[NOT TO COMMIT!] Replace third_party/tcmalloc/chromium with tcmalloc r136 (the latest).

third_party/tcmalloc/chromium/src/windows/port.cc

Index: third_party/tcmalloc/chromium/src/windows/port.cc
diff --git a/third_party/tcmalloc/chromium/src/windows/port.cc b/third_party/tcmalloc/chromium/src/windows/port.cc
index ec01fd60c9583a74249fe5faf459aca03995758e..e68de163d3ef91229ed305af8148d394710223d4 100644
--- a/third_party/tcmalloc/chromium/src/windows/port.cc
+++ b/third_party/tcmalloc/chromium/src/windows/port.cc
@@ -61,7 +61,7 @@ int getpagesize() {
   return pagesize;
 }
 
-extern "C" PERFTOOLS_DLL_DECL void* __sbrk(std::ptrdiff_t increment) {
+extern "C" PERFTOOLS_DLL_DECL void* __sbrk(ptrdiff_t increment) {
   LOG(FATAL, "Windows doesn't implement sbrk!\n");
   return NULL;
 }
@@ -149,13 +149,12 @@ static void NTAPI on_tls_callback(HINSTANCE h, DWORD dwReason, PVOID pv) {
 
 #ifdef _MSC_VER
 
-// extern "C" suppresses C++ name mangling so we know the symbol names for the
-// linker /INCLUDE:symbol pragmas above.
+// extern "C" suppresses C++ name mangling so we know the symbol names
+// for the linker /INCLUDE:symbol pragmas above.
 extern "C" {
 // This tells the linker to run these functions.
 #pragma data_seg(push, old_seg)
-  // Use CRT$XLY instead of CRT$XLB to ensure we're called LATER in sequence.
-#pragma data_seg(".CRT$XLY")
+#pragma data_seg(".CRT$XLB")
 void (NTAPI *p_thread_callback_tcmalloc)(
     HINSTANCE h, DWORD dwReason, PVOID pv) = on_tls_callback;
 #pragma data_seg(".CRT$XTU")
@@ -219,10 +218,6 @@ extern "C" int perftools_pthread_once(pthread_once_t *once_control,
 // -----------------------------------------------------------------------
 // These functions replace system-alloc.cc
 
-// The current system allocator. Because we don't link with system-alloc.cc,
-// we need to define our own.
-SysAllocator* sys_alloc = NULL;
-
 // This is mostly like MmapSysAllocator::Alloc, except it does these weird
 // munmap's in the middle of the page, which is forbidden in windows.
 extern void* TCMalloc_SystemAlloc(size_t size, size_t *actual_size,
@@ -232,102 +227,35 @@ extern void* TCMalloc_SystemAlloc(size_t size, size_t *actual_size,
   if (alignment < pagesize) alignment = pagesize;
   size = ((size + alignment - 1) / alignment) * alignment;
 
-  // Report the total number of bytes the OS actually delivered.  This might be
-  // greater than |size| because of alignment concerns.  The full size is
-  // necessary so that adjacent spans can be coalesced.
-  // TODO(antonm): proper processing of alignments
-  // in actual_size and decommitting.
+  // Safest is to make actual_size same as input-size.
   if (actual_size) {
     *actual_size = size;
   }
 
-  // We currently do not support alignments larger than the pagesize or
-  // alignments that are not multiples of the pagesize after being floored.
-  // If this ability is needed it can be done by the caller (assuming it knows
-  // the page size).
-  assert(alignment <= pagesize);
+  // Ask for extra memory if alignment > pagesize
+  size_t extra = 0;
+  if (alignment > pagesize) {
+    extra = alignment - pagesize;
+  }
 
-  void* result = VirtualAlloc(0, size,
+  void* result = VirtualAlloc(0, size + extra,
                               MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE);
   if (result == NULL)
     return NULL;
 
