fix various cases where shutdown did not work if long pollers were present (#7166)

7 files changed, 102 insertions, 48 deletions

diff --git a/src/backend/taler-merchant-httpd.c b/src/backend/taler-merchant-httpd.c
index f2de7373..4ee65ef4 100644
--- a/src/backend/taler-merchant-httpd.c
+++ b/src/backend/taler-merchant-httpd.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2014-2021 Taler Systems SA
+  (C) 2014-2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free Software
diff --git a/src/backend/taler-merchant-httpd_get-orders-ID.c b/src/backend/taler-merchant-httpd_get-orders-ID.c
index d6abdc62..9748f469 100644
--- a/src/backend/taler-merchant-httpd_get-orders-ID.c
+++ b/src/backend/taler-merchant-httpd_get-orders-ID.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2014-2021 Taler Systems SA
+  (C) 2014-2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free Software
@@ -131,9 +131,12 @@ struct GetOrderData
 
   /**
    * Did we suspend @a connection and are thus in
-   * the #god_head DLL?
+   * the #god_head DLL (#GNUNET_YES). Set to
+   * #GNUNET_NO if we are not suspended, and to
+   * #GNUNET_SYSERR if we should close the connection
+   * without a response due to shutdown.
    */
-  bool suspended;
+  enum GNUNET_GenericReturnValue suspended;
 
   /**
    * Set to true if we are dealing with a claimed order
@@ -184,7 +187,7 @@ TMH_force_wallet_get_order_resume (void)
                                  god_tail,
                                  god);
     GNUNET_assert (god->suspended);
-    god->suspended = false;
+    god->suspended = GNUNET_SYSERR;
     MHD_resume_connection (god->sc.con);
     TALER_MHD_daemon_trigger ();   /* we resumed, kick MHD */
   }
@@ -267,7 +270,7 @@ resume_by_event (void *cls,
               god->sc.awaiting_refund,
               (int) extra_size,
               (const char *) extra);
-  god->suspended = false;
+  god->suspended = GNUNET_NO;
   GNUNET_CONTAINER_DLL_remove (god_head,
                                god_tail,
                                god);
@@ -295,7 +298,7 @@ suspend_god (struct GetOrderData *god)
     god->contract_terms = NULL;
   }
   GNUNET_assert (! god->suspended);
-  god->suspended = true;
+  god->suspended = GNUNET_YES;
   GNUNET_CONTAINER_DLL_insert (god_head,
                                god_tail,
                                god);
@@ -1003,9 +1006,11 @@ TMH_get_orders_ID (const struct TMH_RequestHandler *rh,
 
   } /* end of first-time initialization / sanity checks */
 
-  if (god->suspended)
+  if (GNUNET_SYSERR == god->suspended)
+    return MHD_NO; /* we are in shutdown */
+  if (GNUNET_YES == god->suspended)
   {
-    god->suspended = false;
+    god->suspended = GNUNET_NO;
     GNUNET_CONTAINER_DLL_remove (god_head,
                                  god_tail,
                                  god);
diff --git a/src/backend/taler-merchant-httpd_post-orders-ID-refund.c b/src/backend/taler-merchant-httpd_post-orders-ID-refund.c
index c6011d21..80bbbfa8 100644
--- a/src/backend/taler-merchant-httpd_post-orders-ID-refund.c
+++ b/src/backend/taler-merchant-httpd_post-orders-ID-refund.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2020-2021 Taler Systems SA
+  (C) 2020-2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as
@@ -201,9 +201,13 @@ struct PostRefundData
   struct TALER_Amount refund_amount;
 
   /**
-   * Did we suspend @a connection?
+   * Did we suspend @a connection and are thus in
+   * the #prd_head DLL (#GNUNET_YES). Set to
+   * #GNUNET_NO if we are not suspended, and to
+   * #GNUNET_SYSERR if we should close the connection
+   * without a response due to shutdown.
    */
-  bool suspended;
+  enum GNUNET_GenericReturnValue suspended;
 
