Wait on a futex.
#include <zircon/syscalls.h> zx_status_t zx_futex_wait(const zx_futex_t* value_ptr, zx_futex_t current_value, zx_handle_t new_futex_owner, zx_time_t deadline);
zx_futex_wait() atomically verifies that value_ptr still contains the value
current_value and sleeps until the futex is made available by a call to
zx_futex_wake. Optionally, the thread can also be woken up after the
deadline (with respect to ZX_CLOCK_MONOTONIC) passes. deadline may be
automatically adjusted according to the job's [timer slack] policy.
A component that uses futexes should be prepared to handle spurious
wakeups. A spurious wakeup is a situation where
returns successfully even though the component did not wake the waiter
Zircon's implementation of futexes currently does not generate
spurious wakeups itself. However, commonly-used algorithms that use
futexes can sometimes generate spurious wakeups. For example, the
usual implementation of
mutex_unlock can potentially produce a
zx_futex_wake() call on a memory location after the location has been
freed and reused for unrelated purposes.
A successful call to
zx_futex_wait() results in the owner of the futex being
set to the thread referenced by the new_futex_owner handle, or to nothing if
new_futex_owner is ZX_HANDLE_INVALID.
See Ownership and Priority Inheritance in futex for details.
zx_futex_wait() returns ZX_OK on success.
ZX_ERR_INVALID_ARGS One of the following is true:
+ value_ptr is not a valid userspace pointer
+ value_ptr is not aligned to a
+ new_futex_owner is currently a member of the waiters for value_ptr.
ZX_ERR_BAD_HANDLE new_futex_owner is not ZX_HANDLE_INVALID, and not a valid handle. ZX_ERR_WRONG_TYPE new_futex_owner is a valid handle, but is not a handle to a thread. ZX_ERR_BAD_STATE current_value does not match the value at value_ptr. ZX_ERR_TIMED_OUT The thread was not woken before deadline passed.
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.