imap-hibernate: If imap-master socket is busy, retry un-hibernation later.

diff --git a/src/imap-hibernate/imap-client.c b/src/imap-hibernate/imap-client.c
index fd91dc92f95a24753756b1dd9b8befe5b3a83a21..d982624f5e4224033c0943a83b93eebb001723bf 100644 (file)
--- a/src/imap-hibernate/imap-client.c
+++ b/src/imap-hibernate/imap-client.c
@@ -11,6 +11,7 @@
 #include "istream.h"
 #include "ostream.h"
 #include "llist.h"
+#include "priorityq.h"
 #include "base64.h"
 #include "str.h"
 #include "strescape.h"
@@ -28,6 +29,16 @@
 /* we only need enough for "DONE\r\nIDLE\r\n" */
 #define IMAP_MAX_INBUF 12
 
+/* If client has sent input and we can't recreate imap process in this
+   many seconds, disconnect the client. */
+#define IMAP_CLIENT_MOVE_BACK_WITH_INPUT_TIMEOUT_SECS 10
+/* If there's a change notification and we can't recreate imap process in this
+   many seconds, disconnect the client. */
+#define IMAP_CLIENT_MOVE_BACK_WITHOUT_INPUT_TIMEOUT_SECS (60*5)
+
+/* How often to try to unhibernate clients. */
+#define IMAP_UNHIBERNATE_RETRY_MSECS 10
+
 enum imap_client_input_state {
        IMAP_CLIENT_INPUT_STATE_UNKNOWN,
        IMAP_CLIENT_INPUT_STATE_BAD,
@@ -42,11 +53,16 @@ struct imap_client_notify {
 };
 
 struct imap_client {
+       struct priorityq_item item;
+
        struct imap_client *prev, *next;
        pool_t pool;
        struct imap_client_state state;
        ARRAY(struct imap_client_notify) notifys;
 
+       time_t move_back_start;
+       struct timeout *to_move_back;
+
        int fd;
        struct io *io;
        struct istream *input;
@@ -57,14 +73,19 @@ struct imap_client {
        unsigned int imap_still_here_text_pos;
        unsigned int next_read_threshold;
        bool bad_done, idle_done;
+       bool unhibernate_queued;
+       bool input_pending;
 };
 
 static struct imap_client *imap_clients;
+static struct priorityq *unhibernate_queue;
+static struct timeout *to_unhibernate;
 static const char imap_still_here_text[] = "* OK Still here\r\n";
 
 static void imap_client_stop(struct imap_client *client);
 void imap_client_destroy(struct imap_client **_client, const char *reason);
 static void imap_client_add_idle_keepalive_timeout(struct imap_client *client);
+static void imap_clients_unhibernate(void *context);
 
 static void imap_client_disconnected(struct imap_client **_client)
 {
@@ -174,22 +195,53 @@ imap_client_move_back_read_callback(void *context, const char *line)
        }
 }
 
-static void imap_client_move_back(struct imap_client *client)
+static bool imap_client_try_move_back(struct imap_client *client)
 {
        const struct master_service_settings *master_set;
-       const char *path;
-
-       imap_client_stop(client);
+       const char *path, *error;
+       int ret;
 
