Originally posted by: SystemAdmin

Hi All, require help in understanding the problem. I have a multithreaded program that uses fopen() quite frequently and at some point a thread calling fopen() hangs.
Stack trace of a thread that hangs is as follows

ptrgl._ptrgl() at 0xd0215a70
_rec_mutex_lock(??) at 0xd022eff0
_rec_mutex_lock(??) at 0xd022eff0
_endopen(??, ??, ??, ??) at 0xd0230304
fopen64(??, ??) at 0xd0230808
inv_internal_flush(), line 435 in "inven_disk.c"
inv_disk_commit(), line 529 in "inven_disk.c"

Machine Configuration: AIX 5.3.0, POWERPC, IBM,7044-170, Single CPU, User and Kernel both running in 32 - bit.

Questions:
1 ) Is it some kind of deadlock inside kernel?
2 ) If my program as well as kernel are running in 32-bit, then why is dbx where command showing fopen64()?
3 ) Can anybody point out in what scenairo such problem can arise?

Regards,
Amit Dang

Originally posted by: dickdunbar

Wow. No responses.

fopen64() is the function which handles LARGE_FILES in a 32-bit pgm.
The problem with open is it had only a signed integer for the seek address, which means 2**31 or 2GB filesize limit.

A compiler macro definition causes fopen() in your source to be converted to fopen64(). Manipulation of the 64-bit seek value is handled by the compiler using 32-bit instructions to perform arithmetic on the 64-bit field.

Why is it hanging? Perhaps the way you've opened the file for exclusive use? You didn't show the code.