Squashed 'third_party/gperftools/' content from commit 54505f1
Change-Id: Id02e833828732b0efe7dac722b8485279e67c5fa
git-subtree-dir: third_party/gperftools
git-subtree-split: 54505f1d50c2d1f4676f5e87090b64a117fd980e
diff --git a/src/windows/patch_functions.cc b/src/windows/patch_functions.cc
new file mode 100644
index 0000000..ff1bec7
--- /dev/null
+++ b/src/windows/patch_functions.cc
@@ -0,0 +1,1077 @@
+// Copyright (c) 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---
+// Author: Craig Silverstein
+//
+// The main purpose of this file is to patch the libc allocation
+// routines (malloc and friends, but also _msize and other
+// windows-specific libc-style routines). However, we also patch
+// windows routines to do accounting. We do better at the former than
+// the latter. Here are some comments from Paul Pluzhnikov about what
+// it might take to do a really good job patching windows routines to
+// keep track of memory usage:
+//
+// "You should intercept at least the following:
+// HeapCreate HeapDestroy HeapAlloc HeapReAlloc HeapFree
+// RtlCreateHeap RtlDestroyHeap RtlAllocateHeap RtlFreeHeap
+// malloc calloc realloc free
+// malloc_dbg calloc_dbg realloc_dbg free_dbg
+// Some of these call the other ones (but not always), sometimes
+// recursively (i.e. HeapCreate may call HeapAlloc on a different
+// heap, IIRC)."
+//
+// Since Paul didn't mention VirtualAllocEx, he may not have even been
+// considering all the mmap-like functions that windows has (or he may
+// just be ignoring it because he's seen we already patch it). Of the
+// above, we do not patch the *_dbg functions, and of the windows
+// functions, we only patch HeapAlloc and HeapFree.
+//
+// The *_dbg functions come into play with /MDd, /MTd, and /MLd,
+// probably. It may be ok to just turn off tcmalloc in those cases --
+// if the user wants the windows debug malloc, they probably don't
+// want tcmalloc! We should also test with all of /MD, /MT, and /ML,
+// which we're not currently doing.
+
+// TODO(csilvers): try to do better here? Paul does conclude:
+// "Keeping track of all of this was a nightmare."
+
+#ifndef _WIN32
+# error You should only be including windows/patch_functions.cc in a windows environment!
+#endif
+
+#include <config.h>
+
+#ifdef WIN32_OVERRIDE_ALLOCATORS
+#error This file is intended for patching allocators - use override_functions.cc instead.
+#endif
+
+// We use psapi. Non-MSVC systems will have to link this in themselves.
+#ifdef _MSC_VER
+#pragma comment(lib, "Psapi.lib")
+#endif
+
+// Make sure we always use the 'old' names of the psapi functions.
+#ifndef PSAPI_VERSION
+#define PSAPI_VERSION 1
+#endif
+
+#include <windows.h>
+#include <stdio.h>
+#include <malloc.h> // for _msize and _expand
+#include <psapi.h> // for EnumProcessModules, GetModuleInformation, etc.
+#include <set>
+#include <map>
+#include <vector>
+#include <base/logging.h>
+#include "base/spinlock.h"
+#include "gperftools/malloc_hook.h"
+#include "malloc_hook-inl.h"
+#include "preamble_patcher.h"
+
+// The maximum number of modules we allow to be in one executable
+const int kMaxModules = 8182;
+
+// These are hard-coded, unfortunately. :-( They are also probably
+// compiler specific. See get_mangled_names.cc, in this directory,
+// for instructions on how to update these names for your compiler.
+const char kMangledNew[] = "??2@YAPAXI@Z";
+const char kMangledNewArray[] = "??_U@YAPAXI@Z";
+const char kMangledDelete[] = "??3@YAXPAX@Z";
+const char kMangledDeleteArray[] = "??_V@YAXPAX@Z";
+const char kMangledNewNothrow[] = "??2@YAPAXIABUnothrow_t@std@@@Z";
+const char kMangledNewArrayNothrow[] = "??_U@YAPAXIABUnothrow_t@std@@@Z";
+const char kMangledDeleteNothrow[] = "??3@YAXPAXABUnothrow_t@std@@@Z";
+const char kMangledDeleteArrayNothrow[] = "??_V@YAXPAXABUnothrow_t@std@@@Z";
+
+// This is an unused but exported symbol that we can use to tell the
+// MSVC linker to bring in libtcmalloc, via the /INCLUDE linker flag.
+// Without this, the linker will likely decide that libtcmalloc.dll
+// doesn't add anything to the executable (since it does all its work
+// through patching, which the linker can't see), and ignore it
+// entirely. (The name 'tcmalloc' is already reserved for a
+// namespace. I'd rather export a variable named "_tcmalloc", but I
+// couldn't figure out how to get that to work. This function exports
+// the symbol "__tcmalloc".)
+extern "C" PERFTOOLS_DLL_DECL void _tcmalloc();
+void _tcmalloc() { }
+
+// This is the version needed for windows x64, which has a different
+// decoration scheme which doesn't auto-add a leading underscore.
+extern "C" PERFTOOLS_DLL_DECL void __tcmalloc();
+void __tcmalloc() { }
+
+namespace { // most everything here is in an unnamed namespace
+
+typedef void (*GenericFnPtr)();
+
+using sidestep::PreamblePatcher;
+
+struct ModuleEntryCopy; // defined below
+
+// These functions are how we override the memory allocation
+// functions, just like tcmalloc.cc and malloc_hook.cc do.
+
+// This is information about the routines we're patching, for a given
+// module that implements libc memory routines. A single executable
+// can have several libc implementations running about (in different
+// .dll's), and we need to patch/unpatch them all. This defines
+// everything except the new functions we're patching in, which
+// are defined in LibcFunctions, below.
+class LibcInfo {
+ public:
+ LibcInfo() {
+ memset(this, 0, sizeof(*this)); // easiest way to initialize the array
+ }
+
+ bool patched() const { return is_valid(); }
+ void set_is_valid(bool b) { is_valid_ = b; }
+ // According to http://msdn.microsoft.com/en-us/library/ms684229(VS.85).aspx:
+ // "The load address of a module (lpBaseOfDll) is the same as the HMODULE
+ // value."
