Add new usbmuxd_events_subscribe/unsubscribe functions with a context so it can be used in different threads
diff --git a/common/collection.c b/common/collection.c
index ccc4016..d120b3e 100644
--- a/common/collection.c
+++ b/common/collection.c
@@ -57,16 +57,17 @@
col->capacity *= 2;
}
-void collection_remove(struct collection *col, void *element)
+int collection_remove(struct collection *col, void *element)
{
int i;
for(i=0; i<col->capacity; i++) {
if(col->list[i] == element) {
col->list[i] = NULL;
- return;
+ return 0;
}
}
fprintf(stderr, "%s: WARNING: element %p not present in collection %p (cap %d)", __func__, element, col, col->capacity);
+ return -1;
}
int collection_count(struct collection *col)
diff --git a/common/collection.h b/common/collection.h
index a91a465..47b9b7f 100644
--- a/common/collection.h
+++ b/common/collection.h
@@ -29,7 +29,7 @@
void collection_init(struct collection *col);
void collection_add(struct collection *col, void *element);
-void collection_remove(struct collection *col, void *element);
+int collection_remove(struct collection *col, void *element);
int collection_count(struct collection *col);
void collection_free(struct collection *col);
diff --git a/include/usbmuxd.h b/include/usbmuxd.h
index 6d035a2..9323717 100644
--- a/include/usbmuxd.h
+++ b/include/usbmuxd.h
@@ -80,19 +80,57 @@
typedef void (*usbmuxd_event_cb_t) (const usbmuxd_event_t *event, void *user_data);
/**
- * Subscribe a callback function so that applications get to know about
- * device add/remove events.
+ * Subscription context type.
+ */
+typedef struct usbmuxd_subscription_context* usbmuxd_subscription_context_t;
+
+/**
+ * Subscribe a callback function to be called upon device add/remove events.
+ * This method can be called multiple times to register multiple callbacks
+ * since every subscription will have its own context (returned in the
+ * first parameter).
+ *
+ * @param context A pointer to a usbmuxd_subscription_context_t that will be
+ * set upon creation of the subscription. The returned context must be
+ * passed to usbmuxd_events_unsubscribe() to unsubscribe the callback.
+ * @param callback A callback function that is executed when an event occurs.
+ * @param user_data Custom data passed on to the callback function. The data
+ * needs to be kept available until the callback function is unsubscribed.
+ *
+ * @return 0 on success or a negative errno value.
+ */
+int usbmuxd_events_subscribe(usbmuxd_subscription_context_t *context, usbmuxd_event_cb_t callback, void *user_data);
+
+/**
+ * Unsubscribe callback function
+ *
+ * @param context A valid context as returned from usbmuxd_events_subscribe().
+ *
+ * @return 0 on success or a negative errno value.
+ */
+int usbmuxd_events_unsubscribe(usbmuxd_subscription_context_t context);
+
+/**
+ * Subscribe a callback (deprecated)
*
* @param callback A callback function that is executed when an event occurs.
+ * @param user_data Custom data passed on to the callback function. The data
+ * needs to be kept available until the callback function is unsubscribed.
*
* @return 0 on success or negative on error.
+ *
+ * @note Deprecated. Use usbmuxd_events_subscribe and usbmuxd_events_unsubscribe instead.
+ * @see usbmuxd_events_subscribe
*/
int usbmuxd_subscribe(usbmuxd_event_cb_t callback, void *user_data);
/**
- * Unsubscribe callback.
+ * Unsubscribe callback (deprecated)
*
- * @return only 0 for now.
+ * @return 0 on success or negative on error.
+ *
+ * @note Deprecated. Use usbmuxd_events_subscribe and usbmuxd_events_unsubscribe instead.
+ * @see usbmuxd_events_unsubscribe
*/
int usbmuxd_unsubscribe();
diff --git a/src/libusbmuxd.c b/src/libusbmuxd.c
index 4a52f67..340d75a 100644
--- a/src/libusbmuxd.c
+++ b/src/libusbmuxd.c
@@ -1,7 +1,7 @@
/*
* libusbmuxd.c
*
- * Copyright (C) 2009-2018 Nikias Bassen <nikias@gmx.li>
+ * Copyright (C) 2009-2019 Nikias Bassen <nikias@gmx.li>
* Copyright (C) 2009-2014 Martin Szulecki <m.szulecki@libimobiledevice.org>
* Copyright (C) 2009 Paul Sladen <libiphone@paul.sladen.org>
*
@@ -115,14 +115,25 @@
#define LIBUSBMUXD_ERROR(format, ...) LIBUSBMUXD_DEBUG(0, format, __VA_ARGS__)
static struct collection devices;
-static usbmuxd_event_cb_t event_cb = NULL;
static THREAD_T devmon = THREAD_T_NULL;
static int listenfd = -1;
+static int cancelling = 0;
static volatile int use_tag = 0;
static volatile int proto_version = 1;
static volatile int try_list_devices = 1;
+struct usbmuxd_subscription_context {
+ usbmuxd_event_cb_t callback;
+ void *user_data;
+};
+
+static struct usbmuxd_subscription_context *event_ctx = NULL;
+
+static struct collection listeners;
+thread_once_t listener_init_once = THREAD_ONCE_INIT;
+mutex_t listener_mutex;
+
/**
* Finds a device info record by its handle.
