gatchat: add g_at_chat_retry()

The current API doesn't support canceling an in-progress command;
instead g_at_chat_cancel() simply removes the callback.

In cases where the modem doesn't respond at all to a command, a chat is
simply stalled without any way to write new commands to the modem.

Support that case by adding a g_at_chat_retry() function to the API. The
function does nothing if the command is not yet in-progress, or if the
command is finished. Otherwise, it resets the bytes-written counter to
re-write the command string.

1 files changed, 7 insertions, 0 deletions

diff --git a/gatchat/gatchat.h b/gatchat/gatchat.h
index 7290b34f..32870318 100644
--- a/gatchat/gatchat.h
+++ b/gatchat/gatchat.h
@@ -147,6 +147,13 @@ guint g_at_chat_send_and_expect_short_prompt(GAtChat *chat, const char *cmd,
 				const char **valid_resp, GAtResultFunc func,
 				gpointer user_data, GDestroyNotify notify);
 
+/*!
+ * Retry an already created command. This does nothing if the command is
+ * still waiting in the queue. If the command has been written to the channel,
+ * but no response is received yet, the retry writes the command again.
+ */
+gboolean g_at_chat_retry(GAtChat *chat, guint id);
+
 gboolean g_at_chat_cancel(GAtChat *chat, guint id);
 gboolean g_at_chat_cancel_all(GAtChat *chat);