+ HMODULE hmodule() const {
+ return reinterpret_cast<HMODULE>(const_cast<void*>(module_base_address_));
+ }
+
+ // Populates all the windows_fn_[] vars based on our module info.
+ // Returns false if windows_fn_ is all NULL's, because there's
+ // nothing to patch. Also populates the rest of the module_entry
+ // info, such as the module's name.
+ bool PopulateWindowsFn(const ModuleEntryCopy& module_entry);
+
+ protected:
+ void CopyFrom(const LibcInfo& that) {
+ if (this == &that)
+ return;
+ this->is_valid_ = that.is_valid_;
+ memcpy(this->windows_fn_, that.windows_fn_, sizeof(windows_fn_));
+ this->module_base_address_ = that.module_base_address_;
+ this->module_base_size_ = that.module_base_size_;
+ }
+
+ enum {
+ kMalloc, kFree, kRealloc, kCalloc,
+ kNew, kNewArray, kDelete, kDeleteArray,
+ kNewNothrow, kNewArrayNothrow, kDeleteNothrow, kDeleteArrayNothrow,
+ // These are windows-only functions from malloc.h
+ k_Msize, k_Expand,
+ // A MS CRT "internal" function, implemented using _calloc_impl
+ k_CallocCrt,
+ kNumFunctions
+ };
+
+ // I'd like to put these together in a struct (perhaps in the
+ // subclass, so we can put in perftools_fn_ as well), but vc8 seems
+ // to have a bug where it doesn't initialize the struct properly if
+ // we try to take the address of a function that's not yet loaded
+ // from a dll, as is the common case for static_fn_. So we need
+ // each to be in its own array. :-(
+ static const char* const function_name_[kNumFunctions];
+
+ // This function is only used when statically linking the binary.
+ // In that case, loading malloc/etc from the dll (via
+ // PatchOneModule) won't work, since there are no dlls. Instead,
+ // you just want to be taking the address of malloc/etc directly.
+ // In the common, non-static-link case, these pointers will all be
+ // NULL, since this initializer runs before msvcrt.dll is loaded.
+ static const GenericFnPtr static_fn_[kNumFunctions];
+
+ // This is the address of the function we are going to patch
+ // (malloc, etc). Other info about the function is in the
+ // patch-specific subclasses, below.
+ GenericFnPtr windows_fn_[kNumFunctions];
+
+ // This is set to true when this structure is initialized (because
+ // we're patching a new library) and set to false when it's
+ // uninitialized (because we've freed that library).
+ bool is_valid_;
+
+ const void *module_base_address_;
+ size_t module_base_size_;
+
+ public:
+ // These shouldn't have to be public, since only subclasses of
+ // LibcInfo need it, but they do. Maybe something to do with
+ // templates. Shrug. I hide them down here so users won't see
+ // them. :-) (OK, I also need to define ctrgProcAddress late.)
+ bool is_valid() const { return is_valid_; }
+ GenericFnPtr windows_fn(int ifunction) const {
+ return windows_fn_[ifunction];
+ }
+ // These three are needed by ModuleEntryCopy.
+ static const int ctrgProcAddress = kNumFunctions;
+ static GenericFnPtr static_fn(int ifunction) {
+ return static_fn_[ifunction];
+ }
+ static const char* const function_name(int ifunction) {
+ return function_name_[ifunction];
+ }
+};
+
+// Template trickiness: logically, a LibcInfo would include
+// Windows_malloc_, origstub_malloc_, and Perftools_malloc_: for a
+// given module, these three go together. And in fact,
+// Perftools_malloc_ may need to call origstub_malloc_, which means we
+// either need to change Perftools_malloc_ to take origstub_malloc_ as
+// an argument -- unfortunately impossible since it needs to keep the
+// same API as normal malloc -- or we need to write a different
+// version of Perftools_malloc_ for each LibcInfo instance we create.
+// We choose the second route, and use templates to implement it (we
+// could have also used macros). So to get multiple versions
+// of the struct, we say "struct<1> var1; struct<2> var2;". The price
+// we pay is some code duplication, and more annoying, each instance
+// of this var is a separate type.
+template<int> class LibcInfoWithPatchFunctions : public LibcInfo {
+ public:
+ // me_info should have had PopulateWindowsFn() called on it, so the
+ // module_* vars and windows_fn_ are set up.
+ bool Patch(const LibcInfo& me_info);
+ void Unpatch();
+
+ private:
+ // This holds the original function contents after we patch the function.
+ // This has to be defined static in the subclass, because the perftools_fns
+ // reference origstub_fn_.
+ static GenericFnPtr origstub_fn_[kNumFunctions];
+
+ // This is the function we want to patch in
+ static const GenericFnPtr perftools_fn_[kNumFunctions];
+
+ static void* Perftools_malloc(size_t size) __THROW;
+ static void Perftools_free(void* ptr) __THROW;
+ static void* Perftools_realloc(void* ptr, size_t size) __THROW;
+ static void* Perftools_calloc(size_t nmemb, size_t size) __THROW;
+ static void* Perftools_new(size_t size);
+ static void* Perftools_newarray(size_t size);
+ static void Perftools_delete(void *ptr);
+ static void Perftools_deletearray(void *ptr);
+ static void* Perftools_new_nothrow(size_t size,
+ const std::nothrow_t&) __THROW;
+ static void* Perftools_newarray_nothrow(size_t size,
+ const std::nothrow_t&) __THROW;
+ static void Perftools_delete_nothrow(void *ptr,
+ const std::nothrow_t&) __THROW;
+ static void Perftools_deletearray_nothrow(void *ptr,
+ const std::nothrow_t&) __THROW;
+ static size_t Perftools__msize(void *ptr) __THROW;
+ static void* Perftools__expand(void *ptr, size_t size) __THROW;
+ // malloc.h also defines these functions:
+ // _aligned_malloc, _aligned_free,
+ // _recalloc, _aligned_offset_malloc, _aligned_realloc, _aligned_recalloc
+ // _aligned_offset_realloc, _aligned_offset_recalloc, _malloca, _freea
+ // But they seem pretty obscure, and I'm fine not overriding them for now.
