What is a Windows 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. The most common form of deadlock occurs when two or more threads wait for a resource that is owned by the other thread.
How do you fix a deadlock on a computer?
A deadlock occurs when the first process locks the first resource at the same time as the second process locks the second resource. The deadlock can be resolved by cancelling and restarting the first process.
How do you debug a deadlock?
Here are the steps to take to debug 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.
What causes PC deadlock?
Heat can do this, whether because of dust clogging the cpu or gpu heatsink or a failing fan. Power can also do this, such as a power supply becoming flaky, or the power capacitors on the motherboard failing. Memory can cause this, due to chips becoming unstable over time.
How do you start a WinDbg?
Launch your own application and attach WinDbg
- Open WinDbg.
- On the File menu, choose Open Executable. In the Open Executable dialog box, navigate to C:\MyApp\Debug.
- Enter these commands: .symfix.
- Enter these commands: .reload.
- On the Debug menu, choose Step Into (or press F11).
- Enter this command:
Is there a driver for deadlock detection in Windows XP?
The Deadlock Detection option of Driver Verifier, along with the !deadlock kernel debugger extension, is an effective tool for making sure your code avoids poor use of these resources. Deadlock Detection is supported only in Windows XP and later versions of Windows.
What does the deadlock extension do on Windows 10?
This extension will only provide useful information if Driver Verifier’s Deadlock Detection option has detected a lock hierarchy violation and issued bug check 0xC4 (DRIVER_VERIFIER_DETECTED_VIOLATION). Without any arguments, the !deadlock extension causes the basic lock hierarchy topology to be displayed.
What causes the most unambiguous deadlocks in Windows 10?
The most unambiguous deadlocks are the result of owned resources. These include spin locks, mutexes, fast mutexes, and ERESOURCEs. Resources that are signaled rather than acquired (such as events and LPC ports) tend to cause much more ambiguous deadlocks.
What happens when two threads are in deadlock?
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. At best this causes the threads involved to halt, and at worst causes the system to stop responding. Deadlocks are not limited to two threads and two resources.