266 lines
6.9 KiB
C++
266 lines
6.9 KiB
C++
// vim: set sts=8 ts=2 sw=2 tw=99 et:
|
|
//
|
|
// Copyright (C) 2013, David Anderson and AlliedModders LLC
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright notice, this
|
|
// list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above copyright notice,
|
|
// this list of conditions and the following disclaimer in the documentation
|
|
// and/or other materials provided with the distribution.
|
|
// * Neither the name of AlliedModders LLC nor the names of its contributors
|
|
// may be used to endorse or promote products derived from this software
|
|
// without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
// POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
#ifndef _include_amtl_threads_
|
|
#define _include_amtl_threads_
|
|
|
|
#include <assert.h>
|
|
#if defined(_MSC_VER)
|
|
# include <windows.h>
|
|
# include <WinBase.h>
|
|
#else
|
|
# include <pthread.h>
|
|
#endif
|
|
#include <am-utility.h>
|
|
|
|
// Thread primitives for SourcePawn.
|
|
//
|
|
// Linking Requirements:
|
|
//
|
|
// OS X: None (-lpthread and -ldl are optional)
|
|
// Windows: None
|
|
// Linux: -lpthread -lrt required
|
|
//
|
|
// -- Mutexes --
|
|
//
|
|
// A Lockable is a mutual exclusion primitive. It can be owned by at most one
|
|
// thread at a time, and ownership blocks any other thread from taking taking
|
|
// ownership. Ownership must be acquired and released on the same thread.
|
|
// Lockables are not re-entrant.
|
|
//
|
|
// While a few classes support the Lockable interface, the simplest Lockable
|
|
// object that can be instantiated is a Mutex.
|
|
//
|
|
// -- Condition Variables --
|
|
//
|
|
// A ConditionVariable provides mutually exclusive access based on a
|
|
// condition ocurring. CVs provide two capabilities: Wait(), which will block
|
|
// until the condition is triggered, and Notify(), which signals any blocking
|
|
// thread that the condition has occurred.
|
|
//
|
|
// Condition variables have an underlying mutex lock. This lock must be
|
|
// acquired before calling Wait() or Notify(). It is automatically released
|
|
// once Wait begins blocking. This operation is atomic with respect to other
|
|
// threads and the mutex. For example, it is not possible for the lock to be
|
|
// acquired by another thread in between unlocking and blocking. Since Notify
|
|
// also requires the lock to be acquired, there is no risk of an event
|
|
// accidentally dissipating into thin air because it was sent before the other
|
|
// thread began blocking.
|
|
//
|
|
// When Wait() returns, the lock is automatically re-acquired. This operation
|
|
// is NOT atomic. In between waking up and re-acquiring the lock, another
|
|
// thread may steal the lock and issue another event. Applications must
|
|
// account for this. For example, a message pump should check that there are
|
|
// no messages left to process before blocking again.
|
|
//
|
|
// Likewise, it is also not defined whether a Signal() will have any effect
|
|
// while a thread is not waiting on the monitor. This is yet another reason
|
|
// the above paragraph is so important - applications should, under a lock of
|
|
// the condition variable - check for state changes before waiting.
|
|
//
|
|
// -- Threads --
|
|
//
|
|
// A Thread object, when created, spawns a new thread with the given callback
|
|
// (the callbacks must implement IRunnable). Threads have one method of
|
|
// interest, Join(), which will block until the thread's execution finishes.
|
|
// Deleting a thread object will free any operating system resources associated
|
|
// with that thread, if the thread has finished executing.
|
|
//
|
|
// Threads can fail to spawn; make sure to check Succeeded().
|
|
//
|
|
|
|
namespace ke {
|
|
|
|
// Abstraction for getting a unique thread identifier. Debug-only.
|
|
#if defined(_MSC_VER)
|
|
typedef DWORD ThreadId;
|
|
|
|
static inline ThreadId GetCurrentThreadId()
|
|
{
|
|
return ::GetCurrentThreadId();
|
|
}
|
|
#else
|
|
typedef pthread_t ThreadId;
|
|
|
|
static inline ThreadId GetCurrentThreadId()
|
|
{
|
|
return pthread_self();
|
|
}
|
|
#endif
|
|
|
|
// Classes which use non-reentrant, same-thread lock/unlock semantics should
|
|
// inherit from this and implement DoLock/DoUnlock.