+ // It may be they all call into malloc/free anyway.
+};
+
+// This is a subset of MODDULEENTRY32, that we need for patching.
+struct ModuleEntryCopy {
+ LPVOID modBaseAddr; // the same as hmodule
+ DWORD modBaseSize;
+ // This is not part of MODDULEENTRY32, but is needed to avoid making
+ // windows syscalls while we're holding patch_all_modules_lock (see
+ // lock-inversion comments at patch_all_modules_lock definition, below).
+ GenericFnPtr rgProcAddresses[LibcInfo::ctrgProcAddress];
+
+ ModuleEntryCopy() {
+ modBaseAddr = NULL;
+ modBaseSize = 0;
+ for (int i = 0; i < sizeof(rgProcAddresses)/sizeof(*rgProcAddresses); i++)
+ rgProcAddresses[i] = LibcInfo::static_fn(i);
+ }
+ ModuleEntryCopy(const MODULEINFO& mi) {
+ this->modBaseAddr = mi.lpBaseOfDll;
+ this->modBaseSize = mi.SizeOfImage;
+ LPVOID modEndAddr = (char*)mi.lpBaseOfDll + mi.SizeOfImage;
+ for (int i = 0; i < sizeof(rgProcAddresses)/sizeof(*rgProcAddresses); i++) {
+ FARPROC target = ::GetProcAddress(
+ reinterpret_cast<const HMODULE>(mi.lpBaseOfDll),
+ LibcInfo::function_name(i));
+ // Sometimes a DLL forwards a function to a function in another
+ // DLL. We don't want to patch those forwarded functions --
+ // they'll get patched when the other DLL is processed.
+ if (target >= modBaseAddr && target < modEndAddr)
+ rgProcAddresses[i] = (GenericFnPtr)target;
+ else
+ rgProcAddresses[i] = (GenericFnPtr)NULL;
+ }
+ }
+};
+
+// This class is easier because there's only one of them.
+class WindowsInfo {
+ public:
+ void Patch();
+ void Unpatch();
+
+ private:
+ // TODO(csilvers): should we be patching GlobalAlloc/LocalAlloc instead,
+ // for pre-XP systems?
+ enum {
+ kHeapAlloc, kHeapFree, kVirtualAllocEx, kVirtualFreeEx,
+ kMapViewOfFileEx, kUnmapViewOfFile, kLoadLibraryExW, kFreeLibrary,
+ kNumFunctions
+ };
+
+ struct FunctionInfo {
+ const char* const name; // name of fn in a module (eg "malloc")
+ GenericFnPtr windows_fn; // the fn whose name we call (&malloc)
+ GenericFnPtr origstub_fn; // original fn contents after we patch
+ const GenericFnPtr perftools_fn; // fn we want to patch in
+ };
+
+ static FunctionInfo function_info_[kNumFunctions];
+
+ // A Windows-API equivalent of malloc and free
+ static LPVOID WINAPI Perftools_HeapAlloc(HANDLE hHeap, DWORD dwFlags,
+ DWORD_PTR dwBytes);
+ static BOOL WINAPI Perftools_HeapFree(HANDLE hHeap, DWORD dwFlags,
+ LPVOID lpMem);
+ // A Windows-API equivalent of mmap and munmap, for "anonymous regions"
+ static LPVOID WINAPI Perftools_VirtualAllocEx(HANDLE process, LPVOID address,
+ SIZE_T size, DWORD type,
+ DWORD protect);
+ static BOOL WINAPI Perftools_VirtualFreeEx(HANDLE process, LPVOID address,
+ SIZE_T size, DWORD type);
+ // A Windows-API equivalent of mmap and munmap, for actual files
+ static LPVOID WINAPI Perftools_MapViewOfFileEx(HANDLE hFileMappingObject,
+ DWORD dwDesiredAccess,
+ DWORD dwFileOffsetHigh,
+ DWORD dwFileOffsetLow,
+ SIZE_T dwNumberOfBytesToMap,
+ LPVOID lpBaseAddress);
+ static BOOL WINAPI Perftools_UnmapViewOfFile(LPCVOID lpBaseAddress);
+ // We don't need the other 3 variants because they all call this one. */
+ static HMODULE WINAPI Perftools_LoadLibraryExW(LPCWSTR lpFileName,
+ HANDLE hFile,
+ DWORD dwFlags);
+ static BOOL WINAPI Perftools_FreeLibrary(HMODULE hLibModule);
+};
+
+// If you run out, just add a few more to the array. You'll also need
+// to update the switch statement in PatchOneModule(), and the list in
+// UnpatchWindowsFunctions().
+// main_executable and main_executable_windows are two windows into
+// the same executable. One is responsible for patching the libc
+// routines that live in the main executable (if any) to use tcmalloc;
+// the other is responsible for patching the windows routines like
+// HeapAlloc/etc to use tcmalloc.
+static LibcInfoWithPatchFunctions<0> main_executable;
+static LibcInfoWithPatchFunctions<1> libc1;
+static LibcInfoWithPatchFunctions<2> libc2;
+static LibcInfoWithPatchFunctions<3> libc3;
+static LibcInfoWithPatchFunctions<4> libc4;
+static LibcInfoWithPatchFunctions<5> libc5;
+static LibcInfoWithPatchFunctions<6> libc6;
+static LibcInfoWithPatchFunctions<7> libc7;
+static LibcInfoWithPatchFunctions<8> libc8;
+static LibcInfo* g_module_libcs[] = {
+ &libc1, &libc2, &libc3, &libc4, &libc5, &libc6, &libc7, &libc8
+};
+static WindowsInfo main_executable_windows;
+
+const char* const LibcInfo::function_name_[] = {
+ "malloc", "free", "realloc", "calloc",
+ kMangledNew, kMangledNewArray, kMangledDelete, kMangledDeleteArray,
+ // Ideally we should patch the nothrow versions of new/delete, but
+ // at least in msvcrt, nothrow-new machine-code is of a type we
+ // can't patch. Since these are relatively rare, I'm hoping it's ok
+ // not to patch them. (NULL name turns off patching.)
