postgresql/src/backend/utils
Thomas Munro cf112c1220 Remove dead pread and pwrite replacement code.
pread() and pwrite() are in SUSv2, and all targeted Unix systems have
them.

Previously, we defined pg_pread and pg_pwrite to emulate these function
with lseek() on old Unixen.  The names with a pg_ prefix were a reminder
of a portability hazard: they might change the current file position.
That hazard is gone, so we can drop the prefixes.

Since the remaining replacement code is Windows-only, move it into
src/port/win32p{read,write}.c, and move the declarations into
src/include/port/win32_port.h.

No need for vestigial HAVE_PREAD, HAVE_PWRITE macros as they were only
used for declarations in port.h which have now moved into win32_port.h.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Greg Stark <stark@mit.edu>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA+hUKGJ3LHeP9w5Fgzdr4G8AnEtJ=z=p6hGDEm4qYGEUX5B6fQ@mail.gmail.com
2022-08-05 09:49:21 +12:00
..
activity Remove the restriction that the relmap must be 512 bytes. 2022-07-26 14:56:25 -04:00
adt Remove configure probes for symlink/readlink, and dead code. 2022-08-05 09:22:56 +12:00
cache Move common catalog cache access routines to lsyscache.c 2022-08-02 10:47:22 +05:30
error Provide log_status_format(), useful for an emit_log_hook. 2022-07-11 12:29:33 -07:00
fmgr Remove configure probe for dlopen, and refactor. 2022-08-05 09:12:45 +12:00
hash Update copyright for 2022 2022-01-07 19:04:57 -05:00
init Remove dead pread and pwrite replacement code. 2022-08-05 09:49:21 +12:00
mb Update copyright for 2022 2022-01-07 19:04:57 -05:00
misc Tweak detail and hint messages to be consistent with project policy 2022-07-20 09:50:12 +09:00
mmgr Remove fls(), use pg_leftmost_one_pos32() instead. 2022-07-22 10:41:50 +12:00
resowner Remove extraneous blank lines before block-closing braces 2022-04-13 19:16:02 +02:00
sort Improve speed of hash index build. 2022-07-28 14:34:32 -04:00
time Fix incorrect logic in HaveRegisteredOrActiveSnapshot(). 2022-04-16 16:04:50 -04:00
.gitignore Rearrange makefile rules for running Gen_fmgrtab.pl. 2018-05-03 17:54:18 -04:00
Gen_dummy_probes.pl Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_dummy_probes.pl.prolog Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_dummy_probes.sed Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_fmgrtab.pl Update copyright for 2022 2022-01-07 19:04:57 -05:00
Makefile Clean up temp file from refactored dtrace rule 2022-07-19 07:31:58 +02:00
README.Gen_dummy_probes Tweak generation of Gen_dummy_probes.pl 2021-05-11 20:02:02 -04:00
errcodes.txt Add another SQL/JSON error code 2022-07-18 14:26:43 +02:00
generate-errcodes.pl Add output file argument to generate-errcodes.pl 2022-07-18 12:24:35 -07:00
postprocess_dtrace.sed Refactor dtrace postprocessing make rules 2022-07-18 12:33:02 -07:00
probes.d Update copyright for 2022 2022-01-07 19:04:57 -05:00

README.Gen_dummy_probes

# Generating dummy probes

If Postgres isn't configured with dtrace enabled, we need to generate
dummy probes for the entries in probes.d, that do nothing.

This is accomplished in Unix via the sed script `Gen_dummy_probes.sed`. We
used to use this in MSVC builds using the perl utility `psed`, which mimicked
sed. However, that utility disappeared from Windows perl distributions and so
we converted the sed script to a perl script to be used in MSVC builds.

We still keep the sed script as the authoritative source for generating
these dummy probes because except on Windows perl is not a hard requirement
when building from a tarball.

So, if you need to change the way dummy probes are generated, first change
the sed script, and when it's working generate the perl script. This can
be accomplished by using the perl utility s2p.

s2p is no longer part of the perl core, so it might not be on your system,
but it is available on CPAN and also in many package systems. e.g.
on Fedora it can be installed using `cpan App::s2p` or
`dnf install perl-App-s2p`.

The Makefile contains a recipe for regenerating Gen_dummy_probes.pl, so all
you need to do is once you have s2p installed is `make Gen_dummy_probes.pl`
Note that in a VPATH build this will generate the file in the vpath tree,
not the source tree.