangs))
{
}
const char* GetName() const {
return mName.get();
}
};
} // namespace Telemetry
} // namespace mozilla
#endif // mozilla_BackgroundHangTelemetry_h