Re: parallel restore fixes

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> Tom Lane wrote:
>> How early is early? The proposed call sites for init_dump_utils seem
>> already long past the point where any libc-level infrastructure would
>> think it is "initialization" time.

> Well, I think at least it needs to be done where other threads won't be
> calling it at the same time.

Oh, I see, ye olde race condition. Still, it seems like a bad idea
to expect that we will catch every program that might call fmtId;
as Alvaro notes, that's all over our client-side code.

How about this: by default, fmtId uses the same logic as now (one static
PQExpBuffer). If told to by a call of init_parallel_dump_utils(), which
need only be called by pg_restore during its startup, then it switches to
using per-thread storage. init_parallel_dump_utils can be the place
that calls TlsAlloc. This is almost the same as what you suggested a
couple messages back, but perhaps a bit clearer as to what's going on;
and it definitely cuts the number of places we need to touch.

regards, tom lane