Mercurial > urweb
diff src/c/urweb.c @ 2176:d2a98983f502
Start of support for surviving database-server restarts, for Postgres
author | Adam Chlipala <adam@chlipala.net> |
---|---|
date | Sat, 17 Oct 2015 10:49:25 -0400 |
parents | 8a01e8f21de9 |
children | 00cf8214c2e3 |
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--- a/src/c/urweb.c Thu Oct 15 07:52:37 2015 -0400 +++ b/src/c/urweb.c Sat Oct 17 10:49:25 2015 -0400 @@ -797,10 +797,37 @@ return r; } +static void uw_try_reconnecting(uw_context ctx) { + // Hm, error starting transaction. + // Maybe the database server died but has since come back up. + // Let's try starting from scratch. + if (ctx->db) { + ctx->app->db_close(ctx); + ctx->db = NULL; + } + ctx->app->db_init(ctx); + + if (!ctx->db) + uw_error(ctx, FATAL, "Error reopening database connection"); +} + +int uw_try_reconnecting_if_at_most_one(uw_context ctx) { + if (ctx->at_most_one_query) { + uw_try_reconnecting(ctx); + return 1; + } else + return 0; +} + void uw_ensure_transaction(uw_context ctx) { if (!ctx->transaction_started && !ctx->at_most_one_query) { - if (ctx->app->db_begin(ctx, ctx->could_write_db)) - uw_error(ctx, BOUNDED_RETRY, "Error running SQL BEGIN"); + if (!ctx->db || ctx->app->db_begin(ctx, ctx->could_write_db)) { + uw_try_reconnecting(ctx); + + if (ctx->app->db_begin(ctx, ctx->could_write_db)) + uw_error(ctx, FATAL, "Error running SQL BEGIN"); + } + ctx->transaction_started = 1; } }