// 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.
#include "base/debug/trace_event_impl.h"
#include <algorithm>
#include "base/bind.h"
#include "base/debug/trace_event.h"
#include "base/file_util.h"
#include "base/format_macros.h"
#include "base/lazy_instance.h"
#include "base/memory/singleton.h"
#include "base/process_util.h"
#include "base/stringprintf.h"
#include "base/string_tokenizer.h"
#include "base/threading/platform_thread.h"
#include "base/threading/thread_local.h"
#include "base/utf_string_conversions.h"
#include "base/stl_util.h"
#include "base/sys_info.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "base/time.h"
#if defined(OS_WIN)
#include "base/debug/trace_event_win.h"
#endif
class DeleteTraceLogForTesting {
public:
static void Delete() {
Singleton<base::debug::TraceLog,
StaticMemorySingletonTraits<base::debug::TraceLog> >::OnExit(0);
}
};
namespace base {
namespace debug {
// Controls the number of trace events we will buffer in-memory
// before throwing them away.
const size_t kTraceEventBufferSize = 500000;
const size_t kTraceEventBatchSize = 1000;
#define TRACE_EVENT_MAX_CATEGORIES 100
namespace {
// Parallel arrays g_categories and g_category_enabled are separate so that
// a pointer to a member of g_category_enabled can be easily converted to an
// index into g_categories. This allows macros to deal only with char enabled
// pointers from g_category_enabled, and we can convert internally to determine
// the category name from the char enabled pointer.
const char* g_categories[TRACE_EVENT_MAX_CATEGORIES] = {
"tracing already shutdown",
"tracing categories exhausted; must increase TRACE_EVENT_MAX_CATEGORIES",
"__metadata",
};
// The enabled flag is char instead of bool so that the API can be used from C.
unsigned char g_category_enabled[TRACE_EVENT_MAX_CATEGORIES] = { 0 };
const int g_category_already_shutdown = 0;
const int g_category_categories_exhausted = 1;
const int g_category_metadata = 2;
int g_category_index = 3; // skip initial 3 categories
// The most-recently captured name of the current thread
LazyInstance<ThreadLocalPointer<const char> >::Leaky
g_current_thread_name = LAZY_INSTANCE_INITIALIZER;
void AppendValueAsJSON(unsigned char type,
TraceEvent::TraceValue value,
std::string* out) {
std::string::size_type start_pos;
switch (type) {
case TRACE_VALUE_TYPE_BOOL:
*out += value.as_bool ? "true" : "false";
break;
case TRACE_VALUE_TYPE_UINT:
StringAppendF(out, "%" PRIu64, static_cast<uint64>(value.as_uint));
break;
case TRACE_VALUE_TYPE_INT:
StringAppendF(out, "%" PRId64, static_cast<int64>(value.as_int));
break;
case TRACE_VALUE_TYPE_DOUBLE:
StringAppendF(out, "%f", value.as_double);
break;
case TRACE_VALUE_TYPE_POINTER:
// JSON only supports double and int numbers.
// So as not to lose bits from a 64-bit pointer, output as a hex string.
StringAppendF(out, "\"%" PRIx64 "\"", static_cast<uint64>(
reinterpret_cast<intptr_t>(
value.as_pointer)));
break;
case TRACE_VALUE_TYPE_STRING:
case TRACE_VALUE_TYPE_COPY_STRING:
*out += "\"";
start_pos = out->size();
*out += value.as_string ? value.as_string : "NULL";
// insert backslash before special characters for proper json format.
while ((start_pos = out->find_first_of("\\\"", start_pos)) !=
std::string::npos) {
out->insert(start_pos, 1, '\\');
// skip inserted escape character and following character.
start_pos += 2;
}
*out += "\"";
break;
default:
NOTREACHED() << "Don't know how to print this value";
break;
}
}
} // namespace
////////////////////////////////////////////////////////////////////////////////
//
// TraceEvent
//
////////////////////////////////////////////////////////////////////////////////
namespace {
size_t GetAllocLength(const char* str) { return str ? strlen(str) + 1 : 0; }
// Copies |*member| into |*buffer|, sets |*member| to point to this new
// location, and then advances |*buffer| by the amount written.