   /**
    * Return code: #TALER_EC_NONE if successful.
@@ -304,7 +308,7 @@ TMH_force_wallet_refund_order_resume (void)
                                  prd_tail,
                                  prd);
     GNUNET_assert (prd->suspended);
-    prd->suspended = false;
+    prd->suspended = GNUNET_SYSERR;
     MHD_resume_connection (prd->sc.con);
   }
 }
@@ -346,7 +350,7 @@ check_resume_prd (struct PostRefundData *prd)
                                prd_tail,
                                prd);
   GNUNET_assert (prd->suspended);
-  prd->suspended = false;
+  prd->suspended = GNUNET_NO;
   MHD_resume_connection (prd->sc.con);
   TALER_MHD_daemon_trigger ();
 }
@@ -646,6 +650,8 @@ TMH_post_orders_ID_refund (const struct TMH_RequestHandler *rh,
       }
     }
   }
+  if (GNUNET_SYSERR == prd->suspended)
+    return MHD_NO; /* we are in shutdown */
 
   if (TALER_EC_NONE != prd->ec)
   {
@@ -733,9 +739,9 @@ TMH_post_orders_ID_refund (const struct TMH_RequestHandler *rh,
   /* Check if there are still exchange operations pending */
   if (exchange_operations_pending (prd))
   {
-    if (! prd->suspended)
+    if (GNUNET_NO == prd->suspended)
     {
-      prd->suspended = true;
+      prd->suspended = GNUNET_YES;
       MHD_suspend_connection (connection);
       GNUNET_CONTAINER_DLL_insert (prd_head,
                                    prd_tail,
diff --git a/src/backend/taler-merchant-httpd_private-get-orders-ID.c b/src/backend/taler-merchant-httpd_private-get-orders-ID.c
index b4067f56..5cfba15e 100644
--- a/src/backend/taler-merchant-httpd_private-get-orders-ID.c
+++ b/src/backend/taler-merchant-httpd_private-get-orders-ID.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2017-2021 Taler Systems SA
+  (C) 2017-2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU General Public License as published by the Free Software
@@ -259,9 +259,13 @@ struct GetOrderRequestContext
   unsigned int wire_hc;
 
   /**
-   * Set to true if this request is currently suspended.
+   * Did we suspend @a connection and are thus in
+   * the #gorc_head DLL (#GNUNET_YES). Set to
+   * #GNUNET_NO if we are not suspended, and to
+   * #GNUNET_SYSERR if we should close the connection
+   * without a response due to shutdown.
    */
-  bool suspended;
+  enum GNUNET_GenericReturnValue suspended;
 
   /**
    * Set to true if this payment has been refunded and
@@ -295,6 +299,23 @@ static struct GetOrderRequestContext *gorc_head;
 static struct GetOrderRequestContext *gorc_tail;
 
 
+void
+TMH_force_gorc_resume (void)
+{
+  struct GetOrderRequestContext *gorc;
+
+  while (NULL != (gorc = gorc_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (gorc_head,
+                                 gorc_tail,
+                                 gorc);
+    GNUNET_assert (GNUNET_YES == gorc->suspended);
+    gorc->suspended = GNUNET_SYSERR;
+    MHD_resume_connection (gorc->sc.con);
+  }
+}
+
+
 /**
  * Resume processing the request, cancelling all pending asynchronous
  * operations.
@@ -330,11 +351,11 @@ gorc_resume (struct GetOrderRequestContext *gorc,
   }
   gorc->wire_hc = http_status;
   gorc->wire_ec = ec;
-  GNUNET_assert (gorc->suspended);
+  GNUNET_assert (GNUNET_YES == gorc->suspended);
   GNUNET_CONTAINER_DLL_remove (gorc_head,
                                gorc_tail,
                                gorc);
-  gorc->suspended = false;
+  gorc->suspended = GNUNET_NO;
   MHD_resume_connection (gorc->sc.con);
   TALER_MHD_daemon_trigger ();   /* we resumed, kick MHD */
 }
@@ -360,9 +381,9 @@ resume_by_event (void *cls,
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Resuming request %p by trigger\n",
               gorc);
-  if (! gorc->suspended)
+  if (GNUNET_NO == gorc->suspended)
     return; /* duplicate event is possible */
-  gorc->suspended = false;
+  gorc->suspended = GNUNET_NO;
   GNUNET_CONTAINER_DLL_remove (gorc_head,
                                gorc_tail,
                                gorc);
@@ -965,10 +986,11 @@ TMH_private_get_orders_ID (const struct TMH_RequestHandler *rh,
         gorc->sc.long_poll_timeout = GNUNET_TIME_UNIT_ZERO_ABS;
       }
     }
-
-
   } /* end first-time per-request initialization */
 
