From 5a882d775db34a277c793e81137db1d30d22603b Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Mon, 21 Apr 2003 06:26:08 +0000
Subject: [PATCH] Implement a two new flags, and change the meaning of another
 one. 'd': now means don't do daemon(). 'D': Debug 'n': Don't wait to process
 all pending events before calling daemon.

In the past, devd would call daemon immediately.  However, this causes
a race.  If anything in the boot process depends on configuring the
devices configured by devd, maybe they would be configured in time,
maybe not.  Now we don't call daemon until all pending events are
processed, unless -n is specified.

# -n is actually the default for a while due to the select(2) bug in devctl
# that I just fixed to give people a chance to upgrade.
---
 sbin/devd/devd.8  | 10 +++++++---
 sbin/devd/devd.cc | 49 ++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/sbin/devd/devd.8 b/sbin/devd/devd.8
index bcdc0944c67f..ebff8dd96190 100644
--- a/sbin/devd/devd.8
+++ b/sbin/devd/devd.8
@@ -33,7 +33,7 @@
 .Nd "device state change daemon"
 .Sh SYNOPSIS
 .Nm
-.Op Fl d
+.Op Fl Ddn
 .Sh DESCRIPTION
 The
 .Nm
@@ -42,9 +42,13 @@ kernel events happen.
 .Pp
 The following options are accepted.
 .Bl -tag -width indent
+.It Fl D
+Enable debugging messages.
 .It Fl d
-Enable debugging messages and run in the foreground instead of
-becoming a daemon.
+Run in the foreground instead of becoming a daemon.
+.It Fl n
+Don't process all pending events before becoming a daemon.
+Instaed, call daemon right away.
 .El
 .Sh IMPLEMENTATION NOTES
 The
diff --git a/sbin/devd/devd.cc b/sbin/devd/devd.cc
index bc598fe7ffcd..28e30e3f5f54 100644
--- a/sbin/devd/devd.cc
+++ b/sbin/devd/devd.cc
@@ -70,7 +70,9 @@ static const char nomatch = '?';
 static const char attach = '+';
 static const char detach = '-';
 
+int Dflag;
 int dflag;
+int nflag = 1;
 int romeo_must_die = 0;
 
 static void event_loop(void);
@@ -245,7 +247,7 @@ bool
 action::do_action(config &c)
 {
 	string s = c.expand_string(_cmd);
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Executing '%s'\n", s.c_str());
 	::system(s.c_str());
 	return (true);
@@ -272,7 +274,7 @@ match::do_match(config &c)
 	string value = c.get_variable(_var);
 	bool retval;
 
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Testing %s=%s against %s\n", _var.c_str(),
 		    value.c_str(), _re.c_str());
 
@@ -303,7 +305,7 @@ var_list::is_set(const string &var) const
 void
 var_list::set_variable(const string &var, const string &val)
 {
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "%s=%s\n", var.c_str(), val.c_str());
 	_vars[var] = val;
 }
@@ -321,7 +323,7 @@ config::reset(void)
 void
 config::parse_one_file(const char *fn)
 {
-	if (dflag)
+	if (Dflag)
 		printf("Parsing %s\n", fn);
 	yyin = fopen(fn, "r");
 	if (yyin == NULL)
@@ -338,7 +340,7 @@ config::parse_files_in_dir(const char *dirname)
 	struct dirent *dp;
 	char path[PATH_MAX];
 
-	if (dflag)
+	if (Dflag)
 		printf("Parsing files in %s\n", dirname);
 	dirp = opendir(dirname);
 	if (dirp == NULL)
@@ -435,7 +437,7 @@ config::push_var_table()
 	
 	vl = new var_list();
 	_var_list_table.push_back(vl);
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Pushing table\n");
 }
 
@@ -444,7 +446,7 @@ config::pop_var_table()
 {
 	delete _var_list_table.back();
 	_var_list_table.pop_back();
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Popping table\n");
 }
 
@@ -618,7 +620,7 @@ config::find_and_execute(char type)
 		s = "detach";
 		break;
 	}
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Processing %s event\n", s);
 	for (i = l->begin(); i != l->end(); i++) {
 		if ((*i)->matches(*this)) {
@@ -637,7 +639,7 @@ process_event(char *buffer)
 	char *sp;
 
 	sp = buffer + 1;
-	if (dflag)
+	if (Dflag)
 		fprintf(stderr, "Processing event '%s'\n", buffer);
 	type = *buffer++;
 	cfg.push_var_table();
@@ -674,6 +676,9 @@ event_loop(void)
 	int rv;
 	int fd;
 	char buffer[DEVCTL_MAXBUF];
+	int once = 0;
+	timeval tv;
+	fd_set fds;
 
 	fd = open(PATH_DEVCTL, O_RDONLY);
 	if (fd == -1)
@@ -683,6 +688,22 @@ event_loop(void)
 	while (1) {
 		if (romeo_must_die)
 			break;
+		if (!once && !dflag && !nflag) {
+			// Check to see if we have any events pending.
+			tv.tv_sec = 0;
+			tv.tv_usec = 0;
+			FD_ZERO(&fds);
+			FD_SET(fd, &fds);
+			rv = select(fd + 1, &fds, &fds, &fds, &tv);
+			// No events -> we've processed all pending events
+			fprintf(stderr, "Select returns %d\n", rv);
+			if (rv == 0) {
+				if (Dflag)
+					fprintf(stderr, "Calling daemon\n");
+				daemon(0, 0);
+				once++;
+			}
+		}
 		rv = read(fd, buffer, sizeof(buffer) - 1);
 		if (rv > 0) {
 			buffer[rv] = '\0';
@@ -810,18 +831,24 @@ main(int argc, char **argv)
 	int ch;
 
 	check_devd_enabled();
-	while ((ch = getopt(argc, argv, "d")) != -1) {
+	while ((ch = getopt(argc, argv, "Ddn")) != -1) {
 		switch (ch) {
+		case 'D':
+			Dflag++;
+			break;
 		case 'd':
 			dflag++;
 			break;
+		case 'n':
+			nflag++;
+			break;
 		default:
 			usage();
 		}
 	}
 
 	cfg.parse();
-	if (!dflag)
+	if (!dflag && nflag)
 		daemon(0, 0);
 	cfg.drop_pidfile();
 	signal(SIGHUP, gensighand);