Users need to be extra careful using the cancel functions because there's a potential race condition where an OK or ERROR for the command being cancelled arrives just the same moment the next command in the queue is being submitted, and is treated as a response to that command. Ideally we would have some kind of "barrier" command that could be inserted into the queue and whose response would be different than OK or ERROR. --- gatchat/gatchat.c | 32 +++++++++++++++----------------- 1 files changed, 15 insertions(+), 17 deletions(-) diff --git a/gatchat/gatchat.c b/gatchat/gatchat.c index f94605f..4552767 100644 --- a/gatchat/gatchat.c +++ b/gatchat/gatchat.c @@ -1026,6 +1026,7 @@ guint g_at_chat_send_pdu_listing(GAtChat *chat, const char *cmd, gboolean g_at_chat_cancel(GAtChat *chat, guint id) { GList *l; + gboolean head; if (chat == NULL || chat->command_queue == NULL) return FALSE; @@ -1040,18 +1041,20 @@ gboolean g_at_chat_cancel(GAtChat *chat, guint id) if (!l) return FALSE; - if (l == g_queue_peek_head(chat->command_queue) && - chat->cmd_bytes_written > 0) { - struct at_command *c = l->data; + head = l->data == g_queue_peek_head(chat->command_queue); - /* We can't actually remove it since it is most likely - * already in progress, just null out the callback - * so it won't be called - */ - c->callback = NULL; - } else { - at_command_destroy(l->data); - g_queue_remove(chat->command_queue, l->data); + at_command_destroy(l->data); + g_queue_remove(chat->command_queue, l->data); + + if (head) { + chat->cmd_bytes_written = 0; + + g_slist_foreach(chat->response_lines, (GFunc)g_free, NULL); + g_slist_free(chat->response_lines); + chat->response_lines = NULL; + + if (g_queue_get_length(chat->command_queue) > 0) + chat_wakeup_writer(chat); } return TRUE; @@ -1071,15 +1074,10 @@ gboolean g_at_chat_cancel_all(GAtChat *chat) continue; } - if (n == 0 && chat->cmd_bytes_written > 0) { - c->callback = NULL; - n += 1; - continue; - } - at_command_destroy(c); g_queue_remove(chat->command_queue, c); } + chat->cmd_bytes_written = 0; return TRUE; } -- 1.6.1