From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- ipc/glue/CrossProcessMutex.h | 118 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 ipc/glue/CrossProcessMutex.h (limited to 'ipc/glue/CrossProcessMutex.h') diff --git a/ipc/glue/CrossProcessMutex.h b/ipc/glue/CrossProcessMutex.h new file mode 100644 index 0000000000..7376fb1b15 --- /dev/null +++ b/ipc/glue/CrossProcessMutex.h @@ -0,0 +1,118 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_CrossProcessMutex_h +#define mozilla_CrossProcessMutex_h + +#include "base/process.h" +#include "mozilla/Mutex.h" + +#if defined(OS_WIN) +# include "mozilla/UniquePtrExtensions.h" +#endif +#if !defined(OS_WIN) && !defined(OS_NETBSD) && !defined(OS_OPENBSD) +# include +# include "mozilla/ipc/SharedMemoryBasic.h" +# include "mozilla/Atomics.h" +#endif + +namespace IPC { +template +struct ParamTraits; +} // namespace IPC + +// +// Provides: +// +// - CrossProcessMutex, a non-recursive mutex that can be shared across +// processes +// - CrossProcessMutexAutoLock, an RAII class for ensuring that Mutexes are +// properly locked and unlocked +// +// Using CrossProcessMutexAutoLock/CrossProcessMutexAutoUnlock is MUCH +// preferred to making bare calls to CrossProcessMutex.Lock and Unlock. +// +namespace mozilla { +#if defined(OS_WIN) +typedef mozilla::UniqueFileHandle CrossProcessMutexHandle; +#elif !defined(OS_NETBSD) && !defined(OS_OPENBSD) +typedef mozilla::ipc::SharedMemoryBasic::Handle CrossProcessMutexHandle; +#else +// Stub for other platforms. We can't use uintptr_t here since different +// processes could disagree on its size. +typedef uintptr_t CrossProcessMutexHandle; +#endif + +class CrossProcessMutex { + public: + /** + * CrossProcessMutex + * @param name A name which can reference this lock (currently unused) + **/ + explicit CrossProcessMutex(const char* aName); + /** + * CrossProcessMutex + * @param handle A handle of an existing cross process mutex that can be + * opened. + */ + explicit CrossProcessMutex(CrossProcessMutexHandle aHandle); + + /** + * ~CrossProcessMutex + **/ + ~CrossProcessMutex(); + + /** + * Lock + * This will lock the mutex. Any other thread in any other process that + * has access to this mutex calling lock will block execution until the + * initial caller of lock has made a call to Unlock. + * + * If the owning process is terminated unexpectedly the mutex will be + * released. + **/ + void Lock(); + + /** + * Unlock + * This will unlock the mutex. A single thread currently waiting on a lock + * call will resume execution and aquire ownership of the lock. No + * guarantees are made as to the order in which waiting threads will resume + * execution. + **/ + void Unlock(); + + /** + * CloneHandle + * This function is called to generate a serializable structure that can + * be sent to the specified process and opened on the other side. + * + * @returns A handle that can be shared to another process + */ + CrossProcessMutexHandle CloneHandle(); + + private: + friend struct IPC::ParamTraits; + + CrossProcessMutex(); + CrossProcessMutex(const CrossProcessMutex&); + CrossProcessMutex& operator=(const CrossProcessMutex&); + +#if defined(OS_WIN) + HANDLE mMutex; +#elif !defined(OS_NETBSD) && !defined(OS_OPENBSD) + RefPtr mSharedBuffer; + pthread_mutex_t* mMutex; + mozilla::Atomic* mCount; +#endif +}; + +typedef detail::BaseAutoLock CrossProcessMutexAutoLock; +typedef detail::BaseAutoUnlock CrossProcessMutexAutoUnlock; + +} // namespace mozilla + +#endif -- cgit v1.2.3