+ NULL, // kMangledNewNothrow,
+ NULL, // kMangledNewArrayNothrow,
+ NULL, // kMangledDeleteNothrow,
+ NULL, // kMangledDeleteArrayNothrow,
+ "_msize", "_expand", "_calloc_crt",
+};
+
+// For mingw, I can't patch the new/delete here, because the
+// instructions are too small to patch. Luckily, they're so small
+// because all they do is call into malloc/free, so they still end up
+// calling tcmalloc routines, and we don't actually lose anything
+// (except maybe some stacktrace goodness) by not patching.
+const GenericFnPtr LibcInfo::static_fn_[] = {
+ (GenericFnPtr)&::malloc,
+ (GenericFnPtr)&::free,
+ (GenericFnPtr)&::realloc,
+ (GenericFnPtr)&::calloc,
+#ifdef __MINGW32__
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+#else
+ (GenericFnPtr)(void*(*)(size_t))&::operator new,
+ (GenericFnPtr)(void*(*)(size_t))&::operator new[],
+ (GenericFnPtr)(void(*)(void*))&::operator delete,
+ (GenericFnPtr)(void(*)(void*))&::operator delete[],
+ (GenericFnPtr)
+ (void*(*)(size_t, struct std::nothrow_t const &))&::operator new,
+ (GenericFnPtr)
+ (void*(*)(size_t, struct std::nothrow_t const &))&::operator new[],
+ (GenericFnPtr)
+ (void(*)(void*, struct std::nothrow_t const &))&::operator delete,
+ (GenericFnPtr)
+ (void(*)(void*, struct std::nothrow_t const &))&::operator delete[],
+#endif
+ (GenericFnPtr)&::_msize,
+ (GenericFnPtr)&::_expand,
+ (GenericFnPtr)&::calloc,
+};
+
+template<int T> GenericFnPtr LibcInfoWithPatchFunctions<T>::origstub_fn_[] = {
+ // This will get filled in at run-time, as patching is done.
+};
+
+template<int T>
+const GenericFnPtr LibcInfoWithPatchFunctions<T>::perftools_fn_[] = {
+ (GenericFnPtr)&Perftools_malloc,
+ (GenericFnPtr)&Perftools_free,
+ (GenericFnPtr)&Perftools_realloc,
+ (GenericFnPtr)&Perftools_calloc,
+ (GenericFnPtr)&Perftools_new,
+ (GenericFnPtr)&Perftools_newarray,
+ (GenericFnPtr)&Perftools_delete,
+ (GenericFnPtr)&Perftools_deletearray,
+ (GenericFnPtr)&Perftools_new_nothrow,
+ (GenericFnPtr)&Perftools_newarray_nothrow,
+ (GenericFnPtr)&Perftools_delete_nothrow,
+ (GenericFnPtr)&Perftools_deletearray_nothrow,
+ (GenericFnPtr)&Perftools__msize,
+ (GenericFnPtr)&Perftools__expand,
+ (GenericFnPtr)&Perftools_calloc,
+};
+
+/*static*/ WindowsInfo::FunctionInfo WindowsInfo::function_info_[] = {
+ { "HeapAlloc", NULL, NULL, (GenericFnPtr)&Perftools_HeapAlloc },
+ { "HeapFree", NULL, NULL, (GenericFnPtr)&Perftools_HeapFree },
+ { "VirtualAllocEx", NULL, NULL, (GenericFnPtr)&Perftools_VirtualAllocEx },
+ { "VirtualFreeEx", NULL, NULL, (GenericFnPtr)&Perftools_VirtualFreeEx },
+ { "MapViewOfFileEx", NULL, NULL, (GenericFnPtr)&Perftools_MapViewOfFileEx },
+ { "UnmapViewOfFile", NULL, NULL, (GenericFnPtr)&Perftools_UnmapViewOfFile },
+ { "LoadLibraryExW", NULL, NULL, (GenericFnPtr)&Perftools_LoadLibraryExW },
+ { "FreeLibrary", NULL, NULL, (GenericFnPtr)&Perftools_FreeLibrary },
+};
+
+bool LibcInfo::PopulateWindowsFn(const ModuleEntryCopy& module_entry) {
+ // First, store the location of the function to patch before
+ // patching it. If none of these functions are found in the module,
+ // then this module has no libc in it, and we just return false.
+ for (int i = 0; i < kNumFunctions; i++) {
+ if (!function_name_[i]) // we can turn off patching by unsetting name
+ continue;
+ // The ::GetProcAddress calls were done in the ModuleEntryCopy
+ // constructor, so we don't have to make any windows calls here.
+ const GenericFnPtr fn = module_entry.rgProcAddresses[i];
+ if (fn) {
+ windows_fn_[i] = PreamblePatcher::ResolveTarget(fn);
+ }
+ }
+
+ // Some modules use the same function pointer for new and new[]. If
+ // we find that, set one of the pointers to NULL so we don't double-
+ // patch. Same may happen with new and nothrow-new, or even new[]
+ // and nothrow-new. It's easiest just to check each fn-ptr against
+ // every other.
+ for (int i = 0; i < kNumFunctions; i++) {
+ for (int j = i+1; j < kNumFunctions; j++) {
+ if (windows_fn_[i] == windows_fn_[j]) {
+ // We NULL the later one (j), so as to minimize the chances we
+ // NULL kFree and kRealloc. See comments below. This is fragile!
+ windows_fn_[j] = NULL;
+ }
+ }
+ }
+
+ // There's always a chance that our module uses the same function
+ // as another module that we've already loaded. In that case, we
+ // need to set our windows_fn to NULL, to avoid double-patching.
+ for (int ifn = 0; ifn < kNumFunctions; ifn++) {
+ for (int imod = 0;
+ imod < sizeof(g_module_libcs)/sizeof(*g_module_libcs); imod++) {
+ if (g_module_libcs[imod]->is_valid() &&
+ this->windows_fn(ifn) == g_module_libcs[imod]->windows_fn(ifn)) {
+ windows_fn_[ifn] = NULL;
+ }
+ }
+ }
+
+ bool found_non_null = false;
+ for (int i = 0; i < kNumFunctions; i++) {
+ if (windows_fn_[i])
+ found_non_null = true;
+ }
+ if (!found_non_null)
+ return false;
+
+ // It's important we didn't NULL out windows_fn_[kFree] or [kRealloc].
