futex_wake()

Wakes up one thread that is blocked on a futex_wait() operation on the specified futex.

Description

The futex_wake() function wakes up one thread that is waiting on the specified futex. It returns true if a thread was successfully woken up, or false if no thread was waiting on the futex.

Syntax

  ;;; or false if no thread was waiting on this futex.
  ;;; Returns true if this actually woke up such a thread,
  ;;;
  ;;; Wake up one thread that's blocked on futex_wait on this futex.
  (@interface func (export "futex_wake")
    ;;; Memory location that holds a futex that others may be waiting on
    (param $futex (@witx pointer u32))
    (result $error (expected $bool (error $errno)))
  )

Parameters

• ctx: A mutable reference to the function environment.
• futex_ptr: A pointer to the memory location holding the futex.
• ret_woken: A pointer to a Boolean value that will be set to true if a thread was woken up, or false otherwise.

Return Value

The function returns an Errno value indicating the outcome of the operation. If the operation is successful, Errno::Success is returned. If an error occurs, an appropriate Errno value is returned.

Notes

• The futex_wake() function is used to wake up a thread that is blocked on a futex_wait() operation.
• It takes a pointer to the memory location holding the futex as the futex_ptr parameter.
• If a thread is waiting on the specified futex, futex_wake() wakes up one thread and returns true. If no thread is waiting on the futex, it returns false.
• The ret_woken parameter is a pointer to a Boolean value that indicates whether a thread was woken up. If true, it means a thread was woken up. If false, it means no thread was waiting on the futex.
• The behavior and limitations of the futex_wake() function may vary depending on the specific runtime environment and underlying operating system. It is important to consult the documentation or specifications of the specific environment to understand its behavior in that context.