blob: 2a900bb4314f055b67a24bfea4bcdc766a569424 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This file contains the Windows-specific declarations for trace_event.h.
#ifndef BASE_DEBUG_TRACE_EVENT_WIN_H_
#define BASE_DEBUG_TRACE_EVENT_WIN_H_
#include <string>
#include "base/base_export.h"
#include "base/debug/trace_event.h"
#include "base/win/event_trace_provider.h"
// Fwd.
template <typename Type>
struct StaticMemorySingletonTraits;
namespace base {
namespace debug {
// This EtwTraceProvider subclass implements ETW logging
// for the macros above on Windows.
class BASE_EXPORT TraceEventETWProvider : public base::win::EtwTraceProvider {
public:
// Start logging trace events.
// This is a noop in this implementation.
static bool StartTracing();
// Trace begin/end/instant events, this is the bottleneck implementation
// all the others defer to.
// Allowing the use of std::string for name or extra is a convenience,
// whereas passing name or extra as a const char* avoids the construction
// of temporary std::string instances.
// If -1 is passed for name_len or extra_len, the strlen of the string will
// be used for length.
static void Trace(const char* name,
size_t name_len,
char type,
const void* id,
const char* extra,
size_t extra_len);
// Allows passing extra as a std::string for convenience.
static void Trace(const char* name,
char type,
const void* id,
const std::string& extra) {
return Trace(name, -1, type, id, extra.c_str(), extra.length());
}
// Allows passing extra as a const char* to avoid constructing temporary
// std::string instances where not needed.
static void Trace(const char* name,
char type,
const void* id,
const char* extra) {
return Trace(name, -1, type, id, extra, -1);
}
// Retrieves the singleton.
// Note that this may return NULL post-AtExit processing.
static TraceEventETWProvider* GetInstance();
// Returns true iff tracing is turned on.
bool IsTracing() {
return enable_level() >= TRACE_LEVEL_INFORMATION;
}
// Emit a trace of type |type| containing |name|, |id|, and |extra|.
// Note: |name| and |extra| must be NULL, or a zero-terminated string of
// length |name_len| or |extra_len| respectively.
// Note: if name_len or extra_len are -1, the length of the corresponding
// string will be used.
void TraceEvent(const char* name,
size_t name_len,
char type,
const void* id,
const char* extra,
size_t extra_len);
// Exposed for unittesting only, allows resurrecting our
// singleton instance post-AtExit processing.
static void Resurrect();
private:
// Ensure only the provider can construct us.
friend struct StaticMemorySingletonTraits<TraceEventETWProvider>;
TraceEventETWProvider();
DISALLOW_COPY_AND_ASSIGN(TraceEventETWProvider);
};
// The ETW trace provider GUID.
BASE_EXPORT extern const GUID kChromeTraceProviderName;
// The ETW event class GUID for 32 bit events.
BASE_EXPORT extern const GUID kTraceEventClass32;
// The ETW event class GUID for 64 bit events.
BASE_EXPORT extern const GUID kTraceEventClass64;
// The ETW event types, IDs 0x00-0x09 are reserved, so start at 0x10.
const base::win::EtwEventType kTraceEventTypeBegin = 0x10;
const base::win::EtwEventType kTraceEventTypeEnd = 0x11;
const base::win::EtwEventType kTraceEventTypeInstant = 0x12;
// If this flag is set in enable flags
enum TraceEventETWFlags {
CAPTURE_STACK_TRACE = 0x0001,
};
// The event format consists of:
// The "name" string as a zero-terminated ASCII string.
// The id pointer in the machine bitness.
// The "extra" string as a zero-terminated ASCII string.
// Optionally the stack trace, consisting of a DWORD "depth", followed
// by an array of void* (machine bitness) of length "depth".
} // namespace debug
} // namespace base
#endif // BASE_DEBUG_TRACE_EVENT_WIN_H_