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Diffstat (limited to 'memory/replace/dmd/DMD.cpp')
| -rw-r--r-- | memory/replace/dmd/DMD.cpp | 2122 |
1 files changed, 0 insertions, 2122 deletions
diff --git a/memory/replace/dmd/DMD.cpp b/memory/replace/dmd/DMD.cpp deleted file mode 100644 index 49eb279702..0000000000 --- a/memory/replace/dmd/DMD.cpp +++ /dev/null @@ -1,2122 +0,0 @@ -/* -*- 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 <ctype.h> -#include <errno.h> -#include <limits.h> -#include <stdarg.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -#if !defined(MOZ_PROFILING) -#error "DMD requires MOZ_PROFILING" -#endif - -#ifdef XP_WIN -#include <windows.h> -#include <process.h> -#else -#include <unistd.h> -#endif - -#ifdef ANDROID -#include <android/log.h> -#endif - -#include "nscore.h" -#include "mozilla/StackWalk.h" - -#include "js/HashTable.h" -#include "js/Vector.h" - -#include "mozilla/Assertions.h" -#include "mozilla/FastBernoulliTrial.h" -#include "mozilla/HashFunctions.h" -#include "mozilla/IntegerPrintfMacros.h" -#include "mozilla/JSONWriter.h" -#include "mozilla/Likely.h" -#include "mozilla/MemoryReporting.h" - -// CodeAddressService is defined entirely in the header, so this does not make -// DMD depend on XPCOM's object file. -#include "CodeAddressService.h" - -// replace_malloc.h needs to be included before replace_malloc_bridge.h, -// which DMD.h includes, so DMD.h needs to be included after replace_malloc.h. -// MOZ_REPLACE_ONLY_MEMALIGN saves us from having to define -// replace_{posix_memalign,aligned_alloc,valloc}. It requires defining -// PAGE_SIZE. Nb: sysconf() is expensive, but it's only used for (the obsolete -// and rarely used) valloc. -#define MOZ_REPLACE_ONLY_MEMALIGN 1 - -#ifndef PAGE_SIZE -#define DMD_DEFINED_PAGE_SIZE -#ifdef XP_WIN -#define PAGE_SIZE GetPageSize() -static long GetPageSize() -{ - SYSTEM_INFO si; - GetSystemInfo(&si); - return si.dwPageSize; -} -#else // XP_WIN -#define PAGE_SIZE sysconf(_SC_PAGESIZE) -#endif // XP_WIN -#endif // PAGE_SIZE -#include "replace_malloc.h" -#undef MOZ_REPLACE_ONLY_MEMALIGN -#ifdef DMD_DEFINED_PAGE_SIZE -#undef DMD_DEFINED_PAGE_SIZE -#undef PAGE_SIZE -#endif // DMD_DEFINED_PAGE_SIZE - -#include "DMD.h" - -namespace mozilla { -namespace dmd { - -class DMDBridge : public ReplaceMallocBridge -{ - virtual DMDFuncs* GetDMDFuncs() override; -}; - -static DMDBridge* gDMDBridge; -static DMDFuncs gDMDFuncs; - -DMDFuncs* -DMDBridge::GetDMDFuncs() -{ - return &gDMDFuncs; -} - -inline void -StatusMsg(const char* aFmt, ...) -{ - va_list ap; - va_start(ap, aFmt); - gDMDFuncs.StatusMsg(aFmt, ap); - va_end(ap); -} - -//--------------------------------------------------------------------------- -// Utilities -//--------------------------------------------------------------------------- - -#ifndef DISALLOW_COPY_AND_ASSIGN -#define DISALLOW_COPY_AND_ASSIGN(T) \ - T(const T&); \ - void operator=(const T&) -#endif - -static const malloc_table_t* gMallocTable = nullptr; - -// Whether DMD finished initializing. -static bool gIsDMDInitialized = false; - -// This provides infallible allocations (they abort on OOM). We use it for all -// of DMD's own allocations, which fall into the following three cases. -// -// - Direct allocations (the easy case). -// -// - Indirect allocations in js::{Vector,HashSet,HashMap} -- this class serves -// as their AllocPolicy. -// -// - Other indirect allocations (e.g. MozStackWalk) -- see the comments on -// Thread::mBlockIntercepts and in replace_malloc for how these work. -// -// It would be nice if we could use the InfallibleAllocPolicy from mozalloc, -// but DMD cannot use mozalloc. -// -class InfallibleAllocPolicy -{ - static void ExitOnFailure(const void* aP); - -public: - template <typename T> - static T* maybe_pod_malloc(size_t aNumElems) - { - if (aNumElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) - return nullptr; - return (T*)gMallocTable->malloc(aNumElems * sizeof(T)); - } - - template <typename T> - static T* maybe_pod_calloc(size_t aNumElems) - { - return (T*)gMallocTable->calloc(aNumElems, sizeof(T)); - } - - template <typename T> - static T* maybe_pod_realloc(T* aPtr, size_t aOldSize, size_t aNewSize) - { - if (aNewSize & mozilla::tl::MulOverflowMask<sizeof(T)>::value) - return nullptr; - return (T*)gMallocTable->realloc(aPtr, aNewSize * sizeof(T)); - } - - static void* malloc_(size_t aSize) - { - void* p = gMallocTable->malloc(aSize); - ExitOnFailure(p); - return p; - } - - template <typename T> - static T* pod_malloc(size_t aNumElems) - { - T* p = maybe_pod_malloc<T>(aNumElems); - ExitOnFailure(p); - return p; - } - - static void* calloc_(size_t aSize) - { - void* p = gMallocTable->calloc(1, aSize); - ExitOnFailure(p); - return p; - } - - template <typename T> - static T* pod_calloc(size_t aNumElems) - { - T* p = maybe_pod_calloc<T>(aNumElems); - ExitOnFailure(p); - return p; - } - - // This realloc_ is the one we use for direct reallocs within DMD. - static void* realloc_(void* aPtr, size_t aNewSize) - { - void* p = gMallocTable->realloc(aPtr, aNewSize); - ExitOnFailure(p); - return p; - } - - // This realloc_ is required for this to be a JS container AllocPolicy. - template <typename T> - static T* pod_realloc(T* aPtr, size_t aOldSize, size_t aNewSize) - { - T* p = maybe_pod_realloc(aPtr, aOldSize, aNewSize); - ExitOnFailure(p); - return p; - } - - static void* memalign_(size_t aAlignment, size_t aSize) - { - void* p = gMallocTable->memalign(aAlignment, aSize); - ExitOnFailure(p); - return p; - } - - static void free_(void* aPtr) { gMallocTable->free(aPtr); } - - static char* strdup_(const char* aStr) - { - char* s = (char*) InfallibleAllocPolicy::malloc_(strlen(aStr) + 1); - strcpy(s, aStr); - return s; - } - - template <class T> - static T* new_() - { - void* mem = malloc_(sizeof(T)); - return new (mem) T; - } - - template <class T, typename P1> - static T* new_(P1 aP1) - { - void* mem = malloc_(sizeof(T)); - return new (mem) T(aP1); - } - - template <class T> - static void delete_(T* aPtr) - { - if (aPtr) { - aPtr->~T(); - InfallibleAllocPolicy::free_(aPtr); - } - } - - static void reportAllocOverflow() { ExitOnFailure(nullptr); } - bool checkSimulatedOOM() const { return true; } -}; - -// This is only needed because of the |const void*| vs |void*| arg mismatch. -static size_t -MallocSizeOf(const void* aPtr) -{ - return gMallocTable->malloc_usable_size(const_cast<void*>(aPtr)); -} - -void -DMDFuncs::StatusMsg(const char* aFmt, va_list aAp) -{ -#ifdef ANDROID - __android_log_vprint(ANDROID_LOG_INFO, "DMD", aFmt, aAp); -#else - // The +64 is easily enough for the "DMD[<pid>] " prefix and the NUL. - char* fmt = (char*) InfallibleAllocPolicy::malloc_(strlen(aFmt) + 64); - sprintf(fmt, "DMD[%d] %s", getpid(), aFmt); - vfprintf(stderr, fmt, aAp); - InfallibleAllocPolicy::free_(fmt); -#endif -} - -/* static */ void -InfallibleAllocPolicy::ExitOnFailure(const void* aP) -{ - if (!aP) { - MOZ_CRASH("DMD out of memory; aborting"); - } -} - -static double -Percent(size_t part, size_t whole) -{ - return (whole == 0) ? 