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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /ipc/chromium/src/base/thread_local_storage.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ipc/chromium/src/base/thread_local_storage.h')
-rw-r--r-- | ipc/chromium/src/base/thread_local_storage.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/thread_local_storage.h b/ipc/chromium/src/base/thread_local_storage.h new file mode 100644 index 0000000000..cf488a2d8d --- /dev/null +++ b/ipc/chromium/src/base/thread_local_storage.h @@ -0,0 +1,95 @@ +/* -*- 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) 2006-2008 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_THREAD_LOCAL_STORAGE_H_ +#define BASE_THREAD_LOCAL_STORAGE_H_ + +#include "base/basictypes.h" + +#if defined(OS_POSIX) +# include <pthread.h> +#endif + +// Wrapper for thread local storage. This class doesn't do much except provide +// an API for portability. +class ThreadLocalStorage { + public: + // Prototype for the TLS destructor function, which can be optionally used to + // cleanup thread local storage on thread exit. 'value' is the data that is + // stored in thread local storage. + typedef void (*TLSDestructorFunc)(void* value); + + // A key representing one value stored in TLS. + class Slot { + public: + explicit Slot(TLSDestructorFunc destructor = NULL); + + // This constructor should be used for statics. + // It returns an uninitialized Slot. + explicit Slot(base::LinkerInitialized x) {} + + // Set up the TLS slot. Called by the constructor. + // 'destructor' is a pointer to a function to perform per-thread cleanup of + // this object. If set to NULL, no cleanup is done for this TLS slot. + // Returns false on error. + bool Initialize(TLSDestructorFunc destructor); + + // Free a previously allocated TLS 'slot'. + // If a destructor was set for this slot, removes + // the destructor so that remaining threads exiting + // will not free data. + void Free(); + + // Get the thread-local value stored in slot 'slot'. + // Values are guaranteed to initially be zero. + void* Get() const; + + // Set the thread-local value stored in slot 'slot' to + // value 'value'. + void Set(void* value); + + bool initialized() const { return initialized_; } + + private: + // The internals of this struct should be considered private. + bool initialized_; +#if defined(OS_WIN) + int slot_; +#elif defined(OS_POSIX) + pthread_key_t key_; +#endif + + DISALLOW_COPY_AND_ASSIGN(Slot); + }; + +#if defined(OS_WIN) + // Function called when on thread exit to call TLS + // destructor functions. This function is used internally. + static void ThreadExit(); + + private: + // Function to lazily initialize our thread local storage. + static void** Initialize(); + + private: + // The maximum number of 'slots' in our thread local storage stack. + // For now, this is fixed. We could either increase statically, or + // we could make it dynamic in the future. + static const int kThreadLocalStorageSize = 64; + + static long tls_key_; + static long tls_max_; + static TLSDestructorFunc tls_destructors_[kThreadLocalStorageSize]; +#endif // OS_WIN + + DISALLOW_COPY_AND_ASSIGN(ThreadLocalStorage); +}; + +// Temporary backwards-compatible name. +// TODO(evanm): replace all usage of TLSSlot. +typedef ThreadLocalStorage::Slot TLSSlot; + +#endif // BASE_THREAD_LOCAL_STORAGE_H_ |