+  if (GNUNET_SYSERR == gorc->suspended)
+    return MHD_NO; /* we are in shutdown */
+
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Starting GET /private/orders/%s processing with timeout %s\n",
               hc->infix,
@@ -1229,7 +1251,7 @@ TMH_private_get_orders_ID (const struct TMH_RequestHandler *rh,
       GNUNET_CONTAINER_DLL_insert (gorc_head,
                                    gorc_tail,
                                    gorc);
-      gorc->suspended = true;
+      gorc->suspended = GNUNET_YES;
       MHD_suspend_connection (gorc->sc.con);
       return MHD_YES;
     }
@@ -1265,7 +1287,7 @@ TMH_private_get_orders_ID (const struct TMH_RequestHandler *rh,
       GNUNET_CONTAINER_DLL_insert (gorc_head,
                                    gorc_tail,
                                    gorc);
-      gorc->suspended = true;
+      gorc->suspended = GNUNET_YES;
       MHD_suspend_connection (connection);
       gorc->tt = GNUNET_SCHEDULER_add_delayed (EXCHANGE_TIMEOUT,
                                                &exchange_timeout_cb,
@@ -1280,11 +1302,11 @@ TMH_private_get_orders_ID (const struct TMH_RequestHandler *rh,
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Suspending GET /private/orders/%s\n",
                 hc->infix);
-    GNUNET_assert (! gorc->suspended);
+    GNUNET_assert (GNUNET_NO == gorc->suspended);
     GNUNET_CONTAINER_DLL_insert (gorc_head,
                                  gorc_tail,
                                  gorc);
-    gorc->suspended = true;
+    gorc->suspended = GNUNET_YES;
     MHD_suspend_connection (gorc->sc.con);
     return MHD_YES;
   }
diff --git a/src/backend/taler-merchant-httpd_private-get-orders-ID.h b/src/backend/taler-merchant-httpd_private-get-orders-ID.h
index af7f7938..8c118519 100644
--- a/src/backend/taler-merchant-httpd_private-get-orders-ID.h
+++ b/src/backend/taler-merchant-httpd_private-get-orders-ID.h
@@ -38,4 +38,12 @@ TMH_private_get_orders_ID (const struct TMH_RequestHandler *rh,
                            struct MHD_Connection *connection,
                            struct TMH_HandlerContext *hc);
 
+
+/**
+ * Force resuming all long polling GET orders ID requests, we are shutting
+ * down.
+ */
+void
+TMH_force_gorc_resume (void);
+
 #endif
diff --git a/src/backend/taler-merchant-httpd_private-post-reserves.c b/src/backend/taler-merchant-httpd_private-post-reserves.c
index 37b887ef..0351ab10 100644
--- a/src/backend/taler-merchant-httpd_private-post-reserves.c
+++ b/src/backend/taler-merchant-httpd_private-post-reserves.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2021 Taler Systems SA
+  (C) 2021, 2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as
@@ -109,9 +109,13 @@ struct PostReserveContext
   enum TALER_ErrorCode ec;
 
   /**
-   * Are we suspended?
+   * Did we suspend @a connection and are thus in
+   * the #rc_head DLL (#GNUNET_YES). Set to
+   * #GNUNET_NO if we are not suspended, and to
+   * #GNUNET_SYSERR if we should close the connection
+   * without a response due to shutdown.
    */
-  bool suspended;
+  enum GNUNET_GenericReturnValue suspended;
 };
 
 
@@ -145,9 +149,9 @@ TMH_force_rc_resume ()
       GNUNET_SCHEDULER_cancel (rc->timeout_task);
       rc->timeout_task = NULL;
     }
-    if (rc->suspended)
+    if (GNUNET_YES == rc->suspended)
     {
-      rc->suspended = false;
+      rc->suspended = GNUNET_SYSERR;
       MHD_resume_connection (rc->connection);
       GNUNET_CONTAINER_DLL_remove (rc_head,
                                    rc_tail,
@@ -182,7 +186,7 @@ reserve_context_cleanup (void *cls)
     GNUNET_SCHEDULER_cancel (rc->timeout_task);
     rc->timeout_task = NULL;
   }
-  GNUNET_assert (! rc->suspended);
+  GNUNET_assert (GNUNET_YES != rc->suspended);
   GNUNET_free (rc->payto_uri);
   GNUNET_free (rc);
 }
@@ -211,12 +215,12 @@ handle_exchange (void *cls,
   const struct TALER_EXCHANGE_Keys *keys;
 