void CopyTraceEventParameter(char** buffer,
const char** member,
const char* end) {
if (*member) {
size_t written = strlcpy(*buffer, *member, end - *buffer) + 1;
DCHECK_LE(static_cast<int>(written), end - *buffer);
*member = *buffer;
*buffer += written;
}
}
} // namespace
TraceEvent::TraceEvent()
: id_(0u),
category_enabled_(NULL),
name_(NULL),
thread_id_(0),
phase_(TRACE_EVENT_PHASE_BEGIN),
flags_(0) {
arg_names_[0] = NULL;
arg_names_[1] = NULL;
memset(arg_values_, 0, sizeof(arg_values_));
}
TraceEvent::TraceEvent(int thread_id,
TimeTicks timestamp,
char phase,
const unsigned char* category_enabled,
const char* name,
unsigned long long id,
int num_args,
const char** arg_names,
const unsigned char* arg_types,
const unsigned long long* arg_values,
unsigned char flags)
: timestamp_(timestamp),
id_(id),
category_enabled_(category_enabled),
name_(name),
thread_id_(thread_id),
phase_(phase),
flags_(flags) {
// Clamp num_args since it may have been set by a third_party library.
num_args = (num_args > kTraceMaxNumArgs) ? kTraceMaxNumArgs : num_args;
int i = 0;
for (; i < num_args; ++i) {
arg_names_[i] = arg_names[i];
arg_values_[i].as_uint = arg_values[i];
arg_types_[i] = arg_types[i];
}
for (; i < kTraceMaxNumArgs; ++i) {
arg_names_[i] = NULL;
arg_values_[i].as_uint = 0u;
arg_types_[i] = TRACE_VALUE_TYPE_UINT;
}
bool copy = !!(flags & TRACE_EVENT_FLAG_COPY);
size_t alloc_size = 0;
if (copy) {
alloc_size += GetAllocLength(name);
for (i = 0; i < num_args; ++i) {
alloc_size += GetAllocLength(arg_names_[i]);
if (arg_types_[i] == TRACE_VALUE_TYPE_STRING)
arg_types_[i] = TRACE_VALUE_TYPE_COPY_STRING;
}
}
bool arg_is_copy[kTraceMaxNumArgs];
for (i = 0; i < num_args; ++i) {
// We only take a copy of arg_vals if they are of type COPY_STRING.
arg_is_copy[i] = (arg_types_[i] == TRACE_VALUE_TYPE_COPY_STRING);
if (arg_is_copy[i])
alloc_size += GetAllocLength(arg_values_[i].as_string);
}
if (alloc_size) {
parameter_copy_storage_ = new base::RefCountedString;
parameter_copy_storage_->data().resize(alloc_size);
char* ptr = string_as_array(¶meter_copy_storage_->data());
const char* end = ptr + alloc_size;
if (copy) {
CopyTraceEventParameter(&ptr, &name_, end);
for (i = 0; i < num_args; ++i)
CopyTraceEventParameter(&ptr, &arg_names_[i], end);
}
for (i = 0; i < num_args; ++i) {
if (arg_is_copy[i])
CopyTraceEventParameter(&ptr, &arg_values_[i].as_string, end);
}
DCHECK_EQ(end, ptr) << "Overrun by " << ptr - end;
}
}
TraceEvent::~TraceEvent() {
}
void TraceEvent::AppendEventsAsJSON(const std::vector<TraceEvent>& events,
size_t start,
size_t count,
std::string* out) {
for (size_t i = 0; i < count && start + i < events.size(); ++i) {
if (i > 0)
*out += ",";
events[i + start].AppendAsJSON(out);
}
}
void TraceEvent::AppendAsJSON(std::string* out) const {
int64 time_int64 = timestamp_.ToInternalValue();
int process_id = TraceLog::GetInstance()->process_id();
// Category name checked at category creation time.
