Mon May 22 13:11:52 PDT 2000
So , after a long fight I have Japhar compiled and running
"Hello, world!" program with the following result:
[zaitcev@js006 java]$ /usr/local/japhar/bin/japhar
Assertion failure: mon != NULL, at
fatal signal handler called, signal = 10
Bus error (core dumped)
Now I am faced with a task of debugging a huge blob of code,
roughly divided between NSPR and pthreads. I reckon that
I could cut my task in half if I dispose of pthreads.
I tried to discuss that with helpful hacker comrades (yeah,
<zaitcev> What sort of threading does Mozilla use on
<zaitcev> I am asking in the following context:
<zaitcev> If it uses pthreads, then we have a stack
<zaitcev> (if pthreads are considered a part of libc,
<shaver> zaitcev: yes, that's true
<zaitcev> But I wonder if it is feasible to put NSPR
on top of kernel, without pthreads.
<zaitcev> This is a quote from NSPR overview
<shaver> user-space threads via setjmp are in NSPR
<zaitcev> operating systems provide
everything from no concept of threading at all up to and
<zaitcev> scalable and efficient
implementations. NSPR makes as much use of what the systems
offer as it can.
<zaitcev> Yes, but look at it this way: NSPR has a
pile of code that can work off some simple abstractions
<zaitcev> Such as setjmp
<zaitcev> So, why don't we make a same or smaller pile
of code to work off Linux kernel
<shaver> you could
<shaver> is there a lot of gain there?
<zaitcev> shaver: Suppose I do something like that,
would it be useful for Mozilla?
<zaitcev> Yeah, do we get any speed?
<zaitcev> My problem at the moment is that I am stuck
with a system with buggy pthreads, they fault assertions. I
can fix and replace kernel easily, but I am afraid of
touching libc and other libraries
<zaitcev> So I thought why don't I sidestep that
<shaver> knock yourself out
<shaver> or ask on the NSPR list
<zaitcev> Was Brother Yosh or Don Miguel around?
<zaitcev> I need a hint about threading from a
userland expert, e.g. what threading packages are available,
what does kernel provide, and what code can I read (besides
<_Anarchy_> zaitcev: glibc provides most of posix
<_Anarchy_> Apache has a threading library
<_Anarchy_> Netscape has a nice MPL threading
*>* prumpf (prumpf@p3E9C29B3.dip.t-dialin.net) has joined
<_Anarchy_> and there is clone() which is what real
<_Anarchy_> pthreads is painful, badly designed and a
crock to make it work user and kernel space
<_Anarchy_> clone is a bit too raw
<_Anarchy_> NSPR looks a nice balance
<phil> _A_: NSPR will be dual licensed if it's not
already, unless I'm mistaken
<shaver> phil: still collecting permission from the
<phil> ah, ok.
<zaitcev> _anarchy_: NSPR has several variants inside,
depending on the underlying implementation. e.g. ./configure
time options. So NSPR either runs on top of pthreads or on
top of setjmp and signal.
<prumpf> NSPR is what netscape uses ?
<wiggy> setjmp and signal? that sounds evil
<phil> prumpf: NSPR == NetScape Portable Runtime
<prumpf> (or mozilla)
<zaitcev> My problem is that my pthreads are buggy and
<Micksa> _A_: do glibc peethreads use clone(2)?
<shaver> 4.x used NSPR 1.0
<_Anarchy_> micksa; yes
<zaitcev> So I thought why not to write NSPR code that
works over clone().
<shaver> Netscape servers use NSPR 2.0 and 3.0 now
<zaitcev> Shaver sais it's dumb
<_Anarchy_> zait: so fix your peethreads
<_Anarchy_> Apache has a similar lib too
<Micksa> woo, I've coined a term :)
* _Anarchy_ sprays air freshener
<zaitcev> "<_Anarchy_> pthreads is painful,
badly designed and a crock to make it work user and kernel
<Micksa> _A_: is clone(2) optimal? or has it been
kludged up to work with peethreads?
<shaver> Apache should have just used NSPR, but they
<zaitcev> Why bother to fix them if we better use NSPR
as the interface
<shaver> oh well, their loss
<_Anarchy_> Micksa: clone() is basically optimal
<arjan> _A_: Unless you must have portability
<_Anarchy_> arjan: to what ? NT doesnt use pthreads,
macos doesnt use pthreads
<_Anarchy_> *BSD emulates clone() nowdays
<arjan> _A_: I thought there was pthreads for NT
<_Anarchy_> arjan: not seen it
<shaver> Micksa: widely implemented?
<shaver> Micksa: "usable on greatest number of
platforms" is probably NSPR
* arjan will convert his code to clone() tomorrow
<zaitcev> So in the end I do not follow what _A_
suggests. Either "<_Anarchy_> zait: so fix your
peethreads" or "<_Anarchy_> pthreads is
<_Anarchy_> you said yours were broken
<zaitcev> If they are bad, I do not need to fix them,
as I need to use NSPR anyways
<_Anarchy_> zait:glibc has support binaries depending
on pthreads btw
<Micksa> shaver: yeah well you would say that :)
<Micksa> shaver: I was hoping for one that I could
count on to be already installed on any machine.
<zaitcev> _A_: "support binaries for libc",
this is a
novel concept... are you talking about PAMs?
<_Anarchy_> zaitcev: nscd
<zaitcev> I don't think I have it running
<_Anarchy_> zait: the pty get stuff is a support
binary too for example - so it has some
<_Anarchy_> but nscd is the pthread usr
<_Anarchy_> and stuff like current gimp 8)
<shaver> Micksa: NSPR is pretty widely installed, but
it would be a pain to link against in some forms
<Micksa> shaver: is it its own .so? :)
<shaver> Micksa: with Mozilla yes, with Communicator
no, with Netscape servers usually
<Micksa> hmm, with a bit of fooling around I guess I
could set up some auto* stuff that checked for an already
installed .so, and just compiled and installed it if it
<Micksa> wasn't there.
<shaver> Micksa: we have such autoconf stuff in
Mozilla already, if you'd like to crib
It does not pay to be an IRC junkie.