===================================== 160129 12:07:26 INNODB MONITOR OUTPUT #第二行是当前日期和时间 ===================================== Per second averages calculated from the last 24 seconds #第四行显示的是计算出这一平均值的时间间隔，即自上次输出以来的时间，或者是距上次内部复位的时长
---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 68581015, signal count 218437328 --Thread 140653057947392 has waited at btr0pcur.c line 437 for 0.00 seconds the semaphore: S-lock on RW-latch at 0x7ff536c7d3c0 created in file buf0buf.c line 916 a writer (thread id 140653057947392) has reserved it in mode exclusive number of readers 0, waiters flag 1, lock_word: 0 Last time read locked in file row0sel.c line 3097 Last time write locked in file /usr/local/src/soft/mysql-5.5.24/storage/innobase/buf/buf0buf.c line 3151 --Thread 140653677291264 has waited at btr0pcur.c line 437 for 0.00 seconds the semaphore: S-lock on RW-latch at 0x7ff53945b240 created in file buf0buf.c line 916 a writer (thread id 140653677291264) has reserved it in mode exclusive number of readers 0, waiters flag 1, lock_word: 0 Last time read locked in file row0sel.c line 3097 Last time write locked in file /usr/local/src/soft/mysql-5.5.24/storage/innobase/buf/buf0buf.c line 3151 Mutex spin waits 1157217380, rounds 1783981614, OS waits 10610359 RW-shared spins 103830012, rounds 1982690277, OS waits 52051891 RW-excl spins 43730722, rounds 602114981, OS waits 3495769 Spin rounds per wait: 1.54 mutex, 19.10 RW-shared, 13.77 RW-excl
--Thread 140653057947392 has waited at btr0pcur.c line 437 for 0.00 seconds the semaphore: S-lock on RW-latch at 0x7ff536c7d3c0 created in file buf0buf.c line 916 a writer (thread id 140653057947392) has reserved it in mode exclusive number of readers 0, waiters flag 1, lock_word: 0 Last time read locked in file row0sel.c line 3097 Last time write locked in file /usr/local/src/soft/mysql-5.5.24/storage/innobase/buf/buf0buf.c line 3151 --Thread 140653677291264 has waited at btr0pcur.c line 437 for 0.00 seconds the semaphore: S-lock on RW-latch at 0x7ff53945b240 created in file buf0buf.c line 916 a writer (thread id 140653677291264) has reserved it in mode exclusive number of readers 0, waiters flag 1, lock_word: 0 Last time read locked in file row0sel.c line 3097 Last time write locked in file /usr/local/src/soft/mysql-5.5.24/storage/innobase/buf/buf0buf.c line 3151 这部分显示的是当前正在等待互斥量的innodb线程，在这里可以看到有两个线程正在等待，每一个都是以--Thread <数字> has waited...开始，这一段内容在正常情况下应该是空的（即查看的时候没有这部分内容），除非服务器运行着高并发的工作负载，促使innodb采取让操作系统等待的措施，除非你对innodb源码熟悉，否则这里看到的最有用的信息就是发生线程等待的代码文件名 /usr/local/src/soft/mysql-5.5.24/storage/innobase/buf/buf0buf.c line 3151。
