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/* -*- Mode: C++; tab-width: 2; 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/AutoProfilerLabel.h"
#include "mozilla/Assertions.h"
#include "mozilla/PlatformMutex.h"
namespace mozilla {
// RAII class that encapsulates all shared static data, and enforces locking
// when accessing this data.
class MOZ_RAII AutoProfilerLabelData {
public:
AutoProfilerLabelData() { sAPLMutex.Lock(); }
~AutoProfilerLabelData() { sAPLMutex.Unlock(); }
AutoProfilerLabelData(const AutoProfilerLabelData&) = delete;
void operator=(const AutoProfilerLabelData&) = delete;
const ProfilerLabelEnter& EnterCRef() const { return sEnter; }
ProfilerLabelEnter& EnterRef() { return sEnter; }
const ProfilerLabelExit& ExitCRef() const { return sExit; }
ProfilerLabelExit& ExitRef() { return sExit; }
const uint32_t& GenerationCRef() const { return sGeneration; }
uint32_t& GenerationRef() { return sGeneration; }
static bool RacyIsProfilerPresent() { return !!sGeneration; }
private:
// Thin shell around mozglue PlatformMutex, for local internal use.
// Does not preserve behavior in JS record/replay.
class Mutex : private mozilla::detail::MutexImpl {
public:
Mutex() = default;
void Lock() { mozilla::detail::MutexImpl::lock(); }
void Unlock() { mozilla::detail::MutexImpl::unlock(); }
};
// Mutex protecting access to the following static members.
static Mutex sAPLMutex MOZ_UNANNOTATED;
static ProfilerLabelEnter sEnter;
static ProfilerLabelExit sExit;
// Current "generation" of RegisterProfilerLabelEnterExit calls.
static uint32_t sGeneration;
};
/* static */ AutoProfilerLabelData::Mutex AutoProfilerLabelData::sAPLMutex;
/* static */ ProfilerLabelEnter AutoProfilerLabelData::sEnter = nullptr;
/* static */ ProfilerLabelExit AutoProfilerLabelData::sExit = nullptr;
/* static */ uint32_t AutoProfilerLabelData::sGeneration = 0;
void RegisterProfilerLabelEnterExit(ProfilerLabelEnter aEnter,
ProfilerLabelExit aExit) {
MOZ_ASSERT(!aEnter == !aExit, "Must provide both null or both non-null");
AutoProfilerLabelData data;
MOZ_ASSERT(!aEnter != !data.EnterRef(),
"Must go from null to non-null, or from non-null to null");
data.EnterRef() = aEnter;
data.ExitRef() = aExit;
++data.GenerationRef();
}
bool IsProfilerPresent() {
return AutoProfilerLabelData::RacyIsProfilerPresent();
}
ProfilerLabel ProfilerLabelBegin(const char* aLabelName,
const char* aDynamicString, void* aSp) {
const AutoProfilerLabelData data;
void* entryContext = (data.EnterCRef())
? data.EnterCRef()(aLabelName, aDynamicString, aSp)
: nullptr;
uint32_t generation = data.GenerationCRef();
return std::make_tuple(entryContext, generation);
}
void ProfilerLabelEnd(const ProfilerLabel& aLabel) {
if (!IsValidProfilerLabel(aLabel)) {
return;
}
const AutoProfilerLabelData data;
if (data.ExitCRef() && (std::get<1>(aLabel) == data.GenerationCRef())) {
data.ExitCRef()(std::get<0>(aLabel));
}
}
AutoProfilerLabel::AutoProfilerLabel(const char* aLabel,
const char* aDynamicString) {
std::tie(mEntryContext, mGeneration) =
ProfilerLabelBegin(aLabel, aDynamicString, this);
}
AutoProfilerLabel::~AutoProfilerLabel() {
ProfilerLabelEnd(std::make_tuple(mEntryContext, mGeneration));
}
} // namespace mozilla
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