MEDIUM: startup: remove MODE_MWORKER_WAIT

MODE_MWORKER_WAIT becames redundant with MODE_MWORKER, due to moving
master-worker fork in init(). This change allows master no longer perform
reexec just after forking in order to free additional memory.

As after the fork in the master process we set 'master' variable, we can
replace now MODE_MWORKER_WAIT in some 'if' statements by simple check of this
'master' variable.

Let's also continue to get rid of HAPROXY_MWORKER_WAIT_ONLY environment
variable, as it's no longer needed as well.

In cfg_program_postparser(), which is used to check if cmdline is defined to
launch a program, we completely remove the check of mode for now, because
the master process does not parse the configuration for the moment. 'program'
section parsing will be reintroduced in master later in the next commits.

include/haproxy/global-t.h

@@ -35,7 +35,7 @@
 #define	MODE_STARTING	0x20
 #define	MODE_FOREGROUND	0x40
 #define	MODE_MWORKER	0x80    /* Master Worker */
-#define	MODE_MWORKER_WAIT	0x100    /* Master Worker wait mode */
+/* (1<<8) unused */
 #define	MODE_ZERO_WARNING       0x200    /* warnings cause a failure */
 #define	MODE_DIAG	0x400   /* extra warnings */
 #define	MODE_CHECK_CONDITION	0x800    /* -cc mode */

src/errors.c

@@ -129,8 +129,7 @@ void startup_logs_init_shm()
 	/* during startup, or just after a reload.
 	 * Note: the WAIT_ONLY env variable must be
 	 * check in case of an early call  */
-	if (!(global.mode & MODE_MWORKER_WAIT) &&
+	if (!(global.mode & MODE_MWORKER)) {
-	    getenv("HAPROXY_MWORKER_WAIT_ONLY") == NULL) {
 		if (fd != -1)
 			close(fd);
 

src/haproxy.c

@@ -776,35 +776,33 @@ static void mworker_reexec(int hardreload)
 
 	/* insert the new options just after argv[0] in case we have a -- */
 
-	if (getenv("HAPROXY_MWORKER_WAIT_ONLY") == NULL) {
+	/* add -sf <PID>*  to argv */
-		/* add -sf <PID>*  to argv */
+	if (mworker_child_nb() > 0) {
-		if (mworker_child_nb() > 0) {
+		struct mworker_proc *child;
-			struct mworker_proc *child;
 
-			if (hardreload)
+		if (hardreload)
-				next_argv[next_argc++] = "-st";
+			next_argv[next_argc++] = "-st";
-			else
+		else
-				next_argv[next_argc++] = "-sf";
+			next_argv[next_argc++] = "-sf";
 
-			list_for_each_entry(child, &proc_list, list) {
+		list_for_each_entry(child, &proc_list, list) {
-				if (!(child->options & PROC_O_LEAVING) && (child->options & PROC_O_TYPE_WORKER))
+			if (!(child->options & PROC_O_LEAVING) && (child->options & PROC_O_TYPE_WORKER))
-					current_child = child;
+				current_child = child;
 
-				if (!(child->options & (PROC_O_TYPE_WORKER|PROC_O_TYPE_PROG)) || child->pid <= -1)
+			if (!(child->options & (PROC_O_TYPE_WORKER|PROC_O_TYPE_PROG)) || child->pid <= -1)
-					continue;
+				continue;
-				if ((next_argv[next_argc++] = memprintf(&msg, "%d", child->pid)) == NULL)
+			if ((next_argv[next_argc++] = memprintf(&msg, "%d", child->pid)) == NULL)
-					goto alloc_error;
-				msg = NULL;
-			}
-		}
-		if (!x_off && current_child) {
-			/* add the -x option with the socketpair of the current worker */
-			next_argv[next_argc++] = "-x";
-			if ((next_argv[next_argc++] = memprintf(&msg, "sockpair@%d", current_child->ipc_fd[0])) == NULL)
 				goto alloc_error;
 			msg = NULL;
 		}
 	}
+	if (!x_off && current_child) {
+		/* add the -x option with the socketpair of the current worker */
+		next_argv[next_argc++] = "-x";
+		if ((next_argv[next_argc++] = memprintf(&msg, "sockpair@%d", current_child->ipc_fd[0])) == NULL)
+			goto alloc_error;
+		msg = NULL;
+	}
 
 	if (x_off) {
 		/* if the cmdline contained a -x /dev/null, continue to use it */
@@ -2028,12 +2026,6 @@ static void init(int argc, char **argv)
 				    | MODE_DIAG | MODE_CHECK_CONDITION | MODE_DUMP_LIBS | MODE_DUMP_KWD
 				    | MODE_DUMP_CFG | MODE_DUMP_NB_L));
 
-	if (getenv("HAPROXY_MWORKER_WAIT_ONLY")) {
-		unsetenv("HAPROXY_MWORKER_WAIT_ONLY");
-		global.mode |= MODE_MWORKER_WAIT;
-		global.mode &= ~MODE_MWORKER;
-	}
-
 	/* Do check_condition, if we started with -cc, and exit. */
 	if (global.mode & MODE_CHECK_CONDITION)
 		do_check_condition(progname);
@@ -2045,7 +2037,6 @@ static void init(int argc, char **argv)
 
 	usermsgs_clr("config");
 
-	/* in wait mode, we don't try to read the configuration files */
 	if (!(global.mode & MODE_MWORKER)) {
 		ret = read_cfg(progname);
 		/* free memory to store config file content */
@@ -2120,7 +2111,7 @@ static void init(int argc, char **argv)
 
