| Server IP : 127.0.0.2 / Your IP : 3.149.249.124 Web Server : Apache/2.4.18 (Ubuntu) System : User : www-data ( ) PHP Version : 7.0.33-0ubuntu0.16.04.16 Disable Function : disk_free_space,disk_total_space,diskfreespace,dl,exec,fpaththru,getmyuid,getmypid,highlight_file,ignore_user_abord,leak,listen,link,opcache_get_configuration,opcache_get_status,passthru,pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,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,php_uname,phpinfo,posix_ctermid,posix_getcwd,posix_getegid,posix_geteuid,posix_getgid,posix_getgrgid,posix_getgrnam,posix_getgroups,posix_getlogin,posix_getpgid,posix_getpgrp,posix_getpid,posix,_getppid,posix_getpwnam,posix_getpwuid,posix_getrlimit,posix_getsid,posix_getuid,posix_isatty,posix_kill,posix_mkfifo,posix_setegid,posix_seteuid,posix_setgid,posix_setpgid,posix_setsid,posix_setuid,posix_times,posix_ttyname,posix_uname,pclose,popen,proc_open,proc_close,proc_get_status,proc_nice,proc_terminate,shell_exec,source,show_source,system,virtual MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /lib/modules/4.4.0-1049-aws/build/include/asm-generic/ |
Upload File : |
/*
* include/asm-generic/mutex-dec.h
*
* Generic implementation of the mutex fastpath, based on atomic
* decrement/increment.
*/
#ifndef _ASM_GENERIC_MUTEX_DEC_H
#define _ASM_GENERIC_MUTEX_DEC_H
/**
* __mutex_fastpath_lock - try to take the lock by moving the count
* from 1 to a 0 value
* @count: pointer of type atomic_t
* @fail_fn: function to call if the original value was not 1
*
* Change the count from 1 to a value lower than 1, and call <fail_fn> if
* it wasn't 1 originally. This function MUST leave the value lower than
* 1 even when the "1" assertion wasn't true.
*/
static inline void
__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_dec_return_acquire(count) < 0))
fail_fn(count);
}
/**
* __mutex_fastpath_lock_retval - try to take the lock by moving the count
* from 1 to a 0 value
* @count: pointer of type atomic_t
*
* Change the count from 1 to a value lower than 1. This function returns 0
* if the fastpath succeeds, or -1 otherwise.
*/
static inline int
__mutex_fastpath_lock_retval(atomic_t *count)
{
if (unlikely(atomic_dec_return_acquire(count) < 0))
return -1;
return 0;
}
/**
* __mutex_fastpath_unlock - try to promote the count from 0 to 1
* @count: pointer of type atomic_t
* @fail_fn: function to call if the original value was not 0
*
* Try to promote the count from 0 to 1. If it wasn't 0, call <fail_fn>.
* In the failure case, this function is allowed to either set the value to
* 1, or to set it to a value lower than 1.
*
* If the implementation sets it to a value of lower than 1, then the
* __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs
* to return 0 otherwise.
*/
static inline void
__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_inc_return_release(count) <= 0))
fail_fn(count);
}
#define __mutex_slowpath_needs_to_unlock() 1
/**
* __mutex_fastpath_trylock - try to acquire the mutex, without waiting
*
* @count: pointer of type atomic_t
* @fail_fn: fallback function
*
* Change the count from 1 to a value lower than 1, and return 0 (failure)
* if it wasn't 1 originally, or return 1 (success) otherwise. This function
* MUST leave the value lower than 1 even when the "1" assertion wasn't true.
* Additionally, if the value was < 0 originally, this function must not leave
* it to 0 on failure.
*
* If the architecture has no effective trylock variant, it should call the
* <fail_fn> spinlock-based trylock variant unconditionally.
*/
static inline int
__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *))
{
if (likely(atomic_cmpxchg_acquire(count, 1, 0) == 1))
return 1;
return 0;
}
#endif