[20181130]control file sequential read.txt

来源:https://www.cnblogs.com/lfree/archive/2018/11/30/10043013.html
-Advertisement-
Play Games

[20181130]control file sequential read.txt--//昨天上午探究了大量控制文件讀的情況,鏈接:http://blog.itpub.net/267265/viewspace-2222146/--//今天做一些細節探究:1.環境:SYS@xxxxx1> @ ver ...


[20181130]control file sequential read.txt

--//昨天上午探究了大量控制文件讀的情況,鏈接:http://blog.itpub.net/267265/viewspace-2222146/
--//今天做一些細節探究:

1.環境:
SYS@xxxxx1> @ 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

--//建立執行腳本如下:
$ cat c.txt
select 'flashpct;'||trim(ceil(percent_space_used)) from V$FLASH_RECOVERY_AREA_USAGE where file_type='FLASHBACK LOG'
union all
select 'flashtime;'||to_char(OLDEST_FLASHBACK_TIME,'yyyy-mm-dd hh24:mi:ss') from V$FLASHBACK_DATABASE_LOG;

--//session 1:
SYS@xxxxx1> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
        60      26633 1442                     DEDICATED 1443       418        203 alter system kill session '60,26633' immediate;
--//記下spid=1443.

2.使用strace跟蹤
--//session 2:
$ strace -p 1443 -t -e pread  -o /tmp/aa1

--//切換到session 1:
SYS@xxxxx1> @ c.txt
'FLASHPCT;'||TRIM(CEIL(PERCENT_SPACE_USED))
-------------------------------------------------
flashpct;0

--//session 2,按ctrl+c退出:
# strace -p 1443 -t -e pread  -o /tmp/aa1
Process 1443 attached - interrupt to quit
^CProcess 1443 detached

# cat /tmp/aa1
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0J\3\0\0\1\255\3338\377\377\1\4B\27\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 476741632) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0r\0\0\0\306\333\2638\377\377\1\4{Z\0\0\3\0\2\0\0\0\0\0\0\0+D"..., 16384, 475168768) = 16384
16:10:10 pread(256, "\25\302\0\0s\0\0\0\377\254\3338\377\377\1\4u\31\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 475185152) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0i\4\0\0P<\3338\377\377\1\4(\324\0\0=\2\0\0\30\1\0\0v\0301;"..., 16384, 480395264) = 16384
16:10:10 pread(258, "\25\302\0\0|\4\0\0\200\212\3338\377\377\1\4\25q\0\0L\2\0\0000\2\0\0Z(2;"..., 16384, 480444416) = 16384
16:10:10 pread(257, "\25\302\0\0\232\4\0\0<r\3338\377\377\1\4\345\354\0\0`\2\0\0`\4\0\0\301]3;"..., 16384, 478445568) = 16384
16:10:10 pread(257, "\25\302\0\0\301\4\0\0!{\3338\377\377\1\4\3\247\0\0\216\2\0\0\301\10\0\0r\3015;"..., 16384, 477511680) = 16384
16:10:10 pread(257, "\25\302\0\0\35\5\0\0005\254\3218\377\377\1\4\376\274\0\0\350\2\0\0\177\21\0\0\36\7\24;"..., 16384, 478756864) = 16384
16:10:10 pread(258, "\25\302\0\0\323\1\0\00040\3338\377\377\1\4\261\306\0\0R\3650;\n\5\1\0\342\225\0\0"..., 16384, 473874432) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(257, "\25\302\0\0T\2\0\0qD\2407\377\377\1\4\251a\0\0u\332\2047\0\0\0\0\0\0\0\0"..., 16384, 475201536) = 16384
16:10:10 pread(257, "\25\302\0\0U\2\0\0\262\342\2638\377\377\1\4U\226\0\0bracontrolfi"..., 16384, 475217920) = 16384
16:10:10 pread(258, "\25\302\0\0X\2\0\0 \201\2708\377\377\1\4\t:\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 476184576) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384

# rev /tmp/aa1 | cut -f1 -d'=' | rev | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
950272

--//可以讀的文件句柄是256,257,258.
# ls -l /proc/1443/fd | grep 25[678]
lrwx------ 1 root root 64 2018-11-29 16:10:11 256 -> /dev/asm-diskf
lrwx------ 1 root root 64 2018-11-29 16:10:11 257 -> /dev/asm-diskg
lrwx------ 1 root root 64 2018-11-29 16:10:11 258 -> /dev/asm-diske
--//可以發現對應以上裸設備.

