gecko-dev/xpcom/base/nsTraceRefcnt.cpp

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33 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 "nsTraceRefcnt.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "mozilla/Path.h"
#include "mozilla/StaticPtr.h"
#include "nsXPCOMPrivate.h"
#include "nscore.h"
#include "nsClassHashtable.h"
#include "nsISupports.h"
#include "nsHashKeys.h"
#include "nsTArray.h"
#include "nsTHashtable.h"
#include "prenv.h"
#include "plstr.h"
#include "prlink.h"
#include "nsCRT.h"
#include <math.h>
#include "nsHashKeys.h"
#include "mozilla/StackWalk.h"
#include "nsThreadUtils.h"
#include "CodeAddressService.h"
#include "nsXULAppAPI.h"
#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#else
#include <unistd.h>
#endif
#include "mozilla/Atomics.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/BlockingResourceBase.h"
#include "mozilla/PoisonIOInterposer.h"
#include "mozilla/UniquePtr.h"
#include <string>
#include <vector>
#ifdef HAVE_DLOPEN
#include <dlfcn.h>
#endif
#ifdef MOZ_DMD
#include "base/process_util.h"
#include "nsMemoryInfoDumper.h"
#endif
////////////////////////////////////////////////////////////////////////////////
#include "prthread.h"
// We use a spin lock instead of a regular mutex because this lock is usually
// only held for a very short time, and gets grabbed at a very high frequency
// (~100000 times per second). On Mac, the overhead of using a regular lock
// is very high, see bug 1137963.
static mozilla::Atomic<uintptr_t, mozilla::ReleaseAcquire> gTraceLogLocked;
struct MOZ_STACK_CLASS AutoTraceLogLock final
{
bool doRelease;
AutoTraceLogLock()
: doRelease(true)
{
uintptr_t currentThread = reinterpret_cast<uintptr_t>(PR_GetCurrentThread());
if (gTraceLogLocked == currentThread) {
doRelease = false;
} else {
while (!gTraceLogLocked.compareExchange(0, currentThread)) {
PR_Sleep(PR_INTERVAL_NO_WAIT); /* yield */
}
}
}
~AutoTraceLogLock() { if (doRelease) gTraceLogLocked = 0; }
};
class BloatEntry;
struct SerialNumberRecord;
using BloatHash = nsClassHashtable<nsDepCharHashKey, BloatEntry>;
using CharPtrSet = nsTHashtable<nsCharPtrHashKey>;
using IntPtrSet = nsTHashtable<IntPtrHashKey>;
using SerialHash = nsClassHashtable<nsVoidPtrHashKey, SerialNumberRecord>;
static StaticAutoPtr<BloatHash> gBloatView;
static StaticAutoPtr<CharPtrSet> gTypesToLog;
static StaticAutoPtr<IntPtrSet> gObjectsToLog;
static StaticAutoPtr<SerialHash> gSerialNumbers;
static intptr_t gNextSerialNumber;
static bool gDumpedStatistics = false;
static bool gLogJSStacks = false;
// By default, debug builds only do bloat logging. Bloat logging
// only tries to record when an object is created or destroyed, so we
// optimize the common case in NS_LogAddRef and NS_LogRelease where
// only bloat logging is enabled and no logging needs to be done.
enum LoggingType
{
NoLogging,
OnlyBloatLogging,
FullLogging
};
static LoggingType gLogging;
static bool gLogLeaksOnly;
#define BAD_TLS_INDEX ((unsigned)-1)
// if gActivityTLS == BAD_TLS_INDEX, then we're
// unitialized... otherwise this points to a NSPR TLS thread index
// indicating whether addref activity is legal. If the PTR_TO_INT32 is 0 then
// activity is ok, otherwise not!
static unsigned gActivityTLS = BAD_TLS_INDEX;
static bool gInitialized;
static nsrefcnt gInitCount;
static FILE* gBloatLog = nullptr;
static FILE* gRefcntsLog = nullptr;
static FILE* gAllocLog = nullptr;
static FILE* gCOMPtrLog = nullptr;
static void
WalkTheStackSavingLocations(std::vector<void*>& aLocations);
struct SerialNumberRecord
{
SerialNumberRecord()
: serialNumber(++gNextSerialNumber)
, refCount(0)
, COMPtrCount(0)
{}
intptr_t serialNumber;
int32_t refCount;
int32_t COMPtrCount;
// We use std:: classes here rather than the XPCOM equivalents because the
// XPCOM equivalents do leak-checking, and if you try to leak-check while
// leak-checking, you're gonna have a bad time.
std::vector<void*> allocationStack;
mozilla::UniquePtr<char[]> jsStack;
void SaveJSStack() {
// If this thread isn't running JS, there's nothing to do.
if (!CycleCollectedJSContext::Get()) {
return;
}
JSContext* cx = nsContentUtils::GetCurrentJSContext();
if (!cx) {
return;
}
JS::UniqueChars chars = xpc_PrintJSStack(cx,
/*showArgs=*/ false,
/*showLocals=*/ false,
/*showThisProps=*/ false);
size_t len = strlen(chars.get());
jsStack = MakeUnique<char[]>(len + 1);
memcpy(jsStack.get(), chars.get(), len + 1);
}
};
struct nsTraceRefcntStats
{
uint64_t mCreates;
uint64_t mDestroys;
bool HaveLeaks() const
{
return mCreates != mDestroys;
}
void Clear()
{
mCreates = 0;
mDestroys = 0;
}
int64_t NumLeaked() const
{
return (int64_t)(mCreates - mDestroys);
}
};
#ifdef DEBUG
static const char kStaticCtorDtorWarning[] =
"XPCOM objects created/destroyed from static ctor/dtor";
static void
AssertActivityIsLegal()
{
if (recordreplay::IsRecordingOrReplaying()) {
// Avoid recorded events in the TLS accesses below.
return;
}
if (gActivityTLS == BAD_TLS_INDEX || PR_GetThreadPrivate(gActivityTLS)) {
if (PR_GetEnv("MOZ_FATAL_STATIC_XPCOM_CTORS_DTORS")) {
MOZ_CRASH_UNSAFE_OOL(kStaticCtorDtorWarning);
} else {
NS_WARNING(kStaticCtorDtorWarning);
}
}
}
# define ASSERT_ACTIVITY_IS_LEGAL \
do { \
AssertActivityIsLegal(); \
} while(0)
#else
# define ASSERT_ACTIVITY_IS_LEGAL do { } while(0)
#endif // DEBUG
////////////////////////////////////////////////////////////////////////////////
class CodeAddressServiceStringTable final
{
public:
CodeAddressServiceStringTable() : mSet(32) {}
const char* Intern(const char* aString)
{
nsCharPtrHashKey* e = mSet.PutEntry(aString);
return e->GetKey();
}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
{
return mSet.SizeOfExcludingThis(aMallocSizeOf);
}
private:
typedef nsTHashtable<nsCharPtrHashKey> StringSet;
StringSet mSet;
};
struct CodeAddressServiceStringAlloc final
{
static char* copy(const char* aStr) { return strdup(aStr); }
static void free(char* aPtr) { ::free(aPtr); }
};
// WalkTheStack does not hold any locks needed by MozDescribeCodeAddress, so
// this class does not need to do anything.
struct CodeAddressServiceLock final
{
static void Unlock() {}
static void Lock() {}
static bool IsLocked() { return true; }
};
typedef mozilla::CodeAddressService<CodeAddressServiceStringTable,
CodeAddressServiceStringAlloc,
CodeAddressServiceLock> WalkTheStackCodeAddressService;
mozilla::StaticAutoPtr<WalkTheStackCodeAddressService> gCodeAddressService;
////////////////////////////////////////////////////////////////////////////////
class BloatEntry
{
public:
BloatEntry(const char* aClassName, uint32_t aClassSize)
: mClassSize(aClassSize)
, mStats()
{
MOZ_ASSERT(strlen(aClassName) > 0, "BloatEntry name must be non-empty");
mClassName = PL_strdup(aClassName);
mStats.Clear();
mTotalLeaked = 0;
}
~BloatEntry()
{
PL_strfree(mClassName);
}
uint32_t GetClassSize()
{
return (uint32_t)mClassSize;
}
const char* GetClassName()
{
return mClassName;
}
void Ctor()
{
mStats.mCreates++;
}
void Dtor()
{
mStats.mDestroys++;
}
void Total(BloatEntry* aTotal)
{
aTotal->mStats.mCreates += mStats.mCreates;
aTotal->mStats.mDestroys += mStats.mDestroys;
aTotal->mClassSize += mClassSize * mStats.mCreates; // adjust for average in DumpTotal
aTotal->mTotalLeaked += mClassSize * mStats.NumLeaked();
}
void DumpTotal(FILE* aOut)
{
mClassSize /= mStats.mCreates;
Dump(-1, aOut);
}
bool PrintDumpHeader(FILE* aOut, const char* aMsg)
{
fprintf(aOut, "\n== BloatView: %s, %s process %d\n", aMsg,
XRE_ChildProcessTypeToString(XRE_GetProcessType()), getpid());
if (gLogLeaksOnly && !mStats.HaveLeaks()) {
return false;
}
fprintf(aOut,
"\n" \
" |<----------------Class--------------->|<-----Bytes------>|<----Objects---->|\n" \
" | | Per-Inst Leaked| Total Rem|\n");
this->DumpTotal(aOut);
return true;
}
void Dump(int aIndex, FILE* aOut)
{
if (gLogLeaksOnly && !mStats.HaveLeaks()) {
return;
}
if (mStats.HaveLeaks() || mStats.mCreates != 0) {
fprintf(aOut, "%4d |%-38.38s| %8d %8" PRId64 "|%8" PRIu64 " %8" PRId64"|\n",
aIndex + 1, mClassName,
GetClassSize(),
nsCRT::strcmp(mClassName, "TOTAL") ? (mStats.NumLeaked() * GetClassSize()) : mTotalLeaked,
mStats.mCreates,
mStats.NumLeaked());
}
}
protected:
char* mClassName;
double mClassSize; // This is stored as a double because of the way we compute the avg class size for total bloat.
