gecko/tools/profiler/platform.cpp

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/* 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 <ostream>
#include <fstream>
#include <sstream>
#include <errno.h>
#include "IOInterposer.h"
#include "ProfilerIOInterposeObserver.h"
#include "platform.h"
#include "PlatformMacros.h"
#include "prenv.h"
#include "mozilla/ThreadLocal.h"
#include "PseudoStack.h"
#include "TableTicker.h"
#include "UnwinderThread2.h"
#include "nsIObserverService.h"
#include "nsDirectoryServiceUtils.h"
#include "nsDirectoryServiceDefs.h"
#include "mozilla/Services.h"
#include "nsThreadUtils.h"
#if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK)
#include "AndroidBridge.h"
#endif
mozilla::ThreadLocal<PseudoStack *> tlsPseudoStack;
mozilla::ThreadLocal<TableTicker *> tlsTicker;
// We need to track whether we've been initialized otherwise
// we end up using tlsStack without initializing it.
// Because tlsStack is totally opaque to us we can't reuse
// it as the flag itself.
bool stack_key_initialized;
TimeStamp sLastTracerEvent; // is raced on
TimeStamp sStartTime;
int sFrameNumber = 0;
int sLastFrameNumber = 0;
int sInitCount = 0; // Each init must have a matched shutdown.
static bool sIsProfiling = false; // is raced on
/* used to keep track of the last event that we sampled during */
unsigned int sLastSampledEventGeneration = 0;
/* a counter that's incremented everytime we get responsiveness event
* note: it might also be worth trackplaing everytime we go around
* the event loop */
unsigned int sCurrentEventGeneration = 0;
/* we don't need to worry about overflow because we only treat the
* case of them being the same as special. i.e. we only run into
* a problem if 2^32 events happen between samples that we need
* to know are associated with different events */
std::vector<ThreadInfo*>* Sampler::sRegisteredThreads = nullptr;
mozilla::Mutex* Sampler::sRegisteredThreadsMutex = nullptr;
TableTicker* Sampler::sActiveSampler;
static mozilla::ProfilerIOInterposeObserver* sInterposeObserver = nullptr;
void Sampler::Startup() {
sRegisteredThreads = new std::vector<ThreadInfo*>();
sRegisteredThreadsMutex = new mozilla::Mutex("sRegisteredThreads mutex");
}
void Sampler::Shutdown() {
while (sRegisteredThreads->size() > 0) {
delete sRegisteredThreads->back();
sRegisteredThreads->pop_back();
}
delete sRegisteredThreadsMutex;
delete sRegisteredThreads;
// UnregisterThread can be called after shutdown in XPCShell. Thus
// we need to point to null to ignore such a call after shutdown.
sRegisteredThreadsMutex = nullptr;
sRegisteredThreads = nullptr;
}
ThreadInfo::~ThreadInfo() {
free(mName);
if (mProfile)
delete mProfile;
Sampler::FreePlatformData(mPlatformData);
}
bool sps_version2()
{
static int version = 0; // Raced on, potentially
if (version == 0) {
bool allow2 = false; // Is v2 allowable on this platform?
# if defined(SPS_PLAT_amd64_linux) || defined(SPS_PLAT_arm_android) \
|| defined(SPS_PLAT_x86_linux)
allow2 = true;
# elif defined(SPS_PLAT_amd64_darwin) || defined(SPS_PLAT_x86_darwin) \
|| defined(SPS_PLAT_x86_windows) || defined(SPS_PLAT_x86_android) \
|| defined(SPS_PLAT_amd64_windows)
allow2 = false;
# else
# error "Unknown platform"
# endif
bool req2 = PR_GetEnv("MOZ_PROFILER_NEW") != NULL; // Has v2 been requested?
bool elfhackd = false;
# if defined(USE_ELF_HACK)
bool elfhackd = true;
# endif
if (req2 && allow2) {
version = 2;
LOG("------------------- MOZ_PROFILER_NEW set -------------------");
} else if (req2 && !allow2) {
version = 1;
LOG("--------------- MOZ_PROFILER_NEW requested, ----------------");
LOG("---------- but is not available on this platform -----------");
} else if (req2 && elfhackd) {
version = 1;
LOG("--------------- MOZ_PROFILER_NEW requested, ----------------");
LOG("--- but this build was not done with --disable-elf-hack ----");
} else {
version = 1;
LOG("----------------- MOZ_PROFILER_NEW not set -----------------");
}
}
return version == 2;
}
#if !defined(ANDROID)
/* Has MOZ_PROFILER_VERBOSE been set? */
bool moz_profiler_verbose()
{
/* 0 = not checked, 1 = unset, 2 = set */
static int status = 0; // Raced on, potentially
if (status == 0) {
if (PR_GetEnv("MOZ_PROFILER_VERBOSE") != NULL)
status = 2;
else
status = 1;
}
return status == 2;
}
#endif
static inline const char* name_UnwMode(UnwMode m)
{
switch (m) {
case UnwINVALID: return "invalid";
case UnwNATIVE: return "native";
case UnwPSEUDO: return "pseudo";
case UnwCOMBINED: return "combined";
default: return "??name_UnwMode??";
}
}
// Read env vars at startup, so as to set sUnwindMode and sInterval.
