How can find deadlock in WinDbg?
How can find deadlock in WinDbg?
Automatically detect Deadlocks with WinDbg
- Create a memory dump of your hanged program. A memory dump is a “snapshot” of the current program memory.
- Install WinDbg. You can install WinDbg with Debugging Tools for Windows.
- Add SOSEX to WinDbg.
- Load your Dump in WinDbg.
- Find the Deadlock.
How do you detect a mutex deadlock?
To detect deadlock between threads, we need to track blocked threads and the mutexes they are blocked on, as well as be able to easily find the owner of a given mutex. This information needs to be updated every time a mutex lock is attempted (whether it succeeds or not).
How do you debug a mutex deadlock?
- Run your program using GDB. $ gdb program.
- When the program freezes, stop it using Ctrl-C. ^C.
- Do a backtrace to see where we’re deadlocked. (gdb) backtrace.
- Switch to the frame. (gdb) frame 4.
- Determine which thread currently holds the lock we’re attempting to obtain.
- Switch to the owning thread.
What causes computer deadlock?
A deadlock is caused when two or more threads come into conflict over some resource, in such a way that no execution is possible. If both sequences happen at the same time, Thread 1 will never get Lock B because it is owned by Thread 2, and Thread 2 will never get Lock A because it is owned by Thread 1.
How do you deal with deadlocks?
A deadlock is resolved by aborting and restarting a process, relinquishing all the resources that the process held.
- This technique does not limit resources access or restrict process action.
- Requested resources are granted to processes whenever possible.
What causes mutex deadlock?
Mutexes provide a mechanism for allowing one thread to block the execution of another. This opens up the possibility of a new class of bugs, called deadlocks. A deadlock occurs when one or more threads are stuck waiting for something that never will occur.
How do you avoid deadlock?
Deadlock can be prevented by eliminating any of the four necessary conditions, which are mutual exclusion, hold and wait, no preemption, and circular wait. Mutual exclusion, hold and wait and no preemption cannot be violated practically. Circular wait can be feasibly eliminated by assigning a priority to each resource.
How do I fix a deadlocked computer?
Try moving the mouse cursor on the screen. If it doesn’t move even after waiting for a couple of minutes, you probably are dealing with a deadlock. Hit the Caps Lock button located on the keyboard. If it is working, then it probably is a software problem and you can resolve the issue using the Windows task manager.
How can deadlock be resolved?
Deadlock frequency can sometimes be reduced by ensuring that all applications access their common data in the same order – meaning, for example, that they access (and therefore lock) rows in Table A, followed by Table B, followed by Table C, and so on.
How can we recover from deadlock?
There are two approaches of breaking a Deadlock:
- Process Termination: To eliminate the deadlock, we can simply kill one or more processes.
- Resource Preemption: To eliminate deadlocks using resource preemption, we preempt some resources from processes and give those resources to other processes.