From 98c1186cb8d4e8902c7d5156ac90f7ae9cd60670 Mon Sep 17 00:00:00 2001
From: Soner Tari <sonertari@gmail.com>
Date: Sun, 24 Mar 2019 01:31:19 +0300
Subject: [PATCH] Improve documentation, and simplify code

---
 pxythrmgr.c |  2 +-
 pxythrmgr.h | 20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/pxythrmgr.c b/pxythrmgr.c
index 8302622..c1fb7b6 100644
--- a/pxythrmgr.c
+++ b/pxythrmgr.c
@@ -275,7 +275,7 @@ pxy_thrmgr_timer_cb(UNUSED evutil_socket_t fd, UNUSED short what, UNUSED void *a
 	// @attention Print thread info only if stats logging is enabled, if disabled debug logs are not printed either
 	if (ctx->thrmgr->opts->statslog) {
 		ctx->timeout_count++;
-		if (ctx->timeout_count * ctx->thrmgr->opts->expired_conn_check_period >= ctx->thrmgr->opts->stats_period * ctx->thrmgr->opts->expired_conn_check_period) {
+		if (ctx->timeout_count >= ctx->thrmgr->opts->stats_period) {
 			ctx->timeout_count = 0;
 			pxy_thrmgr_print_thr_info(ctx);
 		}
diff --git a/pxythrmgr.h b/pxythrmgr.h
index 51bd37f..f3fa968 100644
--- a/pxythrmgr.h
+++ b/pxythrmgr.h
@@ -53,7 +53,12 @@ typedef struct pxy_thr_ctx {
 	struct event_base *evbase;
 	struct evdns_base *dnsbase;
 	int running;
-	unsigned int timeout_count;
+
+	// Per-thread locking is necessary during connection setup and termination
+	// to prevent multithreading issues between thrmgr thread and conn handling threads
+	pthread_mutex_t mutex;
+
+	// Statistics
 	evutil_socket_t max_fd;
 	size_t max_load;
 	size_t timedout_conns;
@@ -64,10 +69,19 @@ typedef struct pxy_thr_ctx {
 	long long unsigned int intif_out_bytes;
 	long long unsigned int extif_in_bytes;
 	long long unsigned int extif_out_bytes;
+	// Each stats has an id, incremented on each stats print
 	unsigned short stats_id;
+	// Used to print statistics, compared against stats_period
+	unsigned int timeout_count;
+
+	// List of active connections on the thread
 	pxy_conn_ctx_t *conns;
+
+	// Per-thread sqlite stmt is necessary to prevent multithreading issues between threads
 	struct sqlite3_stmt *get_user;
-	pthread_mutex_t mutex;
+
+	// SSL conns wait for the first readcb to complete connection setup
+	// We keep track of conns at that stage using this list, to close them if they time out
 	pxy_conn_ctx_t *pending_ssl_conns;
 	long long unsigned int pending_ssl_conn_count;
 } pxy_thr_ctx_t;
@@ -76,6 +90,8 @@ struct pxy_thrmgr_ctx {
 	int num_thr;
 	opts_t *opts;
 	pxy_thr_ctx_t **thr;
+	// Provides unique conn id, always goes up, never down
+	// There is no risk of collision if/when it rolls back to 0
 	long long unsigned int conn_count;
 };