From 5da911bce0310761514298444fde65d0a51ed85d Mon Sep 17 00:00:00 2001 From: Alexander Larsson Date: Thu, 20 Feb 2003 10:00:48 +0000 Subject: 2003-02-20 Alexander Larsson * dbus/dbus-transport-unix.c (unix_do_iteration): Unlock the connection mutex during a blocking select call. Add todo about how we need a way to wake up the select. * dbus/dbus-connection-internal.h: * dbus/dbus-connection.c: Add _dbus_connection_lock and _dbus_connection_unlock. --- ChangeLog | 10 ++++++++++ dbus/dbus-connection-internal.h | 3 +++ dbus/dbus-connection.c | 27 ++++++++++++++++++++++++--- dbus/dbus-transport-unix.c | 27 +++++++++++++++++++++++++-- 4 files changed, 62 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index 4404bdf3..070196df 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2003-02-20 Alexander Larsson + + * dbus/dbus-transport-unix.c (unix_do_iteration): + Unlock the connection mutex during a blocking select call. + Add todo about how we need a way to wake up the select. + + * dbus/dbus-connection-internal.h: + * dbus/dbus-connection.c: + Add _dbus_connection_lock and _dbus_connection_unlock. + 2003-02-19 Havoc Pennington * Doxyfile.in (PREDEFINED): put DOXYGEN_SHOULD_SKIP_THIS in diff --git a/dbus/dbus-connection-internal.h b/dbus/dbus-connection-internal.h index 0606d1bd..64c4cf39 100644 --- a/dbus/dbus-connection-internal.h +++ b/dbus/dbus-connection-internal.h @@ -38,6 +38,9 @@ typedef enum DBUS_ITERATION_BLOCK = 1 << 2 /**< Block if nothing to do. */ } DBusIterationFlags; +void _dbus_connection_lock (DBusConnection *connection); +void _dbus_connection_unlock (DBusConnection *connection); + void _dbus_connection_ref_unlocked (DBusConnection *connection); dbus_bool_t _dbus_connection_queue_received_message (DBusConnection *connection, diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c index 7da89bdc..64e83d11 100644 --- a/dbus/dbus-connection.c +++ b/dbus/dbus-connection.c @@ -134,6 +134,27 @@ static void _dbus_connection_free_data_slots_nolock (DBusConnection *connection) static void _dbus_connection_remove_timeout_locked (DBusConnection *connection, DBusTimeout *timeout); +/** + * Acquires the connection lock. + * + * @param connection the connection. + */ +void +_dbus_connection_lock (DBusConnection *connection) +{ + dbus_mutex_lock (connection->mutex); +} + +/** + * Releases the connection lock. + * + * @param connection the connection. + */ +void +_dbus_connection_unlock (DBusConnection *connection) +{ + dbus_mutex_unlock (connection->mutex); +} /** @@ -336,9 +357,9 @@ static void _dbus_connection_remove_timeout_locked (DBusConnection *connection, DBusTimeout *timeout) { - dbus_mutex_lock (connection->mutex); - _dbus_connection_remove_timeout (connection, timeout); - dbus_mutex_unlock (connection->mutex); + dbus_mutex_lock (connection->mutex); + _dbus_connection_remove_timeout (connection, timeout); + dbus_mutex_unlock (connection->mutex); } diff --git a/dbus/dbus-transport-unix.c b/dbus/dbus-transport-unix.c index c5dce8d7..b30dc1d6 100644 --- a/dbus/dbus-transport-unix.c +++ b/dbus/dbus-transport-unix.c @@ -884,6 +884,13 @@ unix_messages_pending (DBusTransport *transport, } /* FIXME use _dbus_poll(), not select() */ +/** + * @todo We need to have a way to wake up the select sleep if + * a new iteration request comes in with a flag (read/write) that + * we're not currently serving. Otherwise a call that just reads + * could block a write call forever (if there are no incoming + * messages). + */ static void unix_do_iteration (DBusTransport *transport, unsigned int flags, @@ -893,6 +900,7 @@ unix_do_iteration (DBusTransport *transport, fd_set read_set; fd_set write_set; dbus_bool_t do_select; + int select_res; _dbus_verbose (" iteration flags = %s%s timeout = %d\n", flags & DBUS_ITERATION_DO_READING ? "read" : "", @@ -984,9 +992,24 @@ unix_do_iteration (DBusTransport *transport, timeout.tv_usec = 0; use_timeout = TRUE; } + + /* For blocking selects we drop the connection lock here + * to avoid blocking out connection access during a potentially + * indefinite blocking call. The io path is still protected + * by the io_path_cond condvar, so we won't reenter this. + */ + if (flags & DBUS_ITERATION_BLOCK) + _dbus_connection_unlock (transport->connection); + + select_res = select (unix_transport->fd + 1, + &read_set, &write_set, &err_set, + use_timeout ? &timeout : NULL); + + if (flags & DBUS_ITERATION_BLOCK) + _dbus_connection_lock (transport->connection); + - if (select (unix_transport->fd + 1, &read_set, &write_set, &err_set, - use_timeout ? &timeout : NULL) >= 0) + if (select_res >= 0) { if (FD_ISSET (unix_transport->fd, &err_set)) do_io_error (transport); -- cgit