tools/perf/bench/futex.h

Source file repositories/reference/linux-study-clean/tools/perf/bench/futex.h

File Facts

System
Linux kernel
Corpus path
tools/perf/bench/futex.h
Extension
.h
Size
4570 bytes
Lines
152
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct bench_futex_parameters {
	bool silent;
	bool fshared;
	bool mlockall;
	bool multi; /* lock-pi */
	bool pi; /* requeue-pi */
	bool broadcast; /* requeue */
	unsigned int runtime; /* seconds*/
	unsigned int nthreads;
	unsigned int nfutexes;
	unsigned int nwakes;
	unsigned int nrequeue;
	int nbuckets;
};

/**
 * futex_syscall() - SYS_futex syscall wrapper
 * @uaddr:	address of first futex
 * @op:		futex op code
 * @val:	typically expected value of uaddr, but varies by op
 * @timeout:	typically an absolute struct timespec (except where noted
 *		otherwise). Overloaded by some ops
 * @uaddr2:	address of second futex for some ops
 * @val3:	varies by op
 * @opflags:	flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
 *
 * futex_syscall() is used by all the following futex op wrappers. It can also be
 * used for misuse and abuse testing. Generally, the specific op wrappers
 * should be used instead.
 *
 * These argument descriptions are the defaults for all
 * like-named arguments in the following wrappers except where noted below.
 */
static inline int
futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout,
	      volatile u_int32_t *uaddr2, int val3, int opflags)
{
	return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3);
}

static inline int
futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue,
			 volatile u_int32_t *uaddr2, int val3, int opflags)
{
	return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);
}

/**
 * futex_wait() - block on uaddr with optional timeout
 * @timeout:	relative timeout
 */
static inline int
futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
{
	return futex_syscall(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
}

/**
 * futex_wake() - wake one or more tasks blocked on uaddr
 * @nr_wake:	wake up to this many tasks
 */
static inline int
futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
{
	return futex_syscall(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
}

/**
 * futex_lock_pi() - block on uaddr as a PI mutex
 */
static inline int
futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
{
	return futex_syscall(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
}

/**
 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter
 */
static inline int
futex_unlock_pi(u_int32_t *uaddr, int opflags)
{
	return futex_syscall(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
}

/**
* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
* @nr_wake:        wake up to this many tasks
* @nr_requeue:     requeue up to this many tasks
*/

Annotation

Implementation Notes