ERROR_SEM_OWNER_DIED - 105 (0x69)
The previous ownership of this semaphore has ended.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_SEM_OWNER_DIED error code indicates that the previous ownership of a semaphore has ended. This typically occurs when a process or thread that was holding onto a semaphore exits without properly releasing it, leading to an invalid state for other processes or threads waiting on the same semaphore.
Error Details
This error is specific to Windows API operations involving semaphores. Semaphores are synchronization objects used in concurrent programming to control access to shared resources. When a process or thread acquires ownership of a semaphore and subsequently exits without releasing it, the semaphore's state becomes invalid for other processes or threads.
Usage Context
This error is commonly encountered when using Windows API functions such as WaitForSingleObject, WaitForMultipleObjects, or ReleaseSemaphore. It can also be relevant in scenarios where semaphores are used to coordinate access between multiple threads or processes within the same application or across different applications.
Developer Interpretation
When this error is returned, it signifies that a synchronization issue has occurred. Specifically, the process or thread that was supposed to release the semaphore has terminated unexpectedly, leaving other waiting entities in an indefinite wait state. Developers should ensure proper management of semaphores by always releasing them when they are no longer needed.
Related Errors
ERROR_SEM_TIMEOUT(0x1B2): Indicates a timeout while waiting for a semaphore to be released.ERROR_INVALID_HANDLE(0x5): Occurs if an invalid handle is used in a semaphore operation.
FAQ
Q: What causes the ERROR_SEM_OWNER_DIED error?
A: This error typically occurs when a process or thread that was holding onto a semaphore exits without properly releasing it, leaving other waiting entities in an indefinite wait state.
Q: How can I prevent this error from occurring?
A: Ensure that all processes and threads release semaphores they have acquired before exiting. Use appropriate synchronization mechanisms to manage access to shared resources.
Summary
The ERROR_SEM_OWNER_DIED error code is a specific technical issue related to semaphore ownership in Windows API operations. It indicates an invalid state due to improper handling of semaphores, which can lead to deadlocks or indefinite waits for other processes or threads. Developers should ensure proper management and release of semaphores to avoid this error.