        master_set = master_service_settings_get(master_service);
        path = t_strconcat(master_set->base_dir,
                           "/"IMAP_MASTER_SOCKET_NAME, NULL);
-       if (imap_master_connection_init(path,
-                                       imap_client_move_back_send_callback,
-                                       imap_client_move_back_read_callback,
-                                       client, &client->master_conn) < 0) {
+       ret = imap_master_connection_init(path,
+                                         imap_client_move_back_send_callback,
+                                         imap_client_move_back_read_callback,
+                                         client, &client->master_conn, &error);
+       if (ret > 0) {
+               /* success */
+               imap_client_stop(client);
+               return TRUE;
+       } else if (ret < 0) {
                /* failed to connect to the imap-master socket */
-               imap_client_destroy(&client, "Failed to connect to master socket");
+               imap_client_destroy(&client, error);
+               return TRUE;
+       }
+
+       int max_secs = client->input_pending ?
+               IMAP_CLIENT_MOVE_BACK_WITH_INPUT_TIMEOUT_SECS :
+               IMAP_CLIENT_MOVE_BACK_WITHOUT_INPUT_TIMEOUT_SECS;
+       if (ioloop_time - client->move_back_start > max_secs) {
+               /* we've waited long enough */
+               imap_client_destroy(&client, error);
+               return TRUE;
+       }
+       return FALSE;
+}
+
+static void imap_client_move_back(struct imap_client *client)
+{
+       if (imap_client_try_move_back(client))
+               return;
+
+       /* imap-master socket is busy. retry in a while. */
+       if (client->move_back_start == 0)
+               client->move_back_start = ioloop_time;
+       client->unhibernate_queued = TRUE;
+       priorityq_add(unhibernate_queue, &client->item);
+       if (to_unhibernate == NULL) {
+               to_unhibernate = timeout_add_short(IMAP_UNHIBERNATE_RETRY_MSECS,
+                                                  imap_clients_unhibernate, NULL);
        }
 }
 
@@ -269,6 +321,7 @@ static void imap_client_input_idle_cmd(struct imap_client *client)
                return;
        }
        client->idle_done = TRUE;
+       client->input_pending = TRUE;
        imap_client_move_back(client);
 }
 
@@ -276,8 +329,10 @@ static void imap_client_input_nonidle(struct imap_client *client)
 {
        if (i_stream_read(client->input) < 0)
                imap_client_disconnected(&client);
-       else
+       else {
+               client->input_pending = TRUE;
                imap_client_move_back(client);
+       }
 }
 
 static void imap_client_input_notify(struct imap_client *client)
@@ -459,6 +514,8 @@ static void imap_client_stop(struct imap_client *client)
 {
        struct imap_client_notify *notify;
 
+       if (client->unhibernate_queued)
+               priorityq_remove(unhibernate_queue, &client->item);
        if (client->io != NULL)
                io_remove(&client->io);
        if (client->to_keepalive != NULL)
@@ -541,6 +598,44 @@ void imap_client_create_finish(struct imap_client *client)
        }
 }
 
+static int client_unhibernate_cmp(const void *p1, const void *p2)
+{
+       const struct imap_client *c1 = p1, *c2 = p2;
+       time_t t1, t2;
+
+       t1 = c1->move_back_start +
+               (c1->input_pending ?
+                IMAP_CLIENT_MOVE_BACK_WITH_INPUT_TIMEOUT_SECS :
+                IMAP_CLIENT_MOVE_BACK_WITHOUT_INPUT_TIMEOUT_SECS);
+       t2 = c2->move_back_start +
+               (c1->input_pending ?
+                IMAP_CLIENT_MOVE_BACK_WITH_INPUT_TIMEOUT_SECS :
+                IMAP_CLIENT_MOVE_BACK_WITHOUT_INPUT_TIMEOUT_SECS);
+       if (t1 < t2)
+               return -1;
+       if (t1 > t2)
+               return 1;
+       return 0;
+}
+
+static void imap_clients_unhibernate(void *context ATTR_UNUSED)
+{
+       struct priorityq_item *item;
+
+       while ((item = priorityq_pop(unhibernate_queue)) != NULL) {
+               struct imap_client *client = (struct imap_client *)item;
+
+               if (!imap_client_try_move_back(client))
+                       return;
+       }
+       timeout_remove(&to_unhibernate);
+}
+
+void imap_clients_init(void)
+{
+       unhibernate_queue = priorityq_init(client_unhibernate_cmp, 64);
+}
+
 void imap_clients_deinit(void)
 {
        while (imap_clients != NULL) {
@@ -549,4 +644,7 @@ void imap_clients_deinit(void)
                imap_client_io_activate_user(client);
                imap_client_destroy(&client, "Shutting down");
        }
+       if (to_unhibernate != NULL)
+               timeout_remove(&to_unhibernate);
+       priorityq_deinit(&unhibernate_queue);
 }

diff --git a/src/imap-hibernate/imap-client.h b/src/imap-hibernate/imap-client.h
index a57c974db97a3e3d004f99eb953a1f27affd301a..dfee3de0135bf8a1fe9fbf4968fbdb18978ab93d 100644 (file)
--- a/src/imap-hibernate/imap-client.h
+++ b/src/imap-hibernate/imap-client.h
@@ -31,6 +31,7 @@ void imap_client_add_notify_fd(struct imap_client *client, int fd);
 void imap_client_create_finish(struct imap_client *client);
 void imap_client_destroy(struct imap_client **_client, const char *reason);
 
