Function safety refers to whether or not it's safe to use the Screen API functions in certain situations.
Screen API functions are thread-safe and behave as documented even in a multithreaded environment. However, Screen API functions are neither interrupt-safe nor signal-safe. Don't use Screen API functions in an interrupt handler or a signal handler.
Screen API
| Safety | |
|---|---|
| Cancellation point | Read the Caveats |
| Interrupt handler | No |
| Signal handler | No |
| Thread | Yes |
It's possible to cancel any Screen API function call if it invokes sending a message (MsgSend*()) between the application and Screen. However, whether a message is sent varies not only from function to function, but also for the same function, depending on the circumstances under which it was called.