04-30-2007
thanks for your reply grumpf , I've wrote a header file that contains several function to handle data structure swapping, i used message passing (message queues) but the thing is that i had to send everything by value (my data structures are complex :each node contains a queue and are filled with pointers).
I was hoping to be able to find a solution similar to the threads where all the processes share all the variables...
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LEARN ABOUT FREEBSD
setrunqueue
RUNQUEUE(9) BSD Kernel Developer's Manual RUNQUEUE(9)
NAME
choosethread, procrunnable, remrunqueue, setrunqueue -- manage the queue of runnable processes
SYNOPSIS
#include <sys/param.h>
#include <sys/proc.h>
extern struct rq itqueues[];
extern struct rq rtqueues[];
extern struct rq queues[];
extern struct rq idqueues[];
struct thread *
choosethread(void);
int
procrunnable(void);
void
remrunqueue(struct thread *td);
void
setrunqueue(struct thread *td);
DESCRIPTION
The run queue consists of four priority queues: itqueues for interrupt threads, rtqueues for realtime priority processes, queues for time
sharing processes, and idqueues for idle priority processes. Each priority queue consists of an array of NQS queue header structures. Each
queue header identifies a list of runnable processes of equal priority. Each queue also has a single word that contains a bit mask identify-
ing non-empty queues to assist in selecting a process quickly. These are named itqueuebits, rtqueuebits, queuebits, and idqueuebits. The
run queues are protected by the sched_lock mutex.
procrunnable() returns zero if there are no runnable processes other than the idle process. If there is at least one runnable process other
than the idle process, it will return a non-zero value. Note that the sched_lock mutex does not need to be held when this function is
called. There is a small race window where one CPU may place a process on the run queue when there are currently no other runnable processes
while another CPU is calling this function. In that case the second CPU will simply travel through the idle loop one additional time before
noticing that there is a runnable process. This works because idle CPUs are not halted in SMP systems. If idle CPUs are halted in SMP sys-
tems, then this race condition might have more serious repercussions in the losing case, and procrunnable() may have to require that the
sched_lock mutex be acquired.
choosethread() returns the highest priority runnable thread. If there are no runnable threads, then the idle thread is returned. This func-
tion is called by cpu_switch() and cpu_throw() to determine which thread to switch to. choosethread() must be called with the sched_lock
mutex held.
setrunqueue() adds the thread td to the tail of the appropriate queue in the proper priority queue. The thread must be runnable, i.e. p_stat
must be set to SRUN. This function must be called with the sched_lock mutex held.
remrunqueue() removes thread td from its run queue. If td is not on a run queue, then the kernel will panic(9). This function must be
called with the sched_lock mutex held.
SEE ALSO
cpu_switch(9), scheduler(9), sleepqueue(9)
BSD
August 15, 2010 BSD