--//我发现一些细节问题以前没有注意,我重复做一次,当时做的确实有点乱.这次看看整理一下.

1.环境:
SYS@book> @ ver1
PORT_STRING         VERSION        BANNER
------------------- -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx 11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

2.测试脚本建立:
$ cat viewlatch.sql
SELECT addr, name, level#, GETS, MISSES, SLEEPS, IMMEDIATE_GETS, IMMEDIATE_MISSES, WAITERS_WOKEN,
       WAITS_HOLDING_LATCH, SPIN_GETS, WAIT_TIME
  FROM v$latch_parent
 WHERE lower(name) like '%'||lower('&&1')||'%';

--//补充一点我发现空扫描v$latch也会导致gets的增加.扫描 v$latch_parent不会.
--//另外"gcs partitioned table hash" latch是共享的.

$ cat peek.sh
#! /bib/bash
# 参数如下:latch_name Monitoring_duration or laddr
sqlplus -s -l / as sysdba <<EOF
col laddr new_value laddr
SELECT sysdate,addr laddr FROM v\$latch_parent WHERE NAME='$1';
oradebug setmypid
$(seq $2|xargs -I{} echo -e 'oradebug peek 0x&laddr 8\nhost sleep 1' )
EOF
--//定时1秒间隔通过oradebug peek查看该latch地址处的长度60字节内容..

$ cat shared_latch.txt
/* 参数如下: @ shared_latch.txt latch_name willing why where mode sleep_num */
--//connect / as sysdba
col laddr new_value laddr
col vmode  new_value vmode
select decode(lower('&&5'),'s',8,'x',16,'8',8,'16',16) vmode from dual ;
SELECT addr laddr FROM v$latch_parent WHERE NAME='&&1';
oradebug setmypid
oradebug call kslgetsl_w 0x&laddr &&2 &&3 &&4  &vmode
host sleep &&6
oradebug call kslfre 0x&laddr
--//exit

$ cat latch_free.sql
/*
     This file is part of demos for "Contemporary Latch Internals" seminar v.18.09.2010
     Andrey S. Nikolaev (Andrey.Nikolaev@rdtex.ru)
    
     This query shows trees of processes currently holding and waiting for latches
     Tree output enumerates these processes and latches as following:
Process <PID1>
 <latch1 holding by PID1>
    <processes waiting for latch1>
       ...
 <latch2 holding by PID1>
    <processes waiting for latch2>
       ...
Process <PID2>
...
*/

set head off
set feedback off
set linesize 120
select sysdate from dual;
select   LPAD(' ', (LEVEL - 1) )
     ||case when latch_holding is null then 'Process '||pid
             else 'holding: '||latch_holding||'  "'||name||'" lvl='||level#||' whr='||whr||' why='||why ||', SID='||sid
       end
     || case when latch_waiting  is not  null then ', waiting for: '||latch_waiting||' whr='||whr||' why='||why
       end latchtree
 from (
/* Latch holders */
select ksuprpid pid,ksuprlat latch_holding, null latch_waiting, to_char(ksuprpid) parent_id, rawtohex(ksuprlat) id,
       ksuprsid sid,ksuprllv level#,ksuprlnm name,ksuprlmd mode_,ksulawhy why,ksulawhr whr  from x$ksuprlat
union all
/* Latch waiters */
select indx pid,null latch_holding, ksllawat latch_waiting,rawtohex(ksllawat) parent_id,to_char(indx) id,
       null,null,null,null,ksllawhy why,ksllawer whr from x$ksupr where ksllawat !='00'
union all
/*  The roots of latch trees: processes holding latch but not waiting for latch */
select pid, null, null, null, to_char(pid),null,null,null,null,null,null from (
select distinct ksuprpid pid  from x$ksuprlat
minus
select indx pid from x$ksupr where ksllawat !='00')
) latch_op
connect by prior id=parent_id
start with parent_id  is null;

$ cat i5.sh
#! /bin/bash
zdate=$(date '+%H%M%S')
echo $zdate
source peek.sh 'gcs partitioned table hash' 10 | timestamp.pl >| /tmp/peeks_${zdate}.txt &
seq 10 | xargs -I{} echo -e 'sqlplus -s -l / as sysdba <<< @latch_free\nsleep 1'  | bash >| /tmp/latch_free_${zdate}.txt &
sleep 1
# 参数如下: @ latch.txt latch_name willing why where mode sleep_num
seq 150 | xargs -I {} -P 150 sqlplus -s -l / as sysdba  @ shared_latch.txt 'gcs partitioned table hash' 1 4 {}  s 6 > /dev/null
wait

$ cat $(which timestamp.pl)
#!/usr/bin/perl
while (<>) {
($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime();
printf("%02d:%02d:%02d", $hour, $min, $sec);
print  ": $_";
#print localtime() . ": $_";
}