merchant

commit 0e86dfd5135d9ee706224be894915ab873a57a77
parent 74add07b81510d98e76ac33353304ddf05500781
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Tue, 14 Jul 2026 23:36:29 +0200

retry outer transaction instead of aborting on inner statement on serialization failures

Diffstat:
M
src/backend/taler-merchant-httpd_post-orders-ORDER_ID-abort.c
 | 
50
+++++++++++++++++++++++++++++++++++++++-----------

1 file changed, 39 insertions(+), 11 deletions(-)
diff --git a/src/backend/taler-merchant-httpd_post-orders-ORDER_ID-abort.c b/src/backend/taler-merchant-httpd_post-orders-ORDER_ID-abort.c
@@ -198,6 +198,16 @@ struct AbortContext
   const char *current_exchange;
 
   /**
+   * Status of the database operations performed by the
+   * #refund_coins() row callback.  Set to
+   * #GNUNET_DB_STATUS_SUCCESS_ONE_RESULT before starting the
+   * iteration over the deposits, and to the failed query status if
+   * one of the refund_coin() operations failed.  Inspected by
+   * #begin_transaction() once the iteration has finished.
+   */
+  enum GNUNET_DB_QueryStatus row_qs;
+
+  /**
    * Number of coins this abort is for.  Length of the @e rd array.
    */
   size_t coins_cnt;
@@ -652,6 +662,10 @@ find_next_exchange (struct AbortContext *ac)
 
 /**
  * Function called with information about a coin that was deposited.
+ * Note that we must not roll back or restart the transaction here, as
+ * we are called from within the iteration over the deposits.  Failures
+ * are merely recorded in @a ac->row_qs and then handled by
+ * #begin_transaction() once the iteration has completed.
  *
  * @param cls closure
  * @param exchange_url exchange where @a coin_pub was deposited
@@ -676,6 +690,8 @@ refund_coins (void *cls,
   (void) deposit_fee;
   (void) refund_fee;
   (void) wire_fee;
+  if (0 > ac->row_qs)
+    return; /* already failed, do not touch the DB any further */
   now = GNUNET_TIME_timestamp_get ();
   for (size_t i = 0; i<ac->coins_cnt; i++)
   {
@@ -701,18 +717,9 @@ refund_coins (void *cls,
                                        "incomplete abortment aborted");
     if (0 > qs)
     {
-      TALER_MERCHANTDB_rollback (TMH_db);
-      if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
-      {
-        begin_transaction (ac);
-        return;
-      }
-      /* Always report on hard error as well to enable diagnostics */
+      /* Always report on hard error to enable diagnostics */
       GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
-      resume_abort_with_error (ac,
-                               MHD_HTTP_INTERNAL_SERVER_ERROR,
-                               TALER_EC_GENERIC_DB_STORE_FAILED,
-                               "refund_coin");
+      ac->row_qs = qs;
       return;
     }
   } /* for all coins */
@@ -832,6 +839,7 @@ begin_transaction (struct AbortContext *ac)
   }
 
   /* Mark all deposits we have in our database for the order as refunded. */
+  ac->row_qs = GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
   qs = TALER_MERCHANTDB_lookup_deposits (TMH_db,
                                          ac->hc->instance->settings.id,
                                          &ac->h_contract_terms,
@@ -853,6 +861,26 @@ begin_transaction (struct AbortContext *ac)
                              "deposits");
     goto cleanup;
   }
+  /* Check if one of the refund_coin() operations done by the
+     #refund_coins() row callback failed; we must handle this here (and
+     not in the callback) as we may only roll back and restart the
+     transaction from outside of the row iteration. */
+  if (0 > ac->row_qs)
+  {
+    TALER_MERCHANTDB_rollback (TMH_db);
+    if (GNUNET_DB_STATUS_SOFT_ERROR == ac->row_qs)
+    {
+      begin_transaction (ac);
+      goto cleanup;
+    }
+    /* Always report on hard error as well to enable diagnostics */
+    GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == ac->row_qs);
+    resume_abort_with_error (ac,
+                             MHD_HTTP_INTERNAL_SERVER_ERROR,
+                             TALER_EC_GENERIC_DB_STORE_FAILED,
+                             "refund_coin");
+    goto cleanup;
+  }
 
   qs = TALER_MERCHANTDB_commit (TMH_db);
   if (0 > qs)