postgresql/src/port
Tom Lane 67f8cf0f0a Clean up Windows-specific mutex code in libpq and ecpglib.
Fix pthread-win32.h and pthread-win32.c to provide a more complete
emulation of POSIX pthread mutexes: define PTHREAD_MUTEX_INITIALIZER
and make sure that pthread_mutex_lock() can operate on a mutex
object that's been initialized that way.  Then we don't need the
duplicative platform-specific logic in default_threadlock() and
pgtls_init(), which we'd otherwise need yet a third copy of for
an upcoming bug fix.

Also, since default_threadlock() supposes that pthread_mutex_lock()
cannot fail, try to ensure that that's actually true, by getting
rid of the malloc call that was formerly involved in initializing
an emulated mutex.  We can define an extra state for the spinlock
field instead.

Also, replace the similar code in ecpglib/misc.c with this version.
While ecpglib's version at least had a POSIX-compliant API, it
also had the potential of failing during mutex init (but here,
because of CreateMutex failure rather than malloc failure).  Since
all of misc.c's callers ignore failures, it seems like a wise idea
to avoid failures here too.

A further improvement in this area could be to unify libpq's and
ecpglib's implementations into a src/port/pthread-win32.c file.
But that doesn't seem like a bug fix, so I'll desist for now.

In preparation for the aforementioned bug fix, back-patch to all
supported branches.

Discussion: https://postgr.es/m/264860.1707163416@sss.pgh.pa.us
2024-02-09 11:11:39 -05:00
..
.gitignore Build src/port files as a library with -fPIC, and use that in libpq. 2018-09-27 11:23:43 -04:00
Makefile Split all OBJS style lines in makefiles into one-line-per-entry style. 2019-11-05 14:41:07 -08:00
README AIX: Fix missing libpq symbols by respecting SHLIB_EXPORTS. 2021-09-06 11:28:02 -07:00
chklocale.c Be more careful about extracting encoding from locale strings on Windows. 2020-03-30 11:14:58 -04:00
dirent.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
dirmod.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
dlopen.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
erand48.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
explicit_bzero.c Initial pgindent and pgperltidy run for v13. 2020-05-14 13:06:50 -04:00
fls.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
getaddrinfo.c Cleanup more code related to ws2_32.dll loading in src/port/getaddrinfo.c 2020-02-20 11:57:41 +09:00
getopt.c Use our own getopt() on OpenBSD. 2019-01-18 15:06:26 -05:00
getopt_long.c Fix our getopt_long's behavior for a command line argument of just "-". 2020-03-23 11:58:00 -04:00
getpeereid.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
getrusage.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
gettimeofday.c Clean up newlines following left parentheses 2020-01-30 13:42:14 -03:00
inet_aton.c Correct include file name in inet_aton fallback. 2017-10-01 17:41:00 -07:00
inet_net_ntop.c Avoid conflicts with library versions of inet_net_ntop() and friends. 2019-08-18 19:27:23 -04:00
kill.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
link.c Move pg_upgrade's Windows link() implementation to AC_REPLACE_FUNCS 2020-03-04 08:22:54 +01:00
mkdtemp.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
noblock.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
open.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
path.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_bitutils.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_crc32c_armv8.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_crc32c_armv8_choose.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_crc32c_sb8.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_crc32c_sse42.c pg_attribute_no_sanitize_alignment() macro 2021-02-13 17:49:08 -05:00
pg_crc32c_sse42_choose.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pg_strong_random.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pgcheckdir.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pgmkdirp.c Fix various typos and grammar errors in comments. 2015-04-26 18:42:31 +02:00
pgsleep.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pgstrcasecmp.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pgstrsignal.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pqsignal.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
pread.c Include c.h instead of postgres.h in src/port/*p{read,write}*.c 2022-09-17 09:25:08 -07:00
pthread-win32.h Clean up Windows-specific mutex code in libpq and ecpglib. 2024-02-09 11:11:39 -05:00
pwrite.c Include c.h instead of postgres.h in src/port/*p{read,write}*.c 2022-09-17 09:25:08 -07:00
qsort.c Get rid of trailing semicolons in C macro definitions. 2020-05-01 17:28:00 -04:00
qsort_arg.c Get rid of trailing semicolons in C macro definitions. 2020-05-01 17:28:00 -04:00
quotes.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
random.c Clear some style deviations. 2020-05-21 08:31:16 -07:00
setenv.c Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00
snprintf.c Re-allow building on Microsoft Visual Studio 2013. 2022-11-10 10:23:49 -05:00
sprompt.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
srandom.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
strerror.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
strlcat.c pgindent run for 9.4 2014-05-06 12:12:18 -04:00
strlcpy.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
strnlen.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
strtof.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
system.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
tar.c Make the order of the header file includes consistent in non-backend modules. 2019-10-25 07:41:52 +05:30
thread.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
unsetenv.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
win32.ico Revert binary change in copyright year adjustment. 2012-01-01 19:40:13 -05:00
win32env.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
win32error.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
win32security.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
win32setlocale.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
win32ver.rc Remove win32ver.rc from version_stamp.pl 2020-03-10 11:21:41 +01:00

README

src/port/README

libpgport
=========

libpgport must have special behavior.  It supplies functions to both
libraries and applications.  However, there are two complexities:

1)  Libraries need to use object files that are compiled with exactly
the same flags as the library.  libpgport might not use the same flags,
so it is necessary to recompile the object files for individual
libraries.  This is done by removing -lpgport from the link line:

        # Need to recompile any libpgport object files
        LIBS := $(filter-out -lpgport, $(LIBS))

and adding infrastructure to recompile the object files:

        OBJS= execute.o typename.o descriptor.o data.o error.o prepare.o memory.o \
                connect.o misc.o path.o exec.o \
                $(filter strlcat.o, $(LIBOBJS))

The problem is that there is no testing of which object files need to be
added, but missing functions usually show up when linking user
applications.

2) For applications, we use -lpgport before -lpq, so the static files
from libpgport are linked first.  This avoids having applications
dependent on symbols that are _used_ by libpq, but not intended to be
exported by libpq.  libpq's libpgport usage changes over time, so such a
dependency is a problem.  Windows, Linux, AIX, and macOS use an export
list to control the symbols exported by libpq.