Avoid infinite loops in caching layer

[ps-cgit] / cgit.c

diff --git a/cgit.c b/cgit.c
index 110facec5867ad0912da6b41c24758a6c3f798cf..dc911257afdbc3350e69f124f2b725b656e912d3 100644 (file)
--- a/cgit.c
+++ b/cgit.c
@@ -31,6 +31,7 @@ char *cgit_virtual_root = NULL;
 
 char *cgit_cache_root   = "/var/cache/cgit";
 
+int cgit_max_lock_attempts     =  5;
 int cgit_cache_root_ttl        =  5;
 int cgit_cache_repo_ttl        =  5;
 int cgit_cache_dynamic_ttl     =  5;
@@ -465,20 +466,26 @@ static void cgit_fill_cache(struct cacheitem *item)
 
 static void cgit_refresh_cache(struct cacheitem *item)
 {
+       int i = 0;
+
+       cache_prepare(item);
  top:
-       if (!cache_lookup(item)) {
-               if (cache_lock(item)) {
-                       cgit_fill_cache(item);
-                       cache_unlock(item);
-               } else {
-                       sched_yield();
+       if (++i > cgit_max_lock_attempts) {
+               die("cgit_refresh_cache: unable to lock %s: %s",
+                   item->name, strerror(errno));
+       }
+       if (!cache_exist(item)) {
+               if (!cache_lock(item)) {
+                       sleep(1);
                        goto top;
                }
-       } else if (cache_expired(item)) {
-               if (cache_lock(item)) {
+               if (!cache_exist(item))
                        cgit_fill_cache(item);
-                       cache_unlock(item);
-               }
+               cache_unlock(item);
+       } else if (cache_expired(item) && cache_lock(item)) {
+               if (cache_expired(item))
+                       cgit_fill_cache(item);
+               cache_unlock(item);
        }
 }