Re: [HACKERS] Alpha Size (size_t) != int problem - Mailing list pgsql-hackers

> 
> I've gotten a fairly recent snapshot from FTP and compiled it
> up on Alpha/linux.
> 
> On running, the forked process dies with a palloc error....it
> was trying to grab 4 gig worth of memory.
> 
> I've tracked this problem down to
> backend/utils/cache/relcache.c
> 
> in function init_irels:
> len is defined as Size, which I've checked out and it turns
> out to be size_t...which happens to be 8 byte on an alpha.
> len is uninitialised.
> 
> further down in init_irels
> if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))
> 
> which should set len to be the size of the relation read from disk.
> What is happening is that 4 bytes are being read from the file
> and saved in len. Writing 4 into 8 doesn't work too well so a
> complete mess is made.
> 
> Initialising len to 0 fixes the problem, but I'm thinking that this
> isn't the best solution. Since len is size_t, I'm figuring that the
> big scheme of things is to allow for larger tables on 64 bit machines.
> 
> I'm new to the internals so I don't know if the DB files are architecture
> independant (still wading through documentation)....if it isn't...then I
> guess Size should be replaced with int...and all should be happy.
> 
> What is the correct way about fixing this?
> 
> My ultimate goal here is to get timestamps working correctly on the alpha.
> You probably already know...but incase you didn't...
> 
> create table dat ( d date, t timestamp);
> CREATE
> insert into dat values ('1999-01-22', '1999-01-22 16:00:00'); 
> INSERT 18602 1
> select * from dat;
>          d|t                     
> ----------+----------------------
> 01-22-1999|2135-02-28 22:28:16+00
> (1 row)
> 
> Sometimes...the select the first time returns the correct values...
> but on doing the select again immidately after the first select
> will return 2135 again (probably due to the caching).
> 
> Any help on where I should be looking would be greatly received!

I have applied a fix to the tree.  The fix is to replace sizeof(int)
with sizeof(len).  I checked the rest of the source code, and couldn't
find any other places where this would be a problem.

Patch is attached.

---------------------------------------------------------------------------

Index: relcache.c
===================================================================
RCS file: /usr/local/cvsroot/pgsql/src/backend/utils/cache/relcache.c,v
retrieving revision 1.53
retrieving revision 1.54
diff -c -r1.53 -r1.54
*** relcache.c    1999/01/17 06:18:51    1.53
--- relcache.c    1999/01/22 16:49:25    1.54
***************
*** 7,13 ****  *  *  * IDENTIFICATION
!  *      $Header: /usr/local/cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.53 1999/01/17 06:18:51 momjian Exp $
*  *-------------------------------------------------------------------------  */
 
--- 7,13 ----  *  *  * IDENTIFICATION
!  *      $Header: /usr/local/cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.54 1999/01/22 16:49:25 momjian Exp $
*  *-------------------------------------------------------------------------  */
 
***************
*** 1876,1882 ****     for (relno = 0; relno < Num_indices_bootstrap; relno++)     {         /* first read the relation
descriptorlength */
 
!         if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))         {             write_irels();
         return;
 
--- 1876,1882 ----     for (relno = 0; relno < Num_indices_bootstrap; relno++)     {         /* first read the relation
descriptorlength */
 
!         if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))         {             write_irels();
         return;
 
***************
*** 1899,1905 ****         ird->lockInfo = (char *) NULL;          /* next, read the access method tuple form */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))         {             write_irels();
         return;
 
--- 1899,1905 ----         ird->lockInfo = (char *) NULL;          /* next, read the access method tuple form */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))         {             write_irels();
         return;
 
***************
*** 1915,1921 ****         ird->rd_am = am;          /* next read the relation tuple form */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))         {             write_irels();
         return;
 
--- 1915,1921 ----         ird->rd_am = am;          /* next read the relation tuple form */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))         {             write_irels();
         return;
 
***************
*** 1937,1943 ****         len = ATTRIBUTE_TUPLE_SIZE;         for (i = 0; i < relform->relnatts; i++)         {
!             if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))             {
write_irels();                return;
 
--- 1937,1943 ----         len = ATTRIBUTE_TUPLE_SIZE;         for (i = 0; i < relform->relnatts; i++)         {
!             if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))             {
write_irels();                return;
 
***************
*** 1953,1959 ****         }          /* next, read the index strategy map */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))         {             write_irels();
         return;
 
