(gdb) where
#0  0x000000308080adfb in __lll_mutex_lock_wait () from /lib64/tls/libpthread.so.0
#1  0x0000000000000001 in ?? ()
#2  0x0000000000000011 in ?? ()
#3  0x0000003080807c07 in pthread_mutex_lock () from /lib64/tls/libpthread.so.0
#4  0x0000002a960bc38f in js_Enumerate (cx=0x665450, obj=0x65efe0, enum_op=JSENUMERATE_INIT, statep=0x40304358, 
    idp=0x2a9608b717) at jsobj.c:3285
#5  0x0000002a9608e0b1 in prop_iterator_finalize (cx=0x665e10, obj=0xc2e540) at jsinterp.c:145
#6  0x0000002a960b675d in js_FinalizeObject (cx=0x665e10, obj=0xc2e540) at jsobj.c:1983
#7  0x0000002a9608ceda in js_GC (cx=0x665e10, gcflags=0) at jsgc.c:1348
#8  0x0000002a9608c29c in js_ForceGC (cx=0x665e10, gcflags=0) at jsgc.c:1030
#9  0x0000002a96061a4f in js_DestroyContext (cx=0x665e10, gcmode=JS_FORCE_GC) at jscntxt.c:255
#10 0x0000002a96050fcd in JS_DestroyContext (cx=0x665e10) at jsapi.c:929