int64_t mTotalLeaked; // Used only for TOTAL entry.
nsTraceRefcntStats mStats;
};
static void
RecreateBloatView()
{
gBloatView = new BloatHash(256);
}
static BloatEntry*
GetBloatEntry(const char* aTypeName, uint32_t aInstanceSize)
{
if (!gBloatView) {
RecreateBloatView();
}
BloatEntry* entry = gBloatView->Get(aTypeName);
if (!entry && aInstanceSize > 0) {
entry = new BloatEntry(aTypeName, aInstanceSize);
gBloatView->Put(aTypeName, entry);
} else {
MOZ_ASSERT(aInstanceSize == 0 || entry->GetClassSize() == aInstanceSize,
"Mismatched sizes were recorded in the memory leak logging table. "
"The usual cause of this is having a templated class that uses "
"MOZ_COUNT_{C,D}TOR in the constructor or destructor, respectively. "
"As a workaround, the MOZ_COUNT_{C,D}TOR calls can be moved to a "
"non-templated base class. Another possible cause is a runnable with "
"an mName that matches another refcounted class.");
}
return entry;
}
static void
DumpSerialNumbers(const SerialHash::Iterator& aHashEntry, FILE* aFd)
{
SerialNumberRecord* record = aHashEntry.Data();
auto* outputFile = aFd;
#ifdef HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
fprintf(outputFile, "%" PRIdPTR
" @%p (%d references; %d from COMPtrs)\n",
record->serialNumber,
aHashEntry.Key(),
record->refCount,
record->COMPtrCount);
#else
fprintf(outputFile, "%" PRIdPTR
" @%p (%d references)\n",
record->serialNumber,
aHashEntry.Key(),
record->refCount);
#endif
if (!record->allocationStack.empty()) {
static const size_t bufLen = 1024;
char buf[bufLen];
fprintf(outputFile, "allocation stack:\n");
for (size_t i = 0, length = record->allocationStack.size();
i < length;
++i) {
gCodeAddressService->GetLocation(i, record->allocationStack[i],
buf, bufLen);
fprintf(outputFile, "%s\n", buf);
}
}
if (gLogJSStacks) {
if (record->jsStack) {
fprintf(outputFile, "JS allocation stack:\n%s\n", record->jsStack.get());
} else {
fprintf(outputFile, "There is no JS context on the stack.\n");
}
}
}
template<>
class nsDefaultComparator<BloatEntry*, BloatEntry*>
{
public:
bool Equals(BloatEntry* const& aEntry1, BloatEntry* const& aEntry2) const
{
return PL_strcmp(aEntry1->GetClassName(), aEntry2->GetClassName()) == 0;
}
bool LessThan(BloatEntry* const& aEntry1, BloatEntry* const& aEntry2) const
{
return PL_strcmp(aEntry1->GetClassName(), aEntry2->GetClassName()) < 0;
}
};
nsresult
nsTraceRefcnt::DumpStatistics()
{
if (!gBloatLog || !gBloatView) {
return NS_ERROR_FAILURE;
}
AutoTraceLogLock lock;
MOZ_ASSERT(!gDumpedStatistics,
"Calling DumpStatistics more than once may result in "
"bogus positive or negative leaks being reported");
gDumpedStatistics = true;
// Don't try to log while we hold the lock, we'd deadlock.
