Reini Urban said:Bruce Momjian schrieb:
I looked at the APR code to get some ideas for the Win32 port. Some of the ideas were good, but in other places like rename they didn't do very well we were better off doing it ourselves and getting it right.
I remember looking at their code to fix the rename/unlink while the file is open problem, and they didn't seem to have a fix for that so we developed our own method that works like Unix.
sorry, but your rename doesn't work on cygwin. maybe it works with mingw.
cygwin has it's own and working way of doing rename's. maybe you should have looked at the cygwin sources instead. (src/winsup/cygwin/syscalls.cc)
first doing a WinAPI MoveFileEx and then after a failure trying the cygwin version, which will also try its own MoveFile loop, will not work. they are conflicting.
same with unlink, but at least the mingw and cygwin unlink versions don't conflict here. here you don't stack two conflicting loops together. nevertheless cygwin's unlink is much better than pgunlink in case of locking problems. it does its own sort of delayed removal then.
IMHO port/dirmod.c is a dirty and half-baked hack, which works for mingw only.
Are you sure you are reading this code correctly? Your reading would only be correct if WIN32 is defined on Cygwin - it isn't IIRC (don't have a convenient way to test ATM). The relevant code is this:
#ifdef WIN32 while (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING)) #endif #ifdef __CYGWIN__ while (rename(from, to) < 0) #endif
If the code doesn't work, please submit empirical proof, rather than make assertions of "half-baked hack". If it's broken we'll fix it. Bruce's point about the usefulness of APR remains, nonetheless.
I already posted my needed patches to make beta2 work on cygwin. But on the pqsql-cygwin mailinglist: http://xarch.tu-graz.ac.at/home/rurban/software/cygwin/postgresql/postgresql-8.0.0beta2-1 Only a plperl problem is pending. BTW: plperl never worked on cygwin before.
FYI: WIN32 is also defined because <windows.h> is included. (/usr/incluse/w32api/windef.h)
If you want this or that, do proper nesting, and use #else.
#ifdef __CYGWIN__
while (rename(from, to) < 0)
#else
#ifdef WIN32
while (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING))
#endif
#endifYou cannot safely assume WIN32 is only defined on mingw, but not on __CYGWIN__. And you need <windows.h> because of some winapi calls below. The same false assumption was also in src/include/utils/palloc.h
But the whole pgrename #ifdef is fragile and a mess.
cygwin rename works good enough, and I just #ifdef'ed it away.
The two #undef need to be inserted before #include <unistd.h>, otherwise pgrename will be declared, but rename not.
gcc -E -I../include dirmod-orig.c:
int
pgrename(const char *from, const char *to)
{
int loops = 0;
while (!MoveFileExA(from, to, 1))
while (rename(from, to) < 0)
{
if (GetLastError() != 5L)
if ((*__errno()) != 13)
return -1;
pg_usleep(100000);
if (loops == 30)
errstart(0, "dirmod-orig.c", 87, __func__), elog_finish(15, "could not rename \"%s\" to \"%s\", continuing to try",
from, to);
loops++;
}
if (loops > 30)
errstart(0, "dirmod-orig.c", 98, __func__), elog_finish(15, "completed rename of \"%s\" to \"%s\"", from, to);
return 0;
}
-- Reini Urban http://xarch.tu-graz.ac.at/home/rurban/
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