diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /ipc/glue/CrossProcessSemaphore.h | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ipc/glue/CrossProcessSemaphore.h')
-rw-r--r-- | ipc/glue/CrossProcessSemaphore.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/ipc/glue/CrossProcessSemaphore.h b/ipc/glue/CrossProcessSemaphore.h new file mode 100644 index 0000000000..297552853c --- /dev/null +++ b/ipc/glue/CrossProcessSemaphore.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_CrossProcessSemaphore_h +#define mozilla_CrossProcessSemaphore_h + +#include "base/process.h" +#include "mozilla/TimeStamp.h" +#include "mozilla/Maybe.h" + +#if defined(OS_WIN) +# include "mozilla/UniquePtrExtensions.h" +#endif +#if !defined(OS_WIN) && !defined(OS_MACOSX) +# include <pthread.h> +# include <semaphore.h> +# include "mozilla/ipc/SharedMemoryBasic.h" +# include "mozilla/Atomics.h" +#endif + +namespace IPC { +template <typename T> +struct ParamTraits; +} // namespace IPC + +// +// Provides: +// +// - CrossProcessSemaphore, a semaphore that can be shared across processes +namespace mozilla { + +template <typename T> +inline bool IsHandleValid(const T& handle) { + return bool(handle); +} + +#if defined(OS_WIN) +typedef mozilla::UniqueFileHandle CrossProcessSemaphoreHandle; +#elif !defined(OS_MACOSX) +typedef mozilla::ipc::SharedMemoryBasic::Handle CrossProcessSemaphoreHandle; + +template <> +inline bool IsHandleValid<CrossProcessSemaphoreHandle>( + const CrossProcessSemaphoreHandle& handle) { + return !(handle == mozilla::ipc::SharedMemoryBasic::NULLHandle()); +} +#else +// Stub for other platforms. We can't use uintptr_t here since different +// processes could disagree on its size. +typedef uintptr_t CrossProcessSemaphoreHandle; +#endif + +class CrossProcessSemaphore { + public: + /** + * CrossProcessSemaphore + * @param name A name which can reference this lock (currently unused) + **/ + static CrossProcessSemaphore* Create(const char* aName, + uint32_t aInitialValue); + + /** + * CrossProcessSemaphore + * @param handle A handle of an existing cross process semaphore that can be + * opened. + */ + static CrossProcessSemaphore* Create(CrossProcessSemaphoreHandle aHandle); + + ~CrossProcessSemaphore(); + + /** + * Decrements the current value of the semaphore. This will block if the + * current value of the semaphore is 0, up to a maximum of aWaitTime (if + * specified). + * Returns true if the semaphore was succesfully decremented, false otherwise. + **/ + bool Wait(const Maybe<TimeDuration>& aWaitTime = Nothing()); + + /** + * Increments the current value of the semaphore. + **/ + void Signal(); + + /** + * 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 + */ + CrossProcessSemaphoreHandle CloneHandle(); + + void CloseHandle(); + + private: + friend struct IPC::ParamTraits<CrossProcessSemaphore>; + + CrossProcessSemaphore(); + CrossProcessSemaphore(const CrossProcessSemaphore&); + CrossProcessSemaphore& operator=(const CrossProcessSemaphore&); + +#if defined(OS_WIN) + explicit CrossProcessSemaphore(HANDLE aSemaphore); + + HANDLE mSemaphore; +#elif !defined(OS_MACOSX) + RefPtr<mozilla::ipc::SharedMemoryBasic> mSharedBuffer; + sem_t* mSemaphore; + mozilla::Atomic<int32_t>* mRefCount; +#endif +}; + +} // namespace mozilla + +#endif |