Tcl Source Code

The new pluggable filesystem code located in
generic/tclIOUtils.c naively plays with global
Tcl_Obj*, passing them between threads
per-reference and neglecting the proper locks
for all except write operations. 
The spot in question is the global Tcl_Obj *cwdPathPtr.

The net-effect is that paths passed to the OS-calls 
gets garbled, memory is being trashed leading to
process exitus and whole bunch of other ugly things
is happening.

I think this has to be entirely revised, as one can not
simply share Tcl_Objs between threads. One has to 
always make a deep-copy (w/o internal references) 
of the object before passing it to some other thread.

I have some ideas on how to solve this, but it is 
really not that straight-forward, since few of design
issues have to be modified.

This bug is really a show-stopper for MT-apps
therefore the highest priority.

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Applied to head with offsets.

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Zoran says this should also apply to cvs head.

File Added - 50090: tclIOUtil.c.patch.710642

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I've attached Zoran's latest version (with one minor change to 
init char *str) and commited that to core-8-4-branch.  We 
need a version for the HEAD.  It would also be nice to have 
some sort of tests that exercise this (if possible).

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I'll be looking into this soon, now I've resolved the 
various other bugs I was working on.  Your code looks 
like a good template, but I'd like to remove the need 
for 'inner' functions.

File Added - 46565: tclIOUtil.c.diff

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Sure. It is attached. I did the diff against the 8.4.2 version.
Note that I've used some pretty conservative locks in 
Tcl_FSGetCwd and Tcl_FSChdir. This may be relaxed
eventually.

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Can you provide a unified diff (diff -u) for easier 
analysis, please?

File Added - 46156: tclIOUtil.c

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Here is my reworked version which uses char* to
hold the cwd. I know it is not 100% good because
a path may contain NULL chars. We might improve this
and store char* and its length. The Tcl_Obj is really 
not usable in MT-environments since it can't be 
deep-copied
with the current duplicate function (i mean path objects).
Anyways, the entire file is attached.