void read_profiler_env_vars()
{
bool nativeAvail = false;
# if defined(HAVE_NATIVE_UNWIND)
nativeAvail = true;
# endif
MOZ_ASSERT(sUnwindMode == UnwINVALID);
MOZ_ASSERT(sUnwindInterval == 0);
/* Set defaults */
sUnwindMode = nativeAvail ? UnwCOMBINED : UnwPSEUDO;
sUnwindInterval = 0; /* We'll have to look elsewhere */
const char* strM = PR_GetEnv("MOZ_PROFILER_MODE");
const char* strI = PR_GetEnv("MOZ_PROFILER_INTERVAL");
const char* strF = PR_GetEnv("MOZ_PROFILER_STACK_SCAN");
if (strM) {
if (0 == strcmp(strM, "pseudo"))
sUnwindMode = UnwPSEUDO;
else if (0 == strcmp(strM, "native") && nativeAvail)
sUnwindMode = UnwNATIVE;
else if (0 == strcmp(strM, "combined") && nativeAvail)
sUnwindMode = UnwCOMBINED;
else goto usage;
}
if (strI) {
errno = 0;
long int n = strtol(strI, (char**)NULL, 10);
if (errno == 0 && n >= 1 && n <= 1000) {
sUnwindInterval = n;
}
else goto usage;
}
if (strF) {
errno = 0;
long int n = strtol(strF, (char**)NULL, 10);
if (errno == 0 && n >= 0 && n <= 100) {
sUnwindStackScan = n;
}
else goto usage;
}
goto out;
usage:
LOG( "SPS: ");
LOG( "SPS: Environment variable usage:");
LOG( "SPS: ");
LOG( "SPS: MOZ_PROFILER_MODE=native for native unwind only");
LOG( "SPS: MOZ_PROFILER_MODE=pseudo for pseudo unwind only");
LOG( "SPS: MOZ_PROFILER_MODE=combined for combined native & pseudo unwind");
LOG( "SPS: If unset, default is 'combined' on native-capable");
LOG( "SPS: platforms, 'pseudo' on others.");
LOG( "SPS: ");
LOG( "SPS: MOZ_PROFILER_INTERVAL=<number> (milliseconds, 1 to 1000)");
LOG( "SPS: If unset, platform default is used.");
LOG( "SPS: ");
LOG( "SPS: MOZ_PROFILER_VERBOSE");
LOG( "SPS: If set to any value, increases verbosity (recommended).");
LOG( "SPS: ");
LOG( "SPS: MOZ_PROFILER_STACK_SCAN=<number> (default is zero)");
LOG( "SPS: The number of dubious (stack-scanned) frames allowed");
LOG( "SPS: ");
LOG( "SPS: MOZ_PROFILER_NEW");
LOG( "SPS: Needs to be set to use Breakpad-based unwinding.");
LOG( "SPS: ");
LOGF("SPS: This platform %s native unwinding.",
nativeAvail ? "supports" : "does not support");
LOG( "SPS: ");
/* Re-set defaults */
sUnwindMode = nativeAvail ? UnwCOMBINED : UnwPSEUDO;
sUnwindInterval = 0; /* We'll have to look elsewhere */
sUnwindStackScan = 0;
out:
LOG( "SPS:");
LOGF("SPS: Unwind mode = %s", name_UnwMode(sUnwindMode));
LOGF("SPS: Sampling interval = %d ms (zero means \"platform default\")",
(int)sUnwindInterval);
LOGF("SPS: UnwindStackScan = %d (max dubious frames per unwind).",
(int)sUnwindStackScan);
LOG( "SPS: Use env var MOZ_PROFILER_MODE=help for further information.");
LOG( "SPS:");
return;
}
////////////////////////////////////////////////////////////////////////
// BEGIN externally visible functions
void mozilla_sampler_init(void* stackTop)
{
sInitCount++;
if (stack_key_initialized)
return;
LOG("BEGIN mozilla_sampler_init");
if (!tlsPseudoStack.init() || !tlsTicker.init()) {
LOG("Failed to init.");
return;
}
stack_key_initialized = true;
Sampler::Startup();
PseudoStack *stack = new PseudoStack();
tlsPseudoStack.set(stack);
Sampler::RegisterCurrentThread("Gecko", stack, true, stackTop);
// Read mode settings from MOZ_PROFILER_MODE and interval
// settings from MOZ_PROFILER_INTERVAL and stack-scan threshhold
// from MOZ_PROFILER_STACK_SCAN.