DCHECK(!strchr(name_, '"'));
StringAppendF(out,
"{\"cat\":\"%s\",\"pid\":%i,\"tid\":%i,\"ts\":%" PRId64 ","
"\"ph\":\"%c\",\"name\":\"%s\",\"args\":{",
TraceLog::GetCategoryName(category_enabled_),
process_id,
thread_id_,
time_int64,
phase_,
name_);
// Output argument names and values, stop at first NULL argument name.
for (int i = 0; i < kTraceMaxNumArgs && arg_names_[i]; ++i) {
if (i > 0)
*out += ",";
*out += "\"";
*out += arg_names_[i];
*out += "\":";
AppendValueAsJSON(arg_types_[i], arg_values_[i], out);
}
*out += "}";
// If id_ is set, print it out as a hex string so we don't loose any
// bits (it might be a 64-bit pointer).
if (flags_ & TRACE_EVENT_FLAG_HAS_ID)
StringAppendF(out, ",\"id\":\"%" PRIx64 "\"", static_cast<uint64>(id_));
*out += "}";
}
////////////////////////////////////////////////////////////////////////////////
//
// TraceResultBuffer
//
////////////////////////////////////////////////////////////////////////////////
TraceResultBuffer::OutputCallback
TraceResultBuffer::SimpleOutput::GetCallback() {
return base::Bind(&SimpleOutput::Append, base::Unretained(this));
}
void TraceResultBuffer::SimpleOutput::Append(
const std::string& json_trace_output) {
json_output += json_trace_output;
}
TraceResultBuffer::TraceResultBuffer() : append_comma_(false) {
}
TraceResultBuffer::~TraceResultBuffer() {
}
void TraceResultBuffer::SetOutputCallback(
const OutputCallback& json_chunk_callback) {
output_callback_ = json_chunk_callback;
}
void TraceResultBuffer::Start() {
append_comma_ = false;
output_callback_.Run("[");
}
void TraceResultBuffer::AddFragment(const std::string& trace_fragment) {
if (append_comma_)
output_callback_.Run(",");
append_comma_ = true;
output_callback_.Run(trace_fragment);
}
void TraceResultBuffer::Finish() {
output_callback_.Run("]");
}
////////////////////////////////////////////////////////////////////////////////
//
// TraceLog
//
////////////////////////////////////////////////////////////////////////////////
// static
TraceLog* TraceLog::GetInstance() {
return Singleton<TraceLog, StaticMemorySingletonTraits<TraceLog> >::get();
}
TraceLog::TraceLog()
: enabled_(false)
, dispatching_to_observer_list_(false) {
// Trace is enabled or disabled on one thread while other threads are
// accessing the enabled flag. We don't care whether edge-case events are
// traced or not, so we allow races on the enabled flag to keep the trace
// macros fast.
// TODO(jbates): ANNOTATE_BENIGN_RACE_SIZED crashes windows TSAN bots:
// ANNOTATE_BENIGN_RACE_SIZED(g_category_enabled, sizeof(g_category_enabled),
// "trace_event category enabled");
for (int i = 0; i < TRACE_EVENT_MAX_CATEGORIES; ++i) {
ANNOTATE_BENIGN_RACE(&g_category_enabled[i],
"trace_event category enabled");
}
#if defined(OS_NACL) // NaCl shouldn't expose the process id.
SetProcessID(0);
#else
SetProcessID(static_cast<int>(base::GetCurrentProcId()));
#endif
}
TraceLog::~TraceLog() {
}
const unsigned char* TraceLog::GetCategoryEnabled(const char* name) {
TraceLog* tracelog = GetInstance();
if (!tracelog) {
DCHECK(!g_category_enabled[g_category_already_shutdown]);
return &g_category_enabled[g_category_already_shutdown];
}
return tracelog->GetCategoryEnabledInternal(name);
}
const char* TraceLog::GetCategoryName(const unsigned char* category_enabled) {
// Calculate the index of the category by finding category_enabled in
// g_category_enabled array.
uintptr_t category_begin = reinterpret_cast<uintptr_t>(g_category_enabled);
uintptr_t category_ptr = reinterpret_cast<uintptr_t>(category_enabled);
DCHECK(category_ptr >= category_begin &&
category_ptr < reinterpret_cast<uintptr_t>(g_category_enabled +
TRACE_EVENT_MAX_CATEGORIES)) <<
"out of bounds category pointer";
uintptr_t category_index =
(category_ptr - category_begin) / sizeof(g_category_enabled[0]);
return g_categories[category_index];
}
static void EnableMatchingCategory(int category_index,
const std::vector<std::string>& patterns,
unsigned char is_included) {
std::vector<std::string>::const_iterator ci = patterns.begin();
bool is_match = false;
for (; ci != patterns.end(); ++ci) {
is_match = MatchPattern(g_categories[category_index], ci->c_str());
if (is_match)
break;
}
g_category_enabled[category_index] = is_match ?
is_included : (is_included ^ 1);
}
// Enable/disable each category based on the category filters in |patterns|.
