[xml] xmlParseFile Deadlock

["Rhys Palmer" <rpalmer dstore com>]

Hi all,

I'm using libxml2-2.6.6-3.x86_64 on RHEL3.
I am trying to write a program in c that receives URLs to XML files from a database and then creates a thread for each row. 
I'm getting a deadlock when 2 threads call xmlParseFile at the same time. 

I call xmlInitParser() before creating the threads.

The backtrace from gdb is
#0  0x0000002a95907439 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/tls/libpthread.so.0
#1  0x0000002a965cf310 in xmlRMutexLock () from /usr/lib64/libxml2.so.2
#2  0x0000002a965cb5fd in xmlParseCatalogFile () from /usr/lib64/libxml2.so.2
#3  0x0000002a965cc3b7 in xmlParseCatalogFile () from /usr/lib64/libxml2.so.2
#4  0x0000002a965cd5d1 in xmlACatalogResolve () from /usr/lib64/libxml2.so.2
#5  0x0000002a965cdd60 in xmlCatalogResolve () from /usr/lib64/libxml2.so.2
#6  0x0000002a965977ba in xmlCheckHTTPInput () from /usr/lib64/libxml2.so.2
#7  0x0000002a96597896 in xmlLoadExternalEntity () from /usr/lib64/libxml2.so.2
#8  0x0000002a96587f05 in xmlCreateURLParserCtxt () from /usr/lib64/libxml2.so.2
#9  0x0000002a96587f8b in xmlCreateFileParserCtxt () from /usr/lib64/libxml2.so.2
#10 0x0000002a96587fb1 in xmlSAXParseFileWithData () from /usr/lib64/libxml2.so.2
#11 0x0000002a965880bb in xmlSAXParseFile () from /usr/lib64/libxml2.so.2
#12 0x0000002a965880f0 in xmlParseFile () from /usr/lib64/libxml2.so.2
#13 0x0000000000401c4c in search_instance (thread_arg=0x7fbfff8460) at search_thread.c:131
#14 0x0000002a95904c64 in start_thread () from /lib64/tls/libpthread.so.0
#15 0x0000002a969ae243 in thread_start () from /lib64/tls/libc.so.6
#16 0x0000000000000000 in ?? ()

The backtrace is the same for each locked thread. 
If two threads call xmlParseFile at different times everything works.

The thread code looks like

void 
*parse( void *thread_arg )
{
    xmlDocPtr         doc;
    
    search_data *threadData = (search_data *)thread_arg;
    doc = xmlParseFile(threadData->URL);
 
   ....
 }

Am I doing something wrong here? Thanks for any help.

-rhys

-- 
Regards

Rhys Palmer | Developer
___________________________________
dStore Australia Pty Ltd
Level 2, 77 Elizabeth Street
Brisbane QLD 4000
Australia
p. 1800 DSTORE (Australia)
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f. +617 3211 2556
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