freetdm: add asynchronous signal notification

libs/freetdm/src/ftdm_io.c

@@ -51,6 +51,7 @@
 #include "ftdm_cpu_monitor.h"
 
 #define SPAN_PENDING_CHANS_QUEUE_SIZE 1000
+#define SPAN_PENDING_SIGNALS_QUEUE_SIZE 1000
 #define FTDM_READ_TRACE_INDEX 0
 #define FTDM_WRITE_TRACE_INDEX 1
 
@@ -463,6 +464,9 @@ static ftdm_status_t ftdm_span_destroy(ftdm_span_t *span)
 	if (span->pendingchans) {
 		ftdm_queue_destroy(&span->pendingchans);
 	}
+	if (span->pendingsignals) {
+		ftdm_queue_destroy(&span->pendingsignals);
+	}
 	ftdm_mutex_unlock(span->mutex);
 	ftdm_mutex_destroy(&span->mutex);
 	ftdm_safe_free(span->signal_data);
@@ -4097,6 +4101,9 @@ static ftdm_status_t post_configure_span_channels(ftdm_span_t *span)
 	if (ftdm_test_flag(span, FTDM_SPAN_USE_CHAN_QUEUE)) {
 		status = ftdm_queue_create(&span->pendingchans, SPAN_PENDING_CHANS_QUEUE_SIZE);
 	}
+	if (status == FTDM_SUCCESS && ftdm_test_flag(span, FTDM_SPAN_USE_SIGNALS_QUEUE)) {
+		status = ftdm_queue_create(&span->pendingsignals, SPAN_PENDING_SIGNALS_QUEUE_SIZE);
+	}
 	return status;
 }
 
@@ -4362,10 +4369,39 @@ FT_DECLARE(ftdm_status_t) ftdm_group_create(ftdm_group_t **group, const char *na
 	return status;
 }
 
+static ftdm_status_t ftdm_span_trigger_signal(const ftdm_span_t *span, ftdm_sigmsg_t *sigmsg)
+{
+	return span->signal_cb(sigmsg);
+}
+
+static ftdm_status_t ftdm_span_queue_signal(const ftdm_span_t *span, ftdm_sigmsg_t *sigmsg)
+{
+	ftdm_sigmsg_t *new_sigmsg = NULL;
+
+	ftdm_assert_return((sigmsg->raw_data == NULL), FTDM_FAIL, "No raw data should be used with asynchronous notification\n");
+
+	new_sigmsg = ftdm_calloc(1, sizeof(*sigmsg));
+	if (!new_sigmsg) {
+		return FTDM_FAIL;
+	}
+	memcpy(new_sigmsg, sigmsg, sizeof(*sigmsg));
+
+	ftdm_queue_enqueue(span->pendingsignals, new_sigmsg);
+	return FTDM_SUCCESS;
+}
+
+FT_DECLARE(ftdm_status_t) ftdm_span_trigger_signals(const ftdm_span_t *span)
+{
+	ftdm_sigmsg_t *sigmsg = NULL;
+	while ((sigmsg = ftdm_queue_dequeue(span->pendingsignals))) {
+		ftdm_span_trigger_signal(span, sigmsg);
+		ftdm_safe_free(sigmsg);
+	}
+	return FTDM_SUCCESS;
+}
+
 FT_DECLARE(ftdm_status_t) ftdm_span_send_signal(ftdm_span_t *span, ftdm_sigmsg_t *sigmsg)
 {
-	ftdm_status_t status = FTDM_FAIL;
-
 	if (sigmsg->channel) {
 		ftdm_mutex_lock(sigmsg->channel->mutex);
 	}
@@ -4401,9 +4437,11 @@ FT_DECLARE(ftdm_status_t) ftdm_span_send_signal(ftdm_span_t *span, ftdm_sigmsg_t
 
 	}
 	
-	/* call the user callback only if set */
-	if (span->signal_cb) {
-		status = span->signal_cb(sigmsg);
+	/* if the signaling module uses a queue for signaling notifications, then enqueue it */
+	if (ftdm_test_flag(span, FTDM_SPAN_USE_SIGNALS_QUEUE)) {
+		ftdm_span_queue_signal(span, sigmsg);
+	} else {
+		ftdm_span_trigger_signal(span, sigmsg);
 	}
 
 done:
@@ -4411,7 +4449,7 @@ done:
 		ftdm_mutex_unlock(sigmsg->channel->mutex);
 	}
 
