From 8992e7bf2be04e829df494a424f1c86798cfdd4d Mon Sep 17 00:00:00 2001
From: Joachim Nilsson <troglobit@gmail.com>
Date: Fri, 22 Dec 2017 23:56:14 +0100
Subject: [PATCH] Refactor svc_iterator() into a proper iterator, add `first`
 flag

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
---
 plugins/pidfile.c |   4 +-
 src/api.c         |   5 +-
 src/cond-w.c      |   4 +-
 src/inetd.c       |   8 ++--
 src/service.c     |   8 ++--
 src/svc.c         | 119 +++++++++++++++++++++++++---------------------
 src/svc.h         |   8 ++--
 7 files changed, 83 insertions(+), 73 deletions(-)

diff --git a/plugins/pidfile.c b/plugins/pidfile.c
index 7c6827d3..2491d1f1 100644
--- a/plugins/pidfile.c
+++ b/plugins/pidfile.c
@@ -95,13 +95,13 @@ static void pidfile_callback(void *arg, int fd, int events)
 static void pidfile_reconf(void *arg)
 {
 	static char cond[MAX_COND_LEN];
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 	int restart = 0;
 
 	do {
 		restart = 0;
 
-		for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+		for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 			mkcond(cond, sizeof(cond), svc->cmd);
 			if (svc->state == SVC_RUNNING_STATE &&
 			    !svc_is_changed(svc) &&
diff --git a/src/api.c b/src/api.c
index 6d494d63..327dcde9 100644
--- a/src/api.c
+++ b/src/api.c
@@ -225,7 +225,8 @@ static void send_svc(int sd, svc_t *svc)
 static void api_cb(uev_t *w, void *arg, int events)
 {
 	int sd, lvl;
-	static svc_t *svc;
+	svc_t *svc;
+	static svc_t *iter = NULL;
 	struct init_request rq;
 
 	sd = accept(w->fd, NULL, NULL);
@@ -351,7 +352,7 @@ static void api_cb(uev_t *w, void *arg, int events)
 			 * simultaneous client connections, but will
 			 * have to do for now.
 			 */
-			svc = svc_iterator(rq.runlevel ? NULL : svc);
+			svc = svc_iterator(&iter, rq.runlevel);
 			send_svc(sd, svc);
 			goto leave;
 
diff --git a/src/cond-w.c b/src/cond-w.c
index 758de5a3..bb6033ab 100644
--- a/src/cond-w.c
+++ b/src/cond-w.c
@@ -88,10 +88,10 @@ static int svc_has_cond(svc_t *svc)
 
 static void cond_update(const char *name)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
 	_d("%s", name);
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!svc_has_cond(svc) || !cond_affects(name, svc->cond))
 			continue;
 
diff --git a/src/inetd.c b/src/inetd.c
index 00a6face..2b1d4364 100644
--- a/src/inetd.c
+++ b/src/inetd.c
@@ -225,10 +225,10 @@ static void socket_cb(uev_t *w, void *arg, int events)
  */
 int inetd_check_loop(struct sockaddr *sa, socklen_t len, char *name)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
         char pname[NI_MAXHOST];
 
-        for (svc = svc_inetd_iterator(NULL); svc; svc = svc_inetd_iterator(svc)) {
+        for (svc = svc_inetd_iterator(&iter, 1); svc; svc = svc_inetd_iterator(&iter, 0)) {
 		inetd_t *i = &svc->inetd;
 
                 if (!i->builtin || i->type != SOCK_DGRAM)
@@ -665,9 +665,9 @@ int inetd_filter_str(inetd_t *inetd, char *str, size_t len)
 
 svc_t *inetd_find_svc(char *path, char *service, char *proto)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_inetd_iterator(NULL); svc; svc = svc_inetd_iterator(svc)) {
+	for (svc = svc_inetd_iterator(&iter, 1); svc; svc = svc_inetd_iterator(&iter, 0)) {
 		if (strncmp(path, svc->cmd, strlen(svc->cmd)))
 			continue;
 
diff --git a/src/service.c b/src/service.c
index 16fe6b2e..74fb9410 100644
--- a/src/service.c
+++ b/src/service.c
@@ -1027,9 +1027,9 @@ void service_step_all(int types)
  */
 void service_runtask_clean(void)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!svc_is_runtask(svc))
 			continue;
 
