/* $NetBSD: futex.h,v 1.7 2025/03/05 12:02:00 riastradh Exp $ */ /*- * Copyright (c) 2018, 2019 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Taylor R. Campbell and Jason R. Thorpe. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Emmanuel Dreyfus * 4. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef _SYS_FUTEX_H_ #define _SYS_FUTEX_H_ /* * Definitions for the __futex(2) synchronization primitive. * * These definitions are intended to be ABI-compatible with the * Linux futex(2) system call. */ #include <sys/timespec.h> #define FUTEX_WAIT 0 #define FUTEX_WAKE 1 #define FUTEX_FD 2 #define FUTEX_REQUEUE 3 #define FUTEX_CMP_REQUEUE 4 #define FUTEX_WAKE_OP 5 #define FUTEX_LOCK_PI 6 #define FUTEX_UNLOCK_PI 7 #define FUTEX_TRYLOCK_PI 8 #define FUTEX_WAIT_BITSET 9 #define FUTEX_WAKE_BITSET 10 #define FUTEX_WAIT_REQUEUE_PI 11 #define FUTEX_CMP_REQUEUE_PI 12 #define FUTEX_PRIVATE_FLAG __BIT(7) #define FUTEX_CLOCK_REALTIME __BIT(8) #define FUTEX_CMD_MASK \ (~(FUTEX_PRIVATE_FLAG|FUTEX_CLOCK_REALTIME)) #define FUTEX_OP_OP_MASK __BITS(28,31) #define FUTEX_OP_CMP_MASK __BITS(24,27) #define FUTEX_OP_OPARG_MASK __BITS(12,23) #define FUTEX_OP_CMPARG_MASK __BITS(0,11) #define FUTEX_OP(op, oparg, cmp, cmparg) \ (__SHIFTIN((op) & 0xf, FUTEX_OP_OP_MASK) |\ __SHIFTIN((oparg) & 0xfff, FUTEX_OP_OPARG_MASK)|\ __SHIFTIN((cmp) & 0xf, FUTEX_OP_CMP_MASK) |\ __SHIFTIN((cmparg) & 0xfff, FUTEX_OP_CMPARG_MASK)) #define FUTEX_OP_SET 0 #define FUTEX_OP_ADD 1 #define FUTEX_OP_OR 2 #define FUTEX_OP_ANDN 3 #define FUTEX_OP_XOR 4 #define FUTEX_OP_OPARG_SHIFT 8 #define FUTEX_OP_CMP_EQ 0 #define FUTEX_OP_CMP_NE 1 #define FUTEX_OP_CMP_LT 2 #define FUTEX_OP_CMP_LE 3 #define FUTEX_OP_CMP_GT 4 #define FUTEX_OP_CMP_GE 5 /* * FUTEX_SYNCOBJ_0 and FUTEX_SYNCOBJ_1 are extensions to the Linux * futex API that are reserved for individual consumers of futexes * to define information specific to that synchronzation object. * Note that as a result there is a system-wide upper limit of * 268,435,455 threads (as opposed to 1,073,741,823). */ #define FUTEX_WAITERS ((int)__BIT(31)) #define FUTEX_OWNER_DIED ((int)__BIT(30)) #define FUTEX_SYNCOBJ_1 ((int)__BIT(29)) #define FUTEX_SYNCOBJ_0 ((int)__BIT(28)) #define FUTEX_TID_MASK ((int)__BITS(0,27)) #define FUTEX_BITSET_MATCH_ANY ((int)__BITS(0,31)) /* * The robust futex ABI consists of an array of 3 longwords, the address * of which is registered with the kernel on a per-thread basis: * * 0: A pointer to a singly-linked list of "lock entries". If the * list is empty, this points back to the list itself. * * 1: An offset from address of the "lock entry" to the 32-bit futex * word associated with that lock entry (may be negative). * * 2: A "pending" pointer, for locks that are in the process of being * acquired or released. * * PI futexes are handled slightly differently. User-space indicates * an entry is for a PI futex by setting the last-significant bit. */ #define _FUTEX_ROBUST_HEAD_LIST 0 #define _FUTEX_ROBUST_HEAD_OFFSET 1 #define _FUTEX_ROBUST_HEAD_PENDING 2 #define _FUTEX_ROBUST_HEAD_NWORDS 3 #define _FUTEX_ROBUST_HEAD_SIZE (_FUTEX_ROBUST_HEAD_NWORDS * \ sizeof(u_long)) #define _FUTEX_ROBUST_HEAD_SIZE32 (_FUTEX_ROBUST_HEAD_NWORDS * \ sizeof(uint32_t)) #define _FUTEX_ROBUST_ENTRY_PI __BIT(0) #ifdef __LIBC_FUTEX_PRIVATE struct futex_robust_list { struct futex_robust_list *next; }; struct futex_robust_list_head { struct futex_robust_list list; long futex_offset; struct futex_robust_list *pending_list; }; #endif /* __LIBC_FUTEX_PRIVATE */ #ifdef _KERNEL struct lwp; int futex_robust_head_lookup(struct lwp *, lwpid_t, void **); void futex_release_all_lwp(struct lwp *); int do_futex(int *, int, int, const struct timespec *, int *, int, int, register_t *); void futex_sys_init(void); void futex_sys_fini(void); #endif /* _KERNEL */ #endif /* ! _SYS_FUTEX_H_ */