+ // The reason is, if those are NULL-ed out, we'll never patch them
+ // and thus never get an origstub_fn_ value for them, and when we
+ // try to call origstub_fn_[kFree/kRealloc] in Perftools_free and
+ // Perftools_realloc, below, it will fail. We could work around
+ // that by adding a pointer from one patch-unit to the other, but we
+ // haven't needed to yet.
+ CHECK(windows_fn_[kFree]);
+ CHECK(windows_fn_[kRealloc]);
+
+ // OK, we successfully populated. Let's store our member information.
+ module_base_address_ = module_entry.modBaseAddr;
+ module_base_size_ = module_entry.modBaseSize;
+ return true;
+}
+
+template<int T>
+bool LibcInfoWithPatchFunctions<T>::Patch(const LibcInfo& me_info) {
+ CopyFrom(me_info); // copies the module_entry and the windows_fn_ array
+ for (int i = 0; i < kNumFunctions; i++) {
+ if (windows_fn_[i] && windows_fn_[i] != perftools_fn_[i]) {
+ // if origstub_fn_ is not NULL, it's left around from a previous
+ // patch. We need to set it to NULL for the new Patch call.
+ //
+ // Note that origstub_fn_ was logically freed by
+ // PreamblePatcher::Unpatch, so we don't have to do anything
+ // about it.
+ origstub_fn_[i] = NULL; // Patch() will fill this in
+ CHECK_EQ(sidestep::SIDESTEP_SUCCESS,
+ PreamblePatcher::Patch(windows_fn_[i], perftools_fn_[i],
+ &origstub_fn_[i]));
+ }
+ }
+ set_is_valid(true);
+ return true;
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Unpatch() {
+ // We have to cast our GenericFnPtrs to void* for unpatch. This is
+ // contra the C++ spec; we use C-style casts to empahsize that.
+ for (int i = 0; i < kNumFunctions; i++) {
+ if (windows_fn_[i])
+ CHECK_EQ(sidestep::SIDESTEP_SUCCESS,
+ PreamblePatcher::Unpatch((void*)windows_fn_[i],
+ (void*)perftools_fn_[i],
+ (void*)origstub_fn_[i]));
+ }
+ set_is_valid(false);
+}
+
+void WindowsInfo::Patch() {
+ HMODULE hkernel32 = ::GetModuleHandleA("kernel32");
+ CHECK_NE(hkernel32, NULL);
+
+ // Unlike for libc, we know these exist in our module, so we can get
+ // and patch at the same time.
+ for (int i = 0; i < kNumFunctions; i++) {
+ function_info_[i].windows_fn = (GenericFnPtr)
+ ::GetProcAddress(hkernel32, function_info_[i].name);
+ // If origstub_fn is not NULL, it's left around from a previous
+ // patch. We need to set it to NULL for the new Patch call.
+ // Since we've patched Unpatch() not to delete origstub_fn_ (it
+ // causes problems in some contexts, though obviously not this
+ // one), we should delete it now, before setting it to NULL.
+ // NOTE: casting from a function to a pointer is contra the C++
+ // spec. It's not safe on IA64, but is on i386. We use
+ // a C-style cast here to emphasize this is not legal C++.
+ delete[] (char*)(function_info_[i].origstub_fn);
+ function_info_[i].origstub_fn = NULL; // Patch() will fill this in
+ CHECK_EQ(sidestep::SIDESTEP_SUCCESS,
+ PreamblePatcher::Patch(function_info_[i].windows_fn,
+ function_info_[i].perftools_fn,
+ &function_info_[i].origstub_fn));
+ }
+}
+
+void WindowsInfo::Unpatch() {
+ // We have to cast our GenericFnPtrs to void* for unpatch. This is
+ // contra the C++ spec; we use C-style casts to empahsize that.
+ for (int i = 0; i < kNumFunctions; i++) {
+ CHECK_EQ(sidestep::SIDESTEP_SUCCESS,
+ PreamblePatcher::Unpatch((void*)function_info_[i].windows_fn,
+ (void*)function_info_[i].perftools_fn,
+ (void*)function_info_[i].origstub_fn));
+ }
+}
+
+// You should hold the patch_all_modules_lock when calling this.
+void PatchOneModuleLocked(const LibcInfo& me_info) {
+ // If we don't already have info on this module, let's add it. This
+ // is where we're sad that each libcX has a different type, so we
+ // can't use an array; instead, we have to use a switch statement.
+ // Patch() returns false if there were no libc functions in the module.
+ for (int i = 0; i < sizeof(g_module_libcs)/sizeof(*g_module_libcs); i++) {
+ if (!g_module_libcs[i]->is_valid()) { // found an empty spot to add!
+ switch (i) {
+ case 0: libc1.Patch(me_info); return;
+ case 1: libc2.Patch(me_info); return;
+ case 2: libc3.Patch(me_info); return;
+ case 3: libc4.Patch(me_info); return;
+ case 4: libc5.Patch(me_info); return;
+ case 5: libc6.Patch(me_info); return;
+ case 6: libc7.Patch(me_info); return;
+ case 7: libc8.Patch(me_info); return;
+ }
+ }
+ }
+ printf("PERFTOOLS ERROR: Too many modules containing libc in this executable\n");
+}
+
+void PatchMainExecutableLocked() {
+ if (main_executable.patched())
+ return; // main executable has already been patched
+ ModuleEntryCopy fake_module_entry; // make a fake one to pass into Patch()
+ // No need to call PopulateModuleEntryProcAddresses on the main executable.
+ main_executable.PopulateWindowsFn(fake_module_entry);
+ main_executable.Patch(main_executable);
+}
+
+// This lock is subject to a subtle and annoying lock inversion
+// problem: it may interact badly with unknown internal windows locks.
