gdb调试之---当update时第一个持有的Latch是什么Latch锁？ - 数据库编程

one. Loaded symbols for /lib64/ld-linux-x86-64.so.2 Reading symbols from /usr/lib64/libnuma.so.1...done. Loaded symbols for /usr/lib64/libnuma.so.1 Reading symbols from /lib64/libnss_files.so.2...done. Loaded symbols for /lib64/libnss_files.so.2 Reading symbols from /u01/app/oracle/product/11.2.0/lib/libnque11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libnque11.so 0x0000003f0d40d290 in __read_nocancel () from /lib64/libpthread.so.0 (gdb)

3、设一个断点，持有第一个Latch锁(预先知道函数kslgetl就是持有Latch的函数)，并运行（c命令，即continue）（在第二个窗口执行）

(gdb) b kslgetl
Breakpoint 1 at 0x8f96376
(gdb) c
Continuing.

4、执行一个update语句，触发断点的操作，此时update被阻塞了（在第一个窗口执行）

gyj@OCM> update gyj_test set name='AAAAA' where id=1;

5、一执行updater操作，断点就停在这儿了（在第二个窗口执行）

Breakpoint 1, 0x0000000008f96376 in kslgetl ()
(gdb)

6、我们先来看update时持有第一个Latch锁所对应函数kslgetl ()的第一个参数是什么？用命令info all-register显示寄存器（在第二个窗口执行）

(gdb) info all-register
rax            0x0      0
rbx            0x2000   8192
rcx            0xf27    3879
rdx            0x0      0
rsi            0x1      1
rdi            0x601082f0       1611694832
rbp            0x7fff1c5754d0   0x7fff1c5754d0
rsp            0x7fff1c5754d0   0x7fff1c5754d0
r8             0xf27    3879
r9             0xbaf3fa0        196034464
r10            0x0      0
r11            0xf27    3879
r12            0x927db800       2457712640
r13            0x601082f0       1611694832
r14            0x1      1
r15            0x1      1
rip            0x8f96376        0x8f96376 
eflags         0x246    [ PF ZF IF ]
cs             0x33     51
ss             0x2b     43
ds             0x0      0
es             0x0      0
fs             0x0      0
gs             0x0      0
st0            0        (raw 0x00000000000000000000)
---Type  to continue, or q  to quit---
st1            0        (raw 0x00000000000000000000)
st2            0        (raw 0x00000000000000000000)
st3            0        (raw 0x00000000000000000000)
st4            0        (raw 0x00000000000000000000)
st5            0        (raw 0x00000000000000000000)
st6            333296   (raw 0x4011a2be000000000000)
st7            300384   (raw 0x401192ac000000000000)
fctrl          0x27f    639
fstat          0x0      0
ftag           0xffff   65535
fiseg          0x0      0
fioff          0x9394e95        154750613
foseg          0x7fff   32767
fooff          0x1c573f50       475479888
fop            0x0      0
xmm0           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 }, v8_int16 = {0x0, 0x0, 0x0, 0x0, 
    0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000}
xmm1           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 }, v8_int16 = {0x0, 0x0, 0x0, 0x0, 
    0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000}
xmm2           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 }, v8_int16 = {0x0, 0x0, 0x0, 0x0, 
    0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000}
xmm3           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x8000000000000000, 0x8000000000000000}, v16_int8 = {0xfe, 0xff, 0xff, 0xff, 
    0xff, 0xff, 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, v8_int16 = {0xfffe, 0xffff, 0xffff, 0xffff, 0xfffe, 0xffff, 
    0xffff, 0xffff}, v4_int32 = {0xfffffffe, 0xffffffff, 0xfffffffe, 0xffffffff}, v2_int64 = {0xfffffffffffffffe, 0xfffffffffffffffe}, 
  uint128 = 0xfffffffffffffffefffffffffffffffe}
---Type  to continue, or q  to quit---
xmm4           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 }, v8_int16 = {0x0, 0x0, 0x0, 0x0, 
    0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000}
xmm5           {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x32, 0xa3, 0xd7,

gdb调试之---当update时第一个持有的Latch是什么Latch锁？(二)