1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/thread_local_storage.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,94 @@
1.4 +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#ifndef BASE_THREAD_LOCAL_STORAGE_H_
1.9 +#define BASE_THREAD_LOCAL_STORAGE_H_
1.10 +
1.11 +#include "base/basictypes.h"
1.12 +
1.13 +#if defined(OS_POSIX)
1.14 +#include <pthread.h>
1.15 +#endif
1.16 +
1.17 +// Wrapper for thread local storage. This class doesn't do much except provide
1.18 +// an API for portability.
1.19 +class ThreadLocalStorage {
1.20 + public:
1.21 +
1.22 + // Prototype for the TLS destructor function, which can be optionally used to
1.23 + // cleanup thread local storage on thread exit. 'value' is the data that is
1.24 + // stored in thread local storage.
1.25 + typedef void (*TLSDestructorFunc)(void* value);
1.26 +
1.27 + // A key representing one value stored in TLS.
1.28 + class Slot {
1.29 + public:
1.30 + Slot(TLSDestructorFunc destructor = NULL);
1.31 +
1.32 + // This constructor should be used for statics.
1.33 + // It returns an uninitialized Slot.
1.34 + explicit Slot(base::LinkerInitialized x) {}
1.35 +
1.36 + // Set up the TLS slot. Called by the constructor.
1.37 + // 'destructor' is a pointer to a function to perform per-thread cleanup of
1.38 + // this object. If set to NULL, no cleanup is done for this TLS slot.
1.39 + // Returns false on error.
1.40 + bool Initialize(TLSDestructorFunc destructor);
1.41 +
1.42 + // Free a previously allocated TLS 'slot'.
1.43 + // If a destructor was set for this slot, removes
1.44 + // the destructor so that remaining threads exiting
1.45 + // will not free data.
1.46 + void Free();
1.47 +
1.48 + // Get the thread-local value stored in slot 'slot'.
1.49 + // Values are guaranteed to initially be zero.
1.50 + void* Get() const;
1.51 +
1.52 + // Set the thread-local value stored in slot 'slot' to
1.53 + // value 'value'.
1.54 + void Set(void* value);
1.55 +
1.56 + bool initialized() const { return initialized_; }
1.57 +
1.58 + private:
1.59 + // The internals of this struct should be considered private.
1.60 + bool initialized_;
1.61 +#if defined(OS_WIN)
1.62 + int slot_;
1.63 +#elif defined(OS_POSIX)
1.64 + pthread_key_t key_;
1.65 +#endif
1.66 +
1.67 + DISALLOW_COPY_AND_ASSIGN(Slot);
1.68 + };
1.69 +
1.70 +#if defined(OS_WIN)
1.71 + // Function called when on thread exit to call TLS
1.72 + // destructor functions. This function is used internally.
1.73 + static void ThreadExit();
1.74 +
1.75 + private:
1.76 + // Function to lazily initialize our thread local storage.
1.77 + static void **Initialize();
1.78 +
1.79 + private:
1.80 + // The maximum number of 'slots' in our thread local storage stack.
1.81 + // For now, this is fixed. We could either increase statically, or
1.82 + // we could make it dynamic in the future.
1.83 + static const int kThreadLocalStorageSize = 64;
1.84 +
1.85 + static long tls_key_;
1.86 + static long tls_max_;
1.87 + static TLSDestructorFunc tls_destructors_[kThreadLocalStorageSize];
1.88 +#endif // OS_WIN
1.89 +
1.90 + DISALLOW_COPY_AND_ASSIGN(ThreadLocalStorage);
1.91 +};
1.92 +
1.93 +// Temporary backwards-compatible name.
1.94 +// TODO(evanm): replace all usage of TLSSlot.
1.95 +typedef ThreadLocalStorage::Slot TLSSlot;
1.96 +
1.97 +#endif // BASE_THREAD_LOCAL_STORAGE_H_
