Source code

Revision control

Copy as Markdown

Other Tools

/* -*- 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 "ETWTools.h"
#include <atomic>
namespace ETW {
std::atomic<ULONGLONG> gETWCollectionMask = 0;
// Define a handle to a TraceLogging provider.
//
// > All ETW providers are identified by both provider name and provider ID.
// > [...]
// > Microsoft recommends generating the provider ID from the provider name
// > using the ETW name-hashing algorithm described below. This provides
// > several benefits: it's easier to remember just the name; the ID and the
// > name are automatically linked; tools such as tracelog, traceview,
// > EventSource, and WPR have special support for providers that use IDs
// > generated using this algorithm.
//
//
// The GUID generated for "Mozilla.FirefoxTraceLogger" is:
// {c923f508-96e4-5515-e32c-7539d1b10504}
TRACELOGGING_DEFINE_PROVIDER(kFirefoxTraceLoggingProvider,
"Mozilla.FirefoxTraceLogger",
(0xc923f508, 0x96e4, 0x5515, 0xe3, 0x2c, 0x75,
0x39, 0xd1, 0xb1, 0x05, 0x04));
static void NTAPI ETWEnableCallback(LPCGUID aSourceId, ULONG aIsEnabled,
UCHAR aLevel, ULONGLONG aMatchAnyKeyword,
ULONGLONG aMatchAllKeyword,
PEVENT_FILTER_DESCRIPTOR aFilterData,
PVOID aCallbackContext) {
// This is called on a CRT worker thread. This means this might race a bit
// with our main thread, but that is okay.
if (aIsEnabled) {
mozilla::profiler::detail::RacyFeatures::SetETWCollectionActive();
} else {
mozilla::profiler::detail::RacyFeatures::SetETWCollectionInactive();
}
// The lower 48 bits of the provider flags are used to mask markers.
gETWCollectionMask = aMatchAnyKeyword;
}
void Init() {
TraceLoggingRegisterEx(kFirefoxTraceLoggingProvider, ETWEnableCallback,
nullptr);
}
void Shutdown() { TraceLoggingUnregister(kFirefoxTraceLoggingProvider); }
} // namespace ETW