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

third_party/tcmalloc/chromium/src/system-alloc.cc

Index: third_party/tcmalloc/chromium/src/system-alloc.cc
diff --git a/third_party/tcmalloc/chromium/src/system-alloc.cc b/third_party/tcmalloc/chromium/src/system-alloc.cc
index 03fc9340ec9334e4d8eef20c4a653586d2e192c7..ea718b3990f60531b267410d1b075aad4f3a190c 100644
--- a/third_party/tcmalloc/chromium/src/system-alloc.cc
+++ b/third_party/tcmalloc/chromium/src/system-alloc.cc
@@ -61,6 +61,13 @@
 # define MAP_ANONYMOUS MAP_ANON
 #endif
 
+// MADV_FREE is specifically designed for use by malloc(), but only
+// FreeBSD supports it; in linux we fall back to the somewhat inferior
+// MADV_DONTNEED.
+#if !defined(MADV_FREE) && defined(MADV_DONTNEED)
+# define MADV_FREE  MADV_DONTNEED
+#endif
+
 // Solaris has a bug where it doesn't declare madvise() for C++.
 //    http://www.opensolaris.org/jive/thread.jspa?threadID=21035&tstart=0
 #if defined(__sun) && defined(__SVR4)
@@ -76,6 +83,10 @@ static const bool kDebugMode = false;
 static const bool kDebugMode = true;
 #endif
 
+// TODO(sanjay): Move the code below into the tcmalloc namespace
+using tcmalloc::kLog;
+using tcmalloc::Log;
+
 // Anonymous namespace to avoid name conflicts on "CheckAddressBits".
 namespace {
 
@@ -103,7 +114,8 @@ union MemoryAligner {
 
 static SpinLock spinlock(SpinLock::LINKER_INITIALIZED);
 
-#ifdef HAVE_GETPAGESIZE
+#if defined(HAVE_MMAP) || defined(MADV_FREE)
+// Page size is initialized on demand (only needed for mmap-based allocators)
 static size_t pagesize = 0;
 #endif
 
@@ -132,7 +144,6 @@ public:
   SbrkSysAllocator() : SysAllocator() {
   }
   void* Alloc(size_t size, size_t *actual_size, size_t alignment);
-  void FlagsInitialized() {}
 };
 static char sbrk_space[sizeof(SbrkSysAllocator)];
 
@@ -141,7 +152,6 @@ public:
   MmapSysAllocator() : SysAllocator() {
   }
   void* Alloc(size_t size, size_t *actual_size, size_t alignment);
-  void FlagsInitialized() {}
 };
 static char mmap_space[sizeof(MmapSysAllocator)];
 
@@ -150,7 +160,6 @@ public:
   DevMemSysAllocator() : SysAllocator() {
   }
   void* Alloc(size_t size, size_t *actual_size, size_t alignment);
-  void FlagsInitialized() {}
 };
 
 class DefaultSysAllocator : public SysAllocator {
@@ -171,7 +180,6 @@ class DefaultSysAllocator : public SysAllocator {
     }
   }
   void* Alloc(size_t size, size_t *actual_size, size_t alignment);
-  void FlagsInitialized() {}
 
  private:
   static const int kMaxAllocators = 2;
@@ -187,6 +195,7 @@ static const char mmap_name[] = "MmapSysAllocator";
 void* SbrkSysAllocator::Alloc(size_t size, size_t *actual_size,
                               size_t alignment) {
 #ifndef HAVE_SBRK
+  failed_ = true;
   return NULL;
 #else
   // Check if we should use sbrk allocation.
@@ -201,7 +210,7 @@ void* SbrkSysAllocator::Alloc(size_t size, size_t *actual_size,
 
   // sbrk will release memory if passed a negative number, so we do
   // a strict check here
-  if (static_cast<std::ptrdiff_t>(size + alignment) < 0) return NULL;
+  if (static_cast<ptrdiff_t>(size + alignment) < 0) return NULL;
 
   // This doesn't overflow because TCMalloc_SystemAlloc has already
   // tested for overflow at the alignment boundary.
@@ -258,6 +267,7 @@ void* SbrkSysAllocator::Alloc(size_t size, size_t *actual_size,
 void* MmapSysAllocator::Alloc(size_t size, size_t *actual_size,
                               size_t alignment) {
 #ifndef HAVE_MMAP
+  failed_ = true;
   return NULL;
 #else
   // Check if we should use mmap allocation.
@@ -326,6 +336,7 @@ void* MmapSysAllocator::Alloc(size_t size, size_t *actual_size,
 void* DevMemSysAllocator::Alloc(size_t size, size_t *actual_size,
                                 size_t alignment) {
 #ifndef HAVE_MMAP
+  failed_ = true;
   return NULL;
 #else
   static bool initialized = false;
@@ -420,7 +431,6 @@ void* DefaultSysAllocator::Alloc(size_t size, size_t *actual_size,
       if (result != NULL) {
         return result;
       }
-      TCMalloc_MESSAGE(__FILE__, __LINE__, "%s failed.\n", names_[i]);
       failed_[i] = true;
     }
   }
@@ -483,26 +493,11 @@ void* TCMalloc_SystemAlloc(size_t size, size_t *actual_size,
   return result;
 }
 
-size_t TCMalloc_SystemAddGuard(void* start, size_t size) {
-#ifdef HAVE_GETPAGESIZE
-  if (pagesize == 0)
-    pagesize = getpagesize();
-
-  if (size < pagesize || (reinterpret_cast<size_t>(start) % pagesize) != 0)
-    return 0;
-
-  if (!mprotect(start, pagesize, PROT_NONE))
-    return pagesize;
-#endif
-
-  return 0;
-}
-
 void TCMalloc_SystemRelease(void* start, size_t length) {
-#ifdef MADV_DONTNEED
+#ifdef MADV_FREE
   if (FLAGS_malloc_devmem_start) {
-    // It's not safe to use MADV_DONTNEED if we've been mapping
-    // /dev/mem for heap memory
+    // It's not safe to use MADV_FREE/MADV_DONTNEED if we've been
+    // mapping /dev/mem for heap memory.
     return;
   }
   if (pagesize == 0) pagesize = getpagesize();
@@ -526,16 +521,10 @@ void TCMalloc_SystemRelease(void* start, size_t length) {
     // Note -- ignoring most return codes, because if this fails it
     // doesn't matter...
     while (madvise(reinterpret_cast<char*>(new_start), new_end - new_start,
-                   MADV_DONTNEED) == -1 &&
+                   MADV_FREE) == -1 &&
            errno == EAGAIN) {
       // NOP
     }
   }
 #endif
 }
-
-void TCMalloc_SystemCommit(void* start, size_t length) {
-  // Nothing to do here.  TCMalloc_SystemRelease does not alter pages
-  // such that they need to be re-committed before they can be used by the
-  // application.
-}