#ifndef _UAPI_LINUX_FUTEX_H#define _UAPI_LINUX_FUTEX_H #include <linux/compiler.h>#include <linux/types.h> /* Second argument to futex syscall */  #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	128#define FUTEX_CLOCK_REALTIME	256#define FUTEX_CMD_MASK		~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME) #define FUTEX_WAIT_PRIVATE	(FUTEX_WAIT | FUTEX_PRIVATE_FLAG)#define FUTEX_WAKE_PRIVATE	(FUTEX_WAKE | FUTEX_PRIVATE_FLAG)#define FUTEX_REQUEUE_PRIVATE	(FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)#define FUTEX_WAKE_OP_PRIVATE	(FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)#define FUTEX_LOCK_PI_PRIVATE	(FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)#define FUTEX_UNLOCK_PI_PRIVATE	(FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)#define FUTEX_WAIT_BITSET_PRIVATE	(FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)#define FUTEX_WAKE_BITSET_PRIVATE	(FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)#define FUTEX_WAIT_REQUEUE_PI_PRIVATE	(FUTEX_WAIT_REQUEUE_PI | \					 FUTEX_PRIVATE_FLAG)#define FUTEX_CMP_REQUEUE_PI_PRIVATE	(FUTEX_CMP_REQUEUE_PI | \					 FUTEX_PRIVATE_FLAG) /* * Support for robust futexes: the kernel cleans up held futexes at * thread exit time. */ /* * Per-lock list entry - embedded in user-space locks, somewhere close * to the futex field. (Note: user-space uses a double-linked list to * achieve O(1) list add and remove, but the kernel only needs to know * about the forward link) * * NOTE: this structure is part of the syscall ABI, and must not be * changed. */struct robust_list {	struct robust_list __user *next;}; /* * Per-thread list head: * * NOTE: this structure is part of the syscall ABI, and must only be * changed if the change is first communicated with the glibc folks. * (When an incompatible change is done, we'll increase the structure *  size, which glibc will detect) */struct robust_list_head {	/*	 * The head of the list. Points back to itself if empty:	 */	struct robust_list list; 	/*	 * This relative offset is set by user-space, it gives the kernel	 * the relative position of the futex field to examine. This way	 * we keep userspace flexible, to freely shape its data-structure,	 * without hardcoding any particular offset into the kernel:	 */	long futex_offset; 	/*	 * The death of the thread may race with userspace setting	 * up a lock's links. So to handle this race, userspace first	 * sets this field to the address of the to-be-taken lock,	 * then does the lock acquire, and then adds itself to the	 * list, and then clears this field. Hence the kernel will	 * always have full knowledge of all locks that the thread	 * _might_ have taken. We check the owner TID in any case,	 * so only truly owned locks will be handled.	 */	struct robust_list __user *list_op_pending;}; /* * Are there any waiters for this robust futex: */#define FUTEX_WAITERS		0x80000000 /* * The kernel signals via this bit that a thread holding a futex * has exited without unlocking the futex. The kernel also does * a FUTEX_WAKE on such futexes, after setting the bit, to wake * up any possible waiters: */#define FUTEX_OWNER_DIED	0x40000000 /* * The rest of the robust-futex field is for the TID: */#define FUTEX_TID_MASK		0x3fffffff /* * This limit protects against a deliberately circular list. * (Not worth introducing an rlimit for it) */#define ROBUST_LIST_LIMIT	2048 /* * bitset with all bits set for the FUTEX_xxx_BITSET OPs to request a * match of any bit. */#define FUTEX_BITSET_MATCH_ANY	0xffffffff  #define FUTEX_OP_SET		0	/* *(int *)UADDR2 = OPARG; */#define FUTEX_OP_ADD		1	/* *(int *)UADDR2 += OPARG; */#define FUTEX_OP_OR		2	/* *(int *)UADDR2 |= OPARG; */#define FUTEX_OP_ANDN		3	/* *(int *)UADDR2 &= ~OPARG; */#define FUTEX_OP_XOR		4	/* *(int *)UADDR2 ^= OPARG; */ #define FUTEX_OP_OPARG_SHIFT	8	/* Use (1 << OPARG) instead of OPARG.  */ #define FUTEX_OP_CMP_EQ		0	/* if (oldval == CMPARG) wake */#define FUTEX_OP_CMP_NE		1	/* if (oldval != CMPARG) wake */#define FUTEX_OP_CMP_LT		2	/* if (oldval < CMPARG) wake */#define FUTEX_OP_CMP_LE		3	/* if (oldval <= CMPARG) wake */#define FUTEX_OP_CMP_GT		4	/* if (oldval > CMPARG) wake */#define FUTEX_OP_CMP_GE		5	/* if (oldval >= CMPARG) wake */ /* FUTEX_WAKE_OP will perform atomically   int oldval = *(int *)UADDR2;   *(int *)UADDR2 = oldval OP OPARG;   if (oldval CMP CMPARG)     wake UADDR2;  */ #define FUTEX_OP(op, oparg, cmp, cmparg) \  (((op & 0xf) << 28) | ((cmp & 0xf) << 24)		\   | ((oparg & 0xfff) << 12) | (cmparg & 0xfff)) #endif /* _UAPI_LINUX_FUTEX_H */