gdb usage
attach process
gdb attach $pid
查看进程内的所有线程
info thread
切换跟踪线程
thread $thread_id #此thread_id为info thread结果行首的thread id
查看变量值
先bt查看backtrace，再f $n设置栈帧，再p *mutex打印变量值（这里的mutex为一个结构体指针）
(gdb) f 3
#3 __pthread_cond_wait (cond=0x10da6a0, mutex=0x10da688)
at pthread_cond_wait.c:638
638 pthread_cond_wait.c: No such file or directory.
(gdb) p *mutex
$1 = {__data = {__lock = 0, __count = 0, __owner = 0, __kind = 2,
__nusers = 1, {__spins = 0, __list = {__next = 0x0}}},
__size = '\000' <repeats 12 times>, "\002\000\000\000\001\000\000\000\000\000\000", __align = 0}
(gdb)
标签：__,thread,gdb,000,cond,usage,mutex From： https://www.cnblogs.com/aspirs/p/16830138.html