0 : 100 * (double)part / whole; -} - -// Commifies the number. -static char* -Show(size_t n, char* buf, size_t buflen) -{ - int nc = 0, i = 0, lasti = buflen - 2; - buf[lasti + 1] = '\0'; - if (n == 0) { - buf[lasti - i] = '0'; - i++; - } else { - while (n > 0) { - if (((i - nc) % 3) == 0 && i != 0) { - buf[lasti - i] = ','; - i++; - nc++; - } - buf[lasti - i] = static_cast<char>((n % 10) + '0'); - i++; - n /= 10; - } - } - int firstCharIndex = lasti - i + 1; - - MOZ_ASSERT(firstCharIndex >= 0); - return &buf[firstCharIndex]; -} - -//--------------------------------------------------------------------------- -// Options (Part 1) -//--------------------------------------------------------------------------- - -class Options -{ - template <typename T> - struct NumOption - { - const T mDefault; - const T mMax; - T mActual; - NumOption(T aDefault, T aMax) - : mDefault(aDefault), mMax(aMax), mActual(aDefault) - {} - }; - - // DMD has several modes. These modes affect what data is recorded and - // written to the output file, and the written data affects the - // post-processing that dmd.py can do. - // - // Users specify the mode as soon as DMD starts. This leads to minimal memory - // usage and log file size. It has the disadvantage that is inflexible -- if - // you want to change modes you have to re-run DMD. But in practice changing - // modes seems to be rare, so it's not much of a problem. - // - // An alternative possibility would be to always record and output *all* the - // information needed for all modes. This would let you choose the mode when - // running dmd.py, and so you could do multiple kinds of profiling on a - // single DMD run. But if you are only interested in one of the simpler - // modes, you'd pay the price of (a) increased memory usage and (b) *very* - // large log files. - // - // Finally, another alternative possibility would be to do mode selection - // partly at DMD startup or recording, and then partly in dmd.py. This would - // give some extra flexibility at moderate memory and file size cost. But - // certain mode pairs wouldn't work, which would be confusing. - // - enum class Mode - { - // For each live block, this mode outputs: size (usable and slop) and - // (possibly) and allocation stack. This mode is good for live heap - // profiling. - Live, - - // Like "Live", but for each live block it also outputs: zero or more - // report stacks. This mode is good for identifying where memory reporters - // should be added. This is the default mode. - DarkMatter, - - // Like "Live", but also outputs the same data for dead blocks. This mode - // does cumulative heap profiling, which is good for identifying where large - // amounts of short-lived allocations ("heap churn") occur. - Cumulative, - - // Like "Live", but this mode also outputs for each live block the address - // of the block and the values contained in the blocks. This mode is useful - // for investigating leaks, by helping to figure out which blocks refer to - // other blocks. This mode force-enables full stacks coverage. - Scan - }; - - // With full stacks, every heap block gets a stack trace recorded for it. - // This is complete but slow. - // - // With partial stacks, not all heap blocks will get a stack trace recorded. - // A Bernoulli trial (see mfbt/FastBernoulliTrial.h for details) is performed - // for each heap block to decide if it gets one. Because bigger heap blocks - // are more likely to get a stack trace, even though most heap *blocks* won't - // get a stack trace, most heap *bytes* will. - enum class Stacks - { - Full, - Partial - }; - - char* mDMDEnvVar; // a saved copy, for later printing - - Mode mMode; - Stacks mStacks; - bool mShowDumpStats; - - void BadArg(const char* aArg); - static const char* ValueIfMatch(const char* aArg, const char* aOptionName); - static bool GetLong(const char* aArg, const char* aOptionName, - long aMin, long aMax, long* aValue); - static bool GetBool(const char* aArg, const char* aOptionName, bool* aValue); - -public: - explicit Options(const char* aDMDEnvVar); - - bool IsLiveMode() const { return mMode == Mode::Live; } - bool IsDarkMatterMode() const { return mMode == Mode::DarkMatter; } - bool IsCumulativeMode() const { return mMode == Mode::Cumulative; } - bool IsScanMode() const { return mMode == Mode::Scan; } - - const char* ModeString() const; - - const char* DMDEnvVar() const { return mDMDEnvVar; } - - bool DoFullStacks() const { return mStacks == Stacks::Full; } - size_t ShowDumpStats() const { return mShowDumpStats; } -}; - -static Options *gOptions; - -//--------------------------------------------------------------------------- -// The global lock -//--------------------------------------------------------------------------- - -// MutexBase implements the platform-specific parts of a mutex. - -#ifdef XP_WIN - -class MutexBase -{ - CRITICAL_SECTION mCS; - - DISALLOW_COPY_AND_ASSIGN(MutexBase); - -public: - MutexBase() { InitializeCriticalSection(&mCS); } - ~MutexBase() { DeleteCriticalSection(&mCS); } - - void Lock() { EnterCriticalSection(&mCS); } - void Unlock() { LeaveCriticalSection(&mCS); } -}; - -#else - -#include <pthread.h> -#include <sys/types.h> - -class MutexBase -{ - pthread_mutex_t mMutex; - - DISALLOW_COPY_AND_ASSIGN(MutexBase); - -public: - MutexBase() { pthread_mutex_init(&mMutex, nullptr); } - - void Lock() { pthread_mutex_lock(&mMutex); } - void Unlock() { pthread_mutex_unlock(&mMutex); } -}; - -#endif - -class Mutex : private MutexBase -{ - bool mIsLocked; - - DISALLOW_COPY_AND_ASSIGN(Mutex); - -public: - Mutex() - : mIsLocked(false) - {} - - void Lock() - { - MutexBase::Lock(); - MOZ_ASSERT(!mIsLocked); - mIsLocked = true; - } - - void Unlock() - { - MOZ_ASSERT(mIsLocked); - mIsLocked = false; - MutexBase::Unlock(); - } - - bool IsLocked() { return mIsLocked; } -}; - -// This lock must be held while manipulating global state such as -// gStackTraceTable, gLiveBlockTable, gDeadBlockTable. Note that gOptions is -// *not* protected by this lock because it is only written to by Options(), -// which is only invoked at start-up and in ResetEverything(), which is only -// used by SmokeDMD.cpp. -static Mutex* gStateLock = nullptr; - -class AutoLockState -{ - DISALLOW_COPY_AND_ASSIGN(AutoLockState); - -public: - AutoLockState() { gStateLock->Lock(); } - ~AutoLockState() { gStateLock->Unlock(); } -}; - -class AutoUnlockState -{ - DISALLOW_COPY_AND_ASSIGN(AutoUnlockState); - -public: - AutoUnlockState() { gStateLock->Unlock(); } - ~AutoUnlockState() { gStateLock->Lock(); } -}; - -//--------------------------------------------------------------------------- -// Thread-local storage and blocking of intercepts -//--------------------------------------------------------------------------- - -#ifdef XP_WIN - -#define DMD_TLS_INDEX_TYPE DWORD -#define DMD_CREATE_TLS_INDEX(i_) do { \ - (i_) = TlsAlloc(); \ - } while (0) -#define DMD_DESTROY_TLS_INDEX(i_) TlsFree((i_)) -#define DMD_GET_TLS_DATA(i_) TlsGetValue((i_)) -#define DMD_SET_TLS_DATA(i_, v_) TlsSetValue((i_), (v_)) - -#else - -#include <pthread.h> - -#define DMD_TLS_INDEX_TYPE pthread_key_t -#define DMD_CREATE_TLS_INDEX(i_) pthread_key_create(&(i_), nullptr) -#define DMD_DESTROY_TLS_INDEX(i_) pthread_key_delete((i_)) -#define DMD_GET_TLS_DATA(i_) pthread_getspecific((i_)) -#define DMD_SET_TLS_DATA(i_, v_) pthread_setspecific((i_), (v_)) - -#endif - -static DMD_TLS_INDEX_TYPE gTlsIndex; - -class Thread -{ - // Required for allocation via InfallibleAllocPolicy::new_. - friend class InfallibleAllocPolicy; - - // When true, this blocks intercepts, which allows malloc interception - // functions to themselves call malloc. (Nb: for direct calls to malloc we - // can just use InfallibleAllocPolicy::{malloc_,new_}, but we sometimes - // indirectly call vanilla malloc via functions like MozStackWalk.) - bool mBlockIntercepts; - - Thread() - : mBlockIntercepts(false) - {} - - DISALLOW_COPY_AND_ASSIGN(Thread); - -public: - static Thread* Fetch(); - - bool BlockIntercepts() - { - MOZ_ASSERT(!mBlockIntercepts); - return mBlockIntercepts = true; - } - - bool UnblockIntercepts() - { - MOZ_ASSERT(mBlockIntercepts); - return mBlockIntercepts = false; - } - - bool InterceptsAreBlocked() const { return mBlockIntercepts; } -}; - -/* static */ Thread* -Thread::Fetch() -{ - Thread* t = static_cast<Thread*>(DMD_GET_TLS_DATA(gTlsIndex)); - - if (MOZ_UNLIKELY(!t)) { - // This memory is never freed, even if the thread dies. It's a leak, but - // only a tiny one. - t = InfallibleAllocPolicy::new_<Thread>(); - DMD_SET_TLS_DATA(gTlsIndex, t); - } - - return t; -} - -// An object of this class must be created (on the stack) before running any -// code that might allocate. -class AutoBlockIntercepts -{ - Thread* const mT; - - DISALLOW_COPY_AND_ASSIGN(AutoBlockIntercepts); - -public: - explicit AutoBlockIntercepts(Thread* aT) - : mT(aT) - { - mT->BlockIntercepts(); - } - ~AutoBlockIntercepts() - { - MOZ_ASSERT(mT->InterceptsAreBlocked()); - mT->UnblockIntercepts(); - } -}; - -//--------------------------------------------------------------------------- -// Location service -//--------------------------------------------------------------------------- - -class StringTable -{ -public: - StringTable() - { - MOZ_ALWAYS_TRUE(mSet.init(64)); - } - - const char* - Intern(const char* aString) - { - StringHashSet::AddPtr p = mSet.lookupForAdd(aString); - if (p) { - return *p; - } - - const char* newString = InfallibleAllocPolicy::strdup_(aString); - MOZ_ALWAYS_TRUE(mSet.add(p, newString)); - return newString; - } - - size_t - SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const - { - size_t n = 0; - n += mSet.sizeOfExcludingThis(aMallocSizeOf); - for (auto r = mSet.all(); !r.empty(); r.popFront()) { - n += aMallocSizeOf(r.front()); - } - return n; - } - -private: - struct StringHasher - { - typedef const char* Lookup; - - static uint32_t hash(const char* const& aS) - { - return HashString(aS); - } - - static bool match(const char* const& aA, const char* const& aB) - { - return strcmp(aA, aB) == 0; - } - }; - - typedef js::HashSet<const char*, StringHasher, InfallibleAllocPolicy> StringHashSet; - - StringHashSet mSet; -}; - -class StringAlloc -{ -public: - static char* copy(const char* aString) - { - return InfallibleAllocPolicy::strdup_(aString); - } - static void free(char* aString) - { - InfallibleAllocPolicy::free_(aString); - } -}; - -struct DescribeCodeAddressLock -{ - static void Unlock() { gStateLock->Unlock(); } - static void Lock() { gStateLock->Lock(); } - static bool IsLocked() { return gStateLock->IsLocked(); } -}; - -typedef CodeAddressService<StringTable, StringAlloc, DescribeCodeAddressLock> - CodeAddressService; - -//--------------------------------------------------------------------------- -// Stack traces -//--------------------------------------------------------------------------- - -class StackTrace -{ -public: - static const uint32_t MaxFrames = 24; - -private: - uint32_t mLength; // The number of PCs. - const void* mPcs[MaxFrames]; // The PCs themselves. - -public: - StackTrace() : mLength(0) {} - - uint32_t Length() const { return mLength; } - const void* Pc(uint32_t i) const - { - MOZ_ASSERT(i < mLength); - return mPcs[i]; - } - - uint32_t Size() const { return mLength * sizeof(mPcs[0]); } - - // The stack trace returned by this function is interned in gStackTraceTable, - // and so is immortal and unmovable. - static const StackTrace* Get(Thread* aT); - - // Hash policy. - - typedef StackTrace* Lookup; - - static uint32_t hash(const StackTrace* const& aSt) - { - return mozilla::HashBytes(aSt->mPcs, aSt->Size()); - } - - static bool match(const StackTrace* const& aA, - const StackTrace* const& aB) - { - return aA->mLength == aB->mLength && - memcmp(aA->mPcs, aB->mPcs, aA->Size()) == 0; - } - -private: - static void StackWalkCallback(uint32_t aFrameNumber, void* aPc, void* aSp, - void* aClosure) - { - StackTrace* st = (StackTrace*) aClosure; - MOZ_ASSERT(st->mLength < MaxFrames); - st->mPcs[st->mLength] = aPc; - st->mLength++; - MOZ_ASSERT(st->mLength == aFrameNumber); - } -}; - -typedef js::HashSet<StackTrace*, StackTrace, InfallibleAllocPolicy> - StackTraceTable; -static StackTraceTable* gStackTraceTable = nullptr; - -typedef js::HashSet<const StackTrace*, js::DefaultHasher<const StackTrace*>, - InfallibleAllocPolicy> - StackTraceSet; - -typedef js::HashSet<const void*, js::DefaultHasher<const void*>, - InfallibleAllocPolicy> - PointerSet; -typedef js::HashMap<const void*, uint32_t, js::DefaultHasher<const void*>, - InfallibleAllocPolicy> - PointerIdMap; - -// We won't GC the stack trace table until it this many elements. -static uint32_t gGCStackTraceTableWhenSizeExceeds = 4 * 1024; - -/* static */ const StackTrace* -StackTrace::Get(Thread* aT) -{ - MOZ_ASSERT(gStateLock->IsLocked()); - MOZ_ASSERT(aT->InterceptsAreBlocked()); - - // On Windows, MozStackWalk can acquire a lock from the shared library - // loader. Another thread might call malloc while holding that lock (when - // loading a shared library). So we can't be in gStateLock during the call - // to MozStackWalk. For details, see - // https://bugzilla.mozilla.org/show_bug.cgi?id=374829#c8 - // On Linux, something similar can happen; see bug 824340. - // So let's just release it on all platforms. - StackTrace tmp; - { - AutoUnlockState unlock; - uint32_t skipFrames = 2; - if (MozStackWalk(StackWalkCallback, skipFrames, - MaxFrames, &tmp, 0, nullptr)) { - // Handle the common case first. All is ok. Nothing to do. - } else { - tmp.mLength = 0; - } - } - - StackTraceTable::AddPtr p = gStackTraceTable->lookupForAdd(&tmp); - if (!p) { - StackTrace* stnew = InfallibleAllocPolicy::new_<StackTrace>(tmp); - MOZ_ALWAYS_TRUE(gStackTraceTable->add(p, stnew)); - } - return *p; -} - -//--------------------------------------------------------------------------- -// Heap blocks -//--------------------------------------------------------------------------- - -// This class combines a 2-byte-aligned pointer (i.e. one whose bottom bit -// is zero) with a 1-bit tag. -// -// |T| is the pointer type, e.g. |int*|, not the pointed-to type. This makes -// is easier to have const pointers, e.g. |TaggedPtr<const int*>|. -template <typename T> -class TaggedPtr -{ - union - { - T mPtr; - uintptr_t mUint; - }; - - static const uintptr_t kTagMask = uintptr_t(0x1); - static const uintptr_t kPtrMask = ~kTagMask; - - static bool IsTwoByteAligned(T aPtr) - { - return (uintptr_t(aPtr) & kTagMask) == 0; - } - -public: - TaggedPtr() - : mPtr(nullptr) - {} - - TaggedPtr(T aPtr, bool