Happy new year
[pazpar2-moved-to-github.git] / src / connection.c
index fecf51b..e0b809d 100644 (file)
@@ -1,5 +1,5 @@
 /* This file is part of Pazpar2.
-   Copyright (C) 2006-2010 Index Data
+   Copyright (C) 2006-2011 Index Data
 
 Pazpar2 is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
@@ -47,6 +47,25 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "client.h"
 #include "settings.h"
 
+/* connection counting (1) , disable connection counting (0) */
+#if 0
+static YAZ_MUTEX g_mutex = 0;
+static int no_connections = 0;
+
+static void connection_use(int delta)
+{
+    if (!g_mutex)
+        yaz_mutex_create(&g_mutex);
+    yaz_mutex_enter(g_mutex);
+    no_connections += delta;
+    yaz_mutex_leave(g_mutex);
+    yaz_log(YLOG_LOG, "%s connections=%d", delta > 0 ? "INC" : "DEC",
+            no_connections);
+}
+#else
+#define connection_use(x)
+#endif
+
 
 /** \brief Represents a physical, reusable  connection to a remote Z39.50 host
  */
@@ -59,7 +78,8 @@ struct connection {
     enum {
         Conn_Resolving,
         Conn_Connecting,
-        Conn_Open
+        Conn_Open,
+        Conn_Dead
     } state;
     int operation_timeout;
     int session_timeout;
@@ -94,7 +114,6 @@ static void remove_connection_from_host(struct connection *con)
 {
     struct connection **conp = &con->host->connections;
     assert(con);
-    yaz_mutex_enter(con->host->mutex);
     while (*conp)
     {
         if (*conp == con)
@@ -104,27 +123,27 @@ static void remove_connection_from_host(struct connection *con)
         }
         conp = &(*conp)->next;
     }
-    yaz_mutex_leave(con->host->mutex);
+    yaz_cond_broadcast(con->host->cond_ready);
 }
 
 // Close connection and recycle structure
-void connection_destroy(struct connection *co)
+static void connection_destroy(struct connection *co)
 {
     if (co->link)
     {
         ZOOM_connection_destroy(co->link);
         iochan_destroy(co->iochan);
     }
-    yaz_log(YLOG_DEBUG, "Connection destroy %s", co->host->hostport);
+    yaz_log(YLOG_DEBUG, "%p Connection destroy %s", co, co->host->hostport);
 
     if (co->client)
     {
         client_disconnect(co->client);
     }
 
-    remove_connection_from_host(co);
     xfree(co->zproxy);
     xfree(co);
+    connection_use(-1);
 }
 
 // Creates a new connection for client, associated with the host of 
@@ -134,27 +153,29 @@ static struct connection *connection_create(struct client *cl,
                                             int session_timeout,
                                             iochan_man_t iochan_man)
 {
-    struct connection *new;
+    struct connection *co;
     struct host *host = client_get_host(cl);
 
-    new = xmalloc(sizeof(*new));
-    new->host = host;
+    co = xmalloc(sizeof(*co));
+    co->host = host;
+
+    co->client = cl;
+    co->zproxy = 0;
+    client_set_connection(cl, co);
+    co->link = 0;
+    co->state = Conn_Resolving;
+    co->operation_timeout = operation_timeout;
+    co->session_timeout = session_timeout;
+    if (host->ipport)
+        connection_connect(co, iochan_man);
 
     yaz_mutex_enter(host->mutex);
-    new->next = new->host->connections;
-    new->host->connections = new;
+    co->next = co->host->connections;
+    co->host->connections = co;
     yaz_mutex_leave(host->mutex);
 
-    new->client = cl;
-    new->zproxy = 0;
-    client_set_connection(cl, new);
-    new->link = 0;
-    new->state = Conn_Resolving;
-    new->operation_timeout = operation_timeout;
-    new->session_timeout = session_timeout;
-    if (host->ipport)
-        connection_connect(new, iochan_man);
-    return new;
+    connection_use(1);
+    return co;
 }
 
 static void non_block_events(struct connection *co)
@@ -173,24 +194,28 @@ static void non_block_events(struct connection *co)
             continue;
         ev = ZOOM_connection_last_event(link);
         
