Cache: proxy_cache_lock_age and friends.

Once this age is reached, the cache lock is discarded and another
request can acquire the lock.  Requests which failed to acquire
the lock are not allowed to cache the response.

1 files changed, 22 insertions, 9 deletions

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index e7072e10e..043bf5ed5 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -396,13 +396,19 @@ ngx_http_file_cache_lock(ngx_http_request_t *r, ngx_http_cache_t *c)
         return NGX_DECLINED;
     }
 
+    now = ngx_current_msec;
+
     cache = c->file_cache;
 
     ngx_shmtx_lock(&cache->shpool->mutex);
 
-    if (!c->node->updating) {
+    timer = c->node->lock_time - now;
+
+    if (!c->node->updating || (ngx_msec_int_t) timer <= 0) {
         c->node->updating = 1;
+        c->node->lock_time = now + c->lock_age;
         c->updating = 1;
+        c->lock_time = c->node->lock_time;
     }
 
     ngx_shmtx_unlock(&cache->shpool->mutex);
@@ -415,9 +421,11 @@ ngx_http_file_cache_lock(ngx_http_request_t *r, ngx_http_cache_t *c)
         return NGX_DECLINED;
     }
 
-    c->waiting = 1;
+    if (c->lock_timeout == 0) {
+        return NGX_HTTP_CACHE_SCARCE;
+    }
 
-    now = ngx_current_msec;
+    c->waiting = 1;
 
     if (c->wait_time == 0) {
         c->wait_time = now + c->lock_timeout;
@@ -441,7 +449,7 @@ static void
 ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev)
 {
     ngx_uint_t                 wait;
-    ngx_msec_t                 timer;
+    ngx_msec_t                 now, timer;
     ngx_http_cache_t          *c;
     ngx_http_request_t        *r;
     ngx_http_file_cache_t     *cache;
@@ -449,15 +457,17 @@ ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev)
     r = ev->data;
     c = r->cache;
 
+    now = ngx_current_msec;
+
     ngx_log_debug2(NGX_LOG_DEBUG_HTTP, ev->log, 0,
                    "http file cache wait handler wt:%M cur:%M",
-                   c->wait_time, ngx_current_msec);
+                   c->wait_time, now);
 
-    timer = c->wait_time - ngx_current_msec;
+    timer = c->wait_time - now;
 
     if ((ngx_msec_int_t) timer <= 0) {
         ngx_log_error(NGX_LOG_INFO, ev->log, 0, "cache lock timeout");
-        c->lock = 0;
+        c->lock_timeout = 0;
         goto wakeup;
     }
 
@@ -466,7 +476,9 @@ ngx_http_file_cache_lock_wait_handler(ngx_event_t *ev)
 
     ngx_shmtx_lock(&cache->shpool->mutex);
 
-    if (c->node->updating) {
+    timer = c->node->lock_time - now;
+
+    if (c->node->updating && (ngx_msec_int_t) timer > 0) {
         wait = 1;
     }
 
@@ -588,6 +600,7 @@ ngx_http_file_cache_read(ngx_http_request_t *r, ngx_http_cache_t *c)
         } else {
             c->node->updating = 1;
             c->updating = 1;
+            c->lock_time = c->node->lock_time;
             rc = NGX_HTTP_CACHE_STALE;
         }
 
@@ -1453,7 +1466,7 @@ ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf)
     fcn = c->node;
     fcn->count--;
 
-    if (c->updating) {
+    if (c->updating && fcn->lock_time == c->lock_time) {
         fcn->updating = 0;
     }