+// In particular, windows may be holding a lock when it calls
+// LoadLibraryExW and FreeLibrary, which we've patched. We have those
+// routines call PatchAllModules, which acquires this lock. If we
+// make windows system calls while holding this lock, those system
+// calls may need the internal windows locks that are being held in
+// the call to LoadLibraryExW, resulting in deadlock. The solution is
+// to be very careful not to call *any* windows routines while holding
+// patch_all_modules_lock, inside PatchAllModules().
+static SpinLock patch_all_modules_lock(SpinLock::LINKER_INITIALIZED);
+
+// last_loaded: The set of modules that were loaded the last time
+// PatchAllModules was called. This is an optimization for only
+// looking at modules that were added or removed from the last call.
+static std::set<HMODULE> *g_last_loaded;
+
+// Iterates over all the modules currently loaded by the executable,
+// according to windows, and makes sure they're all patched. Most
+// modules will already be in loaded_modules, meaning we have already
+// loaded and either patched them or determined they did not need to
+// be patched. Others will not, which means we need to patch them
+// (if necessary). Finally, we have to go through the existing
+// g_module_libcs and see if any of those are *not* in the modules
+// currently loaded by the executable. If so, we need to invalidate
+// them. Returns true if we did any work (patching or invalidating),
+// false if we were a noop. May update loaded_modules as well.
+// NOTE: you must hold the patch_all_modules_lock to access loaded_modules.
+bool PatchAllModules() {
+ std::vector<ModuleEntryCopy> modules;
+ bool made_changes = false;
+
+ const HANDLE hCurrentProcess = GetCurrentProcess();
+ DWORD num_modules = 0;
+ HMODULE hModules[kMaxModules]; // max # of modules we support in one process
+ if (!::EnumProcessModules(hCurrentProcess, hModules, sizeof(hModules),
+ &num_modules)) {
+ num_modules = 0;
+ }
+ // EnumProcessModules actually set the bytes written into hModules,
+ // so we need to divide to make num_modules actually be a module-count.
+ num_modules /= sizeof(*hModules);
+ if (num_modules >= kMaxModules) {
+ printf("PERFTOOLS ERROR: Too many modules in this executable to try"
+ " to patch them all (if you need to, raise kMaxModules in"
+ " patch_functions.cc).\n");
+ num_modules = kMaxModules;
+ }
+
+ // Now we handle the unpatching of modules we have in g_module_libcs
+ // but that were not found in EnumProcessModules. We need to
+ // invalidate them. To speed that up, we store the EnumProcessModules
+ // output in a set.
+ // At the same time, we prepare for the adding of new modules, by
+ // removing from hModules all the modules we know we've already
+ // patched (or decided don't need to be patched). At the end,
+ // hModules will hold only the modules that we need to consider patching.
+ std::set<HMODULE> currently_loaded_modules;
+ {
+ SpinLockHolder h(&patch_all_modules_lock);
+ if (!g_last_loaded) g_last_loaded = new std::set<HMODULE>;
+ // At the end of this loop, currently_loaded_modules contains the
+ // full list of EnumProcessModules, and hModules just the ones we
+ // haven't handled yet.
+ for (int i = 0; i < num_modules; ) {
+ currently_loaded_modules.insert(hModules[i]);
+ if (g_last_loaded->count(hModules[i]) > 0) {
+ hModules[i] = hModules[--num_modules]; // replace element i with tail
+ } else {
+ i++; // keep element i
+ }
+ }
+ // Now we do the unpatching/invalidation.
+ for (int i = 0; i < sizeof(g_module_libcs)/sizeof(*g_module_libcs); i++) {
+ if (g_module_libcs[i]->patched() &&
+ currently_loaded_modules.count(g_module_libcs[i]->hmodule()) == 0) {
+ // Means g_module_libcs[i] is no longer loaded (no me32 matched).
+ // We could call Unpatch() here, but why bother? The module
+ // has gone away, so nobody is going to call into it anyway.
+ g_module_libcs[i]->set_is_valid(false);
+ made_changes = true;
+ }
+ }
+ // Update the loaded module cache.
+ g_last_loaded->swap(currently_loaded_modules);
+ }
+
+ // Now that we know what modules are new, let's get the info we'll
+ // need to patch them. Note this *cannot* be done while holding the
+ // lock, since it needs to make windows calls (see the lock-inversion
+ // comments before the definition of patch_all_modules_lock).
+ MODULEINFO mi;
+ for (int i = 0; i < num_modules; i++) {
+ if (::GetModuleInformation(hCurrentProcess, hModules[i], &mi, sizeof(mi)))
+ modules.push_back(ModuleEntryCopy(mi));
+ }
+
+ // Now we can do the patching of new modules.
+ {
+ SpinLockHolder h(&patch_all_modules_lock);
+ for (std::vector<ModuleEntryCopy>::iterator it = modules.begin();
+ it != modules.end(); ++it) {
+ LibcInfo libc_info;
+ if (libc_info.PopulateWindowsFn(*it)) { // true==module has libc routines
+ PatchOneModuleLocked(libc_info);
+ made_changes = true;
+ }
+ }
+
+ // Now that we've dealt with the modules (dlls), update the main
+ // executable. We do this last because PatchMainExecutableLocked
+ // wants to look at how other modules were patched.
+ if (!main_executable.patched()) {
+ PatchMainExecutableLocked();
+ made_changes = true;
+ }
+ }
+ // TODO(csilvers): for this to be reliable, we need to also take
+ // into account if we *would* have patched any modules had they not
+ // already been loaded. (That is, made_changes should ignore
+ // g_last_loaded.)
+ return made_changes;
+}
+
+
+} // end unnamed namespace
+
+// ---------------------------------------------------------------------
+// Now that we've done all the patching machinery, let's actually
+// define the functions we're patching in. Mostly these are
+// simple wrappers around the do_* routines in tcmalloc.cc.
+//
+// In fact, we #include tcmalloc.cc to get at the tcmalloc internal
+// do_* functions, the better to write our own hook functions.
+// U-G-L-Y, I know. But the alternatives are, perhaps, worse. This
+// also lets us define _msize(), _expand(), and other windows-specific
+// functions here, using tcmalloc internals, without polluting
+// tcmalloc.cc.
