Time and Timer Implementation
[Linux DDE Common]

This module emulates one-shot kernel timers inside the Linux kernel. More...

Linux Timer Handling
This is from kernel/timer.c
void	add_timer (struct timer_list *timer)
	Add One-Shot Timer.
int	mod_timer (struct timer_list *timer, unsigned long expires)
	Modify One-Shot Timer.
int	del_timer (struct timer_list *timer)
	Delete One-Shot Timer.
static int	__timer_sleep (l4_timeout_t to)
	Delete One-Shot Timer (SMP sync).
Functions
int	l4dde_time_init ()
	Initialize Timer Thread.

---

Detailed Description

This module emulates one-shot kernel timers inside the Linux kernel.

One-shot timers in Linux are executed as a bottom half (TIMER_BH). Therefore only other BHs are prohibited while a timer function is executed.

Requirements: (additionally to Global Requirements)

• jiffies and HZ have to be implemented as time base (perhaps using l4io)

---

Function Documentation

static int __timer_sleep

(

l4_timeout_t

to

)

[inline, static]

Delete One-Shot Timer (SMP sync).

Parameters:

timer

timer reference to be removed

Returns:

0 if timer is pending; 1 if deletion completed

Note:

In non-SMP Mode, del_timer_sync is a define to del_timer() Timer Synchronization Dummy

However, in non-SMP mode, it is an empty define Timer Sleep Implementation

Parameters:

to

IPC timeout

Returns:

1 on timed out IPC (0 = message received and indicates __restart)

Has to be called holding the timerlist lock.

Definition at line 270 of file time.c.

void add_timer

(

struct timer_list *

timer

)

Add One-Shot Timer.

Parameters:

timer

timer reference to be added

Definition at line 175 of file time.c.

int del_timer

(

struct timer_list *

timer

)

Delete One-Shot Timer.

Parameters:

timer

timer reference to be removed

Returns:

0 if timer is pending; 1 if deletion completed

Definition at line 215 of file time.c.

int l4dde_time_init

(

)

Initialize Timer Thread.

Returns:

0 on success; negative error code otherwise

One timer thread is created on initialization.

Definition at line 412 of file time.c.

int mod_timer	(	struct timer_list *	timer,
		unsigned long	expires
	)

Modify One-Shot Timer.

Parameters:

	timer	timer reference to be modified
	expires	new expiration time

Returns:

0 if timer is pending; 1 if modification was okay

Definition at line 196 of file time.c.