* if the record is not found, NULL is returned.
@@ -319,7 +330,9 @@
recv_len = socket_receive_timeout(sfd, &hdr, sizeof(hdr), 0, timeout);
if (recv_len < 0) {
- LIBUSBMUXD_DEBUG(1, "%s: Error receiving packet: %d\n", __func__, recv_len);
+ if (!cancelling) {
+ LIBUSBMUXD_DEBUG(1, "%s: Error receiving packet: %s\n", __func__, strerror(-recv_len));
+ }
return recv_len;
} else if ((size_t)recv_len < sizeof(hdr)) {
LIBUSBMUXD_DEBUG(1, "%s: Received packet is too small, got %d bytes!\n", __func__, recv_len);
@@ -802,18 +815,22 @@
* A reference to a populated usbmuxd_event_t with information about the event
* and the corresponding device will be passed to the callback function.
*/
-static void generate_event(usbmuxd_event_cb_t callback, const usbmuxd_device_info_t *dev, enum usbmuxd_event_type event, void *user_data)
+static void generate_event(const usbmuxd_device_info_t *dev, enum usbmuxd_event_type event)
{
usbmuxd_event_t ev;
- if (!callback || !dev) {
+ if (!dev) {
return;
}
ev.event = event;
memcpy(&ev.device, dev, sizeof(usbmuxd_device_info_t));
- callback(&ev, user_data);
+ mutex_lock(&listener_mutex);
+ FOREACH(struct usbmuxd_subscription_context* context, &listeners) {
+ context->callback(&ev, context->user_data);
+ } ENDFOREACH
+ mutex_unlock(&listener_mutex);
}
static int usbmuxd_listen_poll()
@@ -822,7 +839,13 @@
sfd = connect_usbmuxd_socket();
if (sfd < 0) {
- while (event_cb) {
+ while (1) {
+ mutex_lock(&listener_mutex);
+ int num = collection_count(&listeners);
+ mutex_unlock(&listener_mutex);
+ if (num <= 0) {
+ break;
+ }
if ((sfd = connect_usbmuxd_socket()) >= 0) {
break;
}
@@ -949,19 +972,21 @@
* Waits for an event to occur, i.e. a packet coming from usbmuxd.
* Calls generate_event to pass the event via callback to the client program.
*/
-static int get_next_event(int sfd, usbmuxd_event_cb_t callback, void *user_data)
+static int get_next_event(int sfd)
{
struct usbmuxd_header hdr;
void *payload = NULL;
/* block until we receive something */
if (receive_packet(sfd, &hdr, &payload, 0) < 0) {
- LIBUSBMUXD_DEBUG(1, "%s: Error in usbmuxd connection, disconnecting all devices!\n", __func__);
+ if (!cancelling) {
+ LIBUSBMUXD_DEBUG(1, "%s: Error in usbmuxd connection, disconnecting all devices!\n", __func__);
+ }
// when then usbmuxd connection fails,
// generate remove events for every device that
// is still present so applications know about it
FOREACH(usbmuxd_device_info_t *dev, &devices) {
- generate_event(callback, dev, UE_DEVICE_REMOVE, user_data);
+ generate_event(dev, UE_DEVICE_REMOVE);
collection_remove(&devices, dev);
free(dev);
} ENDFOREACH
@@ -976,7 +1001,7 @@
if (hdr.message == MESSAGE_DEVICE_ADD) {
usbmuxd_device_info_t *devinfo = (usbmuxd_device_info_t*)payload;
collection_add(&devices, devinfo);
- generate_event(callback, devinfo, UE_DEVICE_ADD, user_data);
+ generate_event(devinfo, UE_DEVICE_ADD);
payload = NULL;
} else if (hdr.message == MESSAGE_DEVICE_REMOVE) {
uint32_t handle;
@@ -988,7 +1013,7 @@
if (!devinfo) {
LIBUSBMUXD_DEBUG(1, "%s: WARNING: got device remove message for handle %d, but couldn't find the corresponding handle in the device list. This event will be ignored.\n", __func__, handle);
} else {
- generate_event(callback, devinfo, UE_DEVICE_REMOVE, user_data);
+ generate_event(devinfo, UE_DEVICE_REMOVE);
collection_remove(&devices, devinfo);
free(devinfo);
}
@@ -1002,7 +1027,7 @@
if (!devinfo) {
LIBUSBMUXD_DEBUG(1, "%s: WARNING: got paired message for device handle %d, but couldn't find the corresponding handle in the device list. This event will be ignored.\n", __func__, handle);
} else {
- generate_event(callback, devinfo, UE_DEVICE_PAIRED, user_data);
+ generate_event(devinfo, UE_DEVICE_PAIRED);
}
} else if (hdr.length > 0) {