aBool) - : mPtr(aPtr) - { - MOZ_ASSERT(IsTwoByteAligned(aPtr)); - uintptr_t tag = uintptr_t(aBool); - MOZ_ASSERT(tag <= kTagMask); - mUint |= (tag & kTagMask); - } - - void Set(T aPtr, bool aBool) - { - MOZ_ASSERT(IsTwoByteAligned(aPtr)); - mPtr = aPtr; - uintptr_t tag = uintptr_t(aBool); - MOZ_ASSERT(tag <= kTagMask); - mUint |= (tag & kTagMask); - } - - T Ptr() const { return reinterpret_cast<T>(mUint & kPtrMask); } - - bool Tag() const { return bool(mUint & kTagMask); } -}; - -// A live heap block. Stores both basic data and data about reports, if we're -// in DarkMatter mode. -class LiveBlock -{ - const void* mPtr; - const size_t mReqSize; // size requested - - // The stack trace where this block was allocated, or nullptr if we didn't - // record one. - const StackTrace* const mAllocStackTrace; - - // This array has two elements because we record at most two reports of a - // block. - // - Ptr: |mReportStackTrace| - stack trace where this block was reported. - // nullptr if not reported. - // - Tag bit 0: |mReportedOnAlloc| - was the block reported immediately on - // allocation? If so, DMD must not clear the report at the end of - // Analyze(). Only relevant if |mReportStackTrace| is non-nullptr. - // - // |mPtr| is used as the key in LiveBlockTable, so it's ok for this member - // to be |mutable|. - // - // Only used in DarkMatter mode. - mutable TaggedPtr<const StackTrace*> mReportStackTrace_mReportedOnAlloc[2]; - -public: - LiveBlock(const void* aPtr, size_t aReqSize, - const StackTrace* aAllocStackTrace) - : mPtr(aPtr) - , mReqSize(aReqSize) - , mAllocStackTrace(aAllocStackTrace) - , mReportStackTrace_mReportedOnAlloc() // all fields get zeroed - {} - - const void* Address() const { return mPtr; } - - size_t ReqSize() const { return mReqSize; } - - size_t SlopSize() const - { - return MallocSizeOf(mPtr) - mReqSize; - } - - const StackTrace* AllocStackTrace() const - { - return mAllocStackTrace; - } - - const StackTrace* ReportStackTrace1() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - return mReportStackTrace_mReportedOnAlloc[0].Ptr(); - } - - const StackTrace* ReportStackTrace2() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - return mReportStackTrace_mReportedOnAlloc[1].Ptr(); - } - - bool ReportedOnAlloc1() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - return mReportStackTrace_mReportedOnAlloc[0].Tag(); - } - - bool ReportedOnAlloc2() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - return mReportStackTrace_mReportedOnAlloc[1].Tag(); - } - - void AddStackTracesToTable(StackTraceSet& aStackTraces) const - { - if (AllocStackTrace()) { - MOZ_ALWAYS_TRUE(aStackTraces.put(AllocStackTrace())); - } - if (gOptions->IsDarkMatterMode()) { - if (ReportStackTrace1()) { - MOZ_ALWAYS_TRUE(aStackTraces.put(ReportStackTrace1())); - } - if (ReportStackTrace2()) { - MOZ_ALWAYS_TRUE(aStackTraces.put(ReportStackTrace2())); - } - } - } - - uint32_t NumReports() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - if (ReportStackTrace2()) { - MOZ_ASSERT(ReportStackTrace1()); - return 2; - } - if (ReportStackTrace1()) { - return 1; - } - return 0; - } - - // This is |const| thanks to the |mutable| fields above. - void Report(Thread* aT, bool aReportedOnAlloc) const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - // We don't bother recording reports after the 2nd one. - uint32_t numReports = NumReports(); - if (numReports < 2) { - mReportStackTrace_mReportedOnAlloc[numReports].Set(StackTrace::Get(aT), - aReportedOnAlloc); - } - } - - void UnreportIfNotReportedOnAlloc() const - { - MOZ_ASSERT(gOptions->IsDarkMatterMode()); - if (!ReportedOnAlloc1() && !ReportedOnAlloc2()) { - mReportStackTrace_mReportedOnAlloc[0].Set(nullptr, 0); - mReportStackTrace_mReportedOnAlloc[1].Set(nullptr, 0); - - } else if (!ReportedOnAlloc1() && ReportedOnAlloc2()) { - // Shift the 2nd report down to the 1st one. - mReportStackTrace_mReportedOnAlloc[0] = - mReportStackTrace_mReportedOnAlloc[1]; - mReportStackTrace_mReportedOnAlloc[1].Set(nullptr, 0); - - } else if (ReportedOnAlloc1() && !ReportedOnAlloc2()) { - mReportStackTrace_mReportedOnAlloc[1].Set(nullptr, 0); - } - } - - // Hash policy. - - typedef const void* Lookup; - - static uint32_t hash(const void* const& aPtr) - { - return mozilla::HashGeneric(aPtr); - } - - static bool match(const LiveBlock& aB, const void* const& aPtr) - { - return aB.mPtr == aPtr; - } -}; - -// A table of live blocks where the lookup key is the block address. -typedef js::HashSet<LiveBlock, LiveBlock, InfallibleAllocPolicy> LiveBlockTable; -static LiveBlockTable* gLiveBlockTable = nullptr; - -class AggregatedLiveBlockHashPolicy -{ -public: - typedef const LiveBlock* const Lookup; - - static uint32_t hash(const LiveBlock* const& aB) - { - return gOptions->IsDarkMatterMode() - ? mozilla::HashGeneric(aB->ReqSize(), - aB->SlopSize(), - aB->AllocStackTrace(), - aB->ReportedOnAlloc1(), - aB->ReportedOnAlloc2()) - : mozilla::HashGeneric(aB->ReqSize(), - aB->SlopSize(), - aB->AllocStackTrace()); - } - - static bool match(const LiveBlock* const& aA, const LiveBlock* const& aB) - { - return gOptions->IsDarkMatterMode() - ? aA->ReqSize() == aB->ReqSize() && - aA->SlopSize() == aB->SlopSize() && - aA->AllocStackTrace() == aB->AllocStackTrace() && - aA->ReportStackTrace1() == aB->ReportStackTrace1() && - aA->ReportStackTrace2() == aB->ReportStackTrace2() - : aA->ReqSize() == aB->ReqSize() && - aA->SlopSize() == aB->SlopSize() && - aA->AllocStackTrace() == aB->AllocStackTrace(); - } -}; - -// A table of live blocks where the lookup key is everything but the block -// address. For aggregating similar live blocks at output time. -typedef js::HashMap<const LiveBlock*, size_t, AggregatedLiveBlockHashPolicy, - InfallibleAllocPolicy> - AggregatedLiveBlockTable; - -// A freed heap block. -class DeadBlock -{ - const size_t mReqSize; // size requested - const size_t mSlopSize; // slop above size requested - - // The stack trace where this block was allocated. - const StackTrace* const mAllocStackTrace; - -public: - DeadBlock() - : mReqSize(0) - , mSlopSize(0) - , mAllocStackTrace(nullptr) - {} - - explicit DeadBlock(const LiveBlock& aLb) - : mReqSize(aLb.ReqSize()) - , mSlopSize(aLb.SlopSize()) - , mAllocStackTrace(aLb.AllocStackTrace()) - {} - - ~DeadBlock() {} - - size_t ReqSize() const { return mReqSize; } - size_t SlopSize() const { return mSlopSize; } - - const StackTrace* AllocStackTrace() const - { - return mAllocStackTrace; - } - - void AddStackTracesToTable(StackTraceSet& aStackTraces) const - { - if (AllocStackTrace()) { - MOZ_ALWAYS_TRUE(aStackTraces.put(AllocStackTrace())); - } - } - - // Hash policy. - - typedef DeadBlock Lookup; - - static uint32_t hash(const DeadBlock& aB) - { - return mozilla::HashGeneric(aB.ReqSize(), - aB.SlopSize(), - aB.AllocStackTrace()); - } - - static bool match(const DeadBlock& aA, const DeadBlock& aB) - { - return aA.ReqSize() == aB.ReqSize() && - aA.SlopSize() == aB.SlopSize() && - aA.AllocStackTrace() == aB.AllocStackTrace(); - } -}; - -// For each unique DeadBlock value we store a count of how many actual dead -// blocks have that value. -typedef js::HashMap<DeadBlock, size_t, DeadBlock, InfallibleAllocPolicy> - DeadBlockTable; -static