@@ -1056,9 +1056,9 @@ void service_runtask_clean(void)
  */
 int service_runtask_completed(int skip)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!svc_is_runtask(svc))
 			continue;
 
diff --git a/src/svc.c b/src/svc.c
index b72f9754..d5c1a01d 100644
--- a/src/svc.c
+++ b/src/svc.c
@@ -51,10 +51,10 @@ svc_t *svc_new(char *cmd, int id, int type)
 {
 	int job = -1;
 	char *desc;
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
 	/* Find first job n:o if registering multiple instances */
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!strcmp(svc->cmd, cmd)) {
 			job = svc->job;
 			break;
@@ -103,36 +103,46 @@ int svc_del(svc_t *svc)
 
 /**
  * svc_iterator - Naive iterator over all registered services.
- * @iter: %NULL for first entry, use returned value for subsequent calls
+ * @iter:  Iterator, must be a valid pointer
+ * @first: If set, get first &svc_t, otherwise get next
  *
  * Returns:
- * The first &svc_t when %NULL is given as argument, otherwise the next
- * &svc_t until the end when %NULL is returned.
+ * An &svc_t pointer, or %NULL when no more entries can be found.
  */
-svc_t *svc_iterator(svc_t *iter)
+svc_t *svc_iterator(svc_t **iter, int first)
 {
-	if (!iter)
-		return TAILQ_FIRST(&svc_list);
+	svc_t *svc;
 
-	if (iter && iter != TAILQ_END(&svc_list))
-		return TAILQ_NEXT(iter, link);
-	
-	return NULL;
+	if (!iter) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	if (first)
+		svc = TAILQ_FIRST(&svc_list);
+	else
+		svc = *iter;
+
+	if (svc)
+		*iter = TAILQ_NEXT(svc, link);
+
+	return svc;
 }
 
 /**
  * svc_inetd_iterator - Naive iterator over all registered inetd services.
- * @iter: %NULL for first entry, use returned value for subsequent calls
+ * @iter:  Iterator, must be a valid pointer
+ * @first: If set, get first &svc_t, otherwise get next
  *
  * Returns:
  * The first inetd &svc_t when %NULL is given as argument, otherwise the
  * next inetd &svc_t until the end when %NULL is returned.
  */
-svc_t *svc_inetd_iterator(svc_t *iter)
+svc_t *svc_inetd_iterator(svc_t **iter, int first)
 {
 	svc_t *svc;
 
-	for (svc = svc_iterator(iter); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(iter, first); svc; svc = svc_iterator(iter, 0)) {
 		if (svc_is_inetd(svc))
 			return svc;
 	}
@@ -143,19 +153,20 @@ svc_t *svc_inetd_iterator(svc_t *iter)
 
 /**
  * svc_named_iterator - Iterates over all instances of a service.
- * @iter: %NULL for first entry, use returned value for subsequent calls
- * @cmd:  Service name to look for.
+ * @iter:  Iterator, must be a valid pointer
+ * @first: If set, get first &svc_t, otherwise get next
+ * @cmd:   Service name to look for.
  *
  * Returns:
  * The first matching &svc_t when %NULL is given as argument, otherwise
  * the next &svc_t with the same @cmd name until the end when %NULL is
  * returned.
  */
-svc_t *svc_named_iterator(svc_t *iter, char *cmd)
+svc_t *svc_named_iterator(svc_t **iter, int first, char *cmd)
 {
 	svc_t *svc;
 
