Squashed 'third_party/gperftools/' content from commit 54505f1

Change-Id: Id02e833828732b0efe7dac722b8485279e67c5fa
git-subtree-dir: third_party/gperftools
git-subtree-split: 54505f1d50c2d1f4676f5e87090b64a117fd980e
diff --git a/src/stack_trace_table.cc b/src/stack_trace_table.cc
new file mode 100644
index 0000000..1862124
--- /dev/null
+++ b/src/stack_trace_table.cc
@@ -0,0 +1,160 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// Copyright (c) 2009, 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
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// ---
+// Author: Andrew Fikes
+
+#include <config.h>
+#include "stack_trace_table.h"
+#include <string.h>                     // for NULL, memset
+#include "base/spinlock.h"              // for SpinLockHolder
+#include "common.h"            // for StackTrace
+#include "internal_logging.h"  // for ASSERT, Log
+#include "page_heap_allocator.h"  // for PageHeapAllocator
+#include "static_vars.h"       // for Static
+
+namespace tcmalloc {
+
+bool StackTraceTable::Bucket::KeyEqual(uintptr_t h,
+                                       const StackTrace& t) const {
+  const bool eq = (this->hash == h && this->trace.depth == t.depth);
+  for (int i = 0; eq && i < t.depth; ++i) {
+    if (this->trace.stack[i] != t.stack[i]) {
+      return false;
+    }
+  }
+  return eq;
+}
+
+StackTraceTable::StackTraceTable()
+    : error_(false),
+      depth_total_(0),
+      bucket_total_(0),
+      table_(new Bucket*[kHashTableSize]()) {
+  memset(table_, 0, kHashTableSize * sizeof(Bucket*));
+}
+
+StackTraceTable::~StackTraceTable() {
+  delete[] table_;
+}
+
+void StackTraceTable::AddTrace(const StackTrace& t) {
+  if (error_) {
+    return;
+  }
+
+  // Hash function borrowed from base/heap-profile-table.cc
+  uintptr_t h = 0;
+  for (int i = 0; i < t.depth; ++i) {
+    h += reinterpret_cast<uintptr_t>(t.stack[i]);
+    h += h << 10;
+    h ^= h >> 6;
+  }
+  h += h << 3;
+  h ^= h >> 11;
+
+  const int idx = h % kHashTableSize;
+
+  Bucket* b = table_[idx];
+  while (b != NULL && !b->KeyEqual(h, t)) {
+    b = b->next;
+  }
+  if (b != NULL) {
+    b->count++;
+    b->trace.size += t.size;  // keep cumulative size
+  } else {
+    depth_total_ += t.depth;
+    bucket_total_++;
+    b = Static::bucket_allocator()->New();
+    if (b == NULL) {
+      Log(kLog, __FILE__, __LINE__,
+          "tcmalloc: could not allocate bucket", sizeof(*b));
+      error_ = true;
+    } else {
+      b->hash = h;
+      b->trace = t;
+      b->count = 1;
+      b->next = table_[idx];
+      table_[idx] = b;
+    }
+  }
+}
+
+void** StackTraceTable::ReadStackTracesAndClear() {
+  if (error_) {
+    return NULL;
+  }
+
+  // Allocate output array
+  const int out_len = bucket_total_ * 3 + depth_total_ + 1;
+  void** out = new void*[out_len];
+  if (out == NULL) {
+    Log(kLog, __FILE__, __LINE__,
+        "tcmalloc: allocation failed for stack traces",
+        out_len * sizeof(*out));
+    return NULL;
+  }
+
+  // Fill output array
+  int idx = 0;
+  for (int i = 0; i < kHashTableSize; ++i) {
+    Bucket* b = table_[i];
+    while (b != NULL) {
+      out[idx++] = reinterpret_cast<void*>(static_cast<uintptr_t>(b->count));
+      out[idx++] = reinterpret_cast<void*>(b->trace.size);  // cumulative size
+      out[idx++] = reinterpret_cast<void*>(b->trace.depth);
+      for (int d = 0; d < b->trace.depth; ++d) {
+        out[idx++] = b->trace.stack[d];
+      }
+      b = b->next;
+    }
+  }
+  out[idx++] = NULL;
+  ASSERT(idx == out_len);
+
+  // Clear state
+  error_ = false;
+  depth_total_ = 0;
+  bucket_total_ = 0;
+  SpinLockHolder h(Static::pageheap_lock());
+  for (int i = 0; i < kHashTableSize; ++i) {
+    Bucket* b = table_[i];
+    while (b != NULL) {
+      Bucket* next = b->next;
+      Static::bucket_allocator()->Delete(b);
+      b = next;
+    }
+    table_[i] = NULL;
+  }
+
+  return out;
+}
+
+}  // namespace tcmalloc