Count m(un)map for each stacktrace in MemoryRegionMap instead of HeapProfileTable.

third_party/tcmalloc/chromium/src/memory_region_map.h

Index: third_party/tcmalloc/chromium/src/memory_region_map.h
diff --git a/third_party/tcmalloc/chromium/src/memory_region_map.h b/third_party/tcmalloc/chromium/src/memory_region_map.h
index 988ea707375aed124136fe0bb7db105dbb2952a7..c2887ebc4085ae0e2ac4950c818428efa7d2b109 100644
--- a/third_party/tcmalloc/chromium/src/memory_region_map.h
+++ b/third_party/tcmalloc/chromium/src/memory_region_map.h
@@ -45,6 +45,7 @@
 #include "base/spinlock.h"
 #include "base/thread_annotations.h"
 #include "base/low_level_alloc.h"
+#include "heap-profile-stats.h"
 
 // TODO(maxim): add a unittest:
 //  execute a bunch of mmaps and compare memory map what strace logs
@@ -72,6 +73,10 @@ class MemoryRegionMap {
   // don't take the address of it!
   static const int kMaxStackDepth = 32;
 
+  // Size of the hash table of buckets.  A structure of the bucket table is
+  // described in heap-profile-stats.h.
+  static const int kHashTableSize = 179999;
+
  public:
   // interface ================================================================
 
@@ -87,11 +92,14 @@ class MemoryRegionMap {
   // are automatically shrunk to "max_stack_depth" when they are recorded.
   // Init() can be called more than once w/o harm, largest max_stack_depth
   // will be the effective one.
+  // When "use_buckets" is true, then counts of mmap and munmap sizes will be
+  // recorded with each stack trace.  If Init() is called more than once, then
+  // counting will be effective after any call contained "use_buckets" of true.
   // It will install mmap, munmap, mremap, sbrk hooks
   // and initialize arena_ and our hook and locks, hence one can use
   // MemoryRegionMap::Lock()/Unlock() to manage the locks.
   // Uses Lock/Unlock inside.
-  static void Init(int max_stack_depth);
+  static void Init(int max_stack_depth, bool use_buckets);
 
   // Try to shutdown this module undoing what Init() did.
   // Returns true iff could do full shutdown (or it was not attempted).
@@ -99,6 +107,10 @@ class MemoryRegionMap {
   // the number of Init() calls.
   static bool Shutdown();
 
+  // Return true if MemoryRegionMap is initialized and recording, i.e. when
+  // then number of Init() calls are more than the number of Shutdown() calls.
+  static bool IsRecording();
+
   // Locks to protect our internal data structures.
   // These also protect use of arena_ if our Init() has been done.
   // The lock is recursive.
@@ -214,6 +226,18 @@ class MemoryRegionMap {
   // Returns success. Uses Lock/Unlock inside.
   static bool FindAndMarkStackRegion(uintptr_t stack_top, Region* result);
 
+  // Iterate over the buckets which store mmap and munmap counts per stack
+  // trace.  It calls "callback" for each bucket, and passes "arg" to it.
+  template<class Type>
+  static void IterateBuckets(void (*callback)(const HeapProfileBucket*, Type),
+                             Type arg);
+
+  // Get the bucket whose caller stack trace is "key".  The stack trace is
+  // used to a depth of "depth" at most.  The requested bucket is created if
+  // needed.
+  // The bucket table is described in heap-profile-stats.h.
+  static HeapProfileBucket* GetBucket(int depth, const void* const key[]);
+
  private:  // our internal types ==============================================
 
   // Region comparator for sorting with STL
@@ -295,6 +319,30 @@ class MemoryRegionMap {
   // Total size of all unmapped pages so far
   static int64 unmap_size_;
 
+  // Bucket hash table which is described in heap-profile-stats.h.

[willchan no longer on Chromium, 2013/03/13 21:58:48]

Ugh, this class ordering is wrong. Functions should come first. Silly
csilvers/maxim, writing it incorrectly way back when we were looser about the
style guide.

Not worth fixing though.

[Dai Mikurube (NOT FULLTIME), 2013/03/14 09:33:47]

Yeah, we usually violate the style guide or we need great refactoring in
tcmalloc. ;)

+  static HeapProfileBucket** bucket_table_;
+  static int num_buckets_;
+
+  // The following members are local to MemoryRegionMap::GetBucket()
+  // and MemoryRegionMap::HandleSavedBucketsLocked()
+  // and are file-level to ensure that they are initialized at load time.
+  //
+  // These are used as temporary storage to break the infinite cycle of mmap
+  // calling our hook which (sometimes) causes mmap.  It must be a static
+  // fixed-size array.  The size 20 is just an expected value for safety.
+  // The details are described in memory_region_map.cc.
+
+  // Number of unprocessed bucket inserts.
+  static int saved_buckets_count_;
+
+  // Unprocessed inserts (must be big enough to hold all mmaps that can be
+  // caused by a GetBucket call).
+  // Bucket has no constructor, so that c-tor execution does not interfere
+  // with the any-time use of the static memory behind saved_buckets.
+  static HeapProfileBucket saved_buckets_[20];
+
+  static const void* saved_buckets_keys_[20][kMaxStackDepth];
+
   // helpers ==================================================================
 
   // Helper for FindRegion and FindAndMarkStackRegion:
@@ -308,6 +356,11 @@ class MemoryRegionMap {
   // by calling insert_func on them.
   inline static void HandleSavedRegionsLocked(
                        void (*insert_func)(const Region& region));
+
+  // Restore buckets saved in a tmp static array by GetBucket to the bucket
+  // table where all buckets eventually should be.
+  static void RestoreSavedBucketsLocked();
+
   // Wrapper around DoInsertRegionLocked
   // that handles the case of recursive allocator calls.
   inline static void InsertRegionLocked(const Region& region);
@@ -319,6 +372,13 @@ class MemoryRegionMap {
   // (called from our munmap/mremap/sbrk hooks).
   static void RecordRegionRemoval(const void* start, size_t size);
 
+  // Record deletion of a memory region of size "size" in a bucket whose
+  // caller stack trace is "key".  The stack trace is used to a depth of
+  // "depth" at most.
+  static void RecordRegionRemovalInBucket(int depth,
+                                          const void* const key[],
+                                          size_t size);
+
   // Hooks for MallocHook
   static void MmapHook(const void* result,
                        const void* start, size_t size,
@@ -337,4 +397,16 @@ class MemoryRegionMap {
   DISALLOW_COPY_AND_ASSIGN(MemoryRegionMap);
 };
 
+template <class Type>
+void MemoryRegionMap::IterateBuckets(
+    void (*callback)(const HeapProfileBucket*, Type), Type callback_arg) {
+  for (int index = 0; index < kHashTableSize; index++) {
+    for (HeapProfileBucket* bucket = bucket_table_[index];
+         bucket != NULL;
+         bucket = bucket->next) {
+      callback(bucket, callback_arg);
+    }
+  }
+}
+
 #endif  // BASE_MEMORY_REGION_MAP_H_