minix3/servers/pm/utility.c

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2020-02-21 00:59:27 +05:30
/* This file contains some utility routines for PM.
*
* The entry points are:
* get_free_pid: get a free process or group id
* find_param: look up a boot monitor parameter
* find_proc: return process pointer from pid number
* nice_to_priority convert nice level to priority queue
* pm_isokendpt: check the validity of an endpoint
* tell_vfs: send a request to VFS on behalf of a process
*/
#include "pm.h"
#include <sys/resource.h>
#include <sys/stat.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/endpoint.h>
#include <fcntl.h>
#include <signal.h> /* needed only because mproc.h needs it */
#include "mproc.h"
#include <minix/config.h>
#include <minix/timers.h>
#include <machine/archtypes.h>
#include "kernel/const.h"
#include "kernel/config.h"
#include "kernel/type.h"
#include "kernel/proc.h"
/*===========================================================================*
* get_free_pid *
*===========================================================================*/
pid_t get_free_pid()
{
static pid_t next_pid = INIT_PID + 1; /* next pid to be assigned */
register struct mproc *rmp; /* check process table */
int t; /* zero if pid still free */
/* Find a free pid for the child and put it in the table. */
do {
t = 0;
next_pid = (next_pid < NR_PIDS ? next_pid + 1 : INIT_PID + 1);
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++)
if (rmp->mp_pid == next_pid || rmp->mp_procgrp == next_pid) {
t = 1;
break;
}
} while (t); /* 't' = 0 means pid free */
return(next_pid);
}
/*===========================================================================*
* find_param *
*===========================================================================*/
char *find_param(name)
const char *name;
{
register const char *namep;
register char *envp;
for (envp = (char *) monitor_params; *envp != 0;) {
for (namep = name; *namep != 0 && *namep == *envp; namep++, envp++)
;
if (*namep == '\0' && *envp == '=')
return(envp + 1);
while (*envp++ != 0)
;
}
return(NULL);
}
/*===========================================================================*
* find_proc *
*===========================================================================*/
struct mproc *find_proc(lpid)
pid_t lpid;
{
register struct mproc *rmp;
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++)
if ((rmp->mp_flags & IN_USE) && rmp->mp_pid == lpid)
return(rmp);
return(NULL);
}
/*===========================================================================*
* nice_to_priority *
*===========================================================================*/
int nice_to_priority(int nice, unsigned* new_q)
{
if (nice < PRIO_MIN || nice > PRIO_MAX) return(EINVAL);
*new_q = MAX_USER_Q + (nice-PRIO_MIN) * (MIN_USER_Q-MAX_USER_Q+1) /
(PRIO_MAX-PRIO_MIN+1);
/* Neither of these should ever happen. */
if ((signed) *new_q < MAX_USER_Q) *new_q = MAX_USER_Q;
if (*new_q > MIN_USER_Q) *new_q = MIN_USER_Q;
return (OK);
}
/*===========================================================================*
* pm_isokendpt *
*===========================================================================*/
int pm_isokendpt(int endpoint, int *proc)
{
*proc = _ENDPOINT_P(endpoint);
if (*proc < 0 || *proc >= NR_PROCS)
return EINVAL;
if (endpoint != mproc[*proc].mp_endpoint)
return EDEADEPT;
if (!(mproc[*proc].mp_flags & IN_USE))
return EDEADEPT;
return OK;
}
/*===========================================================================*
* tell_vfs *
*===========================================================================*/
void tell_vfs(rmp, m_ptr)
struct mproc *rmp;
message *m_ptr;
{
/* Send a request to VFS, without blocking.
*/
int r;
if (rmp->mp_flags & VFS_CALL)
panic("tell_vfs: not idle: %d", m_ptr->m_type);
r = asynsend3(VFS_PROC_NR, m_ptr, AMF_NOREPLY);
if (r != OK)
panic("unable to send to VFS: %d", r);
rmp->mp_flags |= VFS_CALL;
}