AutoRestore<LoggingType> saveLogging(gLogging);
gLogging = NoLogging;
BloatEntry total("TOTAL", 0);
for (auto iter = gBloatView->Iter(); !iter.Done(); iter.Next()) {
BloatEntry* entry = iter.Data();
if (nsCRT::strcmp(entry->GetClassName(), "TOTAL") != 0) {
entry->Total(&total);
}
}
const char* msg;
if (gLogLeaksOnly) {
msg = "ALL (cumulative) LEAK STATISTICS";
} else {
msg = "ALL (cumulative) LEAK AND BLOAT STATISTICS";
}
const bool leaked = total.PrintDumpHeader(gBloatLog, msg);
nsTArray<BloatEntry*> entries;
for (auto iter = gBloatView->Iter(); !iter.Done(); iter.Next()) {
entries.AppendElement(iter.Data());
}
const uint32_t count = entries.Length();
if (!gLogLeaksOnly || leaked) {
// Sort the entries alphabetically by classname.
entries.Sort();
for (uint32_t i = 0; i < count; ++i) {
BloatEntry* entry = entries[i];
entry->Dump(i, gBloatLog);
}
fprintf(gBloatLog, "\n");
}
fprintf(gBloatLog, "nsTraceRefcnt::DumpStatistics: %d entries\n", count);
if (gSerialNumbers) {
fprintf(gBloatLog, "\nSerial Numbers of Leaked Objects:\n");
for (auto iter = gSerialNumbers->Iter(); !iter.Done(); iter.Next()) {
DumpSerialNumbers(iter, gBloatLog);
}
}
return NS_OK;
}
void
nsTraceRefcnt::ResetStatistics()
{
AutoTraceLogLock lock;
gBloatView = nullptr;
}
static intptr_t
GetSerialNumber(void* aPtr, bool aCreate)
{
if (!aCreate) {
auto record = gSerialNumbers->Get(aPtr);
return record ? record->serialNumber : 0;
}
auto entry = gSerialNumbers->LookupForAdd(aPtr);
if (entry) {
MOZ_CRASH("If an object already has a serial number, we should be destroying it.");
}
auto record = entry.OrInsert([]() { return new SerialNumberRecord(); });
WalkTheStackSavingLocations(record->allocationStack);
if (gLogJSStacks) {
record->SaveJSStack();
}
return gNextSerialNumber;
}
static void
RecycleSerialNumberPtr(void* aPtr)
{
gSerialNumbers->Remove(aPtr);
}
static bool
LogThisObj(intptr_t aSerialNumber)
{
return gObjectsToLog->Contains(aSerialNumber);
}
using EnvCharType = mozilla::filesystem::Path::value_type;
static bool
InitLog(const EnvCharType* aEnvVar, const char* aMsg, FILE** aResult)
{
#ifdef XP_WIN
// This is gross, I know.
const wchar_t* envvar = reinterpret_cast<const wchar_t*>(aEnvVar);
const char16_t* value = reinterpret_cast<const char16_t*>(::_wgetenv(envvar));
#define ENVVAR_PRINTF "%S"
#else
const char* envvar = aEnvVar;
const char* value = ::getenv(aEnvVar);
#define ENVVAR_PRINTF "%s"
#endif
if (value) {
nsTDependentString<EnvCharType> fname(value);
if (fname.EqualsLiteral("1")) {
*aResult = stdout;
fprintf(stdout, "### " ENVVAR_PRINTF " defined -- logging %s to stdout\n",
envvar, aMsg);
return true;
} else if (fname.EqualsLiteral("2")) {
*aResult = stderr;
fprintf(stdout, "### " ENVVAR_PRINTF " defined -- logging %s to stderr\n",
envvar, aMsg);
return true;
} else {
if (!XRE_IsParentProcess()) {
bool hasLogExtension =
fname.RFind(".log", true, -1, 4) == kNotFound ? false : true;
if (hasLogExtension) {
fname.Cut(fname.Length() - 4, 4);
}
fname.Append('_');
const char* processType = XRE_ChildProcessTypeToString(XRE_GetProcessType());
fname.AppendASCII(processType);
fname.AppendLiteral("_pid");
fname.AppendInt((uint32_t)getpid());
if (hasLogExtension) {
fname.AppendLiteral(".log");
}
}
#ifdef XP_WIN
FILE* stream = ::_wfopen(fname.get(), L"wN");
const wchar_t* fp = (const wchar_t*)fname.get();
#else
FILE* stream = ::fopen(fname.get(), "w");
const char* fp = fname.get();
#endif
if (stream) {
MozillaRegisterDebugFD(fileno(stream));
*aResult = stream;
fprintf(stderr, "### " ENVVAR_PRINTF " defined -- logging %s to " ENVVAR_PRINTF "\n",
envvar, aMsg, fp);
} else {
fprintf(stderr, "### " ENVVAR_PRINTF " defined -- unable to log %s to " ENVVAR_PRINTF "\n",
envvar, aMsg, fp);
MOZ_ASSERT(false, "Tried and failed to create an XPCOM log");
}
#undef ENVVAR_PRINTF
return stream != nullptr;
}
}
return false;
}
static void
maybeUnregisterAndCloseFile(FILE*& aFile)
{
if (!aFile) {
return;
}
MozillaUnRegisterDebugFILE(aFile);
fclose(aFile);
aFile = nullptr;
}
static void
InitTraceLog()
{
#ifdef XP_WIN
#define ENVVAR(x) u"" x
#else
#define ENVVAR(x) x
#endif
if (gInitialized) {
return;
}
gInitialized = true;
// Don't trace refcounts while recording or replaying, these are not
// required to match up between the two executions.
