Causes the calling thread to yield execution to another thread that is ready to run on the current processor. The operating system selects the next thread to be executed.
BOOL SwitchToThread()
Type: BOOL
If calling SwitchToThread causes the operating system to switch execution to another thread, the return value is nonzero.
If there are no other threads ready to execute, the operating system does not switch execution to another thread, and the return value is zero.
SwitchToThread picks the highest-priority thread on the current core that is ready to run even if that thread’s priority is lower than the priority of the calling thread.
The yield of execution is in effect for up to one thread-scheduling time slice on the processor of the calling thread. The operating system will not switch execution to another processor, even if that processor is idle or is running a thread of lower priority.
After the yielding thread’s time slice elapses, the operating system reschedules execution for the yielding thread. The rescheduling is determined by the priority of the yielding thread and the status of other threads that are available to run.
Note that the operating system will not switch to a thread that is being prevented from running only by concurrency control. For example, an I/O completion port or thread pool limits the number of associated threads that can run. If the maximum number of threads is already running, no additional associated thread can run until a running thread finishes. If a thread uses SwitchToThread to wait for one of the additional associated threads to accomplish some work, the process might deadlock.
Header: Declared in processthreadsapi.h.
Library: Use kernelx.lib.