gecko-dev/tools/profiler/core/ProfilerBacktrace.cpp
Gerald Squelart b2df384fc7 Bug 1658232 - ProfilerBacktrace can reference or own a ProfileBuffer and/or ProfileChunkedBuffer - r=canaltinova,gregtatum
Instead of always taking ownership of both heap-allocated `ProfileBuffer` and `ProfileChunkedBuffer`, `ProfilerBacktrace` can now accept:
- Unique pointers to both or either, similar to what it was before, so a ProfilerBacktrace can be kept for later use.
- Non-owning pointers to both or either, to allow callers to use stack-based buffer(s); null pointers are allowed for totally empty backtraces.

Only the `ProfileChunkedBuffer` contains the actual data, we can create a `ProfileBuffer` on the spot if not provided.

Differential Revision: https://phabricator.services.mozilla.com/D86512
2020-08-13 03:30:02 +00:00

99 lines
4.3 KiB
C++

/* -*- 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 "ProfilerBacktrace.h"
#include "ProfileBuffer.h"
#include "ProfiledThreadData.h"
#include "ThreadInfo.h"
#include "mozilla/ProfileJSONWriter.h"
ProfilerBacktrace::ProfilerBacktrace(
const char* aName, int aThreadId,
mozilla::UniquePtr<mozilla::ProfileChunkedBuffer>
aProfileChunkedBufferStorage,
mozilla::UniquePtr<ProfileBuffer>
aProfileBufferStorageOrNull /* = nullptr */)
: mName(aName),
mThreadId(aThreadId),
mOptionalProfileChunkedBufferStorage(
std::move(aProfileChunkedBufferStorage)),
mProfileChunkedBuffer(mOptionalProfileChunkedBufferStorage.get()),
mOptionalProfileBufferStorage(std::move(aProfileBufferStorageOrNull)),
mProfileBuffer(mOptionalProfileBufferStorage.get()) {
MOZ_COUNT_CTOR(ProfilerBacktrace);
if (mProfileBuffer) {
MOZ_RELEASE_ASSERT(mProfileChunkedBuffer,
"If we take ownership of a ProfileBuffer, we must also "
"receive ownership of a ProfileChunkedBuffer");
MOZ_RELEASE_ASSERT(
mProfileChunkedBuffer == &mProfileBuffer->UnderlyingChunkedBuffer(),
"If we take ownership of a ProfileBuffer, we must also receive "
"ownership of its ProfileChunkedBuffer");
}
MOZ_ASSERT(
!mProfileChunkedBuffer || !mProfileChunkedBuffer->IsThreadSafe(),
"ProfilerBacktrace only takes a non-thread-safe ProfileChunkedBuffer");
}
ProfilerBacktrace::ProfilerBacktrace(
const char* aName, int aThreadId,
mozilla::ProfileChunkedBuffer* aExternalProfileChunkedBuffer,
ProfileBuffer* aExternalProfileBuffer)
: mName(aName),
mThreadId(aThreadId),
mProfileChunkedBuffer(aExternalProfileChunkedBuffer),
mProfileBuffer(aExternalProfileBuffer) {
MOZ_COUNT_CTOR(ProfilerBacktrace);
if (!mProfileChunkedBuffer) {
if (mProfileBuffer) {
// We don't have a ProfileChunkedBuffer but we have a ProfileBuffer, use
// the latter's ProfileChunkedBuffer.
mProfileChunkedBuffer = &mProfileBuffer->UnderlyingChunkedBuffer();
MOZ_ASSERT(!mProfileChunkedBuffer->IsThreadSafe(),
"ProfilerBacktrace only takes a non-thread-safe "
"ProfileChunkedBuffer");
}
} else {
if (mProfileBuffer) {
MOZ_RELEASE_ASSERT(
mProfileChunkedBuffer == &mProfileBuffer->UnderlyingChunkedBuffer(),
"If we reference both ProfileChunkedBuffer and ProfileBuffer, they "
"must already be connected");
}
MOZ_ASSERT(!mProfileChunkedBuffer->IsThreadSafe(),
"ProfilerBacktrace only takes a non-thread-safe "
"ProfileChunkedBuffer");
}
}
ProfilerBacktrace::~ProfilerBacktrace() { MOZ_COUNT_DTOR(ProfilerBacktrace); }
void ProfilerBacktrace::StreamJSON(SpliceableJSONWriter& aWriter,
const mozilla::TimeStamp& aProcessStartTime,
UniqueStacks& aUniqueStacks) {
// Unlike ProfiledThreadData::StreamJSON, we don't need to call
// ProfileBuffer::AddJITInfoForRange because ProfileBuffer does not contain
// any JitReturnAddr entries. For synchronous samples, JIT frames get expanded
// at sample time.
if (mProfileBuffer) {
StreamSamplesAndMarkers(mName.c_str(), mThreadId, *mProfileBuffer, aWriter,
""_ns, ""_ns, aProcessStartTime,
/* aRegisterTime */ mozilla::TimeStamp(),
/* aUnregisterTime */ mozilla::TimeStamp(),
/* aSinceTime */ 0, aUniqueStacks);
} else if (mProfileChunkedBuffer) {
ProfileBuffer profileBuffer(*mProfileChunkedBuffer);
StreamSamplesAndMarkers(mName.c_str(), mThreadId, profileBuffer, aWriter,
""_ns, ""_ns, aProcessStartTime,
/* aRegisterTime */ mozilla::TimeStamp(),
/* aUnregisterTime */ mozilla::TimeStamp(),
/* aSinceTime */ 0, aUniqueStacks);
}
// If there are no buffers, the backtrace is empty and nothing is streamed.
}