FreeTDM: Add span start/stop callbacks to ftdm_io_interface.

Callbacks are invoked from ftdm_span_start/_stop().
I/O is started before SIG and shut down in reverse order.

This is needed for ftmod_misdn, to move the mISDN message handling
into a separate thread (solving the mISDN socket vs. FreeTDM API issues).

With these callbacks, the I/O thread can be started after the span I/O configuration
has been (successfully) completed and stopped before destroying the span.

NOTE: Both SIG and I/O callbacks are called with the span mutex locked,
so threads created or destroyed synchronously in either of the custom
start/stop functions, can not use ftdm_span_*() functions that lock
the span mutex (e.g. ftdm_span_get_channel_count()).

Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

libs/freetdm/src/ftdm_io.c

@@ -760,11 +760,16 @@ FT_DECLARE(ftdm_status_t) ftdm_span_stop(ftdm_span_t *span)
 		goto done;
 	}
 
+	/* Stop SIG */
 	status = span->stop(span);
-	if (FTDM_SUCCESS == status) {
+	if (status == FTDM_SUCCESS) {
 		ftdm_clear_flag(span, FTDM_SPAN_STARTED);
 	}
 
+	/* Stop I/O */
+	if (span->fio && span->fio->span_stop) {
+		status = span->fio->span_stop(span);
+	}
 done:
 	ftdm_mutex_unlock(span->mutex);
 
@@ -5309,6 +5314,14 @@ FT_DECLARE(ftdm_status_t) ftdm_span_start(ftdm_span_t *span)
 		goto done;
 	}
 
+	/* Start I/O */
+	if (span->fio && span->fio->span_start) {
+		status = span->fio->span_start(span);
+		if (status != FTDM_SUCCESS)
+			goto done;
+	}
+
+	/* Start SIG */
 	status = ftdm_report_initial_channels_alarms(span);
 	if (status != FTDM_SUCCESS) {
 		goto done;

libs/freetdm/src/include/freetdm.h

@@ -807,6 +807,8 @@ struct ftdm_memory_handler {
 #define FIO_CONFIGURE_SPAN_SIGNALING_ARGS (ftdm_span_t *span, fio_signal_cb_t sig_cb, ftdm_conf_parameter_t *ftdm_parameters)
 #define FIO_SIG_UNLOAD_ARGS (void)
 #define FIO_API_ARGS (ftdm_stream_handle_t *stream, const char *data)
+#define FIO_SPAN_START_ARGS (ftdm_span_t *span)
+#define FIO_SPAN_STOP_ARGS (ftdm_span_t *span)
 
 /*! \brief FreeTDM I/O layer interface function typedefs
  * You don't need these unless your implementing an I/O interface module (most users don't) */
@@ -853,6 +855,8 @@ typedef ftdm_status_t (*fio_configure_span_signaling_t) FIO_CONFIGURE_SPAN_SIGNA
 typedef ftdm_status_t (*fio_io_unload_t) FIO_IO_UNLOAD_ARGS ;
 typedef ftdm_status_t (*fio_sig_unload_t) FIO_SIG_UNLOAD_ARGS ;
 typedef ftdm_status_t (*fio_api_t) FIO_API_ARGS ;
+typedef ftdm_status_t (*fio_span_start_t) FIO_SPAN_START_ARGS ;
+typedef ftdm_status_t (*fio_span_stop_t) FIO_SPAN_STOP_ARGS ;
 
 
 /*! \brief FreeTDM I/O layer interface function prototype wrapper macros
@@ -887,6 +891,8 @@ typedef ftdm_status_t (*fio_api_t) FIO_API_ARGS ;
 #define FIO_IO_UNLOAD_FUNCTION(name) ftdm_status_t name FIO_IO_UNLOAD_ARGS
 #define FIO_SIG_UNLOAD_FUNCTION(name) ftdm_status_t name FIO_SIG_UNLOAD_ARGS
 #define FIO_API_FUNCTION(name) ftdm_status_t name FIO_API_ARGS
+#define FIO_SPAN_START_FUNCTION(name) ftdm_status_t name FIO_SPAN_START_ARGS
+#define FIO_SPAN_STOP_FUNCTION(name) ftdm_status_t name FIO_SPAN_STOP_ARGS
 
 /*! \brief FreeTDM I/O layer function prototype wrapper macros
  * You don't need these unless your implementing an I/O interface module (most users don't) */
@@ -907,6 +913,8 @@ struct ftdm_io_interface {
 	fio_span_next_event_t next_event; /*!< Retrieve an event from the span */
 	fio_channel_next_event_t channel_next_event; /*!< Retrieve an event from channel */
 	fio_api_t api; /*!< Execute a text command */
+	fio_span_start_t span_start; /*!< Start span I/O */
+	fio_span_stop_t span_stop; /*!< Stop span I/O */
 };
 
 /*! \brief FreeTDM supported I/O codecs */