if (mozilla::recordreplay::IsRecordingOrReplaying()) {
return;
}
bool defined = InitLog(ENVVAR("XPCOM_MEM_BLOAT_LOG"), "bloat/leaks", &gBloatLog);
if (!defined) {
gLogLeaksOnly = InitLog(ENVVAR("XPCOM_MEM_LEAK_LOG"), "leaks", &gBloatLog);
}
if (defined || gLogLeaksOnly) {
RecreateBloatView();
if (!gBloatView) {
NS_WARNING("out of memory");
maybeUnregisterAndCloseFile(gBloatLog);
gLogLeaksOnly = false;
}
}
InitLog(ENVVAR("XPCOM_MEM_REFCNT_LOG"), "refcounts", &gRefcntsLog);
InitLog(ENVVAR("XPCOM_MEM_ALLOC_LOG"), "new/delete", &gAllocLog);
const char* classes = getenv("XPCOM_MEM_LOG_CLASSES");
#ifdef HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
if (classes) {
InitLog(ENVVAR("XPCOM_MEM_COMPTR_LOG"), "nsCOMPtr", &gCOMPtrLog);
} else {
if (getenv("XPCOM_MEM_COMPTR_LOG")) {
fprintf(stdout, "### XPCOM_MEM_COMPTR_LOG defined -- but XPCOM_MEM_LOG_CLASSES is not defined\n");
}
}
#else
const char* comptr_log = getenv("XPCOM_MEM_COMPTR_LOG");
if (comptr_log) {
fprintf(stdout, "### XPCOM_MEM_COMPTR_LOG defined -- but it will not work without dynamic_cast\n");
}
#endif // HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
#undef ENVVAR
if (classes) {
// if XPCOM_MEM_LOG_CLASSES was set to some value, the value is interpreted
// as a list of class names to track
gTypesToLog = new CharPtrSet(256);
fprintf(stdout, "### XPCOM_MEM_LOG_CLASSES defined -- only logging these classes: ");
const char* cp = classes;
for (;;) {
char* cm = (char*)strchr(cp, ',');
if (cm) {
*cm = '\0';
}
gTypesToLog->PutEntry(cp);
fprintf(stdout, "%s ", cp);
if (!cm) {
break;
}
*cm = ',';
cp = cm + 1;
}
fprintf(stdout, "\n");
gSerialNumbers = new SerialHash(256);
}
const char* objects = getenv("XPCOM_MEM_LOG_OBJECTS");
if (objects) {
gObjectsToLog = new IntPtrSet(256);
if (!(gRefcntsLog || gAllocLog || gCOMPtrLog)) {
fprintf(stdout, "### XPCOM_MEM_LOG_OBJECTS defined -- but none of XPCOM_MEM_(REFCNT|ALLOC|COMPTR)_LOG is defined\n");
} else {
fprintf(stdout, "### XPCOM_MEM_LOG_OBJECTS defined -- only logging these objects: ");
const char* cp = objects;
for (;;) {
char* cm = (char*)strchr(cp, ',');
if (cm) {
*cm = '\0';
}
intptr_t top = 0;
intptr_t bottom = 0;
while (*cp) {
if (*cp == '-') {
bottom = top;
top = 0;
++cp;
}
top *= 10;
top += *cp - '0';
++cp;
}
if (!bottom) {
bottom = top;
}
for (intptr_t serialno = bottom; serialno <= top; serialno++) {
gObjectsToLog->PutEntry(serialno);
fprintf(stdout, "%" PRIdPTR " ", serialno);
}
if (!cm) {
break;
}
*cm = ',';
cp = cm + 1;
}
fprintf(stdout, "\n");
}
}
if (getenv("XPCOM_MEM_LOG_JS_STACK")) {
fprintf(stdout, "### XPCOM_MEM_LOG_JS_STACK defined\n");
gLogJSStacks = true;
}
if (gBloatLog) {
gLogging = OnlyBloatLogging;
}
if (gRefcntsLog || gAllocLog || gCOMPtrLog) {
gLogging = FullLogging;
}
}
extern "C" {
static void
PrintStackFrame(uint32_t aFrameNumber, void* aPC, void* aSP, void* aClosure)
{
FILE* stream = (FILE*)aClosure;
MozCodeAddressDetails details;
char buf[1024];
MozDescribeCodeAddress(aPC, &details);
MozFormatCodeAddressDetails(buf, sizeof(buf), aFrameNumber, aPC, &details);
fprintf(stream, "%s\n", buf);
fflush(stream);
}
static void
PrintStackFrameCached(uint32_t aFrameNumber, void* aPC, void* aSP,
void* aClosure)
{
auto stream = static_cast<FILE*>(aClosure);
static const size_t buflen = 1024;
char buf[buflen];
gCodeAddressService->GetLocation(aFrameNumber, aPC, buf, buflen);
fprintf(stream, " %s\n", buf);
fflush(stream);
}
static void
RecordStackFrame(uint32_t /*aFrameNumber*/, void* aPC, void* /*aSP*/,
void* aClosure)
{
auto locations = static_cast<std::vector<void*>*>(aClosure);
locations->push_back(aPC);
}
}
void
nsTraceRefcnt::WalkTheStack(FILE* aStream)
{
MozStackWalk(PrintStackFrame, /* skipFrames */ 2, /* maxFrames */ 0, aStream);
}
/**
* This is a variant of |WalkTheStack| that uses |CodeAddressService| to cache
* the results of |NS_DescribeCodeAddress|. If |WalkTheStackCached| is being
* called frequently, it will be a few orders of magnitude faster than
* |WalkTheStack|. However, the cache uses a lot of memory, which can cause
* OOM crashes. Therefore, this should only be used for things like refcount
* logging which walk the stack extremely frequently.
