[porthole] added connection state support

VERSION

@@ -1 +1 @@
-B1-31-gf4ad730cc4+1
+B1-40-g968b313993+1

porthole/include/porthole/device.h

@@ -24,13 +24,20 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 
 typedef struct PortholeDev *PortholeDev;
 typedef int    PortholeID;
+typedef enum   PortholeState
+{
+  PH_STATE_NEW_SESSION,
+  PH_STATE_CONNECTED,
+  PH_STATE_DISCONNECTED
+}
+PortholeState;
 
 /**
  * Open the porthole device
  *
- * @param   handle    The returned handle if successful, otherwise undefined
- * @param   vendor_id The subsystem vendor and device id to match
- * @returns true on success
+ * @param  handle    The returned handle if successful, otherwise undefined
+ * @param  vendor_id The subsystem vendor and device id to match
+ * @return true on success
  *
  * If successful the handle must be closed to free resources when finished.
  */
@@ -45,14 +52,38 @@ bool porthole_dev_open(PortholeDev *handle, const uint32_t vendor_id);
  */
 void porthole_dev_close(PortholeDev *handle);
 
+/**
+ * Get the state of the porthole device
+ *
+ * @param  handle The porthole device handle obtained form porthole_dev_open
+ * @return The current state of the connection
+ *
+ * This method will return the current state of the porthole device
+ *
+ *   * PH_STATE_NEW_SESSION  = The client has connected
+ *   * PH_STATE_CONNECTED    = The client is still connected
+ *   * PH_STATE_DISCONNECTED = There is no client connection
+ */
+PortholeState porthole_dev_get_state(PortholeDev handle);
+
+/**
+ * Wait for the specified state
+ *
+ * @param  handle  The porthole device handle obtained from porthole_dev_open
+ * @param  state   The state to wait for
+ * @param  timeout The maximum amount of time to wait in milliseconds for the state (0 = infinite)
+ * @return true on success, false on timeout
+ */
+bool porthole_dev_wait_state(PortholeDev handle, const PortholeState state, const unsigned int timeout);
+
 /**
  * Share the provided buffer over the porthole device
  *
- * @param   handle The porthole device
- * @param   type   The type
- * @param   buffer The buffer to share
- * @param   size   The size of the buffer
- * @returns the porthole mapping ID, or -1 on failure
+ * @param  handle The porthole device
+ * @param  type   The type
+ * @param  buffer The buffer to share
+ * @param  size   The size of the buffer
+ * @return the porthole mapping ID, or -1 on failure
  *
  * This function locks the supplied buffer in RAM via the porthole device
  * driver and is then shared with the device for use outside the guest.
@@ -73,9 +104,9 @@ PortholeID porthole_dev_map(PortholeDev handle, const uint32_t type, void *buffe
 /**
  * Unmap a previously shared buffer
  *
- * @param handle The porthole device
- * @param id     The porthole map id returned by porthole_dev_share
- * @returns true on success
+ * @param  handle The porthole device
+ * @param  id     The porthole map id returned by porthole_dev_share
+ * @return true on success
  *
  * Unmaps a previously shared buffer. Once this has been done the buffer can
  * be freed or re-used. The client application should no longer attempt to

porthole/src/windows/device.c

@@ -28,7 +28,9 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 
 struct PortholeDev
 {
-  HANDLE dev;
+  HANDLE         dev;
+  bool           connected;
+  PortholeEvents events;
 };
 
 bool porthole_dev_open(PortholeDev *handle, const uint32_t vendor_id)
@@ -113,6 +115,22 @@ bool porthole_dev_open(PortholeDev *handle, const uint32_t vendor_id)
 
   (*handle)->dev = dev;
 
+  /* create the events and register them */
+  (*handle)->events.connect    = CreateEvent(NULL, FALSE, FALSE, NULL);
+  (*handle)->events.disconnect = CreateEvent(NULL, FALSE, FALSE, NULL);
+
+  DWORD returned;
+  if (!DeviceIoControl(dev, IOCTL_PORTHOLE_REGISTER_EVENTS, &(*handle)->events, sizeof(PortholeEvents), NULL, 0, &returned, NULL))
+  {
+    DEBUG_ERROR("Failed to register the events");
+    CloseHandle((*handle)->events.connect   );
+    CloseHandle((*handle)->events.disconnect);
+    CloseHandle(dev);
+    free(*handle);
+    *handle = NULL;
+    return false;
+  }
+
   return true;
 }
 
@@ -120,11 +138,89 @@ void porthole_dev_close(PortholeDev *handle)
 {
   assert(handle && *handle);
 
+  CloseHandle((*handle)->events.connect   );
+  CloseHandle((*handle)->events.disconnect);
   CloseHandle((*handle)->dev);
   free(*handle);
   *handle = NULL;
 }
 
+static PortholeState get_state(PortholeDev handle, unsigned int timeout)
+{
+  if (handle->connected)
+  {
+    switch(WaitForSingleObject(handle->events.disconnect, timeout))
+    {
+      case WAIT_OBJECT_0:
+        handle->connected = false;
+        return PH_STATE_DISCONNECTED;
+
+      case WAIT_TIMEOUT:
+        return PH_STATE_CONNECTED;
+
+      default:
+        DEBUG_FATAL("Error waiting on disconnect event");
+        break;
+    }
+  }
+
+  switch(WaitForSingleObject(handle->events.connect, timeout))
+  {
+    case WAIT_OBJECT_0:
+      handle->connected = true;
+      return PH_STATE_NEW_SESSION;
+
+    case WAIT_TIMEOUT:
+      return PH_STATE_DISCONNECTED;
+
+    default:
+      DEBUG_FATAL("Error waiting on connection event");
+      break;
+  }
+}
+
+PortholeState porthole_dev_get_state(PortholeDev handle)
+{
+  return get_state(handle, 0);
+}
+
+bool porthole_dev_wait_state(PortholeDev handle, const PortholeState state, const unsigned int timeout)
+{
+  const DWORD to = (timeout == 0) ? INFINITE : timeout;
+  PortholeState lastState = get_state(handle, 0);
+
+  if (state == lastState)
+    return true;
+
+  while(true)
+  {
+    PortholeState nextState;
+    switch(lastState)
+    {
+      case PH_STATE_DISCONNECTED:
+        nextState = PH_STATE_NEW_SESSION;
+        break;
+
+      case PH_STATE_NEW_SESSION:
+        nextState = PH_STATE_CONNECTED;
+        break;
+
+      case PH_STATE_CONNECTED:
+        nextState = PH_STATE_DISCONNECTED;
+        break;
+    }
+
+    PortholeState newState = get_state(handle, to);
+    if (newState == lastState || newState != nextState)
+      return false;
+
+    if (newState == state)
+      return true;
+
+    lastState = newState;
+  }
+}
+
 PortholeID porthole_dev_map(PortholeDev handle, const uint32_t type, void *buffer, size_t size)
 {
   assert(handle);