futex_wait.md

mx_futex_wait

NAME

futex_wait - Wait on a futex.

SYNOPSIS

#include <magenta/syscalls.h>

mx_status_t mx_futex_wait(int* value_ptr, int current_value,
                          mx_time_t timeout);

DESCRIPTION

Waiting on a futex (or acquiring it) causes a thread to sleep until the futex is made available by a call to mx_futex_wake. Optionally, the thread can also be woken up after the timeout argument expires.

RETURN VALUE

futex_wait() returns NO_ERROR on success.

ERRORS

ERR_INVALID_ARGS value_ptr is not a valid userspace pointer.

ERR_BUSY current_value does not match the value at value_ptr.

ERR_TIMED_OUT The thread was not woken before timeout expired.

SEE ALSO

futex_requeue futex_wake