--//重复测试:
$ . y1.sh
20190424094217
[3]-  Done                    sqlplus / as sysdba <<< "@ exclusive_latch.txt 'test excl. parent2 l0' 0 1 2 6" > /dev/null
[1]  Done                    source peek.sh 'test excl. parent2 l0' 20 | timestamp.pl >|/tmp/peekx_${zdate}.txt
[4]-  Done                    sqlplus / as sysdba <<< "@ exclusive_latch.txt 'test excl. parent2 l0' 0 3 4 6" > /dev/null
[5]+  Done                    sqlplus / as sysdba <<< "@ exclusive_latch.txt 'test excl. parent2 l0' 0 5 6 6" > /dev/null
[2]+  Done                    seq 20 | xargs -I{} echo -e 'sqlplus -s -l / as sysdba <<< @latch_free\nsleep 1' | bash >|/tmp/latch_freeo_${zdate}.txt

SYS@book> select addr,name,level#,latch#,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('test excl. parent2 l0')||'%';
ADDR            NAME                  LEVEL#    LATCH#      GETS    MISSES    SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- --------------------- ------ ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060009978 test excl. parent2 l0      0          5          4          0          0              6                4            0                  0          0          0

--//可以发现IMMEDIATE_GETS增加2次,IMMEDIATE_MISSES增加1次.