Rechercher une page de manuel
sleep_on
Langue: en
Version: $Date:$ (mandriva - 22/10/07)
Section: 9 (Appels noyau Linux)
NAME
sleep_on - synchronization using a condition variableSYNOPSIS
#include <linux/sched.h>- void sleep_on(struct wait_queue**condition)
DESCRIPTION
- The sleep_on function provides a means for synchronizing between processes and with interrupt handlers. The condition parameter is a pointer to a pointer to the opaque wait_queue type. Initialize the condition variable to zero, then pass a pointer to it to the sleep_on function. The basic idea is as follows:
struct wait_queue*con = 0;
[...]
sleep_on(&con);
While a process is sleeping, it is fully interruptible, no matter what the cpu state when entering the function. The cpu state is restored on being awakened.
If a null(0) is passed to sleep_on, it returns immediately, without sleeping. This is a no-op.
RETURN VALUE
The sleep_on function only returns when explicitly awakened.AVAILABILITY
Linux 1+SEE ALSO
wake_up(9)/usr/src/linux/kernel/sched.c
AUTHOR
Stephen Williams <steve@icarus.com>BUGS
A call to sleep_on(0) seems like an interesting way to test for and momentarily allow interrupts, but that is not what happens.The sleep_on function cannot be called by interrupt handlers.
The function is not atomic with the condition tests that the driver writer might include, so the code executing the sleep_on function is protected from interrupts. Failure to do so generally leads to race conditions.
Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre