Add out-of-process memory logging stream parsing.
This is the receiver end, it is not yet hooked up and there is no sending end yet.
The MemlogConnectionManager get the notifications of new pipe connections and hooks up the parser to it. The events go to a per-process MemlogAllocationTracker object to track all live memory allocations. This is currently just a simple map.
Stacks are de-duplicated across processes. This saves a little memory. This requires that individual stacks are refcounted and atomized. The StackStorage object tracks all globals stacks for this purpose.
Review-Url: https://codereview.chromium.org/2943733002
Cr-Commit-Position: refs/heads/master@{#480715}
diff --git a/chrome/profiling/backtrace_storage.h b/chrome/profiling/backtrace_storage.h
new file mode 100644
index 0000000..a3d7358
--- /dev/null
+++ b/chrome/profiling/backtrace_storage.h
@@ -0,0 +1,52 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_PROFILING_BACKTRACE_STORAGE_H_
+#define CHROME_PROFILING_BACKTRACE_STORAGE_H_
+
+#include <unordered_set>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "chrome/profiling/backtrace.h"
+
+namespace profiling {
+
+// This class is threadsafe.
+class BacktraceStorage {
+ public:
+ using Container = std::unordered_set<Backtrace>;
+ using Key = Container::iterator;
+
+ BacktraceStorage();
+ ~BacktraceStorage();
+
+ // Adds the given backtrace to the storage and returns a key to it. If a
+ // matching backtrace already exists, a key to the existing one will be
+ // returned.
+ //
+ // The returned key will have a reference count associated with it, call
+ // Free when the key is no longer needed.
+ Key Insert(std::vector<Address>&& bt);
+
+ // Frees one reference to a backtrace.
+ void Free(const Key& key);
+ void Free(const std::vector<Key>& keys);
+
+ // Returns the backtrace associated with the given key. Assumes the caller
+ // holds a key to it that will keep the backtrace in scope.
+ const Backtrace& GetBacktraceForKey(const Key& key) const;
+
+ private:
+ mutable base::Lock lock_;
+
+ // List of live backtraces for de-duping. Protected by the lock_.
+ Container backtraces_;
+};
+
+} // namespace profiling
+
+#endif // CHROME_PROFILING_BACKTRACE_STORAGE_H_
