thread_signal()

Send a signal to a particular thread in the current process.

Description

The thread_signal() function sends a signal to a specific thread within the current process. It takes a Tid as input, representing the thread identifier, and a Signal indicating the signal to be raised for the thread.

This function is similar to the signal function in POSIX, which allows sending signals to specific threads or processes.

Syntax

  ;;; Sends a signal to a specific thread
  (@interface func (export "thread_signal")
    ;;; Handle of the thread to send a signal
    (param $tid $tid)
    ;;; Signal to send to the thread
    (param $signal $signal)
    (result $error (expected (error $errno)))
  )

Parameters

• ctx: A mutable reference to the function environment.
• tid: The thread identifier (Tid) of the target thread to which the signal should be sent.
• sig: The signal to be raised for the target thread.

Return Value

The function returns Ok(Errno::Success) if the operation is successful. Otherwise, it returns an appropriate WasiError value.

Logging

This function is instrumented with debug level logging. It includes the following fields for debugging purposes:

• tid: The thread identifier (Tid) of the target thread.
• sig: The signal to be raised for the target thread.

Note

• The thread_signal() function allows sending a signal to a particular thread within the current process.
• It uses the signal_thread() method of the current process to send the signal to the specified thread.
• This function is similar to the signal function in POSIX, which enables sending signals to specific threads or processes.
• After sending the signal, the function calls WasiEnv::process_signals_and_exit() to process any pending signals and handle process termination if necessary.
• Proper handling and interpretation of signals is important for synchronization, communication, and control between threads within an application.
• Signals provide a way to communicate specific instructions or events to threads or processes, enabling various behaviors such as termination, interruption, or custom actions.
• The thread_signal() function in the WASI environment allows you to send signals to individual threads, providing flexibility and control over thread-level operations.
• It's important to note that the behavior and handling of signals may vary depending on the underlying operating system and signal implementation.
• Understanding the semantics and implications of signals in the target platform is crucial for correct and reliable signal handling in multi-threaded environments.
• The thread_signal() function provides a convenient and consistent way to send signals to specific threads in the WASI environment.
• Thread signals can be used for various purposes such as thread synchronization, interruption, termination, or customized thread-specific actions.
• Signal handling should be carefully designed and implemented to ensure correct and reliable behavior in multi-threaded applications.
• The thread_signal() function is a powerful tool for managing and controlling threads by sending signals to specific threads in the current process.