From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 ipc/chromium/src/base/lock.h | 102 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 ipc/chromium/src/base/lock.h

(limited to 'ipc/chromium/src/base/lock.h')

diff --git a/ipc/chromium/src/base/lock.h b/ipc/chromium/src/base/lock.h
new file mode 100644
index 0000000000..17fe0dad6a
--- /dev/null
+++ b/ipc/chromium/src/base/lock.h
@@ -0,0 +1,102 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+// Copyright (c) 2011 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 BASE_LOCK_H_
+#define BASE_LOCK_H_
+
+#include "base/basictypes.h"
+#include "base/lock_impl.h"
+#include "base/platform_thread.h"
+#include "build/build_config.h"
+
+// A convenient wrapper for an OS specific critical section.
+class Lock {
+ public:
+  // Optimized wrapper implementation
+  Lock() : lock_() {}
+  ~Lock() {}
+  void Acquire() { lock_.Lock(); }
+  void Release() { lock_.Unlock(); }
+
+  // If the lock is not held, take it and return true. If the lock is already
+  // held by another thread, immediately return false. This must not be called
+  // by a thread already holding the lock (what happens is undefined and an
+  // assertion may fail).
+  bool Try() { return lock_.Try(); }
+
+  // Null implementation if not debug.
+  void AssertAcquired() const {}
+
+  // Whether Lock mitigates priority inversion when used from different thread
+  // priorities.
+  static bool HandlesMultipleThreadPriorities() {
+#if defined(OS_POSIX)
+    // POSIX mitigates priority inversion by setting the priority of a thread
+    // holding a Lock to the maximum priority of any other thread waiting on it.
+    return base::internal::LockImpl::PriorityInheritanceAvailable();
+#elif defined(OS_WIN)
+    // Windows mitigates priority inversion by randomly boosting the priority of
+    // ready threads.
+    // https://msdn.microsoft.com/library/windows/desktop/ms684831.aspx
+    return true;
+#else
+#  error Unsupported platform
+#endif
+  }
+
+#if defined(OS_POSIX) || defined(OS_WIN)
+  // Both Windows and POSIX implementations of ConditionVariable need to be
+  // able to see our lock and tweak our debugging counters, as they release and
+  // acquire locks inside of their condition variable APIs.
+  friend class ConditionVariable;
+#endif
+
+ private:
+  // Platform specific underlying lock implementation.
+  ::base::internal::LockImpl lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(Lock);
+};
+
+// A helper class that acquires the given Lock while the AutoLock is in scope.
+class AutoLock {
+ public:
+  struct AlreadyAcquired {};
+
+  explicit AutoLock(Lock& lock) : lock_(lock) { lock_.Acquire(); }
+
+  AutoLock(Lock& lock, const AlreadyAcquired&) : lock_(lock) {
+    lock_.AssertAcquired();
+  }
+
+  ~AutoLock() {
+    lock_.AssertAcquired();
+    lock_.Release();
+  }
+
+ private:
+  Lock& lock_;
+  DISALLOW_COPY_AND_ASSIGN(AutoLock);
+};
+
+// AutoUnlock is a helper that will Release() the |lock| argument in the
+// constructor, and re-Acquire() it in the destructor.
+class AutoUnlock {
+ public:
+  explicit AutoUnlock(Lock& lock) : lock_(lock) {
+    // We require our caller to have the lock.
+    lock_.AssertAcquired();
+    lock_.Release();
+  }
+
+  ~AutoUnlock() { lock_.Acquire(); }
+
+ private:
+  Lock& lock_;
+  DISALLOW_COPY_AND_ASSIGN(AutoUnlock);
+};
+
+#endif  // BASE_LOCK_H_
-- 
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