`fatal error: concurrent map writes` in `EnumCodec.lookupAndCacheString` about pgx HOT 4 OPEN

EnumCodec (and any Codec for that matter) is not expected to be concurrency safe. How is this being used?

from pgx.

Hi, sorry for the long delay here.

We're getting this error when reading from a table that has a column who's type is a custom enum (created with create type T as enum (X, Y, Z). Attached is a slightly longer stack trace showing that the error is originating from a DB read (ReadPaymentInstrument just does a select * from table where ...), which calls pgxpool.Pool.QueryRow.

From the trace, it looks like reading from a table that has a custom enum column calls EnumCodec.DecodeValue, which calls the non-concurrency-safe method lookupAndCacheString. Our service performs multiple reads concurrently - do you know of anything between QueryRow and lookupAndCacheString that would prevent concurrent calling of the latter?

Thanks

from pgx.

Every connection gets its own type map and set of codecs. EnumCodec is not concurrency safe -- but I wouldn't have expected it to be possible for it to be used concurrently. 🤔

from pgx.

Okay thanks that's interesting information. I'll dig a bit more into our setup and see if I can reproduce a minimal example

from pgx.