This patch extends the client subscription API, so that signals sent from
PulseAudio can be processed. Within PulseAudio, a signal can be emitted
using pa_signal_post(). The interface can be used to notify the client of
events that are not covered by the subscription API (for example a button
press event on a bluetooth headset).
Setting up signal notification is very similar to using subscriptions.
First the client needs to subscribe with pa_context_subscribe_signals()
and then sets up a signal handler using pa_context_set_signal_callback().
The signal handler will receive three arguments in addition to the usual
context and userdata:
sender - string that specifies the origin of the signal
signal - string that specifies the type of the signal
signal_parameters - optional string for additional information
---
PROTOCOL | 6 ++++
src/map-file | 2 ++
src/pulse/def.h | 6 ++++
src/pulse/internal.h | 2 ++
src/pulse/subscribe.c | 66 +++++++++++++++++++++++++++++++++++++----
src/pulse/subscribe.h | 9 ++++++
src/pulsecore/core.h | 1 +
src/pulsecore/message-handler.c | 16 ++++++++++
src/pulsecore/message-handler.h | 13 ++++++++
src/pulsecore/native-common.h | 3 ++
src/pulsecore/pdispatch.c | 1 +
src/pulsecore/protocol-native.c | 56 ++++++++++++++++++++++++++++++++++
12 files changed, 175 insertions(+), 6 deletions(-)
diff --git a/PROTOCOL b/PROTOCOL
index b57edea5..7f1bf91b 100644
--- a/PROTOCOL
+++ b/PROTOCOL
@@ -434,6 +434,12 @@ parameters:
The command returns a string.
+Added signal sending capability and command PA_COMMAND_SUBSCRIBE_SIGNALS.
+This command allows clients to subscribe to signals that PulseAudio sends.
+
+parameters:
+ uint64_t facility_mask - subscription mask
+
#### If you just changed the protocol, read this
## module-tunnel depends on the sink/source/sink-input/source-input protocol
## internals, so if you changed these, you might have broken module-tunnel.
diff --git a/src/map-file b/src/map-file
index 9f6181f1..b592a21e 100644
--- a/src/map-file
+++ b/src/map-file
@@ -94,6 +94,7 @@ pa_context_set_default_sink;
pa_context_set_default_source;
pa_context_set_event_callback;
pa_context_set_name;
+pa_context_set_signal_callback;
pa_context_set_sink_input_mute;
pa_context_set_sink_input_volume;
pa_context_set_sink_mute_by_index;
@@ -114,6 +115,7 @@ pa_context_set_state_callback;
pa_context_set_subscribe_callback;
pa_context_stat;
pa_context_subscribe;
+pa_context_subscribe_signals;
pa_context_suspend_sink_by_index;
pa_context_suspend_sink_by_name;
pa_context_suspend_source_by_index;
diff --git a/src/pulse/def.h b/src/pulse/def.h
index 87b7dd40..787b7f9a 100644
--- a/src/pulse/def.h
+++ b/src/pulse/def.h
@@ -599,6 +599,11 @@ typedef enum pa_subscription_event_type {
PA_SUBSCRIPTION_EVENT_REMOVE = 0x0020U,
/**< An object was removed */
+/** \cond fulldocs */
+ PA_SUBSCRIPTION_EVENT_SIGNAL = 0x0040U,
+ /** A signal was issued. Only used internally. */
+/** \endcond */
+
PA_SUBSCRIPTION_EVENT_TYPE_MASK = 0x0030U
/**< A mask to extract the event operation from an event value */
@@ -634,6 +639,7 @@ typedef enum pa_subscription_event_type {
#define PA_SUBSCRIPTION_EVENT_NEW PA_SUBSCRIPTION_EVENT_NEW
#define PA_SUBSCRIPTION_EVENT_CHANGE PA_SUBSCRIPTION_EVENT_CHANGE
#define PA_SUBSCRIPTION_EVENT_REMOVE PA_SUBSCRIPTION_EVENT_REMOVE
+#define PA_SUBSCRIPTION_EVENT_SIGNAL PA_SUBSCRIPTION_EVENT_SIGNAL
#define PA_SUBSCRIPTION_EVENT_TYPE_MASK PA_SUBSCRIPTION_EVENT_TYPE_MASK
/** \endcond */
