base-modem-at: add optional wait before sending command in a sequence

Can be used for easier command retries where the generic sequence code
handles the GTimeout source.

Signed-off-by: Dan Williams <dcbw@redhat.com>

src/mm-base-modem-at.c

@@ -91,8 +91,13 @@ typedef struct {
     gpointer                    response_processor_context;
     GDestroyNotify              response_processor_context_free;
     GVariant                   *result;
+    guint                       next_command_wait_id;
 } AtSequenceContext;
 
+static void at_sequence_parse_response (MMPortSerialAt    *port,
+                                        GAsyncResult      *res,
+                                        GTask             *task);
+
 static void
 at_sequence_context_free (AtSequenceContext *ctx)
 {
@@ -109,6 +114,11 @@ at_sequence_context_free (AtSequenceContext *ctx)
         g_object_unref (ctx->parent_cancellable);
     }
 
+    if (ctx->next_command_wait_id > 0) {
+        g_source_remove (ctx->next_command_wait_id);
+        ctx->next_command_wait_id = 0;
+    }
+
     if (ctx->result)
         g_variant_unref (ctx->result);
     g_free (ctx);
@@ -140,6 +150,28 @@ mm_base_modem_at_sequence_full_finish (MMBaseModem   *self,
     return result;
 }
 
+static gboolean
+at_sequence_next_command (GTask *task)
+{
+    AtSequenceContext *ctx;
+
+    ctx = g_task_get_task_data (task);
+    ctx->next_command_wait_id = 0;
+
+    /* Schedule the next command in the probing group */
+    mm_port_serial_at_command (
+        ctx->port,
+        ctx->current->command,
+        ctx->current->timeout,
+        FALSE,
+        ctx->current->allow_cached,
+        g_task_get_cancellable (task),
+        (GAsyncReadyCallback)at_sequence_parse_response,
+        task);
+
+    return G_SOURCE_REMOVE;
+}
+
 static void
 at_sequence_parse_response (MMPortSerialAt    *port,
                             GAsyncResult      *res,
@@ -201,16 +233,8 @@ at_sequence_parse_response (MMPortSerialAt    *port,
     if (processor_result == MM_BASE_MODEM_AT_RESPONSE_PROCESSOR_RESULT_CONTINUE) {
         ctx->current++;
         if (ctx->current->command) {
-            /* Schedule the next command in the probing group */
-            mm_port_serial_at_command (
-                ctx->port,
-                ctx->current->command,
-                ctx->current->timeout,
-                FALSE,
-                ctx->current->allow_cached,
-                g_task_get_cancellable (task),
-                (GAsyncReadyCallback)at_sequence_parse_response,
-                task);
+            g_assert (!ctx->next_command_wait_id);
+            ctx->next_command_wait_id = g_timeout_add_seconds (ctx->current->wait_seconds, (GSourceFunc) at_sequence_next_command, task);
             return;
         }
         /* On last command, end. */

src/mm-base-modem-at.h

@@ -67,6 +67,8 @@ typedef struct {
     gboolean allow_cached;
     /* The response processor */
     MMBaseModemAtResponseProcessor response_processor;
+    /* Time to wait before sending this command (in seconds) */
+    guint wait_seconds;
 } MMBaseModemAtCommand;
 
 /* Generic AT sequence handling, using the best AT port available and without
@@ -220,6 +222,7 @@ typedef struct {
     guint     timeout;
     gboolean  allow_cached;
     MMBaseModemAtResponseProcessor response_processor;
+    guint     wait_seconds;
 } MMBaseModemAtCommandAlloc;
 
 G_STATIC_ASSERT (sizeof (MMBaseModemAtCommandAlloc) == sizeof (MMBaseModemAtCommand));