+// -------------------------------------------------------------------
+
+// TODO(csilvers): refactor tcmalloc.cc into two files, so I can link
+// against the file with do_malloc, and ignore the one with malloc.
+#include "tcmalloc.cc"
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_malloc(size_t size) __THROW {
+ void* result = do_malloc_or_cpp_alloc(size);
+ MallocHook::InvokeNewHook(result, size);
+ return result;
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Perftools_free(void* ptr) __THROW {
+ MallocHook::InvokeDeleteHook(ptr);
+ // This calls the windows free if do_free decides ptr was not
+ // allocated by tcmalloc. Note it calls the origstub_free from
+ // *this* templatized instance of LibcInfo. See "template
+ // trickiness" above.
+ do_free_with_callback(ptr, (void (*)(void*))origstub_fn_[kFree]);
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_realloc(
+ void* old_ptr, size_t new_size) __THROW {
+ if (old_ptr == NULL) {
+ void* result = do_malloc_or_cpp_alloc(new_size);
+ MallocHook::InvokeNewHook(result, new_size);
+ return result;
+ }
+ if (new_size == 0) {
+ MallocHook::InvokeDeleteHook(old_ptr);
+ do_free_with_callback(old_ptr,
+ (void (*)(void*))origstub_fn_[kFree]);
+ return NULL;
+ }
+ return do_realloc_with_callback(
+ old_ptr, new_size,
+ (void (*)(void*))origstub_fn_[kFree],
+ (size_t (*)(const void*))origstub_fn_[k_Msize]);
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_calloc(
+ size_t n, size_t elem_size) __THROW {
+ void* result = do_calloc(n, elem_size);
+ MallocHook::InvokeNewHook(result, n * elem_size);
+ return result;
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_new(size_t size) {
+ void* p = cpp_alloc(size, false);
+ MallocHook::InvokeNewHook(p, size);
+ return p;
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_newarray(size_t size) {
+ void* p = cpp_alloc(size, false);
+ MallocHook::InvokeNewHook(p, size);
+ return p;
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Perftools_delete(void *p) {
+ MallocHook::InvokeDeleteHook(p);
+ do_free_with_callback(p, (void (*)(void*))origstub_fn_[kFree]);
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Perftools_deletearray(void *p) {
+ MallocHook::InvokeDeleteHook(p);
+ do_free_with_callback(p, (void (*)(void*))origstub_fn_[kFree]);
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_new_nothrow(
+ size_t size, const std::nothrow_t&) __THROW {
+ void* p = cpp_alloc(size, true);
+ MallocHook::InvokeNewHook(p, size);
+ return p;
+}
+
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools_newarray_nothrow(
+ size_t size, const std::nothrow_t&) __THROW {
+ void* p = cpp_alloc(size, true);
+ MallocHook::InvokeNewHook(p, size);
+ return p;
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Perftools_delete_nothrow(
+ void *p, const std::nothrow_t&) __THROW {
+ MallocHook::InvokeDeleteHook(p);
+ do_free_with_callback(p, (void (*)(void*))origstub_fn_[kFree]);
+}
+
+template<int T>
+void LibcInfoWithPatchFunctions<T>::Perftools_deletearray_nothrow(
+ void *p, const std::nothrow_t&) __THROW {
+ MallocHook::InvokeDeleteHook(p);
+ do_free_with_callback(p, (void (*)(void*))origstub_fn_[kFree]);
+}
+
+
+// _msize() lets you figure out how much space is reserved for a
+// pointer, in Windows. Even if applications don't call it, any DLL
+// with global constructors will call (transitively) something called
+// __dllonexit_lk in order to make sure the destructors get called
+// when the dll unloads. And that will call msize -- horrible things
+// can ensue if this is not hooked. Other parts of libc may also call
+// this internally.
+
+template<int T>
+size_t LibcInfoWithPatchFunctions<T>::Perftools__msize(void* ptr) __THROW {
+ return GetSizeWithCallback(ptr, (size_t (*)(const void*))origstub_fn_[k_Msize]);
+}
+
+// We need to define this because internal windows functions like to
+// call into it(?). _expand() is like realloc but doesn't move the
+// pointer. We punt, which will cause callers to fall back on realloc.
+template<int T>
+void* LibcInfoWithPatchFunctions<T>::Perftools__expand(void *ptr,
+ size_t size) __THROW {
+ return NULL;
+}
+
+LPVOID WINAPI WindowsInfo::Perftools_HeapAlloc(HANDLE hHeap, DWORD dwFlags,
+ DWORD_PTR dwBytes) {
+ LPVOID result = ((LPVOID (WINAPI *)(HANDLE, DWORD, DWORD_PTR))
+ function_info_[kHeapAlloc].origstub_fn)(
+ hHeap, dwFlags, dwBytes);
+ MallocHook::InvokeNewHook(result, dwBytes);
+ return result;
+}
+
+BOOL WINAPI WindowsInfo::Perftools_HeapFree(HANDLE hHeap, DWORD dwFlags,
+ LPVOID lpMem) {
+ MallocHook::InvokeDeleteHook(lpMem);
+ return ((BOOL (WINAPI *)(HANDLE, DWORD, LPVOID))
+ function_info_[kHeapFree].origstub_fn)(
+ hHeap, dwFlags, lpMem);
+}
+
+LPVOID WINAPI WindowsInfo::Perftools_VirtualAllocEx(HANDLE process,
+ LPVOID address,
+ SIZE_T size, DWORD type,
+ DWORD protect) {
+ LPVOID result = ((LPVOID (WINAPI *)(HANDLE, LPVOID, SIZE_T, DWORD, DWORD))
+ function_info_[kVirtualAllocEx].origstub_fn)(
+ process, address, size, type, protect);
+ // VirtualAllocEx() seems to be the Windows equivalent of mmap()
+ MallocHook::InvokeMmapHook(result, address, size, protect, type, -1, 0);
+ return result;
+}
+
+BOOL WINAPI WindowsInfo::Perftools_VirtualFreeEx(HANDLE process, LPVOID address,
+ SIZE_T size, DWORD type) {
+ MallocHook::InvokeMunmapHook(address, size);
+ return ((BOOL (WINAPI *)(HANDLE, LPVOID, SIZE_T, DWORD))
+ function_info_[kVirtualFreeEx].origstub_fn)(
+ process, address, size, type);
+}
+
+LPVOID WINAPI WindowsInfo::Perftools_MapViewOfFileEx(
+ HANDLE hFileMappingObject, DWORD dwDesiredAccess, DWORD dwFileOffsetHigh,
+ DWORD dwFileOffsetLow, SIZE_T dwNumberOfBytesToMap, LPVOID lpBaseAddress) {
+ // For this function pair, you always deallocate the full block of
+ // data that you allocate, so NewHook/DeleteHook is the right API.