DeadBlockTable* gDeadBlockTable = nullptr; - -// Add the dead block to the dead block table, if that's appropriate. -void MaybeAddToDeadBlockTable(const DeadBlock& aDb) -{ - if (gOptions->IsCumulativeMode() && aDb.AllocStackTrace()) { - AutoLockState lock; - if (DeadBlockTable::AddPtr p = gDeadBlockTable->lookupForAdd(aDb)) { - p->value() += 1; - } else { - MOZ_ALWAYS_TRUE(gDeadBlockTable->add(p, aDb, 1)); - } - } -} - -// Add a pointer to each live stack trace into the given StackTraceSet. (A -// stack trace is live if it's used by one of the live blocks.) -static void -GatherUsedStackTraces(StackTraceSet& aStackTraces) -{ - MOZ_ASSERT(gStateLock->IsLocked()); - MOZ_ASSERT(Thread::Fetch()->InterceptsAreBlocked()); - - aStackTraces.finish(); - MOZ_ALWAYS_TRUE(aStackTraces.init(512)); - - for (auto r = gLiveBlockTable->all(); !r.empty(); r.popFront()) { - r.front().AddStackTracesToTable(aStackTraces); - } - - for (auto r = gDeadBlockTable->all(); !r.empty(); r.popFront()) { - r.front().key().AddStackTracesToTable(aStackTraces); - } -} - -// Delete stack traces that we aren't using, and compact our hashtable. -static void -GCStackTraces() -{ - MOZ_ASSERT(gStateLock->IsLocked()); - MOZ_ASSERT(Thread::Fetch()->InterceptsAreBlocked()); - - StackTraceSet usedStackTraces; - GatherUsedStackTraces(usedStackTraces); - - // Delete all unused stack traces from gStackTraceTable. The Enum destructor - // will automatically rehash and compact the table. - for (StackTraceTable::Enum e(*gStackTraceTable); !e.empty(); e.popFront()) { - StackTrace* const& st = e.front(); - if (!usedStackTraces.has(st)) { - e.removeFront(); - InfallibleAllocPolicy::delete_(st); - } - } - - // Schedule a GC when we have twice as many stack traces as we had right after - // this GC finished. - gGCStackTraceTableWhenSizeExceeds = 2 * gStackTraceTable->count(); -} - -//--------------------------------------------------------------------------- -// malloc/free callbacks -//--------------------------------------------------------------------------- - -static FastBernoulliTrial* gBernoulli; - -// In testing, a probability of 0.003 resulted in ~25% of heap blocks getting -// a stack trace and ~80% of heap bytes getting a stack trace. (This is -// possible because big heap blocks are more likely to get a stack trace.) -// -// We deliberately choose not to give the user control over this probability -// (other than effectively setting it to 1 via --stacks=full) because it's -// quite inscrutable and generally the user just wants "faster and imprecise" -// or "slower and precise". -// -// The random number seeds are arbitrary and were obtained from random.org. If -// you change them you'll need to change the tests as well, because their -// expected output is based on the particular sequence of trial results that we -// get with these seeds. -static void -ResetBernoulli() -{ - new (gBernoulli) FastBernoulliTrial(0.003, 0x8e26eeee166bc8ca, - 0x56820f304a9c9ae0); -} - -static void -AllocCallback(void* aPtr, size_t aReqSize, Thread* aT) -{ - if (!aPtr) { - return; - } - - AutoLockState lock; - AutoBlockIntercepts block(aT); - - size_t actualSize = gMallocTable->malloc_usable_size(aPtr); - - // We may or may not record the allocation stack trace, depending on the - // options and the outcome of a Bernoulli trial. - bool getTrace = gOptions->DoFullStacks() || gBernoulli->trial(actualSize); - LiveBlock b(aPtr, aReqSize, getTrace ? StackTrace::Get(aT) : nullptr); - MOZ_ALWAYS_TRUE(gLiveBlockTable->putNew(aPtr, b)); -} - -static void -FreeCallback(void* aPtr, Thread* aT, DeadBlock* aDeadBlock) -{ - if (!aPtr) { - return; - } - - AutoLockState lock; - AutoBlockIntercepts block(aT); - - if (LiveBlockTable::Ptr lb = gLiveBlockTable->lookup(aPtr)) { - if (gOptions->IsCumulativeMode()) { - // Copy it out so it can be added to the dead block list later. - new (aDeadBlock) DeadBlock(*lb); - } - gLiveBlockTable->remove(lb); - } else { - // We have no record of the block. It must be a bogus pointer, or one that - // DMD wasn't able to see allocated. This should be extremely rare. - } - - if (gStackTraceTable->count() > gGCStackTraceTableWhenSizeExceeds) { - GCStackTraces(); - } -} - -//--------------------------------------------------------------------------- -// malloc/free interception -//--------------------------------------------------------------------------- - -static void Init(const malloc_table_t* aMallocTable); - -} // namespace dmd -} // namespace mozilla - -void -replace_init(const malloc_table_t* aMallocTable) -{ - mozilla::dmd::Init(aMallocTable); -} - -ReplaceMallocBridge* -replace_get_bridge() -{ - return mozilla::dmd::gDMDBridge; -} - -void* -replace_malloc(size_t aSize) -{ - using namespace mozilla::dmd; - - if (!gIsDMDInitialized) { - // DMD hasn't started up, either because it wasn't enabled by the user, or - // we're still in Init() and something has indirectly called malloc. Do a - // vanilla malloc. (In the latter case, if it fails we'll crash. But - // OOM is highly unlikely so early on.) - return gMallocTable->malloc(aSize); - } - - Thread* t = Thread::Fetch(); - if (t->InterceptsAreBlocked()) { - // Intercepts are blocked, which means this must be a call to malloc - // triggered indirectly by DMD (e.g. via MozStackWalk). Be infallible. - return InfallibleAllocPolicy::malloc_(aSize); - } - - // This must be a call to malloc from outside DMD. Intercept it. - void* ptr = gMallocTable->malloc(aSize); - AllocCallback(ptr, aSize, t); - return ptr; -} - -void* -replace_calloc(size_t aCount, size_t aSize) -{ - using namespace mozilla::dmd; - - if (!gIsDMDInitialized) { - return gMallocTable->calloc(aCount, aSize); - } - - Thread* t = Thread::Fetch(); - if (t->InterceptsAreBlocked()) { - return InfallibleAllocPolicy::calloc_(aCount * aSize); - } - - void* ptr = gMallocTable->calloc(aCount, aSize); - AllocCallback(ptr, aCount * aSize, t); - return ptr; -} - -void* -replace_realloc(void* aOldPtr, size_t aSize) -{ - using namespace mozilla::dmd; - - if (!gIsDMDInitialized) { - return gMallocTable->realloc(aOldPtr, aSize); - } - - Thread* t = Thread::Fetch(); - if (t->InterceptsAreBlocked()) { - return InfallibleAllocPolicy::realloc_(aOldPtr, aSize); - } - - // If |aOldPtr| is nullptr, the call is equivalent to |malloc(aSize)|. - if (!aOldPtr) { - return replace_malloc(aSize); - } - - // Be very careful here! Must remove the block from the table before doing - // the realloc to avoid races, just like in replace_free(). - // Nb: This does an unnecessary hashtable remove+add if the block doesn't - // move, but doing better isn't worth the effort. - DeadBlock db; - FreeCallback(aOldPtr, t, &db); - void* ptr = gMallocTable->realloc(aOldPtr, aSize); - if (ptr) { - AllocCallback(ptr, aSize, t); - MaybeAddToDeadBlockTable(db); - } else { - // If realloc fails, we undo the prior operations by re-inserting the old - // pointer into the live block table. We don't have to do anything with the - // dead block list because the dead block hasn't yet been inserted. The - // block will end up looking like it was allocated for the first time here, - // which is untrue, and the slop bytes will be zero, which may be untrue. - // But this case is