read_profiler_env_vars();
// Allow the profiler to be started using signals
OS::RegisterStartHandler();
// Initialize (but don't enable) I/O interposing
sInterposeObserver = new mozilla::ProfilerIOInterposeObserver();
// We can't open pref so we use an environment variable
// to know if we should trigger the profiler on startup
// NOTE: Default
const char *val = PR_GetEnv("MOZ_PROFILER_STARTUP");
if (!val || !*val) {
return;
}
const char* features[] = {"js"
, "leaf"
#if defined(XP_WIN) || defined(XP_MACOSX)
, "stackwalk"
#endif
};
profiler_start(PROFILE_DEFAULT_ENTRY, PROFILE_DEFAULT_INTERVAL,
features, sizeof(features)/sizeof(const char*),
// TODO Add env variable to select threads
NULL, 0);
LOG("END mozilla_sampler_init");
}
void mozilla_sampler_shutdown()
{
sInitCount--;
if (sInitCount > 0)
return;
// Save the profile on shutdown if requested.
TableTicker *t = tlsTicker.get();
if (t) {
const char *val = PR_GetEnv("MOZ_PROFILER_SHUTDOWN");
if (val) {
std::ofstream stream;
stream.open(val);
if (stream.is_open()) {
t->ToStreamAsJSON(stream);
stream.close();
}
}
}
profiler_stop();
delete sInterposeObserver;
sInterposeObserver = nullptr;
mozilla::IOInterposer::ClearInstance();
Sampler::Shutdown();
// We can't delete the Stack because we can be between a
// sampler call_enter/call_exit point.
// TODO Need to find a safe time to delete Stack
}
void mozilla_sampler_save()
{
TableTicker *t = tlsTicker.get();
if (!t) {
return;
}
t->RequestSave();
// We're on the main thread already so we don't
// have to wait to handle the save request.
t->HandleSaveRequest();
}
char* mozilla_sampler_get_profile()
{
TableTicker *t = tlsTicker.get();
if (!t) {
return NULL;
}
std::stringstream stream;
t->ToStreamAsJSON(stream);
char* profile = strdup(stream.str().c_str());
return profile;
}
JSObject *mozilla_sampler_get_profile_data(JSContext *aCx)
{
TableTicker *t = tlsTicker.get();
if (!t) {
return NULL;
}
return t->ToJSObject(aCx);
}
const char** mozilla_sampler_get_features()
{
static const char* features[] = {
#if defined(MOZ_PROFILING) && defined(HAVE_NATIVE_UNWIND)
// Walk the C++ stack.
"stackwalk",
#endif
#if defined(ENABLE_SPS_LEAF_DATA)
// Include the C++ leaf node if not stackwalking. DevTools
// profiler doesn't want the native addresses.
"leaf",
#endif
#if !defined(SPS_OS_windows)
// Use a seperate thread of walking the stack.
"unwinder",
#endif
"java",
// Only record samples during periods of bad responsiveness
"jank",
// Tell the JS engine to emmit pseudostack entries in the
// pro/epilogue.
"js",
// Profile the registered secondary threads.
"threads",
// Do not include user-identifiable information
"privacy",
// Add main thread I/O to the profile
"mainthreadio",
NULL
};
return features;
}
// Values are only honored on the first start
void mozilla_sampler_start(int aProfileEntries, int aInterval,
const char** aFeatures, uint32_t aFeatureCount,
const char** aThreadNameFilters, uint32_t aFilterCount)
{
if (!stack_key_initialized)
profiler_init(NULL);
/* If the sampling interval was set using env vars, use that
in preference to anything else. */
if (sUnwindInterval > 0)
aInterval = sUnwindInterval;
// Reset the current state if the profiler is running
profiler_stop();
TableTicker* t;
t = new TableTicker(aInterval ? aInterval : PROFILE_DEFAULT_INTERVAL,
aProfileEntries ? aProfileEntries : PROFILE_DEFAULT_ENTRY,
aFeatures, aFeatureCount,
aThreadNameFilters, aFilterCount);
if (t->HasUnwinderThread()) {
// Create the unwinder thread. ATM there is only one.