-        client_incref(cl);
-#if 0
-        yaz_log(YLOG_LOG, "ZOOM_EVENT_%s", ZOOM_get_event_str(ev));
+#if 1
+        yaz_log(YLOG_DEBUG, "%p Connection ZOOM_EVENT_%s", co, ZOOM_get_event_str(ev));
 #endif
         switch (ev) 
         {
         case ZOOM_EVENT_END:
             {
                 const char *error, *addinfo;
-               int err;
+                int err;
                 if ((err = ZOOM_connection_error(link, &error, &addinfo)))
                 {
                     yaz_log(YLOG_LOG, "Error %s from %s",
                             error, client_get_url(cl));
+                    client_set_diagnostic(cl, err);
+                    client_set_state(cl, Client_Error);
+                }
+                else
+                {
+                    iochan_settimeout(iochan, co->session_timeout);
+                    client_set_state(cl, Client_Idle);
                 }
-                iochan_settimeout(iochan, co->session_timeout);
-               client_set_diagnostic(cl, err);
-                client_set_state(cl, Client_Idle);
+                yaz_cond_broadcast(co->host->cond_ready);
             }
             break;
         case ZOOM_EVENT_SEND_DATA:
@@ -220,64 +245,87 @@ static void non_block_events(struct connection *co)
             yaz_log(YLOG_LOG, "Unhandled event (%d) from %s",
                     ev, client_get_url(cl));
         }
-        client_destroy(cl);
     }
     if (got_records)
     {
         struct client *cl = co->client;
         if (cl)
         {
-            client_incref(cl); 
+            client_check_preferred_watch(cl);
             client_got_records(cl);
-            client_destroy(cl);
         }
     }
 }
 
 void connection_continue(struct connection *co)
 {
-    non_block_events(co);
+    int r = ZOOM_connection_exec_task(co->link);
+    if (!r)
+        yaz_log(YLOG_WARN, "No task was executed for connection");
+    iochan_setflags(co->iochan, ZOOM_connection_get_mask(co->link));
+    iochan_setfd(co->iochan, ZOOM_connection_get_socket(co->link));
 }
 
 static void connection_handler(IOCHAN iochan, int event)
 {
     struct connection *co = iochan_getdata(iochan);
-    struct client *cl = co->client;
+    struct client *cl;
+    struct host *host = co->host;
 
+    yaz_mutex_enter(host->mutex);
+    cl = co->client;
     if (!cl) 
     {
         /* no client associated with it.. We are probably getting
            a closed connection from the target.. Or, perhaps, an unexpected
            package.. We will just close the connection */
+        yaz_log(YLOG_LOG, "timeout connection %p event=%d", co, event);
+        remove_connection_from_host(co);
+        yaz_mutex_leave(host->mutex);
         connection_destroy(co);
-        return;
     }
-    if (event & EVENT_TIMEOUT)
+    else if (event & EVENT_TIMEOUT)
     {
         if (co->state == Conn_Connecting)
         {
-            yaz_log(YLOG_WARN,  "connect timeout %s", client_get_url(cl));
-            client_fatal(cl);
+            yaz_log(YLOG_WARN, "%p connect timeout %s", co, client_get_url(cl));
+
+            client_set_state(cl, Client_Error);
+            remove_connection_from_host(co);
+            yaz_mutex_leave(host->mutex);
+            connection_destroy(co);
         }
         else
         {
-            yaz_log(YLOG_LOG,  "idle timeout %s", client_get_url(cl));
+            yaz_log(YLOG_LOG,  "%p Connection idle timeout %s", co, client_get_url(cl));
+            remove_connection_from_host(co);
+            yaz_mutex_leave(host->mutex);
             connection_destroy(co);
         }
     }
     else
     {
+        yaz_mutex_leave(host->mutex);
+
+        client_lock(cl);
         non_block_events(co);
 
         ZOOM_connection_fire_event_socket(co->link, event);
         
         non_block_events(co);
+        client_unlock(cl);
+
+        if (co->link)
+        {
+            iochan_setflags(iochan, ZOOM_connection_get_mask(co->link));
+            iochan_setfd(iochan, ZOOM_connection_get_socket(co->link));
+        }
     }
 }
 
 
 // Disassociate connection from client
-void connection_release(struct connection *co)
+static void connection_release(struct connection *co)
 {
     struct client *cl = co->client;
 
@@ -300,6 +348,7 @@ start:
         {
             if (!host->ipport) /* unresolved */
             {
+                remove_connection_from_host(con);
                 yaz_mutex_leave(host->mutex);
                 connection_destroy(con);
                 goto start;
@@ -307,6 +356,7 @@ start:
             }
             else if (!con->client)
             {
+                remove_connection_from_host(con);
                 yaz_mutex_leave(host->mutex);
                 connection_destroy(con);
                 /* start all over .. at some point it will be NULL */
@@ -334,28 +384,6 @@ static struct host *connection_get_host(struct connection *con)
     return con->host;
 }
 