*/
static void
WalkTheStackCached(FILE* aStream)
{
if (!gCodeAddressService) {
gCodeAddressService = new WalkTheStackCodeAddressService();
}
MozStackWalk(PrintStackFrameCached, /* skipFrames */ 2, /* maxFrames */ 0,
aStream);
}
static void
WalkTheStackSavingLocations(std::vector<void*>& aLocations)
{
if (!gCodeAddressService) {
gCodeAddressService = new WalkTheStackCodeAddressService();
}
static const int kFramesToSkip =
0 + // this frame gets inlined
1 + // GetSerialNumber
1; // NS_LogCtor
MozStackWalk(RecordStackFrame, kFramesToSkip, /* maxFrames */ 0, &aLocations);
}
//----------------------------------------------------------------------
EXPORT_XPCOM_API(void)
NS_LogInit()
{
NS_SetMainThread();
// FIXME: This is called multiple times, we should probably not allow that.
if (++gInitCount) {
nsTraceRefcnt::SetActivityIsLegal(true);
}
}
EXPORT_XPCOM_API(void)
NS_LogTerm()
{
mozilla::LogTerm();
}
#ifdef MOZ_DMD
// If MOZ_DMD_SHUTDOWN_LOG is set, dump a DMD report to a file.
// The value of this environment variable is used as the prefix
// of the file name, so you probably want something like "/tmp/".
// By default, this is run in all processes, but you can record a
// log only for a specific process type by setting MOZ_DMD_LOG_PROCESS
// to the process type you want to log, such as "default" or "tab".
// This method can't use the higher level XPCOM file utilities
// because it is run very late in shutdown to avoid recording
// information about refcount logging entries.
static void
LogDMDFile()
{
const char* dmdFilePrefix = PR_GetEnv("MOZ_DMD_SHUTDOWN_LOG");
if (!dmdFilePrefix) {
return;
}
const char* logProcessEnv = PR_GetEnv("MOZ_DMD_LOG_PROCESS");
if (logProcessEnv && !!strcmp(logProcessEnv, XRE_ChildProcessTypeToString(XRE_GetProcessType()))) {
return;
}
nsPrintfCString fileName("%sdmd-%d.log.gz", dmdFilePrefix, base::GetCurrentProcId());
FILE* logFile = fopen(fileName.get(), "w");
if (NS_WARN_IF(!logFile)) {
return;
}
nsMemoryInfoDumper::DumpDMDToFile(logFile);
}
#endif // MOZ_DMD
namespace mozilla {
void
LogTerm()
{
NS_ASSERTION(gInitCount > 0,
"NS_LogTerm without matching NS_LogInit");
if (--gInitCount == 0) {
#ifdef DEBUG
/* FIXME bug 491977: This is only going to operate on the
* BlockingResourceBase which is compiled into
* libxul/libxpcom_core.so. Anyone using external linkage will
* have their own copy of BlockingResourceBase statics which will
* not be freed by this method.
*
* It sounds like what we really want is to be able to register a
* callback function to call at XPCOM shutdown. Note that with
* this solution, however, we need to guarantee that
* BlockingResourceBase::Shutdown() runs after all other shutdown
* functions.
