Deadlock problem - Mailing list pgsql-hackers

Hi, <br />   I am facing a strange problem and thats bugging me for a long time, <br /> I am using postgres version
7.2.1.<br /><br /> I have written an application in C which  tries to drop a trigger and simultaneously read from a
tablethats has data related to that trigger. <br /> the whole database comes into a deadlock stage where drop() keeps
waitingon one hand and select() keeps waiting on other hand. <br /><br /> i have the stack trace of the processes that
areperforming the operation <br /><br /> For Drop: <br /> process doing drop trigger <br /> (gdb) where <br /> #0 
0x420e8a42in semop () from /lib/i686/libc.so.6 <br /> #1  0x0810f028 in IpcSemaphoreLock () <br /> #2  0x081132c0 in
ProcSleep() <br /> #3  0x081124e5 in WaitOnLock () <br /> #4  0x08112289 in LockAcquire () <br /> #5  0x081116d8 in
LockRelation() <br /> #6  0x0807407b in relation_openr () <br /> #7  0x08074195 in heap_openr () <br /> #8  0x080bed34
inDropTrigger () <br /> #9  0x081176c7 in pg_exec_query_string () <br /> #10 0x0811876a in PostgresMain () <br /> #11
0x080fde2ain DoBackend () <br /> #12 0x080fd77d in BackendStartup () <br /> #13 0x080fc8c1 in ServerLoop () <br /> #14
0x080fc2dbin PostmasterMain () <br /> #15 0x080da152 in main () <br /> #16 0x42017499 in __libc_start_main () from
/lib/i686/libc.so.6<br /> (gdb) <br /><br /> For Select() <br /> process's doing select <br /> (gdb) where <br /> #0 
0x420e8a42in semop () from /lib/i686/libc.so.6 <br /> #1  0x0810f028 in IpcSemaphoreLock () <br /> #2  0x081132c0 in
ProcSleep() <br /> #3  0x081124e5 in WaitOnLock () <br /> #4  0x08112289 in LockAcquire () <br /> #5  0x081116d8 in
LockRelation() <br /> #6  0x0807407b in relation_openr () <br /> #7  0x08074195 in heap_openr () <br /> #8  0x0810905a
infireRIRrules () <br /> #9  0x08108e21 in ApplyRetrieveRule () <br /> #10 0x08109134 in fireRIRrules () <br /> #11
0x08108ff9in fireRIRrules () <br /> #12 0x08108e21 in ApplyRetrieveRule () <br /> #13 0x08109134 in fireRIRrules () <br
/>#14 0x08108e21 in ApplyRetrieveRule () <br /> #15 0x08109134 in fireRIRrules () <br /> #16 0x081095ec in QueryRewrite
()<br /> #17 0x081173c9 in pg_analyze_and_rewrite () <br /> #18 0x08117635 in pg_exec_query_string () <br /> #19
0x0811876ain PostgresMain () <br /> #20 0x080fde2a in DoBackend () <br /> #21 0x080fd77d in BackendStartup () <br />
#220x080fc8c1 in ServerLoop () <br /> ---Type <return> to continue, or q <return> to quit--- <br /> #23
0x080fc2dbin PostmasterMain () <br /> #24 0x080da152 in main () <br /> #25 0x42017499 in __libc_start_main () from
/lib/i686/libc.so.6<br /> (gdb) <br /><br /> Looks like both try to have a lock and that leads to a deadlock situation.
<br/> internally does drop  trigger and select try to lock a particluar table? <br /> how can i get details whats
happeninginternally in postgres for these operations? <br /><br /><br /><br /> I can provide more info if needed, hope
thestack traces are helpful. <br /> Kindly help me, this problem is causinig lot of problem for me. <br /><br /> Thanks
inadvance <br /> regards <br /> vatsal <table cellpadding="0" cellspacing="0" width="100%"><tr><td><font
size="2"><b>_</b></font></td></tr></table><table><tr><tdbgcolor="#ffffff"><font
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