diff options
Diffstat (limited to 'src/exchange/taler-exchange-httpd_db.c')
| -rw-r--r-- | src/exchange/taler-exchange-httpd_db.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/src/exchange/taler-exchange-httpd_db.c b/src/exchange/taler-exchange-httpd_db.c index c0828360f..f98116226 100644 --- a/src/exchange/taler-exchange-httpd_db.c +++ b/src/exchange/taler-exchange-httpd_db.c @@ -30,6 +30,12 @@ /** * How often should we retry a transaction before giving up * (for transactions resulting in serialization/dead locks only). + * + * The current value is likely too high for production. We might want to + * benchmark good values once we have a good database setup. The code is + * expected to work correctly with any positive value, albeit inefficiently if + * we too aggressively force clients to retry the HTTP request merely because + * we have database serialization issues. */ #define MAX_TRANSACTION_COMMIT_RETRIES 100 @@ -42,10 +48,10 @@ * it returns the soft error code, the function MAY be called again to * retry and MUST not queue a MHD response. * - * @param cls a `struct DepositContext` - * @param connection MHD request context + * @param cls a `struct TEH_DB_KnowCoinContext` + * @param connection MHD request context, must not be NULL * @param session database session and transaction to use - * @param[out] mhd_ret set to MHD status on error + * @param[out] mhd_ret set to MHD status on error, must not be NULL * @return transaction status */ enum GNUNET_DB_QueryStatus @@ -57,6 +63,7 @@ TEH_DB_know_coin_transaction (void *cls, struct TEH_DB_KnowCoinContext *kcc = cls; enum GNUNET_DB_QueryStatus qs; + GNUNET_assert (NULL != mhd_ret); qs = TEH_plugin->ensure_coin_known (TEH_plugin->cls, session, kcc->coin); @@ -80,9 +87,11 @@ TEH_DB_know_coin_transaction (void *cls, * retries @a cb a few times. Upon hard or persistent soft * errors, generates an error message for @a connection. * - * @param connection MHD connection to run @a cb for + * @param connection MHD connection to run @a cb for, can be NULL * @param name name of the transaction (for debugging) - * @param[out] mhd_ret set to MHD response code, if transaction failed + * @param[out] mhd_ret set to MHD response code, if transaction failed; + * NULL if we are not running with a @a connection and thus + * must not queue MHD replies * @param cb callback implementing transaction logic * @param cb_cls closure for @a cb, must be read-only! * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure @@ -97,7 +106,7 @@ TEH_DB_run_transaction (struct MHD_Connection *connection, struct TALER_EXCHANGEDB_Session *session; if (NULL != mhd_ret) - *mhd_ret = -1; /* invalid value */ + *mhd_ret = -1; /* set to invalid value, to help detect bugs */ if (NULL == (session = TEH_plugin->get_session (TEH_plugin->cls))) { GNUNET_break (0); @@ -108,7 +117,8 @@ TEH_DB_run_transaction (struct MHD_Connection *connection, "could not establish database session"); return GNUNET_SYSERR; } - for (unsigned int retries = 0; retries < MAX_TRANSACTION_COMMIT_RETRIES; + for (unsigned int retries = 0; + retries < MAX_TRANSACTION_COMMIT_RETRIES; retries++) { enum GNUNET_DB_QueryStatus qs; |