Is this a bug or not?

Hello,

I don't know wether I suffer from a bug or ignorance.

Here is a striped dow version of my code which still hit my problem.

What do I expect it do do?
It shold start a thread as some kind of privat server. But this thread
is unable to do a msg_reply to the main thread.
As you can easy figure all goes well until I send the message OPCODE.
This gets received but the thread will hang in the msg_reply.
Why?

/*
 * main.c
 * Main handling loop and startup
 */
#include <sys/namer.h>
#include <hash.h>
#include <stdio.h>
#include <sys/fs.h>
#include <fcntl.h>
#include <std.h>
#include <syslog.h>

#define OPCODE 500

static port_t theRootport; /* Port we receive contacts through */
static port_name theWorkPort;
static long theWorkThread;

/*
 * new_client
 * try to add a new client as supplied
 */
static void
new_client(struct msg *m)
{
  msg_accept(m->m_sender);
}

/*
 * dup_client
 */
static void
dup_client(struct msg *m)
{
  m->m_arg = m->m_arg1 = m->m_buflen = m->m_nseg = 0;
  msg_reply(m->m_sender, m);
}

/*
 * dead_client()
 * Someone has gone away. Free their info.
 */
static void
dead_client(struct msg *m)
{
}

/*
 * serve()
 * Endless loop to receive and serve requests
 */
static void
serve()
{
  int x;
  struct msg msg;

loop:
  /*
   * Receive a message, log an error and then keep going
   */

  x = msg_receive(theRootport, &msg);
  if (x < 0) {
    syslog(LOG_ERR, "msg_receive");
    goto loop;
  }

  /*
   * Categorize by basic message operation
   */

  /*
   * Catch odd cases
   */
printf("\nreceived msg %d from %d",msg.m_op,msg.m_sender);
  switch(msg.m_op) {
    case M_CONNECT: /* New client accept instead of reply */
      new_client(&msg);
      break;
    case M_DISCONNECT: /* Client done, don't reply*/
      dead_client(&msg);
      break;
    case M_DUP:
      dup_client(&msg);
      break;
    case OPCODE:
      msg.m_arg=msg.m_arg1=msg.m_nseg=0;
      msg_reply(msg.m_sender,&msg);
      printf("replied");
      break;
    default: /* regular functions */
      msg_err(msg.m_sender, EINVAL );
      break;
    }

  goto loop;
}

/*
 * work_init()
 *
 */
int work_init()
{
  /*
   * Last check is that we can register with the given name.
   */
  theRootport = msg_port((port_name)0, &theWorkPort);

  theWorkThread=tfork(serve);
  return 0;
}

/*
 *
 */
int work_op(port_t p)
{
  struct msg m;
  m.m_op=OPCODE;
  m.m_arg=m.m_arg1=m.m_nseg=0;
  m.m_buf=0;
  return msg_send(p,&m);
}

port_t work_new()
{
  return msg_connect(theWorkPort, ACC_WRITE );
}

void work_die()
{
  notify(0, theWorkThread, EKILL);
}

main()
{
  struct time t;
  port_t c1;

  work_init();
  c1=work_new();

printf("\ntry the work");
  work_op(c1);
printf("\ngot a reply");

  sleep(20);

  work_die();
  exit(0);
}

Thanx for any help
/Joerg

-----------------------------------------------------------------------------
Joerg Wittenberger | email: joerg.wittenberger@inf.tu-dresden.de
Rietzstr. 32b |
01139 Dresden |
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Received on Sat Jan 7 13:12:12 1995