ERROR_INVALID_SIGNAL_NUMBER - 209 (0xD1)

Technical Meaning

The ERROR_INVALID_SIGNAL_NUMBER error code indicates that a signal being posted to a process or thread is not valid. Signals in the context of Windows are asynchronous notifications used for inter-process communication and synchronization.

Error Details

This error typically occurs when an application attempts to send a signal to another process or thread, but the specified signal number does not correspond to any known signal type supported by the operating system. The signal numbers are predefined constants in the Windows API, such as SIGABRT, SIGINT, etc.

Usage Context

This error can be encountered in various scenarios where signals are used for process or thread communication and synchronization. Common contexts include:

• Sending a termination signal to a process or thread.
• Handling asynchronous events using signal-based mechanisms.

Developer Interpretation

When encountering ERROR_INVALID_SIGNAL_NUMBER, developers should ensure that the signal number being posted is valid and corresponds to one of the predefined constants in the Windows API. Developers must also verify the context in which signals are used, ensuring that they are compatible with the target process or thread.

Related Errors

• ERROR_INVALID_PARAMETER
• ERROR_NO_SUCH_PROCESS

FAQ

Q: What does ERROR_INVALID_SIGNAL_NUMBER mean?

A: It indicates that a signal being posted to a process or thread is not valid.

Q: How can I resolve this error?

A: Ensure the signal number used is valid and check the context in which signals are being used.

Summary

The ERROR_INVALID_SIGNAL_NUMBER error code signifies an invalid signal being posted. Developers should verify that the signal numbers used are correct and compatible with the target process or thread to avoid this error.