   rc->fo = NULL;
-  rc->suspended = false;
   if (NULL != rc->timeout_task)
   {
     GNUNET_SCHEDULER_cancel (rc->timeout_task);
     rc->timeout_task = NULL;
   }
+  rc->suspended = GNUNET_NO;
   MHD_resume_connection (rc->connection);
   GNUNET_CONTAINER_DLL_remove (rc_head,
                                rc_tail,
@@ -275,7 +279,7 @@ handle_exchange_timeout (void *cls)
     TMH_EXCHANGES_find_exchange_cancel (rc->fo);
     rc->fo = NULL;
   }
-  rc->suspended = false;
+  rc->suspended = GNUNET_NO;
   MHD_resume_connection (rc->connection);
   GNUNET_CONTAINER_DLL_remove (rc_head,
                                rc_tail,
@@ -334,15 +338,17 @@ TMH_private_post_reserves (const struct TMH_RequestHandler *rh,
       = GNUNET_SCHEDULER_add_delayed (EXCHANGE_GENERIC_TIMEOUT,
                                       &handle_exchange_timeout,
                                       rc);
-    rc->suspended = true;
+    rc->suspended = GNUNET_YES;
     GNUNET_CONTAINER_DLL_insert (rc_head,
                                  rc_tail,
                                  rc);
     MHD_suspend_connection (connection);
     return MHD_YES;
   }
+  if (GNUNET_SYSERR == rc->suspended)
+    return MHD_NO; /* we are in shutdown */
 
-  GNUNET_assert (! rc->suspended);
+  GNUNET_assert (GNUNET_NO == rc->suspended);
   if (NULL == rc->payto_uri)
   {
     return TALER_MHD_reply_with_error (connection,
diff --git a/src/backend/taler-merchant-httpd_private-post-transfers.c b/src/backend/taler-merchant-httpd_private-post-transfers.c
index f06f25c0..b6745c55 100644
--- a/src/backend/taler-merchant-httpd_private-post-transfers.c
+++ b/src/backend/taler-merchant-httpd_private-post-transfers.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2014-2021 Taler Systems SA
+  (C) 2014-2022 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free Software
@@ -138,6 +138,15 @@ struct PostTransfersContext
   enum GNUNET_GenericReturnValue check_transfer_result;
 
   /**
+   * Did we suspend @a connection and are thus in
+   * the #ptc_head DLL (#GNUNET_YES). Set to
+   * #GNUNET_NO if we are not suspended, and to
+   * #GNUNET_SYSERR if we should close the connection
+   * without a response due to shutdown.
+   */
+  enum GNUNET_GenericReturnValue suspended;
+
+  /**
    * Should we retry the transaction due to a serialization error?
    */
   bool soft_retry;
@@ -147,10 +156,6 @@ struct PostTransfersContext
    */
   bool downloaded;
 
-  /**
-   * Are we currently suspended?
-   */
-  bool suspended;
 };
 
 
@@ -175,7 +180,7 @@ TMH_force_post_transfers_resume ()
     GNUNET_CONTAINER_DLL_remove (ptc_head,
                                  ptc_tail,
                                  ptc);
-    ptc->suspended = false;
+    ptc->suspended = GNUNET_SYSERR;
     MHD_resume_connection (ptc->connection);
     if (NULL != ptc->timeout_task)
     {
@@ -213,7 +218,7 @@ resume_transfer_with_response (struct PostTransfersContext *ptc,
   GNUNET_CONTAINER_DLL_remove (ptc_head,
                                ptc_tail,
                                ptc);
-  ptc->suspended = false;
+  ptc->suspended = GNUNET_NO;
   MHD_resume_connection (ptc->connection);
   TALER_MHD_daemon_trigger ();   /* we resumed, kick MHD */
 }
@@ -891,7 +896,7 @@ download (struct PostTransfersContext *ptc)
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Suspending POST /private/transfers handling while working with exchange\n");
   MHD_suspend_connection (ptc->connection);
-  ptc->suspended = true;
+  ptc->suspended = GNUNET_YES;
   GNUNET_CONTAINER_DLL_insert (ptc_head,
                                ptc_tail,
                                ptc);
@@ -923,6 +928,8 @@ TMH_private_post_transfers (const struct TMH_RequestHandler *rh,
     hc->ctx = ptc;
     hc->cc = &transfer_cleanup;
   }
+  if (GNUNET_SYSERR == ptc->suspended)
+    return MHD_NO; /* we are in shutdown */
   /* resume logic: did we get resumed after a reply was built? */
   if (0 != ptc->response_code)
     return queue (ptc);
@@ -930,7 +937,7 @@ TMH_private_post_transfers (const struct TMH_RequestHandler *rh,
        (NULL != ptc->wdh) )
   {
     /* likely old MHD version causing spurious wake-up */
-    GNUNET_break (ptc->suspended);
+    GNUNET_break (GNUNET_NO == ptc->suspended);
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Not sure why we are here, should be suspended\n");
     return MHD_YES; /* still work in progress */