Core: Keep a list of contexts created by libusb_init()

* This list can be used by backends to determine which contexts
  need notification of device removal (and in the future device arrival).
  The active_contexts_list is protected from multiple access by the active_contexts_lock.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

libusb/core.c

@@ -56,6 +56,9 @@ static int default_context_refcnt = 0;
 static usbi_mutex_static_t default_context_lock = USBI_MUTEX_INITIALIZER;
 static struct timeval timestamp_origin = { 0, 0 };
 
+usbi_mutex_static_t active_contexts_lock = USBI_MUTEX_INITIALIZER;
+struct list_head active_contexts_list;
+
 /**
  * \mainpage libusbx-1.0 API Reference
  *
@@ -1623,6 +1626,7 @@ int API_EXPORTED libusb_init(libusb_context **context)
 {
 	char *dbg;
 	struct libusb_context *ctx;
+	static int first_init = 1;
 	int r = 0;
 
 	usbi_mutex_static_lock(&default_context_lock);
@@ -1688,6 +1692,16 @@ int API_EXPORTED libusb_init(libusb_context **context)
 	}
 	usbi_mutex_static_unlock(&default_context_lock);
 
+	usbi_mutex_static_lock(&active_contexts_lock);
+	if (first_init) {
+		first_init = 0;
+		list_init (&active_contexts_list);
+	}
+
+	list_add (&ctx->list, &active_contexts_list);
+	usbi_mutex_static_unlock(&active_contexts_lock);
+
+
 	return 0;
 
 err_destroy_mutex:
@@ -1724,6 +1738,10 @@ void API_EXPORTED libusb_exit(struct libusb_context *ctx)
 		usbi_mutex_static_unlock(&default_context_lock);
 	}
 
+	usbi_mutex_static_lock(&active_contexts_lock);
+	list_del (&ctx->list);
+	usbi_mutex_static_unlock(&active_contexts_lock);
+
 	/* a little sanity check. doesn't bother with open_devs locking because
 	 * unless there is an application bug, nobody will be accessing this. */
 	if (!list_empty(&ctx->open_devs))

libusb/libusbi.h

@@ -261,6 +261,8 @@ struct libusb_context {
 	 * this timerfd is maintained to trigger on the next pending timeout */
 	int timerfd;
 #endif
+
+	struct list_head list;
 };
 
 #ifdef USBI_TIMERFD_AVAILABLE
@@ -917,4 +919,7 @@ extern const struct usbi_os_backend openbsd_backend;
 extern const struct usbi_os_backend windows_backend;
 extern const struct usbi_os_backend wince_backend;
 
+extern struct list_head active_contexts_list;
+extern usbi_mutex_static_t active_contexts_lock;
+
 #endif

libusb/os/darwin_usb.c

@@ -285,10 +285,8 @@ static kern_return_t darwin_get_device (uint32_t dev_location, usb_device_t ***d
   return kIOReturnSuccess;
 }
 
-
-
 static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
-  struct libusb_context *ctx = (struct libusb_context *)ptr;
+  struct libusb_context *ctx;
   struct libusb_device_handle *handle;
   struct darwin_device_priv *dpriv;
   struct darwin_device_handle_priv *priv;
@@ -311,27 +309,36 @@ static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
       continue;
 
     locationValid = CFGetTypeID(locationCF) == CFNumberGetTypeID() &&
-	    CFNumberGetValue(locationCF, kCFNumberSInt32Type, &location);
+            CFNumberGetValue(locationCF, kCFNumberSInt32Type, &location);
 
     CFRelease (locationCF);
 
     if (!locationValid)
       continue;
 
-    usbi_mutex_lock(&ctx->open_devs_lock);
-    list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
-      dpriv = (struct darwin_device_priv *)handle->dev->os_priv;
+    usbi_mutex_lock(&active_contexts_lock);
 
-      /* the device may have been opened several times. write to each handle's event descriptor */
-      if (dpriv->location == location  && handle->os_priv) {
-	priv  = (struct darwin_device_handle_priv *)handle->os_priv;
+    list_for_each_entry(ctx, &active_contexts_list, list, struct libusb_context) {
+      usbi_mutex_lock(&ctx->open_devs_lock);
 
-	message = MESSAGE_DEVICE_GONE;
-	write (priv->fds[1], &message, sizeof (message));
+      usbi_dbg ("libusb/darwin.c darwin_devices_detached: notifying context %p of device disconnect", ctx);
+
+      list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
+        dpriv = (struct darwin_device_priv *)handle->dev->os_priv;
+
+        /* the device may have been opened several times. write to each handle's event descriptor */
+        if (dpriv->location == location  && handle->os_priv) {
+          priv  = (struct darwin_device_handle_priv *)handle->os_priv;
+
+          message = MESSAGE_DEVICE_GONE;
+          write (priv->fds[1], &message, sizeof (message));
+        }
       }
+
+      usbi_mutex_unlock(&ctx->open_devs_lock);
     }
 
-    usbi_mutex_unlock(&ctx->open_devs_lock);
+    usbi_mutex_unlock(&active_contexts_lock);
   }
 }
 

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 10648
+#define LIBUSB_NANO 10649