 	/* open log & pid files before the chroot */
 	if ((global.mode & MODE_DAEMON || global.mode & MODE_MWORKER) &&
-	    !(global.mode & MODE_MWORKER_WAIT) && global.pidfile != NULL) {
+		global.pidfile != NULL) {
 		unlink(global.pidfile);
 		pidfd = open(global.pidfile, O_CREAT | O_WRONLY | O_TRUNC, 0644);
 		if (pidfd < 0) {
@@ -2174,7 +2165,6 @@ static void init(int argc, char **argv)
 			break;
 		default:
 			/* in parent */
-			global.mode |= MODE_MWORKER_WAIT;
 			master = 1;
 			atexit_flag = 1;
 			atexit(exit_on_failure);
@@ -3405,7 +3395,7 @@ int main(int argc, char **argv)
 	 * is started and run under the same non-root user, this allows
 	 * binding to privileged ports.
 	 */
-	if (!(global.mode & MODE_MWORKER))
+	if (!master)
 	    prepare_caps_from_permitted_set(geteuid(), global.uid, argv[0]);
 #endif
 
@@ -3414,7 +3404,7 @@ int main(int argc, char **argv)
 	 * and check mode
 	 */
 	if (old_unixsocket &&
-	    !(global.mode & (MODE_MWORKER_WAIT|MODE_CHECK|MODE_CHECK_CONDITION))) {
+	    !(global.mode & (MODE_MWORKER|MODE_CHECK|MODE_CHECK_CONDITION))) {
 		if (strcmp("/dev/null", old_unixsocket) != 0) {
 			if (sock_get_old_sockets(old_unixsocket) != 0) {
 				ha_alert("Failed to get the sockets from the old process!\n");
@@ -3464,7 +3454,7 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	if (!(global.mode & MODE_MWORKER_WAIT) && listeners == 0) {
+	if (!master && listeners == 0) {
 		ha_alert("[%s.main()] No enabled listener found (check for 'bind' directives) ! Exiting.\n", argv[0]);
 		/* Note: we don't have to send anything to the old pids because we
 		 * never stopped them. */
@@ -3496,11 +3486,14 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (nb_oldpids && !(global.mode & MODE_MWORKER_WAIT))
+	if (nb_oldpids && !master)
 		nb_oldpids = tell_old_pids(oldpids_sig);
 
-	/* send a SIGTERM to workers who have a too high reloads number  */
+	/* Send a SIGTERM to workers who have a too high reloads number.
-	if ((global.mode & MODE_MWORKER) && !(global.mode & MODE_MWORKER_WAIT))
+	 * master=1 means that fork() was done before. So, at this stage we already
+	 * have at least one new worker with reloads=0, which is bound to sockets.
+	 */
+	if (master)
 		mworker_kill_max_reloads(SIGTERM);
 
 	/* Note that any error at this stage will be fatal because we will not
@@ -3546,7 +3539,7 @@ int main(int argc, char **argv)
 	/* We won't ever use this anymore */
 	ha_free(&global.pidfile);
 
-	if (global.mode & MODE_MWORKER_WAIT) {
+	if (master) {
 		struct mworker_proc *child, *it;
 
 		if ((!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE)) &&

src/http_client.c

@@ -1202,7 +1202,7 @@ struct proxy *httpclient_create_proxy(const char *id)
 	struct server *srv_ssl = NULL;
 #endif
 
-	if (global.mode & MODE_MWORKER_WAIT)
+	if (global.mode & MODE_MWORKER)
 		return ERR_NONE;
 
 	px = alloc_new_proxy(id, PR_CAP_LISTEN|PR_CAP_INT|PR_CAP_HTTPCLIENT, &errmsg);
@@ -1359,7 +1359,7 @@ static int httpclient_postcheck_proxy(struct proxy *curproxy)
 	struct server *srv_ssl = NULL;
 #endif
 
-	if (global.mode & MODE_MWORKER_WAIT)
+	if (global.mode & MODE_MWORKER)
 		return ERR_NONE;
 
 	if (!(curproxy->cap & PR_CAP_HTTPCLIENT))

src/mworker-prog.c

@@ -115,7 +115,6 @@ int mworker_ext_launch_all()
 				/* This one must not be exported, it's internal! */
 				unsetenv("HAPROXY_MWORKER_REEXEC");
 				unsetenv("HAPROXY_STARTUPLOGS_FD");
-				unsetenv("HAPROXY_MWORKER_WAIT_ONLY");
 				unsetenv("HAPROXY_PROCESSES");
 				execvp(child->command[0], child->command);
 
@@ -332,11 +331,6 @@ int cfg_program_postparser()
 	int err_code = 0;
 	struct mworker_proc *child;
 
-	/* we only need to check this during configuration parsing,
-	 * wait mode doesn't have the complete description of a program */
-	if (global.mode & MODE_MWORKER_WAIT)
-		return err_code;
-
 	list_for_each_entry(child, &proc_list, list) {
 		if (child->reloads == 0 && (child->options & PROC_O_TYPE_PROG)) {
 			if (child->command == NULL) {

src/resolvers.c

@@ -3841,7 +3841,7 @@ int resolvers_create_default()
 {
 	int err_code = ERR_NONE;
 
-	if (global.mode & MODE_MWORKER_WAIT) /* does not create the section if in wait mode */
+	if (global.mode & MODE_MWORKER) /* does not create the section if in MODE_MWORKER */
 		return ERR_NONE;
 
 	/* if the section already exists, do nothing */