--//單獨看兩個：
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384

$ man pread
PREAD(2)  Linux Programmer's Manual                                PREAD(2)

NAME
       pread, pwrite - read from or write to a file descriptor at a given offset

SYNOPSIS
       #define _XOPEN_SOURCE 500
       #include
       ssize_t pread(int fd, void *buf, size_t count, off_t offset);
       ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
--//第1個是句柄，第2個參數緩存地址指針，第3個是讀取長度，第4個是偏移量。

473022464/1024/1024 = 451.10937500000000000000
480264192/1024/1024 = 458.01562500000000000000

--//以grid用戶登錄,訪問asm實例:
SQL> column path format a40
SQL> select DISK_NUMBER,GROUP_NUMBER,PATH from v$asm_disk where GROUP_NUMBER=1 and DISK_NUMBER in(1,0,2) order by 1;
DISK_NUMBER GROUP_NUMBER PATH
----------- ------------ ----------------------------------------
          0            1 /dev/asm-diske
          1            1 /dev/asm-diskf
          2            1 /dev/asm-diskg

SQL> SELECT disk_kffxp, au_kffxp, xnum_kffxp,GROUP_KFFXP,NUMBER_KFFXP  FROM x$kffxp  WHERE (au_kffxp=451 or  au_kffxp=458) and disk_kffxp=2;
DISK_KFFXP   AU_KFFXP XNUM_KFFXP GROUP_KFFXP NUMBER_KFFXP
---------- ---------- ---------- ----------- ------------
         2        458          0           1          260
         2        451          4           1          261

--//NUMBER_KFFXP對應的是260,261.
--//使用asmcmd查看:

$ rlwrap asmcmd -p
ASMCMD [+] > ls -l data/xxxxx/controlfile
Type         Redund  Striped  Time                  Sys  Name
CONTROLFILE  UNPROT  FINE     2018/08/20 01:00:00                Y    Current.260.931438443
CONTROLFILE  UNPROT  FINE     2018/08/20 01:00:00                Y    Current.261.931438443

--//如下查詢:

SQL> column type format a12
SQL> select * from v$asm_file where TYPE='CONTROLFILE' order by type;
GROUP_NUMBER FILE_NUMBER COMPOUND_INDEX INCARNATION BLOCK_SIZE     BLOCKS      BYTES      SPACE TYPE         REDUND STRIPE CREATION_ MODIFICAT R PERMISSIONS      USER_NUMBER USER_INCARNATION USERGROUP_NUMBER USERGROUP_INCARNATION PRIM MIRR  HOT_READS HOT_WRITES HOT_BYTES_READ HOT_BYTES_WRITTEN COLD_READS COLD_WRITES COLD_BYTES_READ COLD_BYTES_WRITTEN
------------ ----------- -------------- ----------- ---------- ---------- ---------- ---------- ------------ ------ ------ --------- --------- - ---------------- ----------- ---------------- ---------------- --------------------- ---- ---- ---------- ---------- -------------- ----------------- ---------- ----------- --------------- ------------------
           1         260       16777476   931438443      16384       1837   30097408   33554432 CONTROLFILE  UNPROT FINE   24-DEC-16 20-AUG-18 U rw-rw-rw-                  0                0                0                     0 COLD COLD          0          0            0                  0     3146179    13420526      5.1548E+10         2.1988E+11
           1         261       16777477   931438443      16384       1837   30097408   33554432 CONTROLFILE  UNPROT FINE   24-DEC-16 20-AUG-18 U rw-rw-rw-                  0                0                0                     0 COLD COLD          0          0            0                  0   283440487    13420559      1.9953E+13         2.1988E+11

--//再次證明讀取的是控制文件.

