tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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ProfilingStack.cpp (1432B)


      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "BaseProfilingStack.h"
      8 
      9 #include <algorithm>
     10 
     11 #include "mozilla/BaseProfiler.h"
     12 #include "mozilla/IntegerRange.h"
     13 
     14 namespace mozilla {
     15 namespace baseprofiler {
     16 
     17 ProfilingStack::~ProfilingStack() {
     18  // The label macros keep a reference to the ProfilingStack to avoid a TLS
     19  // access. If these are somehow not all cleared we will get a
     20  // use-after-free so better to crash now.
     21  MOZ_RELEASE_ASSERT(stackPointer == 0);
     22 
     23  delete[] frames;
     24 }
     25 
     26 void ProfilingStack::ensureCapacitySlow() {
     27  MOZ_ASSERT(stackPointer >= capacity);
     28  const uint32_t kInitialCapacity = 128;
     29 
     30  uint32_t sp = stackPointer;
     31  auto newCapacity =
     32      std::max(sp + 1, capacity ? capacity * 2 : kInitialCapacity);
     33 
     34  auto* newFrames = new ProfilingStackFrame[newCapacity];
     35 
     36  // It's important that `frames` / `capacity` / `stackPointer` remain
     37  // consistent here at all times.
     38  for (auto i : IntegerRange(capacity)) {
     39    newFrames[i] = frames[i];
     40  }
     41 
     42  ProfilingStackFrame* oldFrames = frames;
     43  frames = newFrames;
     44  capacity = newCapacity;
     45  delete[] oldFrames;
     46 }
     47 
     48 }  // namespace baseprofiler
     49 }  // namespace mozilla