// If the category name matches one of the patterns, its enabled status is set
// to |is_included|. Otherwise its enabled status is set to !|is_included|.
static void EnableMatchingCategories(const std::vector<std::string>& patterns,
unsigned char is_included) {
for (int i = 0; i < g_category_index; i++)
EnableMatchingCategory(i, patterns, is_included);
}
const unsigned char* TraceLog::GetCategoryEnabledInternal(const char* name) {
AutoLock lock(lock_);
DCHECK(!strchr(name, '"')) << "Category names may not contain double quote";
// Search for pre-existing category matching this name
for (int i = 0; i < g_category_index; i++) {
if (strcmp(g_categories[i], name) == 0)
return &g_category_enabled[i];
}
// Create a new category
DCHECK(g_category_index < TRACE_EVENT_MAX_CATEGORIES) <<
"must increase TRACE_EVENT_MAX_CATEGORIES";
if (g_category_index < TRACE_EVENT_MAX_CATEGORIES) {
int new_index = g_category_index++;
g_categories[new_index] = name;
DCHECK(!g_category_enabled[new_index]);
if (enabled_) {
// Note that if both included and excluded_categories are empty, the else
// clause below excludes nothing, thereby enabling this category.
if (!included_categories_.empty())
EnableMatchingCategory(new_index, included_categories_, 1);
else
EnableMatchingCategory(new_index, excluded_categories_, 0);
} else {
g_category_enabled[new_index] = 0;
}
return &g_category_enabled[new_index];
} else {
return &g_category_enabled[g_category_categories_exhausted];
}
}
void TraceLog::GetKnownCategories(std::vector<std::string>* categories) {
AutoLock lock(lock_);
for (int i = 0; i < g_category_index; i++)
categories->push_back(g_categories[i]);
}
void TraceLog::SetEnabled(const std::vector<std::string>& included_categories,
const std::vector<std::string>& excluded_categories) {
AutoLock lock(lock_);
if (enabled_)
return;
if (dispatching_to_observer_list_) {
DLOG(ERROR) <<
"Cannot manipulate TraceLog::Enabled state from an observer.";
return;
}
dispatching_to_observer_list_ = true;
FOR_EACH_OBSERVER(EnabledStateChangedObserver, enabled_state_observer_list_,
OnTraceLogWillEnable());
dispatching_to_observer_list_ = false;
logged_events_.reserve(1024);
enabled_ = true;
included_categories_ = included_categories;
excluded_categories_ = excluded_categories;
// Note that if both included and excluded_categories are empty, the else
// clause below excludes nothing, thereby enabling all categories.
if (!included_categories_.empty())
EnableMatchingCategories(included_categories_, 1);
else
EnableMatchingCategories(excluded_categories_, 0);
}
void TraceLog::SetEnabled(const std::string& categories) {
std::vector<std::string> included, excluded;
// Tokenize list of categories, delimited by ','.
StringTokenizer tokens(categories, ",");
while (tokens.GetNext()) {
bool is_included = true;
std::string category = tokens.token();
// Excluded categories start with '-'.
if (category.at(0) == '-') {
// Remove '-' from category string.
