[SYSV_IPC] (main): Make a separate process

so we can listen for multiple requests.

1 files changed, 40 insertions, 9 deletions

diff --git a/lib-src/emacsserver.c b/lib-src/emacsserver.c
index fe95381c8f9..ed3493b76ce 100644
--- 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);
         }
     }
 }