Cross-platform way of yielding a thread in C/C++?

In C and C++ is there a cross-platform way of yielding a thread? Something like sched_yield() or Sleep(0)? Does SDL_Delay(0) always yield or will it return immediat开发者_如何学Cely in some implementations?

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Given that neither C nor C++ (up to C++98) has "threads," there is no fully cross-platform way for a thread to yield.

In C++0x, there is a function std::this_thread::yield() that can be called to yield. That will be the portable way for a thread to yield, once people start using the C++0x threads library.

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in the c++ case, boost::thread::yield() does what you ask. On platforms with posix threads, pthread_yield() performs the same function for C and anything that links with it. On platforms where this doesn't immediately stop the thread and start another, it's because the scheduler doesn't support that functionality. I don't think that many such platforms actually exist in the wild.