category = category.substr(1);
is_included = false;
}
if (is_included)
included.push_back(category);
else
excluded.push_back(category);
}
SetEnabled(included, excluded);
}
void TraceLog::GetEnabledTraceCategories(
std::vector<std::string>* included_out,
std::vector<std::string>* excluded_out) {
AutoLock lock(lock_);
if (enabled_) {
*included_out = included_categories_;
*excluded_out = excluded_categories_;
}
}
void TraceLog::SetDisabled() {
{
AutoLock lock(lock_);
if (!enabled_)
return;
if (dispatching_to_observer_list_) {
DLOG(ERROR)
<< "Cannot manipulate TraceLog::Enabled state from an observer.";
return;
}
dispatching_to_observer_list_ = true;
FOR_EACH_OBSERVER(EnabledStateChangedObserver, enabled_state_observer_list_,
OnTraceLogWillDisable());
dispatching_to_observer_list_ = false;
enabled_ = false;
included_categories_.clear();
excluded_categories_.clear();
for (int i = 0; i < g_category_index; i++)
g_category_enabled[i] = 0;
AddThreadNameMetadataEvents();
AddClockSyncMetadataEvents();
} // release lock
Flush();
}
void TraceLog::SetEnabled(bool enabled) {
if (enabled)
SetEnabled(std::vector<std::string>(), std::vector<std::string>());
else
SetDisabled();
}
void TraceLog::AddEnabledStateObserver(EnabledStateChangedObserver* listener) {
enabled_state_observer_list_.AddObserver(listener);
}
void TraceLog::RemoveEnabledStateObserver(
EnabledStateChangedObserver* listener) {
enabled_state_observer_list_.RemoveObserver(listener);
}
float TraceLog::GetBufferPercentFull() const {
return (float)((double)logged_events_.size()/(double)kTraceEventBufferSize);
}
void TraceLog::SetOutputCallback(const TraceLog::OutputCallback& cb) {
AutoLock lock(lock_);
output_callback_ = cb;
}
void TraceLog::SetBufferFullCallback(const TraceLog::BufferFullCallback& cb) {
AutoLock lock(lock_);
buffer_full_callback_ = cb;
}
void TraceLog::Flush() {
std::vector<TraceEvent> previous_logged_events;
OutputCallback output_callback_copy;
{
AutoLock lock(lock_);
previous_logged_events.swap(logged_events_);
output_callback_copy = output_callback_;
} // release lock
if (output_callback_copy.is_null())
return;
for (size_t i = 0;
i < previous_logged_events.size();
i += kTraceEventBatchSize) {
scoped_refptr<RefCountedString> json_events_str_ptr =
new RefCountedString();
TraceEvent::AppendEventsAsJSON(previous_logged_events,
i,
kTraceEventBatchSize,
&(json_events_str_ptr->data()));
output_callback_copy.Run(json_events_str_ptr);
}
}
int TraceLog::AddTraceEvent(char phase,
const unsigned char* category_enabled,
const char* name,
unsigned long long id,
int num_args,
const char** arg_names,
const unsigned char* arg_types,
const unsigned long long* arg_values,
int threshold_begin_id,
long long threshold,
unsigned char flags) {
DCHECK(name);
TimeTicks now = TimeTicks::NowFromSystemTraceTime();
BufferFullCallback buffer_full_callback_copy;
int ret_begin_id = -1;
{
AutoLock lock(lock_);
if (!*category_enabled)
return -1;
if (logged_events_.size() >= kTraceEventBufferSize)
return -1;
int thread_id = static_cast<int>(PlatformThread::CurrentId());
const char* new_name = PlatformThread::GetName();
// Check if the thread name has been set or changed since the previous
// call (if any), but don't bother if the new name is empty. Note this will
// not detect a thread name change within the same char* buffer address: we
// favor common case performance over corner case correctness.
if (new_name != g_current_thread_name.Get().Get() &&
new_name && *new_name) {
g_current_thread_name.Get().Set(new_name);
base::hash_map<int, std::string>::iterator existing_name =
thread_names_.find(thread_id);
if (existing_name == thread_names_.end()) {
// This is a new thread id, and a new name.
thread_names_[thread_id] = new_name;
} else {
// This is a thread id that we've seen before, but potentially with a
// new name.
std::vector<base::StringPiece> existing_names;
Tokenize(existing_name->second, ",", &existing_names);
bool found = std::find(existing_names.begin(),
existing_names.end(),
new_name) != existing_names.end();
if (!found) {
existing_name->second.push_back(',');
existing_name->second.append(new_name);
}
}
}
if (threshold_begin_id > -1) {
DCHECK(phase == TRACE_EVENT_PHASE_END);
size_t begin_i = static_cast<size_t>(threshold_begin_id);
// Return now if there has been a flush since the begin event was posted.
if (begin_i >= logged_events_.size())
return -1;
// Determine whether to drop the begin/end pair.
TimeDelta elapsed = now - logged_events_[begin_i].timestamp();
if (elapsed < TimeDelta::FromMicroseconds(threshold)) {
// Remove begin event and do not add end event.