-  // If the result is not aligned memory fragmentation will result which can
-  // lead to pathological memory use.
-  assert((reinterpret_cast<uintptr_t>(result) & (alignment - 1)) == 0);
-
-  return result;
-}
-
-size_t TCMalloc_SystemAddGuard(void* start, size_t size) {
-  static size_t pagesize = 0;
-  if (pagesize == 0) {
-    SYSTEM_INFO system_info;
-    GetSystemInfo(&system_info);
-    pagesize = system_info.dwPageSize;
-  }
-
-  // We know that TCMalloc_SystemAlloc will give us a correct page alignment
-  // regardless, so we can just assert to detect erroneous callers.
-  assert(reinterpret_cast<size_t>(start) % pagesize == 0);
-
-  // Add a guard page to catch metadata corruption. We're using the
-  // PAGE_GUARD flag rather than NO_ACCESS because we want the unique
-  // exception in crash reports.
-  DWORD permissions = 0;
-  if (size > pagesize &&
-      VirtualProtect(start, pagesize, PAGE_READONLY | PAGE_GUARD,
-                     &permissions)) {
-    return pagesize;
+  // Adjust the return memory so it is aligned
+  uintptr_t ptr = reinterpret_cast<uintptr_t>(result);
+  size_t adjust = 0;
+  if ((ptr & (alignment - 1)) != 0) {
+    adjust = alignment - (ptr & (alignment - 1));
   }
 
-  return 0;
+  ptr += adjust;
+  return reinterpret_cast<void*>(ptr);
 }
 
 void TCMalloc_SystemRelease(void* start, size_t length) {
-  if (VirtualFree(start, length, MEM_DECOMMIT))
-    return;
-
-  // The decommit may fail if the memory region consists of allocations
-  // from more than one call to VirtualAlloc.  In this case, fall back to
-  // using VirtualQuery to retrieve the allocation boundaries and decommit
-  // them each individually.
-
-  char* ptr = static_cast<char*>(start);
-  char* end = ptr + length;
-  MEMORY_BASIC_INFORMATION info;
-  while (ptr < end) {
-    size_t resultSize = VirtualQuery(ptr, &info, sizeof(info));
-    assert(resultSize == sizeof(info));
-    size_t decommitSize = std::min<size_t>(info.RegionSize, end - ptr);
-    BOOL success = VirtualFree(ptr, decommitSize, MEM_DECOMMIT);
-    assert(success == TRUE);
-    ptr += decommitSize;
-  }
-}
-
-void TCMalloc_SystemCommit(void* start, size_t length) {
-  if (VirtualAlloc(start, length, MEM_COMMIT, PAGE_READWRITE) == start)
-    return;
-
-  // The commit may fail if the memory region consists of allocations
-  // from more than one call to VirtualAlloc.  In this case, fall back to
-  // using VirtualQuery to retrieve the allocation boundaries and commit them
-  // each individually.
-
-  char* ptr = static_cast<char*>(start);
-  char* end = ptr + length;
-  MEMORY_BASIC_INFORMATION info;
-  while (ptr < end) {
-    size_t resultSize = VirtualQuery(ptr, &info, sizeof(info));
-    assert(resultSize == sizeof(info));
-
-    size_t commitSize = std::min<size_t>(info.RegionSize, end - ptr);
-    void* newAddress = VirtualAlloc(ptr, commitSize, MEM_COMMIT,
-                                    PAGE_READWRITE);
-    assert(newAddress == ptr);
-    ptr += commitSize;
-  }
+  // TODO(csilvers): should I be calling VirtualFree here?
 }
 
 bool RegisterSystemAllocator(SysAllocator *allocator, int priority) {
@@ -338,6 +266,9 @@ void DumpSystemAllocatorStats(TCMalloc_Printer* printer) {
   // We don't dump stats on windows, right now
 }
 
+// The current system allocator
+SysAllocator* sys_alloc = NULL;
+
 
 // -----------------------------------------------------------------------
 // These functions rework existing functions of the same name in the