-	for (svc = svc_iterator(iter); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(iter, first); svc; svc = svc_iterator(iter, 0)) {
 		char *name = basename(svc->cmd);
 
 		if (!strncmp(name, cmd, strlen(name)))
@@ -168,19 +179,20 @@ svc_t *svc_named_iterator(svc_t *iter, char *cmd)
 
 /**
  * svc_job_iterator - Iterates over all instances of a service.
- * @iter: %NULL for first entry, use returned value for subsequent calls
- * @job:  Job to look for.
+ * @iter:  Iterator, must be a valid pointer
+ * @first: If set, get first &svc_t, otherwise get next
+ * @job:   Job to look for.
  *
  * Returns:
  * The first matching &svc_t when %NULL is given as argument, otherwise
  * the next &svc_t with the same @job ID until the end when %NULL is
  * returned.
  */
-svc_t *svc_job_iterator(svc_t *iter, int job)
+svc_t *svc_job_iterator(svc_t **iter, int first, int job)
 {
 	svc_t *svc;
 
-	for (svc = svc_iterator(iter); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(iter, first); svc; svc = svc_iterator(iter, 0)) {
 		if (svc->job == job)
 			return svc;
 	}
@@ -195,12 +207,12 @@ svc_t *svc_job_iterator(svc_t *iter, int job)
  */
 void svc_foreach(void (*cb)(svc_t *))
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
 	if (!cb)
 		return;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc))
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0))
 		cb(svc);
 }
 
@@ -212,12 +224,12 @@ void svc_foreach(void (*cb)(svc_t *))
  */
 void svc_foreach_type(int types, void (*cb)(svc_t *))
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
 	if (!cb)
 		return;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!(svc->type & types))
 			continue;
 
@@ -235,9 +247,9 @@ void svc_foreach_type(int types, void (*cb)(svc_t *))
  */
 svc_t *svc_stop_completed(void)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (svc->state == SVC_STOPPING_STATE)
 			return svc;
 	}
@@ -254,9 +266,9 @@ svc_t *svc_stop_completed(void)
  */
 svc_t *svc_find(char *cmd, int id)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (svc->id == id && !strncmp(svc->cmd, cmd, strlen(svc->cmd)))
 			return svc;
 	}
@@ -273,9 +285,9 @@ svc_t *svc_find(char *cmd, int id)
  */
 svc_t *svc_find_by_pid(pid_t pid)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (svc->pid == pid)
 			return svc;
 	}
@@ -293,9 +305,9 @@ svc_t *svc_find_by_pid(pid_t pid)
  */
 svc_t *svc_find_by_jobid(int job, int id)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (svc->job == job && svc->id == id)
 			return svc;
 	}
@@ -314,9 +326,9 @@ svc_t *svc_find_by_jobid(int job, int id)
 svc_t *svc_find_by_nameid(char *name, int id)
 {
 	char *ptr;
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		ptr = strrchr(svc->cmd, '/');
 		if (ptr)
 			ptr++;
@@ -342,12 +354,10 @@ svc_t *svc_find_by_nameid(char *name, int id)
  */
 void svc_mark_dynamic(void)
 {
-	svc_t *svc = svc_iterator(NULL);
+	svc_t *svc, *iter = NULL;
 
-	while (svc) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0))
 		*((int *)&svc->dirty) = -1;
-		svc = svc_iterator(svc);
-	}
 }
 
 void svc_mark_dirty(svc_t *svc)
@@ -369,14 +379,13 @@ void svc_mark_clean(svc_t *svc)
  */
 void svc_clean_dynamic(void (*cb)(svc_t *))
 {
-	svc_t *svc = svc_iterator(NULL);
+	svc_t *svc, *iter = NULL;
 
-	while (svc) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (svc->dirty == -1 && cb) {
 			cb(svc);
 			svc_mark_clean(svc);
 		}
-		svc = svc_iterator(svc);
 	}
 }
 