-// Callback for use by event loop
-// We do this because ZOOM connections don't always have (the same) sockets
-static int socketfun(IOCHAN c)
-{
-    struct connection *co = iochan_getdata(c);
-    if (!co->link)
-        return -1;
-    return ZOOM_connection_get_socket(co->link);
-}
-
-// Because ZOOM always knows what events it is interested in; we may not
-static int maskfun(IOCHAN c)
-{
-    struct connection *co = iochan_getdata(c);
-    if (!co->link)
-        return 0;
-
-    // This is cheating a little, and assuming that eventl mask IDs are always
-    // the same as ZOOM-C's.
-    return ZOOM_connection_get_mask(co->link);
-}
-
 static int connection_connect(struct connection *con, iochan_man_t iochan_man)
 {
     ZOOM_connection link = 0;
@@ -410,16 +438,16 @@ static int connection_connect(struct connection *con, iochan_man_t iochan_man)
         strcat(http_hostport, host->hostport);
         ZOOM_connection_connect(link, http_hostport, 0);
     }
+    else if (zproxy && *zproxy)
+        ZOOM_connection_connect(link, host->hostport, 0);        
     else
         ZOOM_connection_connect(link, host->ipport, 0);
     
     con->link = link;
-    con->iochan = iochan_create(0, connection_handler, 0, "connection_socket");
+    con->iochan = iochan_create(-1, connection_handler, 0, "connection_socket");
     con->state = Conn_Connecting;
     iochan_settimeout(con->iochan, con->operation_timeout);
     iochan_setdata(con->iochan, con);
-    iochan_setsocketfun(con->iochan, socketfun);
-    iochan_setmaskfun(con->iochan, maskfun);
     iochan_add(iochan_man, con->iochan);
 
     /* this fragment is bad DRY: from client_prep_connection */
@@ -428,15 +456,11 @@ static int connection_connect(struct connection *con, iochan_man_t iochan_man)
     return 0;
 }
 
-const char *connection_get_url(struct connection *co)
-{
-    return client_get_url(co->client);
-}
-
 // Ensure that client has a connection associated
 int client_prep_connection(struct client *cl,
                            int operation_timeout, int session_timeout,
-                           iochan_man_t iochan_man)
+                           iochan_man_t iochan_man,
+                           const struct timeval *abstime)
 {
     struct connection *co;
     struct host *host = client_get_host(cl);
@@ -455,26 +479,72 @@ int client_prep_connection(struct client *cl,
 
     if (!co)
     {
+        int max_connections = 0;
+        int reuse_connections = 1;
+        const char *v = session_setting_oneval(client_get_database(cl),
+                                               PZ_MAX_CONNECTIONS);
+        if (v && *v)
+            max_connections = atoi(v);
+
+        v = session_setting_oneval(client_get_database(cl),
+                PZ_REUSE_CONNECTIONS);
+        if (v && *v)
+            reuse_connections = atoi(v);
+
         // See if someone else has an idle connection
         // We should look at timestamps here to select the longest-idle connection
         yaz_mutex_enter(host->mutex);
-        for (co = host->connections; co; co = co->next)
-            if (connection_is_idle(co) &&
-                (!co->client || client_get_state(co->client) == Client_Idle) &&
-                !strcmp(ZOOM_connection_option_get(co->link, "user"),
-                        session_setting_oneval(client_get_database(cl),
-                                               PZ_AUTHENTICATION)))
-            {
-                if (zproxy == 0 && co->zproxy == 0)
-                    break;
-                if (zproxy && co->zproxy && !strcmp(zproxy, co->zproxy))
+        while (1)
+        {
+            int num_connections = 0;
+            for (co = host->connections; co; co = co->next)
+                num_connections++;
+            if (reuse_connections) {
+                for (co = host->connections; co; co = co->next)
+                {
+                    if (connection_is_idle(co) &&
+                        (!co->client || client_get_state(co->client) == Client_Idle) &&
+                        !strcmp(ZOOM_connection_option_get(co->link, "user"),
+                                session_setting_oneval(client_get_database(cl),
+                                                       PZ_AUTHENTICATION)))
+                    {
+                        if (zproxy == 0 && co->zproxy == 0)
+                            break;
+                        if (zproxy && co->zproxy && !strcmp(zproxy, co->zproxy))
+                            break;
+                    }
+                }
+                if (co)
+                {
+                    yaz_log(YLOG_LOG, "num_connections = %d (reusing)", num_connections);
                     break;
+                }
             }
+            if (max_connections <= 0 || num_connections < max_connections)
+            {
+                yaz_log(YLOG_LOG, "num_connections = %d (new); max = %d",
+                        num_connections, max_connections);
+                break;
+            }
+            yaz_log(YLOG_LOG, "num_connections = %d (waiting) max = %d",
+                    num_connections, max_connections);
+            if (yaz_cond_wait(host->cond_ready, host->mutex, abstime))
+            {
+                yaz_log(YLOG_LOG, "out of connections %s", client_get_url(cl));
+                client_set_state(cl, Client_Error);
+                yaz_mutex_leave(host->mutex);
+                return 0;
+            }
+        }
         if (co)
         {
+            yaz_log(YLOG_LOG,  "%p Connection reuse. state: %d", co, co->state);
             connection_release(co);
             client_set_connection(cl, co);
             co->client = cl;
+            /* ensure that connection is only assigned to this client
+               by marking the client non Idle */
+            client_set_state(cl, Client_Working);
             yaz_mutex_leave(host->mutex);
             co->operation_timeout = operation_timeout;
             co->session_timeout = session_timeout;