// This will be expensive if there have been other events in the
// mean time (should be rare).
logged_events_.erase(logged_events_.begin() + begin_i);
return -1;
}
}
if (flags & TRACE_EVENT_FLAG_MANGLE_ID)
id ^= process_id_hash_;
ret_begin_id = static_cast<int>(logged_events_.size());
logged_events_.push_back(
TraceEvent(thread_id,
now, phase, category_enabled, name, id,
num_args, arg_names, arg_types, arg_values,
flags));
if (logged_events_.size() == kTraceEventBufferSize) {
buffer_full_callback_copy = buffer_full_callback_;
}
} // release lock
if (!buffer_full_callback_copy.is_null())
buffer_full_callback_copy.Run();
return ret_begin_id;
}
void TraceLog::AddTraceEventEtw(char phase,
const char* name,
const void* id,
const char* extra) {
#if defined(OS_WIN)
TraceEventETWProvider::Trace(name, phase, id, extra);
#endif
INTERNAL_TRACE_EVENT_ADD(phase, "ETW Trace Event", name,
TRACE_EVENT_FLAG_COPY, "id", id, "extra", extra);
}
void TraceLog::AddTraceEventEtw(char phase,
const char* name,
const void* id,
const std::string& extra)
{
#if defined(OS_WIN)
TraceEventETWProvider::Trace(name, phase, id, extra);
#endif
INTERNAL_TRACE_EVENT_ADD(phase, "ETW Trace Event", name,
TRACE_EVENT_FLAG_COPY, "id", id, "extra", extra);
}
void TraceLog::AddClockSyncMetadataEvents() {
#if defined(OS_ANDROID)
// Since Android does not support sched_setaffinity, we cannot establish clock
// sync unless the scheduler clock is set to global. If the trace_clock file
// can't be read, we will assume the kernel doesn't support tracing and do
// nothing.
std::string clock_mode;
if (!file_util::ReadFileToString(
FilePath("/sys/kernel/debug/tracing/trace_clock"),
&clock_mode))
return;
if (clock_mode != "local [global]\n") {
DLOG(WARNING) <<
"The kernel's tracing clock must be set to global in order for " <<
"trace_event to be synchronized with . Do this by\n" <<
" echo global > /sys/kerel/debug/tracing/trace_clock";
return;
}
// Android's kernel trace system has a trace_marker feature: this is a file on
// debugfs that takes the written data and pushes it onto the trace
// buffer. So, to establish clock sync, we write our monotonic clock into that
// trace buffer.
TimeTicks now = TimeTicks::NowFromSystemTraceTime();
double now_in_seconds = now.ToInternalValue() / 1000000.0;
std::string marker =
StringPrintf("trace_event_clock_sync: parent_ts=%f\n",
now_in_seconds);
if (file_util::WriteFile(
FilePath("/sys/kernel/debug/tracing/trace_marker"),
marker.c_str(), marker.size()) == -1) {
DLOG(WARNING) << "Couldn't write to /sys/kernel/debug/tracing/trace_marker";
return;
}
#endif
}
void TraceLog::AddThreadNameMetadataEvents() {
lock_.AssertAcquired();
for(base::hash_map<int, std::string>::iterator it = thread_names_.begin();
it != thread_names_.end();
it++) {
if (!it->second.empty()) {
int num_args = 1;
const char* arg_name = "name";
unsigned char arg_type;
unsigned long long arg_value;
trace_event_internal::SetTraceValue(it->second, &arg_type, &arg_value);
logged_events_.push_back(
TraceEvent(it->first,
TimeTicks(), TRACE_EVENT_PHASE_METADATA,
&g_category_enabled[g_category_metadata],
"thread_name", trace_event_internal::kNoEventId,
num_args, &arg_name, &arg_type, &arg_value,
TRACE_EVENT_FLAG_NONE));
}
}
}
void TraceLog::DeleteForTesting() {
DeleteTraceLogForTesting::Delete();
}
void TraceLog::Resurrect() {
StaticMemorySingletonTraits<TraceLog>::Resurrect();
}
void TraceLog::SetProcessID(int process_id) {
process_id_ = process_id;
// Create a FNV hash from the process ID for XORing.
// See http://isthe.com/chongo/tech/comp/fnv/ for algorithm details.
unsigned long long offset_basis = 14695981039346656037ull;
unsigned long long fnv_prime = 1099511628211ull;
unsigned long long pid = static_cast<unsigned long long>(process_id_);
process_id_hash_ = (offset_basis ^ pid) * fnv_prime;
}
} // namespace debug
} // namespace base