diff --git a/src/pulse/internal.h b/src/pulse/internal.h
index 01d2b6e4..7d024cb1 100644
--- a/src/pulse/internal.h
+++ b/src/pulse/internal.h
@@ -89,6 +89,8 @@ struct pa_context {
void *subscribe_userdata;
pa_context_event_cb_t event_callback;
void *event_userdata;
+ pa_context_signal_cb_t signal_callback;
+ void *signal_userdata;
pa_mempool *mempool;
diff --git a/src/pulse/subscribe.c b/src/pulse/subscribe.c
index e7cce2e3..7ada6d0b 100644
--- a/src/pulse/subscribe.c
+++ b/src/pulse/subscribe.c
@@ -32,7 +32,6 @@
void pa_command_subscribe_event(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
pa_context *c = userdata;
pa_subscription_event_type_t e;
- uint32_t idx;
pa_assert(pd);
pa_assert(command == PA_COMMAND_SUBSCRIBE_EVENT);
@@ -42,15 +41,39 @@ void pa_command_subscribe_event(pa_pdispatch *pd, uint32_t command, uint32_t tag
pa_context_ref(c);
- if (pa_tagstruct_getu32(t, &e) < 0 ||
- pa_tagstruct_getu32(t, &idx) < 0 ||
- !pa_tagstruct_eof(t)) {
+ if (pa_tagstruct_getu32(t, &e) < 0) {
pa_context_fail(c, PA_ERR_PROTOCOL);
goto finish;
}
- if (c->subscribe_callback)
- c->subscribe_callback(c, e, idx, c->subscribe_userdata);
+ if (e != PA_SUBSCRIPTION_EVENT_SIGNAL) {
+ uint32_t idx;
+
+ if (pa_tagstruct_getu32(t, &idx) < 0 ||
+ !pa_tagstruct_eof(t)) {
+ pa_context_fail(c, PA_ERR_PROTOCOL);
+ goto finish;
+ }
+
+ if (c->subscribe_callback)
+ c->subscribe_callback(c, e, idx, c->subscribe_userdata);
+
+ } else {
+ const char *sender;
+ const char *signal;
+ const char *signal_parameters;
+
+ if (pa_tagstruct_gets(t, &sender) < 0 ||
+ pa_tagstruct_gets(t, &signal) < 0 ||
+ pa_tagstruct_gets(t, &signal_parameters) < 0 ||
+ !pa_tagstruct_eof(t)) {
+ pa_context_fail(c, PA_ERR_PROTOCOL);
+ goto finish;
+ }
+
+ if (c->signal_callback)
+ c->signal_callback(c, sender, signal, signal_parameters, c->signal_userdata);
+ }
finish:
pa_context_unref(c);
@@ -86,3 +109,34 @@ void pa_context_set_subscribe_callback(pa_context *c, pa_context_subscribe_cb_t
c->subscribe_callback = cb;
c->subscribe_userdata = userdata;
}
+
+void pa_context_set_signal_callback(pa_context *c, pa_context_signal_cb_t cb, void *userdata) {
+ pa_assert(c);
+ pa_assert(PA_REFCNT_VALUE(c) >= 1);
+
+ if (c->state == PA_CONTEXT_TERMINATED || c->state == PA_CONTEXT_FAILED)
+ return;
+
+ c->signal_callback = cb;
+ c->signal_userdata = userdata;
+}
+
+pa_operation* pa_context_subscribe_signals(pa_context *c, uint64_t signal_mask, pa_context_success_cb_t cb, void *userdata) {
+ pa_operation *o;
+ pa_tagstruct *t;
+ uint32_t tag;
+
+ pa_assert(c);
+ pa_assert(PA_REFCNT_VALUE(c) >= 1);
+
+ PA_CHECK_VALIDITY_RETURN_NULL(c, c->state == PA_CONTEXT_READY, PA_ERR_BADSTATE);
+
+ o = pa_operation_new(c, NULL, (pa_operation_cb_t) cb, userdata);
+
+ t = pa_tagstruct_command(c, PA_COMMAND_SUBSCRIBE_SIGNALS, &tag);
+ pa_tagstruct_putu64(t, signal_mask);
+ pa_pstream_send_tagstruct(c->pstream, t);
+ pa_pdispatch_register_reply(c->pdispatch, tag, DEFAULT_TIMEOUT, pa_context_simple_ack_callback, pa_operation_ref(o), (pa_free_cb_t) pa_operation_unref);
+
+ return o;
+}
diff --git a/src/pulse/subscribe.h b/src/pulse/subscribe.h
index b43c8ea4..59167485 100644
--- a/src/pulse/subscribe.h
+++ b/src/pulse/subscribe.h
@@ -72,12 +72,21 @@ PA_C_DECL_BEGIN
/** Subscription event callback prototype */
typedef void (*pa_context_subscribe_cb_t)(pa_context *c, pa_subscription_event_type_t t, uint32_t idx, void *userdata);
+/** Signal event callback prototype, \since 12.0 */
