From 3bb87227ec440222ff3af536dd76ed392555de9c Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Mon, 19 Oct 2015 13:32:02 -0700
Subject: [PATCH] Locking for map center

---
 tile.cc | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tile.cc b/tile.cc
index 78c5666..58d3e3e 100644
--- a/tile.cc
+++ b/tile.cc
@@ -891,11 +891,21 @@ void *run_thread(void *vargs) {
 				// return z - 1;
 			}
 
+			if (pthread_mutex_lock(&db_lock) != 0) {
+				perror("pthread_mutex_lock");
+				exit(EXIT_FAILURE);
+			}
+
 			if (z == arg->maxzoom && len > *arg->most) {
 				*arg->midx = x;
 				*arg->midy = y;
 				*arg->most = len;
 			}
+
+			if (pthread_mutex_unlock(&db_lock) != 0) {
+				perror("pthread_mutex_unlock");
+				exit(EXIT_FAILURE);
+			}
 		}
 
 		if (munmap(geomstart, arg->geom_size[j]) != 0) {
@@ -1010,9 +1020,9 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			args[thread].stringpool = stringpool;
 			args[thread].min_detail = min_detail;
 			args[thread].basezoom = maxzoom; // XXX rename?
-			args[thread].file_keys = file_keys; // XXX locking
+			args[thread].file_keys = file_keys; // locked with var_lock
 			args[thread].layernames = layernames;
-			args[thread].outdb = outdb; // XXX locking
+			args[thread].outdb = outdb; // locked with db_lock
 			args[thread].droprate = droprate;
 			args[thread].buffer = buffer;
 			args[thread].fname = fname;
@@ -1029,13 +1039,13 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 
 			args[thread].geomfd = geomfd;
 			args[thread].geom_size = geom_size;
-			args[thread].midx = midx; // XXX locking
-			args[thread].midy = midy; // XXX locking
+			args[thread].midx = midx; // locked with var_lock
+			args[thread].midy = midy; // locked with var_lock
 			args[thread].maxzoom = maxzoom;
 			args[thread].minzoom = minzoom;
 			args[thread].full_detail = full_detail;
 			args[thread].low_detail = low_detail;
-			args[thread].most = &most; // XXX locking
+			args[thread].most = &most; // locked with var_lock
 
 			args[thread].tasks = dispatches[thread].tasks;