include/linux/posix-timers_types.h

root/include/linux/posix-timers_types.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _linux_POSIX_TIMERS_TYPES_H
#define _linux_POSIX_TIMERS_TYPES_H

#include <linux/mutex_types.h>
#include <linux/timerqueue_types.h>
#include <linux/types.h>

/*
 * Bit fields within a clockid:
 *
 * The most significant 29 bits hold either a pid or a file descriptor.
 *
 * Bit 2 indicates whether a cpu clock refers to a thread or a process.
 *
 * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
 *
 * A clockid is invalid if bits 2, 1, and 0 are all set.
 */
#define CPUCLOCK_PID(clock)             ((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
        (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)

#define CPUCLOCK_PERTHREAD_MASK 4
#define CPUCLOCK_WHICH(clock)   ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
#define CPUCLOCK_CLOCK_MASK     3
#define CPUCLOCK_PROF           0
#define CPUCLOCK_VIRT           1
#define CPUCLOCK_SCHED          2
#define CPUCLOCK_MAX            3
#define CLOCKFD                 CPUCLOCK_MAX
#define CLOCKFD_MASK            (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)

#ifdef CONFIG_POSIX_TIMERS

/**
 * posix_cputimer_base - Container per posix CPU clock
 * @nextevt:            Earliest-expiration cache
 * @tqhead:             timerqueue head for cpu_timers
 */
struct posix_cputimer_base {
        u64                     nextevt;
        struct timerqueue_head  tqhead;
};

/**
 * posix_cputimers - Container for posix CPU timer related data
 * @bases:              Base container for posix CPU clocks
 * @timers_active:      Timers are queued.
 * @expiry_active:      Timer expiry is active. Used for
 *                      process wide timers to avoid multiple
 *                      task trying to handle expiry concurrently
 *
 * Used in task_struct and signal_struct
 */
struct posix_cputimers {
        struct posix_cputimer_base      bases[CPUCLOCK_MAX];
        unsigned int                    timers_active;
        unsigned int                    expiry_active;
};

/**
 * posix_cputimers_work - Container for task work based posix CPU timer expiry
 * @work:       The task work to be scheduled
 * @mutex:      Mutex held around expiry in context of this task work
 * @scheduled:  @work has been scheduled already, no further processing
 */
struct posix_cputimers_work {
        struct callback_head    work;
        struct mutex            mutex;
        unsigned int            scheduled;
};

#else /* CONFIG_POSIX_TIMERS */

struct posix_cputimers { };

#endif /* CONFIG_POSIX_TIMERS */

#endif /* _linux_POSIX_TIMERS_TYPES_H */
Linux