+typedef void (*pa_context_signal_cb_t)(pa_context *c, const char *sender, const char *signal, const char *signal_parameters, void *userdata);
+
/** Enable event notification */
pa_operation* pa_context_subscribe(pa_context *c, pa_subscription_mask_t m, pa_context_success_cb_t cb, void *userdata);
+/** Enable signal notification, \since 12.0 */
+pa_operation* pa_context_subscribe_signals(pa_context *c, uint64_t signal_mask, pa_context_success_cb_t cb, void *userdata);
+
/** Set the context specific call back function that is called whenever the state of the daemon changes */
void pa_context_set_subscribe_callback(pa_context *c, pa_context_subscribe_cb_t cb, void *userdata);
+/** Set the context specific call back function that is called whenever pulseaudio sends a signal, \since 12.0 */
+void pa_context_set_signal_callback(pa_context *c, pa_context_signal_cb_t cb, void *userdata);
+
PA_C_DECL_END
#endif
diff --git a/src/pulsecore/core.h b/src/pulsecore/core.h
index bc8a371e..f578d07f 100644
--- a/src/pulsecore/core.h
+++ b/src/pulsecore/core.h
@@ -138,6 +138,7 @@ typedef enum pa_core_hook {
PA_CORE_HOOK_SAMPLE_CACHE_NEW,
PA_CORE_HOOK_SAMPLE_CACHE_CHANGED,
PA_CORE_HOOK_SAMPLE_CACHE_UNLINK,
+ PA_CORE_HOOK_SEND_SIGNAL,
PA_CORE_HOOK_MAX
} pa_core_hook_t;
diff --git a/src/pulsecore/message-handler.c b/src/pulsecore/message-handler.c
index 21cb8278..8f8830d6 100644
--- a/src/pulsecore/message-handler.c
+++ b/src/pulsecore/message-handler.c
@@ -126,3 +126,19 @@ int pa_message_handler_set_description(pa_core *c, const char *recipient_name, c
return PA_OK;
}
+
+/* Send a signal */
+void pa_signal_post(pa_core *c, const char *sender, uint64_t facility, const char *signal, const char *signal_parameters) {
+ struct pa_signal_descriptor sd;
+
+ pa_assert(sender);
+ pa_assert(facility);
+ pa_assert(signal);
+
+ sd.sender = sender;
+ sd.facility = facility;
+ sd.signal = signal;
+ sd.parameters = signal_parameters;
+
+ pa_hook_fire(&c->hooks[PA_CORE_HOOK_SEND_SIGNAL], &sd);
+}
diff --git a/src/pulsecore/message-handler.h b/src/pulsecore/message-handler.h
index 8cb34c3a..b38e2ca8 100644
--- a/src/pulsecore/message-handler.h
+++ b/src/pulsecore/message-handler.h
@@ -47,4 +47,17 @@ int pa_message_handler_send_message(pa_core *c, const char *recipient_name, cons
/* Set handler description */
int pa_message_handler_set_description(pa_core *c, const char *recipient_name, const char *description);
+
+/* Signals */
+
+/* Structure to pass signal information */
+struct pa_signal_descriptor {
+ const char *sender;
+ const char *signal;
+ const char *parameters;
+ uint64_t facility;
+};
+
+/* Send a signal */
+void pa_signal_post(pa_core *c, const char *sender, uint64_t facility, const char *signal, const char *signal_parameters);
#endif
diff --git a/src/pulsecore/native-common.h b/src/pulsecore/native-common.h
index 5c3cf521..4a494517 100644
--- a/src/pulsecore/native-common.h
+++ b/src/pulsecore/native-common.h
@@ -190,6 +190,9 @@ enum {
/* Supported since protocol v33 (12.0) */
PA_COMMAND_SEND_OBJECT_MESSAGE,
+ /* Supported since protocol v33 (12.0) */
+ PA_COMMAND_SUBSCRIBE_SIGNALS,
+
PA_COMMAND_MAX
};
diff --git a/src/pulsecore/pdispatch.c b/src/pulsecore/pdispatch.c
index d317a15e..06becc9e 100644
--- a/src/pulsecore/pdispatch.c
+++ b/src/pulsecore/pdispatch.c
@@ -85,6 +85,7 @@ static const char *command_names[PA_COMMAND_MAX] = {
[PA_COMMAND_GET_SOURCE_OUTPUT_INFO] = "GET_SOURCE_OUTPUT_INFO",
[PA_COMMAND_GET_SOURCE_OUTPUT_INFO_LIST] = "GET_SOURCE_OUTPUT_INFO_LIST",
