Deep-Memory-Profiler (DMP) implementation

third_party/tcmalloc/chromium/src/malloc_hook.cc

 // Copyright (c) 2005, 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
@@ skipping 659 matching lines @@
     // and 3 is to account for some hook daisy chaining.
   static const int kStackSize = kMaxSkip + 1;
   void* stack[kStackSize];
   int depth = GetStackTrace(stack, kStackSize, 1);  // skip this function frame
   if (depth == 0)   // silenty propagate cases when GetStackTrace does not work
     return 0;
   for (int i = 0; i < depth; ++i) {  // stack[0] is our immediate caller
     if (InHookCaller(stack[i])) {
       RAW_VLOG(10, "Found hooked allocator at %d: %p <- %p",
                    i, stack[i], stack[i+1]);
-      i += 1;  // skip hook caller frame
+      // i += 1;  // skip hook caller frame
+      // In deep profiler, we want to know the caller frame to
+      // distinguish mmap from tcmalloc
+
       depth -= i;  // correct depth
       if (depth > max_depth) depth = max_depth;
       copy(stack + i, stack + i + depth, result);
       if (depth < max_depth  &&  depth + i == kStackSize) {
         // get frames for the missing depth
         depth +=
           GetStackTrace(result + depth, max_depth - depth, 1 + kStackSize);
       }
       return depth;
     }
@@ skipping 206 matching lines @@
 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) {
   int result;
   if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) {
     result = munmap(start, length);
   }
   return result;
 }
 
 #endif  // defined(__linux) &&
         // (defined(__i386__) || defined(__x86_64__) || defined(__PPC__))