+void imap_clients_init(void);
 void imap_clients_deinit(void);
 
 #endif

diff --git a/src/imap-hibernate/imap-master-connection.c b/src/imap-hibernate/imap-master-connection.c
index 3f9a419e1fc1574df3775a3bd1a21785c1db7656..a99c2caa9c067e832136f438c060087f7e8ba77b 100644 (file)
--- a/src/imap-hibernate/imap-master-connection.c
+++ b/src/imap-hibernate/imap-master-connection.c
@@ -28,7 +28,8 @@ int imap_master_connection_init(const char *path,
                                imap_master_connection_send_callback_t *send_callback,
                                imap_master_connection_read_callback_t *read_callback,
                                void *context,
-                               struct imap_master_connection **conn_r)
+                               struct imap_master_connection **conn_r,
+                               const char **error_r)
 {
        struct imap_master_connection *conn;
 
@@ -38,15 +39,18 @@ int imap_master_connection_init(const char *path,
        conn->context = context;
        connection_init_client_unix(master_clients, &conn->conn, path);
        if (connection_client_connect(&conn->conn) < 0) {
-               i_error("net_connect_unix(%s) failed: %m", path);
+               int ret = errno == EAGAIN ? 0 : -1;
+
+               *error_r = t_strdup_printf(
+                       "net_connect_unix(%s) failed: %m", path);
                connection_deinit(&conn->conn);
                i_free(conn);
-               return -1;
+               return ret;
        }
        conn->to = timeout_add(IMAP_MASTER_CONNECTION_TIMEOUT_MSECS,
                               imap_master_connection_timeout, conn);
        *conn_r = conn;
-       return 0;
+       return 1;
 }
 
 void imap_master_connection_deinit(struct imap_master_connection **_conn)

diff --git a/src/imap-hibernate/imap-master-connection.h b/src/imap-hibernate/imap-master-connection.h
index 2c172b82777b48a9fe76361f78400f49daa03dad..8ed03f36e24e50dacd32274ce1b67b159016cf3b 100644 (file)
--- a/src/imap-hibernate/imap-master-connection.h
+++ b/src/imap-hibernate/imap-master-connection.h
@@ -8,11 +8,13 @@ imap_master_connection_send_callback_t(void *context, struct ostream *output);
 typedef void
 imap_master_connection_read_callback_t(void *context, const char *reply);
 
+/* Returns 1 = success, 0 = retry later, -1 = error */
 int imap_master_connection_init(const char *path,
                                imap_master_connection_send_callback_t *send_callback,
                                imap_master_connection_read_callback_t *read_callback,
                                void *context,
-                               struct imap_master_connection **conn_r);
+                               struct imap_master_connection **conn_r,
+                               const char **error_r);
 void imap_master_connection_deinit(struct imap_master_connection **conn);
 
 void imap_master_connections_init(void);

diff --git a/src/imap-hibernate/main.c b/src/imap-hibernate/main.c
index 32ffdd83098ddfd472baa9614e9423c1317e3900..29c84b319ad07f0de9da8fb2c37373b7e94d4dc0 100644 (file)
--- a/src/imap-hibernate/main.c
+++ b/src/imap-hibernate/main.c
@@ -42,6 +42,7 @@ int main(int argc, char *argv[])
        restrict_access_by_env(NULL, FALSE);
        restrict_access_allow_coredumps(TRUE);
 
+       imap_clients_init();
        imap_master_connections_init();
        imap_hibernate_clients_init();
        master_service_init_finish(master_service);