uwt__init();
}
tlsTicker.set(t);
t->Start();
if (t->ProfileJS() || t->InPrivacyMode()) {
mozilla::MutexAutoLock lock(*Sampler::sRegisteredThreadsMutex);
std::vector<ThreadInfo*> threads = t->GetRegisteredThreads();
for (uint32_t i = 0; i < threads.size(); i++) {
ThreadInfo* info = threads[i];
ThreadProfile* thread_profile = info->Profile();
if (!thread_profile) {
continue;
}
if (t->ProfileJS()) {
thread_profile->GetPseudoStack()->enableJSSampling();
}
if (t->InPrivacyMode()) {
thread_profile->GetPseudoStack()->mPrivacyMode = true;
}
}
}
#if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK)
if (t->ProfileJava()) {
int javaInterval = aInterval;
// Java sampling doesn't accuratly keep up with 1ms sampling
if (javaInterval < 10) {
aInterval = 10;
}
mozilla::AndroidBridge::Bridge()->StartJavaProfiling(javaInterval, 1000);
}
#endif
if (t->AddMainThreadIO()) {
mozilla::IOInterposer::GetInstance()->Enable(true);
}
sIsProfiling = true;
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os)
os->NotifyObservers(nullptr, "profiler-started", nullptr);
}
void mozilla_sampler_stop()
{
if (!stack_key_initialized)
profiler_init(NULL);
TableTicker *t = tlsTicker.get();
if (!t) {
return;
}
bool disableJS = t->ProfileJS();
bool unwinderThreader = t->HasUnwinderThread();
// Shut down and reap the unwinder thread. We have to do this
// before stopping the sampler, so as to guarantee that the unwinder
// thread doesn't try to access memory that the subsequent call to
// mozilla_sampler_stop causes to be freed.
if (unwinderThreader) {
uwt__stop();
}
t->Stop();
delete t;
tlsTicker.set(NULL);
if (disableJS) {
PseudoStack *stack = tlsPseudoStack.get();
ASSERT(stack != NULL);
stack->disableJSSampling();
}
if (unwinderThreader) {
uwt__deinit();
}
mozilla::IOInterposer::GetInstance()->Enable(false);
sIsProfiling = false;
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os)
os->NotifyObservers(nullptr, "profiler-stopped", nullptr);
}
bool mozilla_sampler_is_active()
{
return sIsProfiling;
}
static double sResponsivenessTimes[100];
static unsigned int sResponsivenessLoc = 0;
void mozilla_sampler_responsiveness(const TimeStamp& aTime)
{
if (!sLastTracerEvent.IsNull()) {
if (sResponsivenessLoc == 100) {
for(size_t i = 0; i < 100-1; i++) {
sResponsivenessTimes[i] = sResponsivenessTimes[i+1];
}
sResponsivenessLoc--;
}
TimeDuration delta = aTime - sLastTracerEvent;
sResponsivenessTimes[sResponsivenessLoc++] = delta.ToMilliseconds();
}
sCurrentEventGeneration++;
sLastTracerEvent = aTime;
}
const double* mozilla_sampler_get_responsiveness()
{
return sResponsivenessTimes;
}
void mozilla_sampler_frame_number(int frameNumber)
{
sFrameNumber = frameNumber;
}
void mozilla_sampler_print_location2()
{
// FIXME
}
void mozilla_sampler_lock()
{
profiler_stop();
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os)
os->NotifyObservers(nullptr, "profiler-locked", nullptr);
}
void mozilla_sampler_unlock()
{
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os)
os->NotifyObservers(nullptr, "profiler-unlocked", nullptr);
}
bool mozilla_sampler_register_thread(const char* aName, void* stackTop)
{
PseudoStack* stack = new PseudoStack();
tlsPseudoStack.set(stack);
return Sampler::RegisterCurrentThread(aName, stack, false, stackTop);
}
void mozilla_sampler_unregister_thread()
{
Sampler::UnregisterCurrentThread();
PseudoStack *stack = tlsPseudoStack.get();
if (!stack) {
ASSERT(false);
return;
}
delete stack;
tlsPseudoStack.set(nullptr);
}
double mozilla_sampler_time()
{
TimeDuration delta = TimeStamp::Now() - sStartTime;
return delta.ToMilliseconds();
}
// END externally visible functions
////////////////////////////////////////////////////////////////////////