|
|
class Lockable
|
|
{
|
|
public:
|
|
Lockable()
|
|
{
|
|
#if !defined(NDEBUG)
|
|
owner_ = 0;
|
|
#endif
|
|
}
|
|
virtual ~Lockable() {
|
|
}
|
|
|
|
bool TryLock() {
|
|
if (DoTryLock()) {
|
|
DebugSetLocked();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void Lock() {
|
|
assert(Owner() != GetCurrentThreadId());
|
|
DoLock();
|
|
DebugSetLocked();
|
|
}
|
|
|
|
void Unlock() {
|
|
assert(Owner() == GetCurrentThreadId());
|
|
DebugSetUnlocked();
|
|
DoUnlock();
|
|
}
|
|
|
|
void AssertCurrentThreadOwns() const {
|
|
assert(Owner() == GetCurrentThreadId());
|
|
}
|
|
#if !defined(NDEBUG)
|
|
bool Locked() const {
|
|
return owner_ != 0;
|
|
}
|
|
ThreadId Owner() const {
|
|
return owner_;
|
|
}
|
|
#endif
|
|
|
|
virtual bool DoTryLock() = 0;
|
|
virtual void DoLock() = 0;
|
|
virtual void DoUnlock() = 0;
|
|
|
|
protected:
|
|
void DebugSetUnlocked() {
|
|
#if !defined(NDEBUG)
|
|
owner_ = 0;
|
|
#endif
|
|
}
|
|
void DebugSetLocked() {
|
|
#if !defined(NDEBUG)
|
|
owner_ = GetCurrentThreadId();
|
|
#endif
|
|
}
|
|
|
|
protected:
|
|
#if !defined(NDEBUG)
|
|
ThreadId owner_;
|
|
#endif
|
|
};
|
|
|
|
// RAII for automatically locking and unlocking an object.
|
|
class AutoLock
|
|
{
|
|
public:
|
|
AutoLock(Lockable *lock)
|
|
: lock_(lock)
|
|
{
|
|
lock_->Lock();
|
|
}
|
|
~AutoLock() {
|
|
lock_->Unlock();
|
|
}
|
|
|
|
private:
|
|
Lockable *lock_;
|
|
};
|
|
|
|
class AutoTryLock
|
|
{
|
|
public:
|
|
AutoTryLock(Lockable *lock)
|
|
{
|
|
lock_ = lock->TryLock() ? lock : NULL;
|
|
}
|
|
~AutoTryLock() {
|
|
if (lock_)
|
|
lock_->Unlock();
|
|
}
|
|
|
|
private:
|
|
Lockable *lock_;
|
|
};
|
|
|
|
// RAII for automatically unlocking and relocking an object.
|
|
class AutoUnlock
|
|
{
|
|
public:
|
|
AutoUnlock(Lockable *lock)
|
|
: lock_(lock)
|
|
{
|
|
lock_->Unlock();
|
|
}
|
|
~AutoUnlock() {
|
|
lock_->Lock();
|
|
}
|
|
|
|
private:
|
|
Lockable *lock_;
|
|
};
|
|
|
|
enum WaitResult {
|
|
// Woke up because something happened.
|
|
Wait_Signaled,
|
|
|
|
// Woke up because nothing happened and a timeout was specified.
|
|
Wait_Timeout,
|
|
|
|
// Woke up, but because of an error.
|
|
Wait_Error
|
|
};
|
|
|
|
// This must be implemented in order to spawn a new thread.
|
|
class IRunnable
|
|
{
|
|
public:
|
|
virtual ~IRunnable() {
|
|
}
|
|
|
|
virtual void Run() = 0;
|
|
};
|
|
|
|
} // namespace ke
|
|
|
|
// Include the actual thread implementations.
|
|
#if defined(_MSC_VER)
|
|
# include "am-thread-windows.h"
|
|
#else
|
|
# include "am-thread-posix.h"
|
|
#endif
|
|
|
|
#endif // _include_amtl_threads_
|