MINOR: config: use a standard parser for the "nbthread" keyword

Probably because of some copy-paste from "nbproc", "nbthread" used to
be parsed in cfgparse instead of using a registered parser. Let's fix
this to clean up the code base now.

src/cfgparse-global.c

@@ -38,7 +38,7 @@ static const char *common_kw_list[] = {
 	"tune.sndbuf.client", "tune.sndbuf.server", "tune.pipesize",
 	"tune.http.cookielen", "tune.http.logurilen", "tune.http.maxhdr",
 	"tune.comp.maxlevel", "tune.pattern.cache-size", "uid", "gid",
-	"external-check", "user", "group", "nbproc", "nbthread", "maxconn",
+	"external-check", "user", "group", "nbproc", "maxconn",
 	"ssl-server-verify", "maxconnrate", "maxsessrate", "maxsslrate",
 	"maxcomprate", "maxpipes", "maxzlibmem", "maxcompcpuusage", "ulimit-n",
 	"chroot", "description", "node", "pidfile", "unix-bind", "log",
@@ -576,27 +576,6 @@ int cfg_parse_global(const char *file, int linenum, char **args, int kwm)
 		err_code |= ERR_ALERT | ERR_FATAL;
 		goto out;
 	}
-	else if (strcmp(args[0], "nbthread") == 0) {
-		if (alertif_too_many_args(1, file, linenum, args, &err_code))
-			goto out;
-		if (*(args[1]) == 0) {
-			ha_alert("parsing [%s:%d] : '%s' expects an integer argument.\n", file, linenum, args[0]);
-			err_code |= ERR_ALERT | ERR_FATAL;
-			goto out;
-		}
-
-		HA_DIAG_WARNING_COND(global.nbthread,
-		                     "parsing [%s:%d] : nbthread is already defined and will be overridden.\n",
-		                     file, linenum);
-
-		global.nbthread = parse_nbthread(args[1], &errmsg);
-		if (!global.nbthread) {
-			ha_alert("parsing [%s:%d] : '%s' %s.\n",
-				 file, linenum, args[0], errmsg);
-			err_code |= ERR_ALERT | ERR_FATAL;
-			goto out;
-		}
-	}
 	else if (strcmp(args[0], "maxconn") == 0) {
 		if (alertif_too_many_args(1, file, linenum, args, &err_code))
 			goto out;

src/thread.c

@@ -301,33 +301,51 @@ REGISTER_BUILD_OPTS("Built without multi-threading support (USE_THREAD not set).
 #endif // USE_THREAD
 
 
-/* Parse the number of threads in argument <arg>, returns it and adjusts a few
+/* Parse the "nbthread" global directive, which takes an integer argument that
- * internal variables accordingly, or fails and returns zero with an error
+ * contains the desired number of threads.
- * reason in <errmsg>. May be called multiple times while parsing.
  */
-int parse_nbthread(const char *arg, char **err)
+static int cfg_parse_nbthread(char **args, int section_type, struct proxy *curpx,
+                              const struct proxy *defpx, const char *file, int line,
+                              char **err)
 {
 	long nbthread;
 	char *errptr;
 
-	nbthread = strtol(arg, &errptr, 10);
+	if (too_many_args(1, args, err, NULL))
-	if (!*arg || *errptr) {
+		return -1;
-		memprintf(err, "passed a missing or unparsable integer value in '%s'", arg);
+
-		return 0;
+	nbthread = strtol(args[1], &errptr, 10);
+	if (!*args[1] || *errptr) {
+		memprintf(err, "'%s' passed a missing or unparsable integer value in '%s'", args[0], args[1]);
+		return -1;
 	}
 
 #ifndef USE_THREAD
 	if (nbthread != 1) {
-		memprintf(err, "specified with a value other than 1 while HAProxy is not compiled with threads support. Please check build options for USE_THREAD");
+		memprintf(err, "'%s' specified with a value other than 1 while HAProxy is not compiled with threads support. Please check build options for USE_THREAD", args[0]);
-		return 0;
+		return -1;
 	}
 #else
 	if (nbthread < 1 || nbthread > MAX_THREADS) {
-		memprintf(err, "value must be between 1 and %d (was %ld)", MAX_THREADS, nbthread);
+		memprintf(err, "'%s' value must be between 1 and %d (was %ld)", args[0], MAX_THREADS, nbthread);
-		return 0;
+		return -1;
 	}
 
 	all_threads_mask = nbits(nbthread);
 #endif
-	return nbthread;
+
+	HA_DIAG_WARNING_COND(global.nbthread,
+	                     "parsing [%s:%d] : nbthread is already defined and will be overridden.\n",
+	                     file, line);
+
+	global.nbthread = nbthread;
+	return 0;
 }
+
+/* config keyword parsers */
+static struct cfg_kw_list cfg_kws = {ILH, {
+	{ CFG_GLOBAL, "nbthread",       cfg_parse_nbthread, 0 },
+	{ 0, NULL, NULL }
+}};
+
+INITCALL1(STG_REGISTER, cfg_register_keywords, &cfg_kws);