rare and doing better isn't worth the effort. - AllocCallback(aOldPtr, gMallocTable->malloc_usable_size(aOldPtr), t); - } - return ptr; -} - -void* -replace_memalign(size_t aAlignment, size_t aSize) -{ - using namespace mozilla::dmd; - - if (!gIsDMDInitialized) { - return gMallocTable->memalign(aAlignment, aSize); - } - - Thread* t = Thread::Fetch(); - if (t->InterceptsAreBlocked()) { - return InfallibleAllocPolicy::memalign_(aAlignment, aSize); - } - - void* ptr = gMallocTable->memalign(aAlignment, aSize); - AllocCallback(ptr, aSize, t); - return ptr; -} - -void -replace_free(void* aPtr) -{ - using namespace mozilla::dmd; - - if (!gIsDMDInitialized) { - gMallocTable->free(aPtr); - return; - } - - Thread* t = Thread::Fetch(); - if (t->InterceptsAreBlocked()) { - return InfallibleAllocPolicy::free_(aPtr); - } - - // Do the actual free after updating the table. Otherwise, another thread - // could call malloc and get the freed block and update the table, and then - // our update here would remove the newly-malloc'd block. - DeadBlock db; - FreeCallback(aPtr, t, &db); - MaybeAddToDeadBlockTable(db); - gMallocTable->free(aPtr); -} - -namespace mozilla { -namespace dmd { - -//--------------------------------------------------------------------------- -// Options (Part 2) -//--------------------------------------------------------------------------- - -// Given an |aOptionName| like "foo", succeed if |aArg| has the form "foo=blah" -// (where "blah" is non-empty) and return the pointer to "blah". |aArg| can -// have leading space chars (but not other whitespace). -const char* -Options::ValueIfMatch(const char* aArg, const char* aOptionName) -{ - MOZ_ASSERT(!isspace(*aArg)); // any leading whitespace should not remain - size_t optionLen = strlen(aOptionName); - if (strncmp(aArg, aOptionName, optionLen) == 0 && aArg[optionLen] == '=' && - aArg[optionLen + 1]) { - return aArg + optionLen + 1; - } - return nullptr; -} - -// Extracts a |long| value for an option from an argument. It must be within -// the range |aMin..aMax| (inclusive). -bool -Options::GetLong(const char* aArg, const char* aOptionName, - long aMin, long aMax, long* aValue) -{ - if (const char* optionValue = ValueIfMatch(aArg, aOptionName)) { - char* endPtr; - *aValue = strtol(optionValue, &endPtr, /* base */ 10); - if (!*endPtr && aMin <= *aValue && *aValue <= aMax && - *aValue != LONG_MIN && *aValue != LONG_MAX) { - return true; - } - } - return false; -} - -// Extracts a |bool| value for an option -- encoded as "yes" or "no" -- from an -// argument. -bool -Options::GetBool(const char* aArg, const char* aOptionName, bool* aValue) -{ - if (const char* optionValue = ValueIfMatch(aArg, aOptionName)) { - if (strcmp(optionValue, "yes") == 0) { - *aValue = true; - return true; - } - if (strcmp(optionValue, "no") == 0) { - *aValue = false; - return true; - } - } - return false; -} - -Options::Options(const char* aDMDEnvVar) - : mDMDEnvVar(aDMDEnvVar ? InfallibleAllocPolicy::strdup_(aDMDEnvVar) - : nullptr) - , mMode(Mode::DarkMatter) - , mStacks(Stacks::Partial) - , mShowDumpStats(false) -{ - // It's no longer necessary to set the DMD env var to "1" if you want default - // options (you can leave it undefined) but we still accept "1" for - // backwards compatibility. - char* e = mDMDEnvVar; - if (e && strcmp(e, "1") != 0) { - bool isEnd = false; - while (!isEnd) { - // Consume leading whitespace. - while (isspace(*e)) { - e++; - } - - // Save the start of the arg. - const char* arg = e; - - // Find the first char after the arg, and temporarily change it to '\0' - // to isolate the arg. - while (!isspace(*e) && *e != '\0') { - e++; - } - char replacedChar = *e; - isEnd = replacedChar == '\0'; - *e = '\0'; - - // Handle arg - bool myBool; - if (strcmp(arg, "--mode=live") == 0) { - mMode = Mode::Live; - } else if (strcmp(arg, "--mode=dark-matter") == 0) { - mMode = Mode::DarkMatter; - } else if (strcmp(arg, "--mode=cumulative") == 0) { - mMode = Mode::Cumulative; - } else if (strcmp(arg, "--mode=scan") == 0) { - mMode = Mode::Scan; - - } else if (strcmp(arg, "--stacks=full") == 0) { - mStacks = Stacks::Full; - } else if (strcmp(arg, "--stacks=partial") == 0) { - mStacks = Stacks::Partial; - - } else if (GetBool(arg, "--show-dump-stats", &myBool)) { - mShowDumpStats = myBool; - - } else if (strcmp(arg, "") == 0) { - // This can only happen if there is trailing whitespace. Ignore. - MOZ_ASSERT(isEnd); - - } else { - BadArg(arg); - } - - // Undo the temporary isolation. - *e = replacedChar; - } - } - - if (mMode == Mode::Scan) { - mStacks = Stacks::Full; - } -} - -void -Options::BadArg(const char* aArg) -{ - StatusMsg("\n"); - StatusMsg("Bad entry in the $DMD environment variable: '%s'.\n", aArg); - StatusMsg("See the output of |mach help run| for the allowed options.\n"); - exit(1); -} - -const char* -Options::ModeString() const -{ - switch (mMode) { - case Mode::Live: - return "live"; - case Mode::DarkMatter: - return "dark-matter"; - case Mode::Cumulative: - return "cumulative"; - case Mode::Scan: - return "scan"; - default: - MOZ_ASSERT(false); - return "(unknown DMD mode)"; - } -} - -//--------------------------------------------------------------------------- -// DMD start-up -//--------------------------------------------------------------------------- - -#ifdef XP_MACOSX -static void -NopStackWalkCallback(uint32_t aFrameNumber, void* aPc, void* aSp, - void* aClosure) -{ -} -#endif - -// WARNING: this function runs *very* early -- before all static initializers -// have run. For this reason, non-scalar globals such as gStateLock and -// gStackTraceTable are allocated dynamically (so we can guarantee their -// construction in this function) rather than statically. -static void -Init(const malloc_table_t* aMallocTable) -{ - gMallocTable = aMallocTable; - gDMDBridge = InfallibleAllocPolicy::new_<DMDBridge>(); - - // DMD is controlled by the |DMD| environment variable. - const char* e = getenv("DMD"); - - if (e) { - StatusMsg("$DMD = '%s'\n", e); - } else { - StatusMsg("$DMD is undefined\n", e); - } - - // Parse $DMD env var. - gOptions = InfallibleAllocPolicy::new_<Options>(e); - -#ifdef XP_MACOSX - // On Mac OS X we need to call StackWalkInitCriticalAddress() very early - // (prior to the creation of any mutexes, apparently) otherwise we can get - // hangs when getting stack traces (bug 821577). But - // StackWalkInitCriticalAddress() isn't exported from xpcom/, so instead we - // just call MozStackWalk, because that calls StackWalkInitCriticalAddress(). - // See the comment above StackWalkInitCriticalAddress() for more details. - (void)MozStackWalk(NopStackWalkCallback, /* skipFrames */ 0, - /* maxFrames */ 1, nullptr, 0, nullptr); -#endif - - gStateLock = InfallibleAllocPolicy::new_<Mutex>(); - - gBernoulli = (FastBernoulliTrial*) - InfallibleAllocPolicy::malloc_(sizeof(FastBernoulliTrial)); - ResetBernoulli(); - - DMD_CREATE_TLS_INDEX(gTlsIndex); - - { - AutoLockState lock; - - gStackTraceTable = InfallibleAllocPolicy::new_<StackTraceTable>(); - MOZ_ALWAYS_TRUE(gStackTraceTable->init(8192)); - - gLiveBlockTable = InfallibleAllocPolicy::new_<LiveBlockTable>(); - MOZ_ALWAYS_TRUE(gLiveBlockTable->init(8192)); - - // Create this even if the mode isn't Cumulative (albeit with a small - // size), in case the mode is changed later on (as is done by SmokeDMD.cpp, - // for example). - gDeadBlockTable = InfallibleAllocPolicy::new_<DeadBlockTable>(); - size_t tableSize = gOptions->IsCumulativeMode() ? 