kernel: simplified fork_chain test

qa/kern/fork_chain.c

@@ -22,161 +22,72 @@ int r1;
 int r2;
 
 #define CHILD_READY(pid) ((long)rendezvous(&r1, (void*)(~(pid))))
-#define C2P_READY(pid) ((long)rendezvous(&r2, (void*)(~(pid))))
+//#define C2P_READY(pid) ((long)rendezvous(&r2, (void*)(~(pid))))
 
-int *__libposix_sigchld_target_pid;
+int *__target_pid;
-
-static void
-release_inherited_resources(void)
-{
-	notify(nil);
-	rfork(RFCNAMEG|RFCENVG|RFNOTEG|RFCFDG);
-	bind("#p", "/proc", MREPL);
-	rfork(RFNOMNT);
-}
 
 static void
 forwarding_note_handler(void *ureg, char *note)
 {
-	postnote(PNPROC, *__libposix_sigchld_target_pid, note);
+	postnote(PNPROC, *__target_pid, note);
-	noted(NCONT);
+	noted(NDFLT);
 }
 
 static void
-forward_wait_msg(int sigchld_receiver, char *name)
+donothing(void)
 {
-	int n;
+	int i = 0;
-	char buf[512], err[ERRMAX], note[512], *fld[5];
+	while(i < 100)
-
+		sleep(3000);
-	snprint(buf, sizeof(buf), "/proc/%d/args", getpid());
+	exits(nil);
-	n = open(buf, OWRITE);
-	write(n, name, strlen(name)+1);
-	close(n);
-
-	n = 0;
-WaitInterrupted:
-	n = await(buf, sizeof buf-1);
-	if(n < 0){
-		rerrstr(err, ERRMAX);
-		if(strstr(err, "no living children") == nil)
-			goto WaitInterrupted;
-		snprint(note, sizeof(note), "%s: %r", name);
-		if(sigchld_receiver)
-			postnote(PNPROC, sigchld_receiver, note);
-		exits(note);
-	}
-	buf[n] = '\0';
-	if(jehanne_tokenize(buf, fld, nelem(fld)) != nelem(fld)){
-		snprint(note, sizeof(note), "%s: couldn't parse wait message", name);
-		if(sigchld_receiver)
-			postnote(PNPROC, sigchld_receiver, note);
-		exits(note);
-	}
-	snprint(note, sizeof(note), "posix: 20");
-	if(sigchld_receiver){
-		postnote(PNPROC, sigchld_receiver, note);
-	}
-	exits(fld[4]);
 }
 
-
 static int
-fork_with_sigchld(void)
+crazy_fork(void)
 {
 	int father = getpid();
 	int p2c;
 	long c2p = -1, child = -1;
-	char proxy_name[256];
 
-	/* Father here:
-	 * - create P2C
-	 * - wait for C2P to be ready
-	 * - register P2C in children list
-	 * - return P2C pid
-	 */
 	switch(p2c = rfork(RFPROC|RFMEM)){
 	case -1:
 		return -1;
 	case 0:
-		/* P2C here:
-		 * - create C2P
-		 * - wait for the child pid
-		 * - release all inherited resources
-		 * - install forwarding_note_handler
-		 * - send to father the C2P pid
-		 * - start waiting for the child
-		 */
 		switch(c2p = rfork(RFPROC|RFMEM)){
 		case -1:
-			while(C2P_READY(-2) == -1)
-				;
 			exits("rfork (c2p)");
 		case 0:
-			/* C2P here:
-			 * - create child
-			 * - wait for it to get a copy of everything
-			 * - release all inherited resources
-			 * - install forwarding_note_handler
-			 * - send to P2C the child pid
-			 * - start forwarding notes to the father
-			 */
 			switch(child = fork()){
 			case -1:
-				while(CHILD_READY(-2) == -1)
-					;
 				exits("rfork (child)");
 			case 0:
-				/* Beloved child here
-				 */
-//				__libposix_setup_new_process();
 				return 0;
 			default:
-				release_inherited_resources();
-				*__libposix_sigchld_target_pid = father;
-				notify(forwarding_note_handler);
-				snprint(proxy_name, sizeof(proxy_name), "libposix signal proxy %d < %d", father, child);
 				while(CHILD_READY(child) == -1)
 					;
-				forward_wait_msg(father, proxy_name);
+				*__target_pid = father;
+				notify(forwarding_note_handler);
+				donothing();
 			}
 		default:
 			while((child = CHILD_READY(-3)) == -1)
 				;
 			child = ~child;
-			if(child < 0){
+			*__target_pid = child;
-				while(C2P_READY(-2) == -1)
-					;
-				waitpid();
-				exits("rfork (child)");
-			}
-			release_inherited_resources();
-			*__libposix_sigchld_target_pid = child;
 			notify(forwarding_note_handler);
-			snprint(proxy_name, sizeof(proxy_name), "libposix signal proxy %d > %d", father, child);
+			donothing();
-			while(C2P_READY(c2p) == -1)
-				;
-			forward_wait_msg(0, proxy_name);
 		}
 	default:
-		while((c2p = C2P_READY(-3)) == -1)
-			;
-		c2p = ~c2p;
-		if(c2p < 0){
-			waitpid();
-			return -1;
-		}
 		break;
 	}
 
-	print("f %d; p2c %d, c2p %d\n", father, p2c, c2p);
-
 	return p2c;
 }
 
 int
-passOnSIGCHLD(void *v, char *s)
+pass_on_die(void *v, char *s)
 {
-	if(strncmp(s, "posix: 20", 4) == 0){
+	if(strncmp(s, "die", 4) == 0){
 		print("PASS\n");
 		exits("PASS");
 	}
@@ -187,28 +98,31 @@ void
 main(void)
 {
 	int c, target_pid = 0;
-	__libposix_sigchld_target_pid = &target_pid;
+	__target_pid = &target_pid;
 	
-	if (!atnotify(passOnSIGCHLD, 1)){
+	if (!atnotify(pass_on_die, 1)){
 		fprint(2, "%r\n");
 		exits("atnotify fails");
 	}
 
-	c = fork_with_sigchld();
+	c = crazy_fork();
 	switch(c){
 	case -1:
 		print("FAIL: fork\n");
 		exits("FAIL");
 	case 0:
+		print("child is %d; child's parent is %d\n", getpid(), getppid());
+		*__target_pid = getppid();
+		notify(forwarding_note_handler);
 		/* wait to be killed */
-		print("child is %d\n", getpid());
+		donothing();
-//		for(;;);
-		sleep(30000);
 		break;
 	default:
-		print("father is %d\n", getpid());
+		print("father is %d; forked child is %d\n", getpid(), c);
+		sleep(1000); /* give children time to notify() */
+		print("starting note chain\n");
 		postnote(PNPROC, c, "die");
-		/* wait to be killed */
+		/* wait to be killed by the chain */
 		sleep(30000);
 	}
 	print("FAIL\n");