--- 1953,1959 ----         }          /* next, read the index strategy map */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))         {             write_irels();
         return;
 
***************
*** 1985,1991 ****         ird->rd_istrat = strat;          /* finally, read the vector of support procedures */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(int))) != sizeof(int))         {             write_irels();
         return;
 
--- 1985,1991 ----         ird->rd_istrat = strat;          /* finally, read the vector of support procedures */
!         if ((nread = FileRead(fd, (char *) &len, sizeof(len))) != sizeof(len))         {             write_irels();
         return;
 
***************
*** 2082,2089 ****         len = sizeof(RelationData);          /* first, write the relation descriptor length */
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!             != sizeof(int))             elog(FATAL, "cannot write init file -- descriptor length");          /* next,
writeout the Relation structure */
 
--- 2082,2089 ----         len = sizeof(RelationData);          /* first, write the relation descriptor length */
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!             != sizeof(len))             elog(FATAL, "cannot write init file -- descriptor length");          /* next,
writeout the Relation structure */
 
***************
*** 2092,2099 ****          /* next, write the access method tuple form */         len = sizeof(FormData_pg_am);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!             != sizeof(int))             elog(FATAL, "cannot write init file -- am tuple form length");          if
((nwritten= FileWrite(fd, (char *) am, len)) != len)
 
--- 2092,2099 ----          /* next, write the access method tuple form */         len = sizeof(FormData_pg_am);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!             != sizeof(len))             elog(FATAL, "cannot write init file -- am tuple form length");          if
((nwritten= FileWrite(fd, (char *) am, len)) != len)
 
***************
*** 2101,2108 ****          /* next write the relation tuple form */         len = sizeof(FormData_pg_class);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!             != sizeof(int))             elog(FATAL, "cannot write init file -- relation tuple form length");
if((nwritten = FileWrite(fd, (char *) relform, len)) != len)
 
--- 2101,2108 ----          /* next write the relation tuple form */         len = sizeof(FormData_pg_class);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!             != sizeof(len))             elog(FATAL, "cannot write init file -- relation tuple form length");
if((nwritten = FileWrite(fd, (char *) relform, len)) != len)
 
***************
*** 2112,2119 ****         len = ATTRIBUTE_TUPLE_SIZE;         for (i = 0; i < relform->relnatts; i++)         {
!             if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!                 != sizeof(int))                 elog(FATAL, "cannot write init file -- length of attdesc %d", i);
       if ((nwritten = FileWrite(fd, (char *) ird->rd_att->attrs[i], len))                 != len)
 
--- 2112,2119 ----         len = ATTRIBUTE_TUPLE_SIZE;         for (i = 0; i < relform->relnatts; i++)         {
!             if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!                 != sizeof(len))                 elog(FATAL, "cannot write init file -- length of attdesc %d", i);
       if ((nwritten = FileWrite(fd, (char *) ird->rd_att->attrs[i], len))                 != len)
 
***************
*** 2123,2130 ****         /* next, write the index strategy map */         len =
AttributeNumberGetIndexStrategySize(relform->relnatts,
am->amstrategies);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!             != sizeof(int))             elog(FATAL, "cannot write init file -- strategy map length");          if
((nwritten= FileWrite(fd, (char *) strat, len)) != len)
 
--- 2123,2130 ----         /* next, write the index strategy map */         len =
AttributeNumberGetIndexStrategySize(relform->relnatts,
am->amstrategies);
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!             != sizeof(len))             elog(FATAL, "cannot write init file -- strategy map length");          if
((nwritten= FileWrite(fd, (char *) strat, len)) != len)
 
***************
*** 2132,2139 ****          /* finally, write the vector of support procedures */         len = relform->relnatts *
(am->amsupport* sizeof(RegProcedure));
 
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(int)))
!             != sizeof(int))             elog(FATAL, "cannot write init file -- support vector length");          if
((nwritten= FileWrite(fd, (char *) support, len)) != len)
 
--- 2132,2139 ----          /* finally, write the vector of support procedures */         len = relform->relnatts *
(am->amsupport* sizeof(RegProcedure));
 
!         if ((nwritten = FileWrite(fd, (char *) &len, sizeof(len)))
!             != sizeof(len))             elog(FATAL, "cannot write init file -- support vector length");          if
((nwritten= FileWrite(fd, (char *) support, len)) != len)
 

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
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