* @author Philipp Toelke
* @author Christian Grothoff
*/
+
#ifndef GNUNET_HELPER_LIB_H
#define GNUNET_HELPER_LIB_H
/**
- * @brief Starts a helper and begins reading from it
+ * Callback that will be called when the helper process dies. This is not called
+ * when the helper process is stoped using GNUNET_HELPER_stop()
+ *
+ * @param cls the closure from GNUNET_HELPER_start()
+ */
+typedef void (*GNUNET_HELPER_ExceptionCallback) (void *cls);
+
+
+/**
+ * Starts a helper and begins reading from it. The helper process is
+ * restarted when it dies except when it is stopped using GNUNET_HELPER_stop()
+ * or when the exp_cb callback is not NULL.
*
* @param binary_name name of the binary to run
* @param binary_argv NULL-terminated list of arguments to give when starting the binary (this
* argument must not be modified by the client for
* the lifetime of the helper handle)
* @param cb function to call if we get messages from the helper
- * @param cb_cls Closure for the callback
+ * @param exp_cb the exception callback to call. Set this to NULL if the helper
+ * process has to be restarted automatically when it dies/crashes
+ * @param cb_cls closure for the above callbacks
* @return the new Handle, NULL on error
*/
struct GNUNET_HELPER_Handle *
GNUNET_HELPER_start (const char *binary_name,
char *const binary_argv[],
- GNUNET_SERVER_MessageTokenizerCallback cb, void *cb_cls);
+ GNUNET_SERVER_MessageTokenizerCallback cb,
+ GNUNET_HELPER_ExceptionCallback exp_cb,
+ void *cb_cls);
/**
- * @brief Kills the helper, closes the pipe and frees the handle
+ * Kills the helper, closes the pipe and frees the handle
*
* @param h handle to helper to stop
*/
int result);
+/**
+ * Handle to cancel 'send'
+ */
+struct GNUNET_HELPER_SendHandle;
+
+
/**
* Send an message to the helper.
*
* @param can_drop can the message be dropped if there is already one in the queue?
* @param cont continuation to run once the message is out
* @param cont_cls closure for 'cont'
- * @return GNUNET_YES if the message will be sent
- * GNUNET_NO if the message was dropped
+ * @return NULL if the message was dropped,
+ * otherwise handle to cancel *cont* (actual transmission may
+ * not be abortable)
*/
-int
+struct GNUNET_HELPER_SendHandle *
GNUNET_HELPER_send (struct GNUNET_HELPER_Handle *h,
const struct GNUNET_MessageHeader *msg,
int can_drop,
void *cont_cls);
+/**
+ * Cancel a 'send' operation. If possible, transmitting the
+ * message is also aborted, but at least 'cont' won't be
+ * called.
+ *
+ * @param sh operation to cancel
+ */
+void
+GNUNET_HELPER_send_cancel (struct GNUNET_HELPER_SendHandle *sh);
+
#endif /* end of include guard: GNUNET_HELPER_LIB_H */