+ LPVOID result = ((LPVOID (WINAPI *)(HANDLE, DWORD, DWORD, DWORD,
+ SIZE_T, LPVOID))
+ function_info_[kMapViewOfFileEx].origstub_fn)(
+ hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh,
+ dwFileOffsetLow, dwNumberOfBytesToMap, lpBaseAddress);
+ MallocHook::InvokeNewHook(result, dwNumberOfBytesToMap);
+ return result;
+}
+
+BOOL WINAPI WindowsInfo::Perftools_UnmapViewOfFile(LPCVOID lpBaseAddress) {
+ MallocHook::InvokeDeleteHook(lpBaseAddress);
+ return ((BOOL (WINAPI *)(LPCVOID))
+ function_info_[kUnmapViewOfFile].origstub_fn)(
+ lpBaseAddress);
+}
+
+// g_load_map holds a copy of windows' refcount for how many times
+// each currently loaded module has been loaded and unloaded. We use
+// it as an optimization when the same module is loaded more than
+// once: as long as the refcount stays above 1, we don't need to worry
+// about patching because it's already patched. Likewise, we don't
+// need to unpatch until the refcount drops to 0. load_map is
+// maintained in LoadLibraryExW and FreeLibrary, and only covers
+// modules explicitly loaded/freed via those interfaces.
+static std::map<HMODULE, int>* g_load_map = NULL;
+
+HMODULE WINAPI WindowsInfo::Perftools_LoadLibraryExW(LPCWSTR lpFileName,
+ HANDLE hFile,
+ DWORD dwFlags) {
+ HMODULE rv;
+ // Check to see if the modules is already loaded, flag 0 gets a
+ // reference if it was loaded. If it was loaded no need to call
+ // PatchAllModules, just increase the reference count to match
+ // what GetModuleHandleExW does internally inside windows.
+ if (::GetModuleHandleExW(0, lpFileName, &rv)) {
+ return rv;
+ } else {
+ // Not already loaded, so load it.
+ rv = ((HMODULE (WINAPI *)(LPCWSTR, HANDLE, DWORD))
+ function_info_[kLoadLibraryExW].origstub_fn)(
+ lpFileName, hFile, dwFlags);
+ // This will patch any newly loaded libraries, if patching needs
+ // to be done.
+ PatchAllModules();
+
+ return rv;
+ }
+}
+
+BOOL WINAPI WindowsInfo::Perftools_FreeLibrary(HMODULE hLibModule) {
+ BOOL rv = ((BOOL (WINAPI *)(HMODULE))
+ function_info_[kFreeLibrary].origstub_fn)(hLibModule);
+
+ // Check to see if the module is still loaded by passing the base
+ // address and seeing if it comes back with the same address. If it
+ // is the same address it's still loaded, so the FreeLibrary() call
+ // was a noop, and there's no need to redo the patching.
+ HMODULE owner = NULL;
+ BOOL result = ::GetModuleHandleExW(
+ (GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+ GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT),
+ (LPCWSTR)hLibModule,
+ &owner);
+ if (result && owner == hLibModule)
+ return rv;
+
+ PatchAllModules(); // this will fix up the list of patched libraries
+ return rv;
+}
+
+
+// ---------------------------------------------------------------------
+// PatchWindowsFunctions()
+// This is the function that is exposed to the outside world.
+// It should be called before the program becomes multi-threaded,
+// since main_executable_windows.Patch() is not thread-safe.
+// ---------------------------------------------------------------------
+
+void PatchWindowsFunctions() {
+ // This does the libc patching in every module, and the main executable.
+ PatchAllModules();
+ main_executable_windows.Patch();
+}
+
+#if 0
+// It's possible to unpatch all the functions when we are exiting.
+
+// The idea is to handle properly windows-internal data that is
+// allocated before PatchWindowsFunctions is called. If all
+// destruction happened in reverse order from construction, then we
+// could call UnpatchWindowsFunctions at just the right time, so that
+// that early-allocated data would be freed using the windows
+// allocation functions rather than tcmalloc. The problem is that
+// windows allocates some structures lazily, so it would allocate them
+// late (using tcmalloc) and then try to deallocate them late as well.
+// So instead of unpatching, we just modify all the tcmalloc routines
+// so they call through to the libc rountines if the memory in
+// question doesn't seem to have been allocated with tcmalloc. I keep
+// this unpatch code around for reference.
+
+void UnpatchWindowsFunctions() {
+ // We need to go back to the system malloc/etc at global destruct time,
+ // so objects that were constructed before tcmalloc, using the system
+ // malloc, can destroy themselves using the system free. This depends
+ // on DLLs unloading in the reverse order in which they load!
+ //
+ // We also go back to the default HeapAlloc/etc, just for consistency.
+ // Who knows, it may help avoid weird bugs in some situations.
+ main_executable_windows.Unpatch();
+ main_executable.Unpatch();
+ if (libc1.is_valid()) libc1.Unpatch();
+ if (libc2.is_valid()) libc2.Unpatch();
+ if (libc3.is_valid()) libc3.Unpatch();
+ if (libc4.is_valid()) libc4.Unpatch();
+ if (libc5.is_valid()) libc5.Unpatch();
+ if (libc6.is_valid()) libc6.Unpatch();
+ if (libc7.is_valid()) libc7.Unpatch();
+ if (libc8.is_valid()) libc8.Unpatch();
+}
+#endif