Better comments.

Alexander Korotkov · Alexander Korotkov · commit cd0546ff34ba · 2016-03-24T14:12:46.000+03:00
diff --git a/collector.c b/collector.c
@@ -298,6 +298,7 @@ collector_main(Datum main_arg)
 	alloc_history(&observations, collector_hdr->historySize);
 	MemoryContextSwitchTo(old_context);
 
+	/* Start counting time for history and profile samples */
 	profile_ts = history_ts = GetCurrentTimestamp();
 
 	while (1)
@@ -311,6 +312,7 @@ collector_main(Datum main_arg)
 		bool			write_history,
 						write_profile;
 
+		/* Wait calculate time to next sample for history or profile */
 		current_ts = GetCurrentTimestamp();
 
 		history_diff = millisecs_diff(history_ts, current_ts);
@@ -343,6 +345,10 @@ collector_main(Datum main_arg)
 		if (shutdown_requested)
 			break;
 
+		/*
+		 * Wait until next sample time or request to do something through
+		 * shared memory.
+		 */
 		rc = WaitLatch(&MyProc->procLatch, WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
 				Min(history_period - (int)history_diff,
 					profile_period - (int)profile_diff));
diff --git a/pg_wait_sampling.c b/pg_wait_sampling.c
@@ -290,6 +290,7 @@ pg_wait_sampling_get_current(PG_FUNCTION_ARGS)
 
 		item = &params->items[funcctx->call_cntr];
 
+		/* Make and return next tuple to caller */
 		MemSet(values, 0, sizeof(values));
 		MemSet(nulls, 0, sizeof(nulls));
 
@@ -439,7 +440,7 @@ pg_wait_sampling_get_profile(PG_FUNCTION_ARGS)
 		MemSet(values, 0, sizeof(values));
 		MemSet(nulls, 0, sizeof(nulls));
 
-		/* Values available to all callers */
+		/* Make and return next tuple to caller */
 		event_type = pgstat_get_wait_event_type(item->wait_event_info);
 		event = pgstat_get_wait_event(item->wait_event_info);
 		values[0] = Int32GetDatum(item->pid);
@@ -538,10 +539,10 @@ pg_wait_sampling_get_history(PG_FUNCTION_ARGS)
 
 		item = &history->items[history->index];
 
+		/* Make and return next tuple to caller */
 		MemSet(values, 0, sizeof(values));
 		MemSet(nulls, 0, sizeof(nulls));
 
-		/* Values available to all callers */
 		event_type = pgstat_get_wait_event_type(item->wait_event_info);
 		event = pgstat_get_wait_event(item->wait_event_info);
 		values[0] = Int32GetDatum(item->pid);
diff --git a/pg_wait_sampling.control b/pg_wait_sampling.control
@@ -1,5 +1,5 @@
 # pg_wait_sampling extension
-comment = 'track statistics of wait events using sampling'
+comment = 'sampling based statistics of wait events '
 default_version = '1.0'
 module_pathname = '$libdir/pg_wait_sampling'
 relocatable = true