*/
BlockingResourceBase::Shutdown();
#endif
if (gInitialized) {
nsTraceRefcnt::DumpStatistics();
nsTraceRefcnt::ResetStatistics();
}
nsTraceRefcnt::Shutdown();
nsTraceRefcnt::SetActivityIsLegal(false);
gActivityTLS = BAD_TLS_INDEX;
#ifdef MOZ_DMD
LogDMDFile();
#endif
}
}
} // namespace mozilla
EXPORT_XPCOM_API(void)
NS_LogAddRef(void* aPtr, nsrefcnt aRefcnt,
const char* aClass, uint32_t aClassSize)
{
ASSERT_ACTIVITY_IS_LEGAL;
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == NoLogging) {
return;
}
if (aRefcnt == 1 || gLogging == FullLogging) {
AutoTraceLogLock lock;
if (aRefcnt == 1 && gBloatLog) {
BloatEntry* entry = GetBloatEntry(aClass, aClassSize);
if (entry) {
entry->Ctor();
}
}
// Here's the case where MOZ_COUNT_CTOR was not used,
// yet we still want to see creation information:
bool loggingThisType = (!gTypesToLog || gTypesToLog->Contains(aClass));
intptr_t serialno = 0;
if (gSerialNumbers && loggingThisType) {
serialno = GetSerialNumber(aPtr, aRefcnt == 1);
MOZ_ASSERT(serialno != 0,
"Serial number requested for unrecognized pointer! "
"Are you memmoving a refcounted object?");
auto record = gSerialNumbers->Get(aPtr);
if (record) {
++record->refCount;
}
}
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
if (aRefcnt == 1 && gAllocLog && loggingThisType && loggingThisObject) {
fprintf(gAllocLog, "\n<%s> %p %" PRIdPTR " Create [thread %p]\n", aClass, aPtr, serialno, PR_GetCurrentThread());
WalkTheStackCached(gAllocLog);
}
if (gRefcntsLog && loggingThisType && loggingThisObject) {
// Can't use MOZ_LOG(), b/c it truncates the line
fprintf(gRefcntsLog, "\n<%s> %p %" PRIuPTR " AddRef %" PRIuPTR " [thread %p]\n",
aClass, aPtr, serialno, aRefcnt, PR_GetCurrentThread());
WalkTheStackCached(gRefcntsLog);
fflush(gRefcntsLog);
}
}
}
EXPORT_XPCOM_API(void)
NS_LogRelease(void* aPtr, nsrefcnt aRefcnt, const char* aClass)
{
ASSERT_ACTIVITY_IS_LEGAL;
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == NoLogging) {
return;
}
if (aRefcnt == 0 || gLogging == FullLogging) {
AutoTraceLogLock lock;
if (aRefcnt == 0 && gBloatLog) {
BloatEntry* entry = GetBloatEntry(aClass, 0);
if (entry) {
entry->Dtor();
}
}
bool loggingThisType = (!gTypesToLog || gTypesToLog->Contains(aClass));
intptr_t serialno = 0;
if (gSerialNumbers && loggingThisType) {
serialno = GetSerialNumber(aPtr, false);
MOZ_ASSERT(serialno != 0,
"Serial number requested for unrecognized pointer! "
"Are you memmoving a refcounted object?");
auto record = gSerialNumbers->Get(aPtr);
if (record) {
--record->refCount;
}
}
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
if (gRefcntsLog && loggingThisType && loggingThisObject) {
// Can't use MOZ_LOG(), b/c it truncates the line
fprintf(gRefcntsLog,
"\n<%s> %p %" PRIuPTR " Release %" PRIuPTR " [thread %p]\n",
aClass, aPtr, serialno, aRefcnt, PR_GetCurrentThread());
WalkTheStackCached(gRefcntsLog);
fflush(gRefcntsLog);
}
// Here's the case where MOZ_COUNT_DTOR was not used,
// yet we still want to see deletion information:
if (aRefcnt == 0 && gAllocLog && loggingThisType && loggingThisObject) {
fprintf(gAllocLog, "\n<%s> %p %" PRIdPTR " Destroy [thread %p]\n", aClass, aPtr, serialno, PR_GetCurrentThread());
WalkTheStackCached(gAllocLog);
}
if (aRefcnt == 0 && gSerialNumbers && loggingThisType) {
RecycleSerialNumberPtr(aPtr);
}
}
}
EXPORT_XPCOM_API(void)
NS_LogCtor(void* aPtr, const char* aType, uint32_t aInstanceSize)
{
ASSERT_ACTIVITY_IS_LEGAL;
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == NoLogging) {
return;
}
AutoTraceLogLock lock;
if (gBloatLog) {
BloatEntry* entry = GetBloatEntry(aType, aInstanceSize);
if (entry) {
entry->Ctor();
}
}
bool loggingThisType = (!gTypesToLog || gTypesToLog->Contains(aType));
intptr_t serialno = 0;
if (gSerialNumbers && loggingThisType) {
serialno = GetSerialNumber(aPtr, true);
MOZ_ASSERT(serialno != 0, "GetSerialNumber should never return 0 when passed true");
}
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
if (gAllocLog && loggingThisType && loggingThisObject) {
fprintf(gAllocLog, "\n<%s> %p %" PRIdPTR " Ctor (%d)\n",
aType, aPtr, serialno, aInstanceSize);
WalkTheStackCached(gAllocLog);
}
}
EXPORT_XPCOM_API(void)
NS_LogDtor(void* aPtr, const char* aType, uint32_t aInstanceSize)
{
ASSERT_ACTIVITY_IS_LEGAL;
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == NoLogging) {
return;
}
AutoTraceLogLock lock;
if (gBloatLog) {
BloatEntry* entry = GetBloatEntry(aType, aInstanceSize);
if (entry) {
entry->Dtor();
}
}
bool loggingThisType = (!gTypesToLog || gTypesToLog->Contains(aType));
intptr_t serialno = 0;
if (gSerialNumbers && loggingThisType) {
serialno = GetSerialNumber(aPtr, false);
MOZ_ASSERT(serialno != 0,
"Serial number requested for unrecognized pointer! "
"Are you memmoving a MOZ_COUNT_CTOR-tracked object?");
RecycleSerialNumberPtr(aPtr);
}
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
// (If we're on a losing architecture, don't do this because we'll be
// using LogDeleteXPCOM instead to get file and line numbers.)
