使用bufferevent pair遇到的死锁问题。产生死锁的demo可下载。
1.死锁现象
读回调线程栈：
(gdb) bt
#0 0x00007ffff7bcbcc0 in pthread_rwlock_wrlock () from /lib64/libpthread.so.0
#1 0x0000000000402982 in ReadCallback (bev=0x63d240, arg=0x7fffffffe240) at libevent_dead_lock.cpp:14
#2 0x0000000000403c3c in bufferevent_run_deferred_callbacks_locked (cb=<optimized out>, arg=0x63d240) at bufferevent.c:167
#3 0x000000000040bb5c in event_process_active_single_queue (base=base@entry=0x63cc60, activeq=0x63d0b0, max_to_process=max_to_process@entry=2147483647,
endtime=endtime@entry=0x0) at event.c:1720
#4 0x000000000040c54f in event_process_active (base=0x63cc60) at event.c:1783
#5 event_base_loop (base=0x63cc60, flags=0) at event.c:2006
#6 0x0000000000402cdc in LibEventMgr::Run (this=0x7fffffffe240) at libevent_dead_lock.cpp:53
#7 0x0000000000402b96 in pthread_func1 (arg=0x7fffffffe240) at libevent_dead_lock.cpp:106
#8 0x00007ffff7bc85f0 in start_thread () from /lib64/libpthread.so.0
#9 0x00007ffff72c184d in clone () from /lib64/libc.so.6
#10 0x0000000000