Page 358 - DCAP103_Principle of operating system

Unit 12: Processes and Threads in Windows

semaphore, rather than having one of them create the object and then make duplicate handles Notes
for the others, although the latter approach is certainly an option as well.
The number of Win32 API calls dealing with processes, threads, and fibers is nearly 100, a
substantial number of which deal with IPC in one form or another. A summary of the ones
discussed above as well as some other important ones are given in Figure 12.3.

Figure 12.3: Some of the Win32 Calls for Managing Processes, Threads, and Fibers

Win32 API Function Description

CreateProcess Create a new process

CreateThread Create a new thread in an existing process

CreateFiber Create a new fiber

ExitProcess Terminate current process and all its threads

ExitThread Terminate this thread
ExitFiber Terminate this fiber

SetPriorityClass Set the priority class for a process

SetThreadPriority Set the priority for one thread

CreateSemaphore Create a new semaphore

CreateMutex Create a new mutex

OpenSemaphore Open an existing semaphore
OpenMutex Open an existing mutex

WaitForSingleObject Block on a single semaphore, mutex, etc.

WaitForMultipleObjects Block on a set of objects whose handles are given

PulseEvent Set an event to signaled then to non-signaled

ReleaseMutex Release a mutex to allow another thread to acquire it
ReleaseSemaphore Increase the semaphore count by 1

EnterCriticalSection Acquire the lock on a critical section

LeaveCriticalSection Release the lock on a critical section

Most of the calls in Figure 12.3 were either discussed above or should be self-explanatory. Again
note that not all of these are system calls. As we mentioned earlier, Windows 2000 knows nothing
about fibers. They are entirely implemented in user space. As a consequence, the CreateFiber call
does its work entirely in user space without making any system calls (unless it has to allocate
some memory). Many other Win32 calls have this property as well, including EnterCriticalSection
and LeaveCriticalSection as we noted above.

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