if (gAllocLog && loggingThisType && loggingThisObject) {
fprintf(gAllocLog, "\n<%s> %p %" PRIdPTR " Dtor (%d)\n",
aType, aPtr, serialno, aInstanceSize);
WalkTheStackCached(gAllocLog);
}
}
EXPORT_XPCOM_API(void)
NS_LogCOMPtrAddRef(void* aCOMPtr, nsISupports* aObject)
{
#ifdef HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
// Get the most-derived object.
void* object = dynamic_cast<void*>(aObject);
// This is a very indirect way of finding out what the class is
// of the object being logged. If we're logging a specific type,
// then
if (!gTypesToLog || !gSerialNumbers) {
return;
}
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == FullLogging) {
AutoTraceLogLock lock;
intptr_t serialno = GetSerialNumber(object, false);
if (serialno == 0) {
return;
}
auto record = gSerialNumbers->Get(object);
int32_t count = record ? ++record->COMPtrCount : -1;
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
if (gCOMPtrLog && loggingThisObject) {
fprintf(gCOMPtrLog, "\n<?> %p %" PRIdPTR " nsCOMPtrAddRef %d %p\n",
object, serialno, count, aCOMPtr);
WalkTheStackCached(gCOMPtrLog);
}
}
#endif // HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
}
EXPORT_XPCOM_API(void)
NS_LogCOMPtrRelease(void* aCOMPtr, nsISupports* aObject)
{
#ifdef HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
// Get the most-derived object.
void* object = dynamic_cast<void*>(aObject);
// This is a very indirect way of finding out what the class is
// of the object being logged. If we're logging a specific type,
// then
if (!gTypesToLog || !gSerialNumbers) {
return;
}
if (!gInitialized) {
InitTraceLog();
}
if (gLogging == FullLogging) {
AutoTraceLogLock lock;
intptr_t serialno = GetSerialNumber(object, false);
if (serialno == 0) {
return;
}
auto record = gSerialNumbers->Get(object);
int32_t count = record ? --record->COMPtrCount : -1;
bool loggingThisObject = (!gObjectsToLog || LogThisObj(serialno));
if (gCOMPtrLog && loggingThisObject) {
fprintf(gCOMPtrLog, "\n<?> %p %" PRIdPTR " nsCOMPtrRelease %d %p\n",
object, serialno, count, aCOMPtr);
WalkTheStackCached(gCOMPtrLog);
}
}
#endif // HAVE_CPP_DYNAMIC_CAST_TO_VOID_PTR
}
void
nsTraceRefcnt::Shutdown()
{
gCodeAddressService = nullptr;
gBloatView = nullptr;
gTypesToLog = nullptr;
gObjectsToLog = nullptr;
gSerialNumbers = nullptr;
maybeUnregisterAndCloseFile(gBloatLog);
maybeUnregisterAndCloseFile(gRefcntsLog);
maybeUnregisterAndCloseFile(gAllocLog);
maybeUnregisterAndCloseFile(gCOMPtrLog);
}
void
nsTraceRefcnt::SetActivityIsLegal(bool aLegal)
{
if (gActivityTLS == BAD_TLS_INDEX) {
PR_NewThreadPrivateIndex(&gActivityTLS, nullptr);
}
PR_SetThreadPrivate(gActivityTLS, reinterpret_cast<void*>(!aLegal));
}