搜尋
首頁資料庫mysql教程gdb调试之---当update时第一个持有的Latch是什么Latch锁?

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 disti

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
[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=&#39;AAAAA&#39; 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

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,

sys@OCM>  select  name from v$latch_children where addr=&#39;00000000601082F0&#39;;

NAME
----------------------------------------------------------------
shared pool

10、发现Latch锁就是shared pool Latch。

陳述
本文內容由網友自願投稿,版權歸原作者所有。本站不承擔相應的法律責任。如發現涉嫌抄襲或侵權的內容,請聯絡admin@php.cn
解釋InnoDB緩衝池及其對性能的重要性。解釋InnoDB緩衝池及其對性能的重要性。Apr 19, 2025 am 12:24 AM

InnoDBBufferPool通過緩存數據和索引頁來減少磁盤I/O,提升數據庫性能。其工作原理包括:1.數據讀取:從BufferPool中讀取數據;2.數據寫入:修改數據後寫入BufferPool並定期刷新到磁盤;3.緩存管理:使用LRU算法管理緩存頁;4.預讀機制:提前加載相鄰數據頁。通過調整BufferPool大小和使用多個實例,可以優化數據庫性能。

MySQL與其他編程語言:一種比較MySQL與其他編程語言:一種比較Apr 19, 2025 am 12:22 AM

MySQL与其他编程语言相比,主要用于存储和管理数据,而其他语言如Python、Java、C 则用于逻辑处理和应用开发。MySQL以其高性能、可扩展性和跨平台支持著称,适合数据管理需求,而其他语言在各自领域如数据分析、企业应用和系统编程中各有优势。

學習MySQL:新用戶的分步指南學習MySQL:新用戶的分步指南Apr 19, 2025 am 12:19 AM

MySQL值得學習,因為它是強大的開源數據庫管理系統,適用於數據存儲、管理和分析。 1)MySQL是關係型數據庫,使用SQL操作數據,適合結構化數據管理。 2)SQL語言是與MySQL交互的關鍵,支持CRUD操作。 3)MySQL的工作原理包括客戶端/服務器架構、存儲引擎和查詢優化器。 4)基本用法包括創建數據庫和表,高級用法涉及使用JOIN連接表。 5)常見錯誤包括語法錯誤和權限問題,調試技巧包括檢查語法和使用EXPLAIN命令。 6)性能優化涉及使用索引、優化SQL語句和定期維護數據庫。

MySQL:初學者的基本技能MySQL:初學者的基本技能Apr 18, 2025 am 12:24 AM

MySQL適合初學者學習數據庫技能。 1.安裝MySQL服務器和客戶端工具。 2.理解基本SQL查詢,如SELECT。 3.掌握數據操作:創建表、插入、更新、刪除數據。 4.學習高級技巧:子查詢和窗口函數。 5.調試和優化:檢查語法、使用索引、避免SELECT*,並使用LIMIT。

MySQL:結構化數據和關係數據庫MySQL:結構化數據和關係數據庫Apr 18, 2025 am 12:22 AM

MySQL通過表結構和SQL查詢高效管理結構化數據,並通過外鍵實現表間關係。 1.創建表時定義數據格式和類型。 2.使用外鍵建立表間關係。 3.通過索引和查詢優化提高性能。 4.定期備份和監控數據庫確保數據安全和性能優化。

MySQL:解釋的關鍵功能和功能MySQL:解釋的關鍵功能和功能Apr 18, 2025 am 12:17 AM

MySQL是一個開源的關係型數據庫管理系統,廣泛應用於Web開發。它的關鍵特性包括:1.支持多種存儲引擎,如InnoDB和MyISAM,適用於不同場景;2.提供主從復制功能,利於負載均衡和數據備份;3.通過查詢優化和索引使用提高查詢效率。

SQL的目的:與MySQL數據庫進行交互SQL的目的:與MySQL數據庫進行交互Apr 18, 2025 am 12:12 AM

SQL用於與MySQL數據庫交互,實現數據的增、刪、改、查及數據庫設計。 1)SQL通過SELECT、INSERT、UPDATE、DELETE語句進行數據操作;2)使用CREATE、ALTER、DROP語句進行數據庫設計和管理;3)複雜查詢和數據分析通過SQL實現,提升業務決策效率。

初學者的MySQL:開始數據庫管理初學者的MySQL:開始數據庫管理Apr 18, 2025 am 12:10 AM

MySQL的基本操作包括創建數據庫、表格,及使用SQL進行數據的CRUD操作。 1.創建數據庫:CREATEDATABASEmy_first_db;2.創建表格:CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY,titleVARCHAR(100)NOTNULL,authorVARCHAR(100)NOTNULL,published_yearINT);3.插入數據:INSERTINTObooks(title,author,published_year)VA

See all articles

熱AI工具

Undresser.AI Undress

Undresser.AI Undress

人工智慧驅動的應用程序,用於創建逼真的裸體照片

AI Clothes Remover

AI Clothes Remover

用於從照片中去除衣服的線上人工智慧工具。

Undress AI Tool

Undress AI Tool

免費脫衣圖片

Clothoff.io

Clothoff.io

AI脫衣器

AI Hentai Generator

AI Hentai Generator

免費產生 AI 無盡。

熱工具

PhpStorm Mac 版本

PhpStorm Mac 版本

最新(2018.2.1 )專業的PHP整合開發工具

SublimeText3 Mac版

SublimeText3 Mac版

神級程式碼編輯軟體(SublimeText3)

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

將Eclipse與SAP NetWeaver應用伺服器整合。

EditPlus 中文破解版

EditPlus 中文破解版

體積小,語法高亮,不支援程式碼提示功能

DVWA

DVWA

Damn Vulnerable Web App (DVWA) 是一個PHP/MySQL的Web應用程序,非常容易受到攻擊。它的主要目標是成為安全專業人員在合法環境中測試自己的技能和工具的輔助工具,幫助Web開發人員更好地理解保護網路應用程式的過程,並幫助教師/學生在課堂環境中教授/學習Web應用程式安全性。 DVWA的目標是透過簡單直接的介面練習一些最常見的Web漏洞,難度各不相同。請注意,該軟體中