@@ -407,9 +416,9 @@ int svc_clean_bootstrap(svc_t *svc)
  */
 void svc_prune_bootstrap(void)
 {
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!svc->pid)
 			svc_clean_bootstrap(svc);
 	}
@@ -442,9 +451,9 @@ int svc_enabled(svc_t *svc)
 int svc_next_id(char *cmd)
 {
 	int id = 0;
-	svc_t *svc;
+	svc_t *svc, *iter = NULL;
 
-	for (svc = svc_iterator(NULL); svc; svc = svc_iterator(svc)) {
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
 		if (!strcmp(svc->cmd, cmd) && id < svc->id)
 			id = svc->id;
 	}
@@ -454,10 +463,10 @@ int svc_next_id(char *cmd)
 
 int svc_is_unique(svc_t *svc)
 {
-	svc_t *s;
+	svc_t *s, *iter = NULL;
 	int unique = 1;
 
-	for (s = svc_iterator(NULL); s; s = svc_iterator(svc)) {
+	for (s = svc_iterator(&iter, 1); s; s = svc_iterator(&iter, 0)) {
 		if (svc->type == SVC_TYPE_FREE)
 			continue;
 
@@ -488,21 +497,21 @@ int svc_parse_jobstr(char *str, size_t len, int (*found)(svc_t *), int (not_foun
 	token = strtok_r(input, " ", &pos);
 	while (token) {
 		int id = 1;
-		svc_t *svc;
+		svc_t *svc, *iter = NULL;
 		char *ptr = strchr(token, ':');
 
 		if (isdigit(token[0])) {
 			int job = atonum(token);
 
 			if (!ptr) {
-				svc = svc_job_iterator(NULL, job);
+				svc = svc_job_iterator(&iter, 1, job);
 				if (!svc && not_found)
 					result += not_found(NULL, job);
 
 				while (svc) {
 					if (found)
 						result += found(svc);
-					svc = svc_job_iterator(svc, job);
+					svc = svc_job_iterator(&iter, 0, job);
 				}
 			} else {
 				*ptr++ = 0;
@@ -517,14 +526,14 @@ int svc_parse_jobstr(char *str, size_t len, int (*found)(svc_t *), int (not_foun
 			}
 		} else {
 			if (!ptr) {
-				svc = svc_named_iterator(NULL, token);
+				svc = svc_named_iterator(&iter, 1, token);
 				if (!svc && not_found)
 					result += not_found(token, id);
 
 				while (svc) {
 					if (found)
 						result += found(svc);
-					svc = svc_named_iterator(svc, token);
+					svc = svc_named_iterator(&iter, 0, token);
 				}
 			} else {
 				*ptr++ = 0;
diff --git a/src/svc.h b/src/svc.h
index d804e09b..6242b770 100644
--- a/src/svc.h
+++ b/src/svc.h
@@ -135,10 +135,10 @@ svc_t	   *svc_find_by_pid        (pid_t pid);
 svc_t	   *svc_find_by_jobid      (int job, int id);
 svc_t	   *svc_find_by_nameid     (char *name, int id);
 
-svc_t	   *svc_iterator	   (svc_t *iter);
-svc_t	   *svc_inetd_iterator     (svc_t *iter);
-svc_t	   *svc_named_iterator     (svc_t *iter, char *cmd);
-svc_t      *svc_job_iterator       (svc_t *iter, int job);
+svc_t      *svc_iterator           (svc_t **iter, int first);
+svc_t      *svc_inetd_iterator     (svc_t **iter, int first);
+svc_t      *svc_named_iterator     (svc_t **iter, int first, char *cmd);
+svc_t      *svc_job_iterator       (svc_t **iter, int first, int job);
 
 void	    svc_foreach	           (void (*cb)(svc_t *));
 void        svc_foreach_type       (int types, void (*cb)(svc_t *));