counterdata & uplink: add and fix comments. Remove unused

signal handler from uplink thread.

src/counterdata.c

@@ -39,6 +39,10 @@ struct cdata_t {
 struct cdata_t *counterdata = NULL;
 pthread_mutex_t counterdata_mt = PTHREAD_MUTEX_INITIALIZER;
 
+/*
+ *	allocation and freeing of cdata structures
+ */
+
 struct cdata_t *cdata_alloc(const char *name)
 {
 	int e;
@@ -83,6 +87,10 @@ void cdata_free(struct cdata_t *cd)
 	hfree(cd);
 }
 
+/*
+ *	Find a cdata element by name and lock it for use
+ */
+
 static struct cdata_t *cdata_find_and_lock(const char *name)
 {
 	struct cdata_t *cd = NULL;
@@ -110,6 +118,10 @@ static struct cdata_t *cdata_find_and_lock(const char *name)
 	return cd;
 }
 
+/*
+ *	Add a new data sample to a counter-watching cdata
+ */
+
 void cdata_counter_sample(struct cdata_t *cd, long long value)
 {
 	int e;
@@ -146,6 +158,10 @@ void cdata_counter_sample(struct cdata_t *cd, long long value)
 	}
 }
 
+/*
+ *	Add a new sample to a gauge-watching cdata
+ */
+
 void cdata_gauge_sample(struct cdata_t *cd, long long value)
 {
 	int e;
@@ -171,6 +187,10 @@ void cdata_gauge_sample(struct cdata_t *cd, long long value)
 	}
 }
 
+/*
+ *	Get the last calculated value of a cdata
+ */
+
 long cdata_get_last_value(const char *name)
 {
 	int e;
@@ -196,6 +216,13 @@ long cdata_get_last_value(const char *name)
 	return v;
 }
 
+/*
+ *	Return a JSON string containing the contents of a cdata array.
+ *	Allocated on the heap, needs to be freed by the caller.
+ *	This is called by the http service to provide graph data for the
+ *	web UI.
+ */
+
 char *cdata_json_string(const char *name)
 {
 	struct cdata_t *cd;

src/uplink.c

@@ -10,7 +10,8 @@
  */
 
 /*
- *	uplink.c: processes uplink data within the worker thread
+ *	uplink thread: create uplink connections as necessary
+ *	(and tear them down)
  */
 
 #include <string.h>
@@ -57,24 +58,6 @@ struct portaccount_t uplink_connects = {
   .refcount = 99,	/* Global static blocks have extra-high initial refcount */
 };
 
-
-/*
- *	signal handler
- */
- 
-int uplink_sighandler(int signum)
-{
-	switch (signum) {
-		
-	default:
-		hlog(LOG_WARNING, "* SIG %d ignored", signum);
-		break;
-	}
-	
-	signal(signum, (void *)uplink_sighandler);	/* restore handler */
-	return 0;
-}
-
 /*
  *	Close uplinking sockets
  */
@@ -105,6 +88,10 @@ void close_uplinkers(void)
 	return;
 }
 
+/*
+ *	Log and handle the closing of an uplink.
+ */
+
 void uplink_close(struct client_t *c, int errnum)
 {
 	int rc;