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