8192 : 4; - MOZ_ALWAYS_TRUE(gDeadBlockTable->init(tableSize)); - } - - gIsDMDInitialized = true; -} - -//--------------------------------------------------------------------------- -// Block reporting and unreporting -//--------------------------------------------------------------------------- - -static void -ReportHelper(const void* aPtr, bool aReportedOnAlloc) -{ - if (!gOptions->IsDarkMatterMode() || !aPtr) { - return; - } - - Thread* t = Thread::Fetch(); - - AutoBlockIntercepts block(t); - AutoLockState lock; - - if (LiveBlockTable::Ptr p = gLiveBlockTable->lookup(aPtr)) { - p->Report(t, aReportedOnAlloc); - } else { - // We have no record of the block. It must be a bogus pointer. This should - // be extremely rare because Report() is almost always called in - // conjunction with a malloc_size_of-style function. - } -} - -void -DMDFuncs::Report(const void* aPtr) -{ - ReportHelper(aPtr, /* onAlloc */ false); -} - -void -DMDFuncs::ReportOnAlloc(const void* aPtr) -{ - ReportHelper(aPtr, /* onAlloc */ true); -} - -//--------------------------------------------------------------------------- -// DMD output -//--------------------------------------------------------------------------- - -// The version number of the output format. Increment this if you make -// backwards-incompatible changes to the format. See DMD.h for the version -// history. -static const int kOutputVersionNumber = 5; - -// Note that, unlike most SizeOf* functions, this function does not take a -// |mozilla::MallocSizeOf| argument. That's because those arguments are -// primarily to aid DMD track heap blocks... but DMD deliberately doesn't track -// heap blocks it allocated for itself! -// -// SizeOfInternal should be called while you're holding the state lock and -// while intercepts are blocked; SizeOf acquires the lock and blocks -// intercepts. - -static void -SizeOfInternal(Sizes* aSizes) -{ - MOZ_ASSERT(gStateLock->IsLocked()); - MOZ_ASSERT(Thread::Fetch()->InterceptsAreBlocked()); - - aSizes->Clear(); - - StackTraceSet usedStackTraces; - GatherUsedStackTraces(usedStackTraces); - - for (auto r = gStackTraceTable->all(); !r.empty(); r.popFront()) { - StackTrace* const& st = r.front(); - - if (usedStackTraces.has(st)) { - aSizes->mStackTracesUsed += MallocSizeOf(st); - } else { - aSizes->mStackTracesUnused += MallocSizeOf(st); - } - } - - aSizes->mStackTraceTable = - gStackTraceTable->sizeOfIncludingThis(MallocSizeOf); - - aSizes->mLiveBlockTable = gLiveBlockTable->sizeOfIncludingThis(MallocSizeOf); - - aSizes->mDeadBlockTable = gDeadBlockTable->sizeOfIncludingThis(MallocSizeOf); -} - -void -DMDFuncs::SizeOf(Sizes* aSizes) -{ - aSizes->Clear(); - - AutoBlockIntercepts block(Thread::Fetch()); - AutoLockState lock; - SizeOfInternal(aSizes); -} - -void -DMDFuncs::ClearReports() -{ - if (!gOptions->IsDarkMatterMode()) { - return; - } - - AutoLockState lock; - - // Unreport all blocks that were marked reported by a memory reporter. This - // excludes those that were reported on allocation, because they need to keep - // their reported marking. - for (auto r = gLiveBlockTable->all(); !r.empty(); r.popFront()) { - r.front().UnreportIfNotReportedOnAlloc(); - } -} - -class ToIdStringConverter final -{ -public: - ToIdStringConverter() - : mNextId(0) - { - MOZ_ALWAYS_TRUE(mIdMap.init(512)); - } - - // Converts a pointer to a unique ID. Reuses the existing ID for the pointer - // if it's been seen before. - const char* ToIdString(const void* aPtr) - { - uint32_t id; - PointerIdMap::AddPtr p = mIdMap.lookupForAdd(aPtr); - if (!p) { - id = mNextId++; - MOZ_ALWAYS_TRUE(mIdMap.add(p, aPtr, id)); - } else { - id = p->value(); - } - return Base32(id); - } - - size_t sizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const - { - return mIdMap.sizeOfExcludingThis(aMallocSizeOf); - } - -private: - // This function converts an integer to base-32. We use base-32 values for - // indexing into the traceTable and the frameTable, for the following reasons. - // - // - Base-32 gives more compact indices than base-16. - // - // - 32 is a power-of-two, which makes the necessary div/mod calculations - // fast. - // - // - We can (and do) choose non-numeric digits for base-32. When - // inspecting/debugging the JSON output, non-numeric indices are easier to - // search for than numeric indices. - // - char* Base32(uint32_t aN) - { - static const char digits[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef"; - - char* b = mIdBuf + kIdBufLen - 1; - *b = '\0'; - do { - b--; - if (b == mIdBuf) { - MOZ_CRASH("Base32 buffer too small"); - } - *b = digits[aN % 32]; - aN /= 32; - } while (aN); - - return b; - } - - PointerIdMap mIdMap; - uint32_t mNextId; - - // |mIdBuf| must have space for at least eight chars, which is the space - // needed to hold 'Dffffff' (including the terminating null char), which is - // the base-32 representation of 0xffffffff. - static const size_t kIdBufLen = 16; - char mIdBuf[kIdBufLen]; -}; - -// Helper class for converting a pointer value to a string. -class ToStringConverter -{ -public: - const char* ToPtrString(const void* aPtr) - { - snprintf(kPtrBuf, sizeof(kPtrBuf) - 1, "%" PRIxPTR, (uintptr_t)aPtr); - return kPtrBuf; - } - -private: - char kPtrBuf[32]; -}; - -static void -WriteBlockContents(JSONWriter& aWriter, const LiveBlock& aBlock) -{ - size_t numWords = aBlock.ReqSize() / sizeof(uintptr_t*); - if (numWords == 0) { - return; - } - - aWriter.StartArrayProperty("contents", aWriter.SingleLineStyle); - { - const uintptr_t** block = (const uintptr_t**)aBlock.Address(); - ToStringConverter sc; - for (size_t i = 0; i < numWords; ++i) { - aWriter.StringElement(sc.ToPtrString(block[i])); - } - } - aWriter.EndArray(); -} - -static void -AnalyzeImpl(UniquePtr<JSONWriteFunc> aWriter) -{ - // Some blocks may have been allocated while creating |aWriter|. Those blocks - // will be freed at the end of this function when |write| is destroyed. The - // allocations will have occurred while intercepts were not blocked, so the - // frees better be as well, otherwise we'll get assertion failures. - // Therefore, this declaration must precede the AutoBlockIntercepts - // declaration, to ensure that |write| is destroyed *after* intercepts are - // unblocked. - JSONWriter writer(Move(aWriter)); - - AutoBlockIntercepts block(Thread::Fetch()); - AutoLockState lock; - - // Allocate this on the heap instead of the stack because it's fairly large. - auto locService = InfallibleAllocPolicy::new_<CodeAddressService>(); - - StackTraceSet usedStackTraces; - MOZ_ALWAYS_TRUE(usedStackTraces.init(512)); - - PointerSet usedPcs; - MOZ_ALWAYS_TRUE(usedPcs.init(512)); - - size_t iscSize; - - static int analysisCount = 1; - StatusMsg("Dump %d {\n", analysisCount++); - - writer.Start(); - { - writer.IntProperty("version", kOutputVersionNumber); - - writer.StartObjectProperty("invocation"); - { - const char* var = gOptions->DMDEnvVar(); - if (var) { - writer.StringProperty("dmdEnvVar", var); - } else { - writer.NullProperty("dmdEnvVar"); - } - - writer.StringProperty("mode", gOptions->ModeString()); - } - writer.EndObject(); - - StatusMsg(" Constructing the heap block list...