futex_wake_all()

Wakes up all threads that are blocked on a futex_wait() operation on the specified futex.

Description

The futex_wake_all() function wakes up all threads that are waiting on the specified futex. It returns true if one or more threads were successfully woken up, or false if no threads were waiting on the futex.

Syntax

  ;;; Wake up all threads that are waiting on futex_wait on this futex.
  (@interface func (export "futex_wake_all")
    ;;; 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 one or more threads were 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_all() function is used to wake up all threads that are blocked on a futex_wait() operation.
• It takes a pointer to the memory location holding the futex as the futex_ptr parameter.
• If one or more threads are waiting on the specified futex, futex_wake_all() wakes up all of them and returns true. If no threads are waiting on the futex, it returns false.
• The ret_woken parameter is a pointer to a Boolean value that indicates whether one or more threads were woken up. If true, it means one or more threads were woken up. If false, it means no threads were waiting on the futex.
• The behavior and limitations of the futex_wake_all() 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.