Bizarre SvType [187] at

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187 is 0xBB which immediately makes me think of Microsoft pre-initializing memory to such things (I usually see 0xCC but have seen other values). I'll see if I can dig up information on what these values mean.

But this at least looks like Perl is either failing to initialize some memory, using a pointer to some memory that has been free()d, or using a corrupted pointer.

And that doesn't surprise me since fork emulation in Win32 Perl has always been pretty buggy, even after several releases (and several claims that it should be stable). I've heard claims that Perl v5.8 should make fork emulation less buggy, but it is using a brand new scheme (which does hold promise for being more stable) and so, being new, I'd be a bit surprised if it weren't still at least a little buggy.

I avoid using fork in Win32 Perl. You can probably avoid it in this situation as well, though it can be a challenge. I've covered some aspects of avoiding fork ((tye)Re: How to multiprocess in Win32?) and of pinging (Net::Ping, the mini series).

Update: I managed to find the following special values:

0xCC
uninitialized local variables (if compiled with /GZ)
0xFD
no-man's land (area around a malloc'd block)
0xDD
freed blocks
0xCD
new objects
but no special meaning for 0xBB; there might be one, but I haven't found it.

BTW, SV types go from 0x00 through 0x0F. 4 bits of the SV type are never used.

                - tye

In reply to Re: Ping, fork error on Win32 (bad pointer?) by tye
in thread Ping, fork error on Win32 by Anonymous Monk

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