|
Server : Apache/2.4.18 (Ubuntu) System : Linux canvaswebdesign 3.13.0-71-generic #114-Ubuntu SMP Tue Dec 1 02:34:22 UTC 2015 x86_64 User : oppastar ( 1041) PHP Version : 7.0.33-0ubuntu0.16.04.15 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority, Directory : /usr/src/linux-headers-4.4.0-36/include/linux/ |
Upload File : |
#ifndef __LINUX_OSQ_LOCK_H
#define __LINUX_OSQ_LOCK_H
/*
* An MCS like lock especially tailored for optimistic spinning for sleeping
* lock implementations (mutex, rwsem, etc).
*/
struct optimistic_spin_node {
struct optimistic_spin_node *next, *prev;
int locked; /* 1 if lock acquired */
int cpu; /* encoded CPU # + 1 value */
};
struct optimistic_spin_queue {
/*
* Stores an encoded value of the CPU # of the tail node in the queue.
* If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
*/
atomic_t tail;
};
#define OSQ_UNLOCKED_VAL (0)
/* Init macro and function. */
#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
static inline void osq_lock_init(struct optimistic_spin_queue *lock)
{
atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
}
extern bool osq_lock(struct optimistic_spin_queue *lock);
extern void osq_unlock(struct optimistic_spin_queue *lock);
static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
{
return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
}
#endif