LIBUSBMUXD_DEBUG(1, "%s: Unexpected message type %d length %d received!\n", __func__, hdr.message, hdr.length);
@@ -1032,68 +1057,145 @@
*/
static void *device_monitor(void *data)
{
+ int running = 1;
collection_init(&devices);
+ cancelling = 0;
#ifdef HAVE_THREAD_CLEANUP
thread_cleanup_push(device_monitor_cleanup, NULL);
#endif
- while (event_cb) {
+ do {
listenfd = usbmuxd_listen();
if (listenfd < 0) {
continue;
}
- while (event_cb) {
- int res = get_next_event(listenfd, event_cb, data);
+ while (running) {
+ int res = get_next_event(listenfd);
if (res < 0) {
break;
}
}
- }
+
+ mutex_lock(&listener_mutex);
+ if (collection_count(&listeners) == 0) {
+ running = 0;
+ }
+ mutex_unlock(&listener_mutex);
+ } while (running);
#ifdef HAVE_THREAD_CLEANUP
thread_cleanup_pop(1);
#else
device_monitor_cleanup(NULL);
#endif
+
return NULL;
}
+static void init_listeners(void)
+{
+ collection_init(&listeners);
+ mutex_init(&listener_mutex);
+}
+
+USBMUXD_API int usbmuxd_events_subscribe(usbmuxd_subscription_context_t *ctx, usbmuxd_event_cb_t callback, void *user_data)
+{
+ if (!ctx || !callback) {
+ return -EINVAL;
+ }
+
+ thread_once(&listener_init_once, init_listeners);
+
+ mutex_lock(&listener_mutex);
+ *ctx = malloc(sizeof(struct usbmuxd_subscription_context));
+ if (!*ctx) {
+ mutex_unlock(&listener_mutex);
+ LIBUSBMUXD_ERROR("ERROR: %s: malloc failed\n", __func__);
+ return -ENOMEM;
+ }
+ (*ctx)->callback = callback;
+ (*ctx)->user_data = user_data;
+
+ collection_add(&listeners, *ctx);
+
+ if (devmon == THREAD_T_NULL || !thread_alive(devmon)) {
+ mutex_unlock(&listener_mutex);
+ int res = thread_new(&devmon, device_monitor, NULL);
+ if (res != 0) {
+ free(*ctx);
+ LIBUSBMUXD_DEBUG(1, "%s: ERROR: Could not start device watcher thread!\n", __func__);
+ return res;
+ }
+ } else {
+ /* we need to submit DEVICE_ADD events to the new listener */
+ FOREACH(usbmuxd_device_info_t *dev, &devices) {
+ if (dev) {
+ usbmuxd_event_t ev;
+ ev.event = UE_DEVICE_ADD;
+ memcpy(&ev.device, dev, sizeof(usbmuxd_device_info_t));
+ (*ctx)->callback(&ev, (*ctx)->user_data);
+ }
+ } ENDFOREACH
+ mutex_unlock(&listener_mutex);
+ }
+
+ return 0;
+}
+
+USBMUXD_API int usbmuxd_events_unsubscribe(usbmuxd_subscription_context_t ctx)
+{
+ int ret = 0;
+ int num = 0;
+
+ if (!ctx) {
+ return -EINVAL;
+ }
+
+ mutex_lock(&listener_mutex);
+ if (collection_remove(&listeners, ctx) == 0) {
+ free(ctx);
+ }
+ num = collection_count(&listeners);
+ mutex_unlock(&listener_mutex);
+
+ if (num == 0) {
+ int res = 0;
+ cancelling = 1;
+ socket_shutdown(listenfd, SHUT_RDWR);
+ if (thread_alive(devmon)) {
+ thread_cancel(devmon);
+ res = thread_join(devmon);
+ thread_free(devmon);
+ devmon = THREAD_T_NULL;
+ }
+ if ((res != 0) && (res != ESRCH)) {
+ ret = res;
+ }
+ }
+
+ return ret;
+}
+
USBMUXD_API int usbmuxd_subscribe(usbmuxd_event_cb_t callback, void *user_data)
{
- int res;
-
if (!callback) {
return -EINVAL;
}
- event_cb = callback;
- res = thread_new(&devmon, device_monitor, user_data);
- if (res != 0) {
- LIBUSBMUXD_DEBUG(1, "%s: ERROR: Could not start device watcher thread!\n", __func__);
- return res;
+ if (event_ctx) {
+ usbmuxd_events_unsubscribe(event_ctx);
+ event_ctx = NULL;
}
- return 0;
+ return usbmuxd_events_subscribe(&event_ctx, callback, user_data);
}
USBMUXD_API int usbmuxd_unsubscribe()
{
- int res = 0;
- event_cb = NULL;
-
- socket_shutdown(listenfd, SHUT_RDWR);
-
- if (thread_alive(devmon)) {
- thread_cancel(devmon);
- res = thread_join(devmon);
- thread_free(devmon);
- }
- if ((res != 0) && (res != ESRCH)) {
- return res;
- }
-
- return 0;
+ int res = usbmuxd_events_unsubscribe(event_ctx);
+ event_ctx = NULL;
+ return res;
}
USBMUXD_API int usbmuxd_get_device_list(usbmuxd_device_info_t **device_list)