\n"); - - ToIdStringConverter isc; - ToStringConverter sc; - - writer.StartArrayProperty("blockList"); - { - // Lambda that writes out a live block. - auto writeLiveBlock = [&](const LiveBlock& aB, size_t aNum) { - aB.AddStackTracesToTable(usedStackTraces); - - MOZ_ASSERT_IF(gOptions->IsScanMode(), aNum == 1); - - writer.StartObjectElement(writer.SingleLineStyle); - { - if (gOptions->IsScanMode()) { - writer.StringProperty("addr", sc.ToPtrString(aB.Address())); - WriteBlockContents(writer, aB); - } - writer.IntProperty("req", aB.ReqSize()); - if (aB.SlopSize() > 0) { - writer.IntProperty("slop", aB.SlopSize()); - } - - if (aB.AllocStackTrace()) { - writer.StringProperty("alloc", - isc.ToIdString(aB.AllocStackTrace())); - } - - if (gOptions->IsDarkMatterMode() && aB.NumReports() > 0) { - writer.StartArrayProperty("reps"); - { - if (aB.ReportStackTrace1()) { - writer.StringElement(isc.ToIdString(aB.ReportStackTrace1())); - } - if (aB.ReportStackTrace2()) { - writer.StringElement(isc.ToIdString(aB.ReportStackTrace2())); - } - } - writer.EndArray(); - } - - if (aNum > 1) { - writer.IntProperty("num", aNum); - } - } - writer.EndObject(); - }; - - // Live blocks. - if (!gOptions->IsScanMode()) { - // At this point we typically have many LiveBlocks that differ only in - // their address. Aggregate them to reduce the size of the output file. - AggregatedLiveBlockTable agg; - MOZ_ALWAYS_TRUE(agg.init(8192)); - for (auto r = gLiveBlockTable->all(); !r.empty(); r.popFront()) { - const LiveBlock& b = r.front(); - b.AddStackTracesToTable(usedStackTraces); - - if (AggregatedLiveBlockTable::AddPtr p = agg.lookupForAdd(&b)) { - p->value() += 1; - } else { - MOZ_ALWAYS_TRUE(agg.add(p, &b, 1)); - } - } - - // Now iterate over the aggregated table. - for (auto r = agg.all(); !r.empty(); r.popFront()) { - const LiveBlock& b = *r.front().key(); - size_t num = r.front().value(); - writeLiveBlock(b, num); - } - - } else { - // In scan mode we cannot aggregate because we print each live block's - // address and contents. - for (auto r = gLiveBlockTable->all(); !r.empty(); r.popFront()) { - const LiveBlock& b = r.front(); - b.AddStackTracesToTable(usedStackTraces); - - writeLiveBlock(b, 1); - } - } - - // Dead blocks. - for (auto r = gDeadBlockTable->all(); !r.empty(); r.popFront()) { - const DeadBlock& b = r.front().key(); - b.AddStackTracesToTable(usedStackTraces); - - size_t num = r.front().value(); - MOZ_ASSERT(num > 0); - - writer.StartObjectElement(writer.SingleLineStyle); - { - writer.IntProperty("req", b.ReqSize()); - if (b.SlopSize() > 0) { - writer.IntProperty("slop", b.SlopSize()); - } - if (b.AllocStackTrace()) { - writer.StringProperty("alloc", isc.ToIdString(b.AllocStackTrace())); - } - - if (num > 1) { - writer.IntProperty("num", num); - } - } - writer.EndObject(); - } - } - writer.EndArray(); - - StatusMsg(" Constructing the stack trace table...\n"); - - writer.StartObjectProperty("traceTable"); - { - for (auto r = usedStackTraces.all(); !r.empty(); r.popFront()) { - const StackTrace* const st = r.front(); - writer.StartArrayProperty(isc.ToIdString(st), writer.SingleLineStyle); - { - for (uint32_t i = 0; i < st->Length(); i++) { - const void* pc = st->Pc(i); - writer.StringElement(isc.ToIdString(pc)); - MOZ_ALWAYS_TRUE(usedPcs.put(pc)); - } - } - writer.EndArray(); - } - } - writer.EndObject(); - - StatusMsg(" Constructing the stack frame table...\n"); - - writer.StartObjectProperty("frameTable"); - { - static const size_t locBufLen = 1024; - char locBuf[locBufLen]; - - for (PointerSet::Enum e(usedPcs); !e.empty(); e.popFront()) { - const void* const pc = e.front(); - - // Use 0 for the frame number. See the JSON format description comment - // in DMD.h to understand why. - locService->GetLocation(0, pc, locBuf, locBufLen); - writer.StringProperty(isc.ToIdString(pc), locBuf); - } - } - writer.EndObject(); - - iscSize = isc.sizeOfExcludingThis(MallocSizeOf); - } - writer.End(); - - if (gOptions->ShowDumpStats()) { - Sizes sizes; - SizeOfInternal(&sizes); - - static const size_t kBufLen = 64; - char buf1[kBufLen]; - char buf2[kBufLen]; - char buf3[kBufLen]; - - StatusMsg(" Execution measurements {\n"); - - StatusMsg(" Data structures that persist after Dump() ends {\n"); - - StatusMsg(" Used stack traces: %10s bytes\n", - Show(sizes.mStackTracesUsed, buf1, kBufLen)); - - StatusMsg(" Unused stack traces: %10s bytes\n", - Show(sizes.mStackTracesUnused, buf1, kBufLen)); - - StatusMsg(" Stack trace table: %10s bytes (%s entries, %s used)\n", - Show(sizes.mStackTraceTable, buf1, kBufLen), - Show(gStackTraceTable->capacity(), buf2, kBufLen), - Show(gStackTraceTable->count(), buf3, kBufLen)); - - StatusMsg(" Live block table: %10s bytes (%s entries, %s used)\n", - Show(sizes.mLiveBlockTable, buf1, kBufLen), - Show(gLiveBlockTable->capacity(), buf2, kBufLen), - Show(gLiveBlockTable->count(), buf3, kBufLen)); - - StatusMsg(" Dead block table: %10s bytes (%s entries, %s used)\n", - Show(sizes.mDeadBlockTable, buf1, kBufLen), - Show(gDeadBlockTable->capacity(), buf2, kBufLen), - Show(gDeadBlockTable->count(), buf3, kBufLen)); - - StatusMsg(" }\n"); - StatusMsg(" Data structures that are destroyed after Dump() ends {\n"); - - StatusMsg(" Location service: %10s bytes\n", - Show(locService->SizeOfIncludingThis(MallocSizeOf), buf1, kBufLen)); - StatusMsg(" Used stack traces set: %10s bytes\n", - Show(usedStackTraces.sizeOfExcludingThis(MallocSizeOf), buf1, kBufLen)); - StatusMsg(" Used PCs set: %10s bytes\n", - Show(usedPcs.sizeOfExcludingThis(MallocSizeOf), buf1, kBufLen)); - StatusMsg(" Pointer ID map: %10s bytes\n", - Show(iscSize, buf1, kBufLen)); - - StatusMsg(" }\n"); - StatusMsg(" Counts {\n"); - - size_t hits = locService->NumCacheHits(); - size_t misses = locService->NumCacheMisses(); - size_t requests = hits + misses; - StatusMsg(" Location service: %10s requests\n", - Show(requests, buf1, kBufLen)); - - size_t count = locService->CacheCount(); - size_t capacity = locService->CacheCapacity(); - StatusMsg(" Location service cache: " - "%4.1f%% hit rate, %.1f%% occupancy at end\n", - Percent(hits, requests), Percent(count, capacity)); - - StatusMsg(" }\n"); - StatusMsg(" }\n"); - } - - InfallibleAllocPolicy::delete_(locService); - - StatusMsg("}\n"); -} - -void -DMDFuncs::Analyze(UniquePtr<JSONWriteFunc> aWriter) -{ - AnalyzeImpl(Move(aWriter)); - ClearReports(); -} - -//--------------------------------------------------------------------------- -// Testing -//--------------------------------------------------------------------------- - -void -DMDFuncs::ResetEverything(const char* aOptions) -{ - AutoLockState lock; - - // Reset options. - InfallibleAllocPolicy::delete_(gOptions); - gOptions = InfallibleAllocPolicy::new_<Options>(aOptions); - - // Clear all existing blocks. - gLiveBlockTable->clear(); - gDeadBlockTable->clear(); - - // Reset gBernoulli to a deterministic state. (Its current state depends on - // all previous trials.) - ResetBernoulli(); -} - -} // namespace dmd -} // namespace mozilla |