How to pause / resume any external process under Windows?
process, process-management, windows
Solution
If you "debug the debugger" (for instance, using `logger.exe` to trace all API calls made by `windbg.exe`), it appears that the debugger uses `SuspendThread()`/`ResumeThread()` to suspend all of the threads in the process being debugged.
PsSuspend may use a different way of suspending processes (I'm not sure), but it is still possible to hang other processes: if the process you're suspending is holding a shared synchronization object that is needed by another process, you may block that other process from making any progress. If both programs are well-written, they should recover when you resume the one that you suspended, but not all programs are well-written. And if this causes your program that is doing the suspending to hang, then you have a deadlock.
Problem
I am looking for different ways to pause and resume programmatically a particular process via its process ID under Windows XP. Process suspend/resume tool does it with `SuspendThread` / `ResumeThread` but warns about multi-threaded programs and deadlock problems. PsSuspend looks okay, but I wonder if it does anything special about deadlocks or uses another method? Prefered languages : C++ / Python