-	return status;
+	return FTDM_SUCCESS;
 }
 
 static void *ftdm_cpu_monitor_run(ftdm_thread_t *me, void *obj)

libs/freetdm/src/include/freetdm.h

@@ -317,23 +317,6 @@ typedef struct ftdm_channel_config {
 	float txgain;
 } ftdm_channel_config_t;
 
-/*! \brief Generic signaling message */
-struct ftdm_sigmsg {
-	ftdm_signal_event_t event_id; /*!< The type of message */
-	ftdm_channel_t *channel; /*!< Related channel */
-	uint32_t chan_id; /*!< easy access to chan id */
-	uint32_t span_id; /*!< easy access to span_id */
-	void *raw_data; /*!< Message specific data if any */
-	uint32_t raw_data_len; /*!< Data len in case is needed */
-};
-
-/*! \brief Crash policy 
- *  Useful for debugging only, default policy is never, if you wish to crash on asserts then use ftdm_global_set_crash_policy */
-typedef enum {
-	FTDM_CRASH_NEVER = 0,
-	FTDM_CRASH_ON_ASSERT
-} ftdm_crash_policy_t;
-
 /*!
   \brief Signaling status on a given span or specific channel on protocols that support it
  */
@@ -352,6 +335,24 @@ typedef enum {
 /*! \brief Move from string to ftdm_signaling_status_t and viceversa */
 FTDM_STR2ENUM_P(ftdm_str2ftdm_signaling_status, ftdm_signaling_status2str, ftdm_signaling_status_t)
 
+/*! \brief Generic signaling message */
+struct ftdm_sigmsg {
+	ftdm_signal_event_t event_id; /*!< The type of message */
+	ftdm_channel_t *channel; /*!< Related channel */
+	uint32_t chan_id; /*!< easy access to chan id */
+	uint32_t span_id; /*!< easy access to span_id */
+	ftdm_signaling_status_t sigstatus; /*!< Signaling status (valid if event_id is FTDM_SIGEVENT_SIGSTATUS_CHANGED) */
+	void *raw_data; /*!< Message specific data if any */
+	uint32_t raw_data_len; /*!< Data len in case is needed */
+};
+
+/*! \brief Crash policy 
+ *  Useful for debugging only, default policy is never, if you wish to crash on asserts then use ftdm_global_set_crash_policy */
+typedef enum {
+	FTDM_CRASH_NEVER = 0,
+	FTDM_CRASH_ON_ASSERT
+} ftdm_crash_policy_t;
+
 /*! \brief I/O waiting flags */
 typedef enum {
 	FTDM_NO_FLAGS = 0,

libs/freetdm/src/include/private/ftdm_core.h

@@ -466,6 +466,7 @@ struct ftdm_span {
 	ftdm_state_map_t *state_map;
 	ftdm_caller_data_t default_caller_data;
 	ftdm_queue_t *pendingchans;
+	ftdm_queue_t *pendingsignals;
 	struct ftdm_span *next;
 };
 
@@ -579,6 +580,8 @@ FT_DECLARE(ftdm_status_t) ftdm_span_next_event(ftdm_span_t *span, ftdm_event_t *
  */
 FT_DECLARE(ftdm_status_t) ftdm_channel_queue_dtmf(ftdm_channel_t *ftdmchan, const char *dtmf);
 
+/* dequeue pending signals and notify the user via the span signal callback */
+FT_DECLARE(ftdm_status_t) ftdm_span_trigger_signals(const ftdm_span_t *span);
 
 /*!
   \brief Assert condition

libs/freetdm/src/include/private/ftdm_types.h

@@ -176,6 +176,10 @@ typedef enum {
 	FTDM_SPAN_USE_CHAN_QUEUE = (1 << 6),
 	FTDM_SPAN_SUGGEST_CHAN_ID = (1 << 7),
 	FTDM_SPAN_USE_AV_RATE = (1 << 8),
+	/* If you use this flag, you MUST call ftdm_span_trigger_signals to deliver the user signals
+	 * after having called ftdm_send_span_signal(), which with this flag it will just enqueue the signal
+	 * for later delivery */
+	FTDM_SPAN_USE_SIGNALS_QUEUE = (1 << 9),
 } ftdm_span_flag_t;
 
 /*! \brief Channel supported features */