87 lines
2.9 KiB
C
87 lines
2.9 KiB
C
/* A dummy task. Used to safely remove old tasks, and get notices if they get
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* called by accident (i.e., because of some bug...).
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*
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* Created:
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* Jul 27, 2004 by Jorrit N. Herder
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*/
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#include "kernel.h"
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#include "proc.h"
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#include <minix/com.h>
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/* Allocated space for the global variables. */
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message m_in; /* the input message itself */
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message m_out; /* the output message used for reply */
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int who; /* caller's proc number */
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int callnr; /* system call number */
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/* Declare some local functions. */
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FORWARD _PROTOTYPE(void get_work, (void) );
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FORWARD _PROTOTYPE(void reply, (int whom, int result) );
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/*===========================================================================*
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* dummy_task *
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*===========================================================================*/
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PUBLIC void dummy_task()
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{
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/* This is the main routine of this service. In principle this should block
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* forever on getting new work - the dummy task is not supposed to be called.
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* If new work is received, somehow, diagnostics are printed.
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*/
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int result;
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/* kprintf("DUMMY: do nothing kernel task started (proc. nr %d).\n",
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proc_number(proc_ptr)); */
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/* Main loop - get work and do it, forever. */
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while (TRUE) {
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/* Wait for incoming message, sets 'callnr' and 'who'. */
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get_work();
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/* There is work to do! (re)set some variables first. */
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result = EINVAL; /* illegal send to dummy task */
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/* Print diagnostics: this was not supposed to happen. */
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kprintf("Dummy task: request received from %d.\n", who);
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/* Finally send reply message, unless disabled. */
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if (result != EDONTREPLY) {
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reply(who, result);
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}
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}
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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PRIVATE void get_work()
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{
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int status = 0;
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status = receive(ANY, &m_in); /* this blocks until message arrives */
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if (OK != status)
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kprintf("Dummy task failed to receive message: %d", status);
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who = m_in.m_source; /* message arrived! set sender */
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callnr = m_in.m_type; /* set function call number */
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PRIVATE void reply(who, result)
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int who; /* destination */
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int result; /* report result to replyee */
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{
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int send_status;
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m_out.m_type = result; /* build reply message */
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send_status = send(who, &m_out); /* send the message */
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if (OK != send_status)
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kprintf("Dummy task unable to send reply: %d", send_status);
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}
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