Re: pg_basebackup caused FailedAssertion

Fujii Masao <masao(dot)fujii(at)gmail(dot)com> writes:
> In HEAD, when I ran "pg_basebackup -D hoge -X stream",
> I got the following FailedAssertion error:

> TRAP: FailedAssertion("!((wakeEvents & ((1 << 1) | (1 << 2))) != (1 <<
> 2))", File: "pg_latch.c", Line: 234)

> This error happens after the commit 0b6329130e8e4576e97ff763f0e773347e1a88af.

> This assertion error happens when WL_SOCKET_WRITEABLE without
> WL_SOCKET_READABLE is specified in WaitLatchOrSocket(). This
> condition is met when walsender has received CopyDone from the client,
> but the output buffer is not empty. If reaching such condition is legitimate,
> I think that we should get rid of the Assertion check which caused the above
> FailedAssertion error. Thought?

The reason for the assertion is that that case doesn't actually work.
The code that is passing that combination of flags needs to be changed.
Or else you can try to implement the ability to support READABLE only.
But just removing the Assert is 100% wrong.

regards, tom lane