转载请注明出处:http://blog.csdn.net/guoyjoe/article/details/18456937
1、查出当前会话所对应的系统进程号:SPID=7376,如下语句(在第一个窗口执行)
gyj@OCM> select spid from v$session s,v$process p where s.paddr=p.addr and sid in(select distinct sid from v$mystat); SPID ------------------------ 7376
2、 通过系统进程号7376打开gdb程序(在第二个窗口执行)
[oracle@mydb ~]$ gdb $ORACLE_HOME/bin/oracle 7376 GNU gdb Fedora (6.8-27.el5) Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-redhat-linux-gnu"... (no debugging symbols found) Attaching to program: /u01/app/oracle/product/11.2.0/bin/oracle, process 7376 Reading symbols from /u01/app/oracle/product/11.2.0/lib/libodm11.so...(no debugging symbols found)...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libodm11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libcell11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libcell11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libskgxp11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libskgxp11.so Reading symbols from /lib64/librt.so.1...done. Loaded symbols for /lib64/librt.so.1 Reading symbols from /u01/app/oracle/product/11.2.0/lib/libnnz11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libnnz11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libclsra11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libclsra11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libdbcfg11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libdbcfg11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libhasgen11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libhasgen11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libskgxn2.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libskgxn2.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libocr11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libocr11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libocrb11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libocrb11.so Reading symbols from /u01/app/oracle/product/11.2.0/lib/libocrutl11.so...done. Loaded symbols for /u01/app/oracle/product/11.2.0/lib/libocrutl11.so Reading symbols from /usr/lib64/libaio.so.1...done. Loaded symbols for /usr/lib64/libaio.so.1 Reading symbols from /lib64/libdl.so.2...done. Loaded symbols for /lib64/libdl.so.2 Reading symbols from /lib64/libm.so.6...done. Loaded symbols for /lib64/libm.so.6 Reading symbols from /lib64/libpthread.so.0...done. [Thread debugging using libthread_db enabled] [New Thread 0x2b0b8fef0910 (LWP 7376)] Loaded symbols for /lib64/libpthread.so.0 Reading symbols from /lib64/libnsl.so.1...done. Loaded symbols for /lib64/libnsl.so.1 Reading symbols from /lib64/libc.so.6...done. Loaded symbols for /lib64/libc.so.6 Reading symbols from /lib64/ld-linux-x86-64.so.2...done. 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 <kslgetl+4> 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 <return> to continue, or q <return> 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 <repeats 16 times>}, 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 <repeats 16 times>}, 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 <repeats 16 times>}, 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 <return> to continue, or q <return> to quit--- xmm4 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, 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, 0x2, 0x0 <repeats 12 times>}, v8_int16 = {0xa332, 0x2d7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x2d7a332, 0x0, 0x0, 0x0}, v2_int64 = {0x2d7a332, 0x0}, uint128 = 0x00000000000000000000000002d7a332} xmm6 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm7 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0xda, 0x87, 0xd7, 0x2, 0x0 <repeats 12 times>}, v8_int16 = {0x87da, 0x2d7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x2d787da, 0x0, 0x0, 0x0}, v2_int64 = {0x2d787da, 0x0}, uint128 = 0x00000000000000000000000002d787da} xmm8 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm9 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm10 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm11 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm12 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x18, 0xe, 0x73, 0x90, 0xb, 0x2b, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v8_int16 = {0xe18, 0x9073, 0x2b0b, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x90730e18, 0x2b0b, 0x0, 0x0}, v2_int64 = {0x2b0b90730e18, 0x0}, uint128 = 0x000000000000000000002b0b90730e18} xmm13 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} xmm14 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} ---Type <return> to continue, or q <return> to quit--- xmm15 {v4_float = {0x0, 0x0, 0x0, 0x0}, v2_double = {0x0, 0x0}, v16_int8 = {0x0 <repeats 16 times>}, v8_int16 = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, v4_int32 = {0x0, 0x0, 0x0, 0x0}, v2_int64 = {0x0, 0x0}, uint128 = 0x00000000000000000000000000000000} mxcsr 0x1fa1 [ IE PE IM DM ZM OM UM PM ] (gdb)
7、rdi/edi是第一个参数, rsi/esi是第二个参数,贴出info all-register命令所显示函数kslgetl ()的两个参数,如下
rsi 0x1 1 ----第二个参数
rdi 0x601082f0 1611694832 ----第一个参数
8、找到第一个参数0x601082f0,注意因我的OS是64位,前面要补8个0,在v$latch_children视图中地址的字母要大写,
即0x601082f0要写为00000000601082F0
9、通过视图v$latch_children找Latch锁(在第三个窗口执行)
sys@OCM> select name from v$latch_children where addr=‘00000000601082F0‘; NAME ---------------------------------------------------------------- shared pool
10、发现Latch锁就是shared pool Latch。
QQ:252803295
技术交流QQ群:
DSI&Core Search Ⅰ 群:127149411(2000人技术群:未满)
DSI&Core Search Ⅱ 群:177089463(1000人技术群:未满)
DSI&Core Search Ⅲ 群:284596437(500人技术群:未满)
DSI&Core Search Ⅳ 群:192136702(500人技术群:未满)
DSI&Core Search Ⅴ 群:285030382(500人闲聊群:未满)
MAIL:dbathink@hotmail.com
BLOG: http://blog.csdn.net/guoyjoe
WEIBO:http://weibo.com/guoyJoe0218
ITPUB: http://www.itpub.net/space-uid-28460966.html
OCM: http://education.oracle.com/education/otn/YGuo.HTM
ACONG: http://www.acoug.org/category/membership