[SYSV_IPC] (main): Make a separate process

so we can listen for multiple requests.

diff --git a/lib-src/emacsserver.c b/lib-src/emacsserver.c
index fe95381c8f94a718e4315459b6e0a5afbcaaf39d..ed3493b76cee3b76f8cd36d93cfbf3392a5ac9d3 100644 (file)
--- a/lib-src/emacsserver.c
+++ b/lib-src/emacsserver.c
@@ -245,7 +245,7 @@ msgcatch ()
 
 main ()
 {
-  int s, infd, fromlen;
+  int s, infd, fromlen, ioproc;
   key_t key;
   struct msgbuf * msgp =
     (struct msgbuf *) malloc (sizeof *msgp + BUFSIZ);
@@ -302,7 +302,25 @@ main ()
        }
     }
 
-  /* This is executed in the child made by forking above.  */
+  /* This is executed in the child made by forking above.
+     Call it c1.  Make another process, ioproc.  */
+
+  ioproc = fork ();
+  if (ioproc == 0)
+    {
+      /* In process ioproc, wait for text from Emacs,
+        and send it to the process c1.
+        This way, c1 only has to wait for one source of input.  */
+      while (fgets (msgp->mtext, BUFSIZ, stdin))
+       {
+         msgp->mtype = 1;
+         msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
+       }
+      exit (1);
+    }
+
+  /* In the process c1,
+     listen for messages from clients and pass them to Emacs.  */
   while (1)
     {
       if ((fromlen = msgrcv (s, msgp, BUFSIZ - 1, 1, 0)) < 0)
@@ -313,17 +331,30 @@ main ()
       else
         {
          msgctl (s, IPC_STAT, &msg_st);
+
+         /* Distinguish whether the message came from a client, or from
+            ioproc.  */
+         if (msg_st.msg_lspid == ioproc)
+           {
+             char code[BUFSIZ];
+             int inproc;
+
+             /* Message from ioproc: tell a client we are done.  */
+             msgp->mtext[strlen (msgp->mtext)-1] = 0;
+             sscanf (msgp->mtext, "%s %d", code, &inproc);
+             msgp->mtype = inproc;
+             msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
+             continue;
+           }
+
+         /* This is a request from a client: copy to stdout
+            so that Emacs will get it.  Include msg_lspid
+            so server.el can tell us where to send the reply.  */
          strncpy (string, msgp->mtext, fromlen);
          string[fromlen] = 0;  /* make sure */
          /* Newline is part of string.. */
-         printf ("Client: %d %s", s, string); 
+         printf ("Client: %d %s", msg_st.msg_lspid, string);
          fflush (stdout);
-         /* Now, wait for a wakeup */
-         fgets (msgp->mtext, BUFSIZ, stdin);
-         msgp->mtext[strlen (msgp->mtext)-1] = 0;
-         /*      strcpy (msgp->mtext, "done");*/
-         msgp->mtype = msg_st.msg_lspid;
-         msgsnd (s, msgp, strlen (msgp->mtext)+1, 0);
        }
     }
 }