Package org.qbicc.runtime.linux

Class Futex

java.lang.Object

org.qbicc.runtime.linux.Futex

public class Futex
extends Object

Support for futex(2) on Linux. See the manpage for more information.

Field Summary

Fields

Modifier and Type	Field	Description
static final Stdint.uint32_t	FUTEX_BITSET_MATCH_ANY
static final CNative.c_int	FUTEX_CLOCK_REALTIME
static final CNative.c_int	FUTEX_PRIVATE_FLAG
static final CNative.c_int	FUTEX_WAIT
static final CNative.c_int	FUTEX_WAIT_BITSET
static final CNative.c_int	FUTEX_WAKE

Constructor Summary

Constructors

Constructor	Description
Futex()

Method Summary

Modifier and Type	Method	Description
static boolean	futex_wait(Stdint.uint32_t_ptr uaddr, Stdint.uint32_t val, Time.const_struct_timespec_ptr timeout)	Wait until the value at given address is equal to val.
static boolean	futex_wait_absolute(Stdint.uint32_t_ptr uaddr, Stdint.uint32_t val, Time.const_struct_timespec_ptr timeout)	Wait until the value at given address is equal to val.
static boolean	futex_wake_all(Stdint.uint32_t_ptr uaddr)	Wake all waiters after updating the wait value.
static boolean	futex_wake_single(Stdint.uint32_t_ptr uaddr)	Wake a single waiter after updating the wait value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

FUTEX_PRIVATE_FLAG

public static final CNative.c_int FUTEX_PRIVATE_FLAG

FUTEX_CLOCK_REALTIME

public static final CNative.c_int FUTEX_CLOCK_REALTIME

FUTEX_WAIT

public static final CNative.c_int FUTEX_WAIT

FUTEX_WAIT_BITSET

public static final CNative.c_int FUTEX_WAIT_BITSET

FUTEX_WAKE

public static final CNative.c_int FUTEX_WAKE

FUTEX_BITSET_MATCH_ANY

public static final Stdint.uint32_t FUTEX_BITSET_MATCH_ANY

Constructor Details

Futex

public Futex()

Method Details

futex_wait

public static boolean futex_wait(Stdint.uint32_t_ptr uaddr,
 Stdint.uint32_t val,
 Time.const_struct_timespec_ptr timeout)

Wait until the value at given address is equal to val. Returns when woken (may be spurious). Spurious wakeups may return false and set errno to EAGAIN, or may return true. If the value at the test memory location already does not equal val, a wakeup will result.

Parameters:

uaddr - the address of the memory to test

val - the value to observe

timeout - the relative amount of time to wait

Returns:

true on success, or false on error (in errno)

futex_wait_absolute

public static boolean futex_wait_absolute(Stdint.uint32_t_ptr uaddr,
 Stdint.uint32_t val,
 Time.const_struct_timespec_ptr timeout)

Wait until the value at given address is equal to val. Returns when woken (may be spurious). Spurious wakeups may return false and set errno to EAGAIN, or may return true. If the value at the test memory location already does not equal val, a wakeup will result.

Parameters:

uaddr - the address of the memory to test

val - the value to observe

timeout - the absolute time to wake up

Returns:

true on success, or false on error (in errno)

futex_wake_single

public static boolean futex_wake_single(Stdint.uint32_t_ptr uaddr)

Wake a single waiter after updating the wait value.

Parameters:

uaddr - the address of the memory being waited on

Returns:

true on success, or false on error (in errno)

futex_wake_all

public static boolean futex_wake_all(Stdint.uint32_t_ptr uaddr)

Wake all waiters after updating the wait value.

Parameters:

uaddr - the address of the memory being waited on

Returns:

true on success, or false on error (in errno)