[PA_COMMAND_SUBSCRIBE] = "SUBSCRIBE",
+ [PA_COMMAND_SUBSCRIBE_SIGNALS] = "SUBSCRIBE_SIGNALS",
[PA_COMMAND_SET_SINK_VOLUME] = "SET_SINK_VOLUME",
[PA_COMMAND_SET_SINK_INPUT_VOLUME] = "SET_SINK_INPUT_VOLUME",
diff --git a/src/pulsecore/protocol-native.c b/src/pulsecore/protocol-native.c
index 76905207..11b2bb16 100644
--- a/src/pulsecore/protocol-native.c
+++ b/src/pulsecore/protocol-native.c
@@ -187,6 +187,7 @@ struct pa_native_connection {
pa_idxset *record_streams, *output_streams;
uint32_t rrobin_index;
pa_subscription *subscription;
+ uint64_t signal_mask;
pa_time_event *auth_timeout_event;
pa_srbchannel *srbpending;
};
@@ -204,6 +205,8 @@ struct pa_native_protocol {
pa_hook hooks[PA_NATIVE_HOOK_MAX];
pa_hashmap *extensions;
+
+ pa_hook_slot *signal_hook_slot;
};
enum {
@@ -3722,6 +3725,26 @@ static void command_subscribe(pa_pdispatch *pd, uint32_t command, uint32_t tag,
pa_pstream_send_simple_ack(c->pstream, tag);
}
+static void command_signal_subscribe(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
+ pa_native_connection *c = PA_NATIVE_CONNECTION(userdata);
+ uint64_t m;
+
+ pa_native_connection_assert_ref(c);
+ pa_assert(t);
+
+ if (pa_tagstruct_getu64(t, &m) < 0 ||
+ !pa_tagstruct_eof(t)) {
+ protocol_error(c);
+ return;
+ }
+
+ CHECK_VALIDITY(c->pstream, c->authorized, tag, PA_ERR_ACCESS);
+
+ c->signal_mask = m;
+
+ pa_pstream_send_simple_ack(c->pstream, tag);
+}
+
static void command_set_volume(
pa_pdispatch *pd,
uint32_t command,
@@ -4920,6 +4943,7 @@ static const pa_pdispatch_cb_t command_table[PA_COMMAND_MAX] = {
[PA_COMMAND_GET_SAMPLE_INFO_LIST] = command_get_info_list,
[PA_COMMAND_GET_SERVER_INFO] = command_get_server_info,
[PA_COMMAND_SUBSCRIBE] = command_subscribe,
+ [PA_COMMAND_SUBSCRIBE_SIGNALS] = command_signal_subscribe,
[PA_COMMAND_SET_SINK_VOLUME] = command_set_volume,
[PA_COMMAND_SET_SINK_INPUT_VOLUME] = command_set_volume,
@@ -5268,6 +5292,33 @@ void pa_native_protocol_disconnect(pa_native_protocol *p, pa_module *m) {
native_connection_unlink(c);
}
+static pa_hook_result_t native_protocol_signal_hook(pa_core *core, struct pa_signal_descriptor *sd, pa_native_protocol *p) {
+ pa_native_connection *c;
+ uint32_t idx;
+
+ pa_assert(p);
+ pa_assert(sd);
+
+ PA_IDXSET_FOREACH(c, p->connections, idx) {
+ if (sd->facility & c->signal_mask) {
+ pa_tagstruct *t;
+
+ pa_native_connection_assert_ref(c);
+
+ t = pa_tagstruct_new();
+ pa_tagstruct_putu32(t, PA_COMMAND_SUBSCRIBE_EVENT);
+ pa_tagstruct_putu32(t, (uint32_t) -1);
+ pa_tagstruct_putu32(t, PA_SUBSCRIPTION_EVENT_SIGNAL);
+ pa_tagstruct_puts(t, sd->sender);
+ pa_tagstruct_puts(t, sd->signal);
+ pa_tagstruct_puts(t, sd->parameters);
+ pa_pstream_send_tagstruct(c->pstream, t);
+ }
+ }
+
+ return PA_HOOK_OK;
+}
+
static pa_native_protocol* native_protocol_new(pa_core *c) {
pa_native_protocol *p;
pa_native_hook_t h;
@@ -5286,6 +5337,8 @@ static pa_native_protocol* native_protocol_new(pa_core *c) {
for (h = 0; h < PA_NATIVE_HOOK_MAX; h++)
pa_hook_init(&p->hooks[h], p);
+ p->signal_hook_slot = pa_hook_connect(&c->hooks[PA_CORE_HOOK_SEND_SIGNAL], PA_HOOK_NORMAL, (pa_hook_cb_t) native_protocol_signal_hook, p);
+
pa_assert_se(pa_shared_set(c, "native-protocol", p) >= 0);
return p;
@@ -5326,6 +5379,9 @@ void pa_native_protocol_unref(pa_native_protocol *p) {
pa_strlist_free(p->servers);
+ if (p->signal_hook_slot)
+ pa_hook_slot_free(p->signal_hook_slot);
+
for (h = 0; h < PA_NATIVE_HOOK_MAX; h++)
pa_hook_done(&p->hooks[h]);
--
2.14.1
