blob: 89452c1b5cd8b2bda471c2ec6666529a45892131 [file] [log] [blame]
// Copyright (c) 2012 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.
// WARNING: You should *NOT* be using this class directly. PlatformThread is
// the low-level platform-specific abstraction to the OS's threading interface.
// You should instead be using a message-loop driven Thread, see thread.h.
#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/time.h"
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#elif defined(OS_POSIX)
#include <pthread.h>
#include <unistd.h>
#elif defined(OS_STARBOARD)
#include "starboard/thread.h"
namespace base {
// PlatformThreadHandle should not be assumed to be a numeric type, since the
// standard intends to allow pthread_t to be a structure. This means you
// should not initialize it to a value, like 0. If it's a member variable, the
// constructor can safely "value initialize" using () in the initializer list.
// ... Note that PlatformThreadHandle is assumed to be a scalar type below.
#if defined(OS_WIN)
typedef DWORD PlatformThreadId;
typedef void* PlatformThreadHandle; // HANDLE
const PlatformThreadHandle kNullThreadHandle = NULL;
const PlatformThreadId kInvalidThreadId = 0;
#elif defined(OS_POSIX)
typedef pthread_t PlatformThreadHandle;
const PlatformThreadHandle kNullThreadHandle = 0;
typedef pid_t PlatformThreadId;
const PlatformThreadId kInvalidThreadId = 0;
#if defined(COBALT)
typedef int ThreadAffinity;
const ThreadAffinity kNoThreadAffinity = -1;
#elif defined(OS_STARBOARD)
typedef SbThread PlatformThreadHandle;
const PlatformThreadHandle kNullThreadHandle = kSbThreadInvalid;
typedef SbThreadId PlatformThreadId;
const PlatformThreadId kInvalidThreadId = kSbThreadInvalidId;
typedef SbThreadAffinity ThreadAffinity;
const ThreadAffinity kNoThreadAffinity = kSbThreadNoAffinity;
// Valid values for SetThreadPriority()
enum ThreadPriority {
#if defined(OS_STARBOARD)
// See the priorities defined in "starboard/thread.h"
kThreadPriority_Default = kSbThreadNoPriority,
kThreadPriority_Lowest = kSbThreadPriorityLowest,
kThreadPriority_Low = kSbThreadPriorityLow,
kThreadPriority_Normal = kSbThreadPriorityNormal,
kThreadPriority_High = kSbThreadPriorityHigh,
kThreadPriority_Highest = kSbThreadPriorityHighest,
kThreadPriority_RealTime = kSbThreadPriorityRealTime,
kThreadPriority_RealtimeAudio = kThreadPriority_RealTime,
#elif defined(COBALT)
// Cobalt on non-Starboard platforms.
kThreadPriority_Default = -1,
kThreadPriority_Lowest = 0,
kThreadPriority_RealtimeAudio = kThreadPriority_RealTime,
// The original Chromium priorities.
// Suitable for low-latency, glitch-resistant audio.
// A namespace for low-level thread functions.
class BASE_EXPORT PlatformThread {
// Implement this interface to run code on a background thread. Your
// ThreadMain method will be called on the newly created thread.
class BASE_EXPORT Delegate {
virtual void ThreadMain() = 0;
virtual ~Delegate() {}
#if defined(__LB_SHELL__) || defined(OS_STARBOARD)
struct PlatformThreadOptions {
// <= 0 indicates default stack size
int64_t stack_size;
// The priority to start the thread at, or kThreadPriority_Default for the
// default priority assignment policy.
ThreadPriority priority;
// The CPU index to pin the thread to, or kNoThreadAffinity for no affinity.
ThreadAffinity affinity;
// Gets the current thread id, which may be useful for logging purposes.
static PlatformThreadId CurrentId();
// Yield the current thread so another thread can be scheduled.
static void YieldCurrentThread();
// Sleeps for the specified duration.
static void Sleep(base::TimeDelta duration);
// Sets the thread name visible to debuggers/tools. This has no effect
// otherwise. This name pointer is not copied internally. Thus, it must stay
// valid until the thread ends.
static void SetName(const char* name);
// Gets the thread name, if previously set by SetName.
static const char* GetName();
// Creates a new thread. The |stack_size| parameter can be 0 to indicate
// that the default stack size should be used. Upon success,
// |*thread_handle| will be assigned a handle to the newly created thread,
// and |delegate|'s ThreadMain method will be executed on the newly created
// thread.
// NOTE: When you are done with the thread handle, you must call Join to
// release system resources associated with the thread. You must ensure that
// the Delegate object outlives the thread.
static bool Create(size_t stack_size, Delegate* delegate,
PlatformThreadHandle* thread_handle);
// CreateWithPriority() does the same thing as Create() except the priority of
// the thread is set based on |priority|. Can be used in place of Create()
// followed by SetThreadPriority(). SetThreadPriority() has not been
// implemented on the Linux platform yet, this is the only way to get a high
// priority thread on Linux.
static bool CreateWithPriority(size_t stack_size, Delegate* delegate,
PlatformThreadHandle* thread_handle,
ThreadPriority priority);
// CreateNonJoinable() does the same thing as Create() except the thread
// cannot be Join()'d. Therefore, it also does not output a
// PlatformThreadHandle.
static bool CreateNonJoinable(size_t stack_size, Delegate* delegate);
#if defined(__LB_SHELL__) || defined(OS_STARBOARD)
static bool CreateWithOptions(const PlatformThreadOptions& options,
Delegate* delegate,
PlatformThreadHandle* thread_handle);
// Joins with a thread created via the Create function. This function blocks
// the caller until the designated thread exits. This will invalidate
// |thread_handle|.
static void Join(PlatformThreadHandle thread_handle);
// Sets the priority of the thread specified in |handle| to |priority|.
// This does not work on Linux, use CreateWithPriority() instead.
static void SetThreadPriority(PlatformThreadHandle handle,
ThreadPriority priority);
} // namespace base