3.疑問:
# rev /tmp/aa1 | cut -f1 -d'=' | rev | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
950272

--//我跟蹤看到的讀950272.950272/1024 = 928K.

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50          0        714
physical read total multi block requests                                       51          0        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55          0        714

SYS@xxxxx1> @ c.txt
'FLASHPCT;'||TRIM(CEIL(PERCENT_SPACE_USED))
-------------------------------------------------
flashpct;0

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50         73        714
physical read total multi block requests                                       51         15        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55   13828096        714

--//13828096/1024/1024 = 13.1875M,為什麼呢?
# wc /tmp/aa1
  58  422 7310 /tmp/aa1

--//我重覆使用strace做了跟蹤:
# strace -p 24584 -t  -o /tmp/aa2
# strace -p 24584 -t  -c
Process 24584 attached - interrupt to quit
^CProcess 24584 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
  -nan    0.000000           0         4           read
  -nan    0.000000           0         2           write
  -nan    0.000000           0         2           open
  -nan    0.000000           0         2           close
  -nan    0.000000           0         2           mmap
  -nan    0.000000           0        58           pread
  -nan    0.000000           0         4           semctl
  -nan    0.000000           0        20           getrusage
  -nan    0.000000           0        16           times
  -nan    0.000000           0        16           io_getevents
  -nan    0.000000           0        15           io_submit
  -nan    0.000000           0         2           semtimedop
------ ----------- ----------- --------- --------- ----------------
100.00    0.000000                   143           total

--//可以看到io_submit非同步IO操作.等於15,正好和physical read total multi block requests的數值一致.
--//pread=58(與wc /tmp/aa1看到一致),io_submit=15,相加正好與physical read total IO requests=73一致.不知道是否是巧合.我對非同步io操作的函數不熟悉.

16:45:26 io_submit(140402112221184, 8, {{0x7fb1e81f8210, 0, 0, 0, 256}, {0x7fb1e81f8480, 0, 0, 0, 258},
                                        {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 258},
                                        {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256},
                                        {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}}) = 8

--//猜測裡面的256,257,258對應文件句柄.

# man io_submit
IO_SUBMIT(2)               Linux Programmer's Manual              IO_SUBMIT(2)

NAME
       io_submit - submit asynchronous I/O blocks for processing

SYNOPSIS
       #include <libaio.h>

       int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

       Link with -laio.

DESCRIPTION
       io_submit() queues nr I/O request blocks for processing in the AIO context ctx_id.  iocbpp should be an array of
       nr AIO control blocks, which will be submitted to context ctx_id.

# man io_getevents
IO_GETEVENTS(2)            Linux Programmer's Manual           IO_GETEVENTS(2)

NAME
       io_getevents - read asynchronous I/O events from the completion queue

SYNOPSIS
       #include <linux/time.h>
       #include <libaio.h>

       int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
                        struct io_event *events, struct timespec *timeout);

       Link with -laio.

DESCRIPTION
       io_getevents()  attempts  to read at least min_nr events and up to nr events from the completion queue of the AIO
       context specified by ctx_id.  timeout specifies the amount of time to wait for events, where a NULL timeout waits
       until at least min_nr events have been seen.  Note that timeout is relative and will be updated if not NULL and
       the operation blocks.
       

# egrep 'io_submit|io_getevents' /tmp/aa2
16:45:26 io_submit(140402112221184, 8, {{0x7fb1e81f8210, 0, 0, 0, 256}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}}) = 8
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 81920, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 256}, {0x7fb1e81f86f0, 0, 0, 0, 258}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 49152, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 256}, {0x7fb1e81f86f0, 0, 0, 0, 258}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 49152, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 5, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}}) = 5
16:45:26 io_getevents(140402112221184, 5, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 49152, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 5
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}, {0x7fb1e81f9590, 0, 0, 0, 256}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}}, {0, 0}) = 1
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}}, {0, 0}) = 1
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 3, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}}) = 3
16:45:26 io_getevents(140402112221184, 3, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 114688, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 49152, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}}, {600, 0}) = 3
16:45:26 io_submit(140402112221184, 3, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 258}}) = 3
16:45:26 io_getevents(140402112221184, 3, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 81920, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}}, {600, 0}) = 3
16:45:26 io_submit(140402112221184, 6, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 256}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}}) = 6
16:45:26 io_getevents(140402112221184, 6, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 114688, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 6
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 256}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 7, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}}) = 7
16:45:26 io_getevents(140402112221184, 7, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 16384, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 7
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}, {0x7fb1e81f9590, 0, 0, 0, 256}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 49152, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 81920, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 9

--//我的感覺把io_getevents 函數裡面的16384,131072加起來就是讀取的位元組總數.

# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
12877824

--//12877824+950272 = 13828096
--//^_^.正好和如下看到的一致.佩服一下自己..^_^.

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50         73        714
physical read total multi block requests                                       51         15        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55   13828096        714

---//簡單說明一下以上命令.# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
1. grep 'io_getevents' /tmp/aa2 --//過濾出來io_getevents函數.
2. sed '1,$s/{/\^J/g'           --//將{替換為回車,^J在linux下先輸入ctrl+v在按ctrl+enter就可以了,前面的\避免轉義.
3. grep "^0x"                   --//過濾0x開頭的行.
# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | head -1
0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0},

4.cut -f3 -d,                   --//以,為分隔符,取第3個欄位.也就是裡面16384.輸出.
5.sed -e 's/$/+/g' -e '$s/+$//g'--//在每行結尾加入+,最後一行刪除+號.

# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g' | tail -5
 81920+
 131072+
 131072+
 131072+
 131072

6.xargs echo                   --//也就是把多行變成一行,這裡註意命令行緩存大小,一般情況下不會溢出的.
7.bc -l                        --//也就是計算.

--//順便說一下bash shell編程一般不考慮執行效率,僅僅考慮快速編程,完成對應的工作.估計awk也許更好.

4.總結:
--//寫這篇blog我參考以前遇到的問題,鏈接:http://blog.itpub.net/267265/viewspace-751787/,當時我應該看到讀取調用函數是pread.
--//這個函數應該不支持非同步IO.僅僅io_submit,io_getevents才表明系統執行非同步IO.

--//也就是講實際上就算是asm系統,實際上有1部分讀取使用pread函數.而不是全部使用非同步IO.



您的分享是我們最大的動力!

-Advertisement-
Play Games
更多相關文章
  • 【原】Oracle EBS 11無法打開Form及Form顯示亂碼的解決
    問題：Oracle EBS 11無法打開Form及Form顯示亂碼 解決： 1、嘗試使用jre1.5或1.6安裝目錄下jre/bin/server目錄里的jvm.dll替換JInitiator安裝目錄里的bin/hotspot目錄下的jvm.dll文件，如果替換後，後續操作提示錯誤，不妨再換為預設的 ...
  • Mysql丨資料庫基本概念
    以前記錄數據可能很少也很簡單，比如說老王借了老李半斤肉，這樣的數據老李直接就寫到牆上就行了。 後來數據多了人們就以表格的方式開始記錄，寫到一張A4紙上，比如學生的檔案，有表頭和序號等。 表頭裡有姓名、性別、年齡、籍貫等等，有橫向的信息有豎向的信息。這樣的A4紙散放在那裡肯定是不行的。 於是人們把它們 ...
  • oracle中scott用戶的創建
    oracle11g中沒有scott用戶的解決，通過創建scott.sql文件，然後授予許可權，解鎖，修改密碼等一系列的操作來完成賬號建立 ...
  • redis 系列17 持久化 AOF
    一.概述 除了上篇介紹的RDB持久化功能之外，Redis還提供了AOF(Append Only File)持久化功能。與RDB保存資料庫中的鍵值對來記錄資料庫狀態不同，AOF是通過保存redis伺服器所執行的寫命令來記錄資料庫狀態的。AOF持久化方式記錄每次對伺服器寫的操作,當伺服器啟動時，就會通過 ...
  • 資料庫表欄位命名規範
    摘要：當前研發工作中經常出現因資料庫表、資料庫表欄位格式不規則而影響開發進度的問題，在後續開發使用原來資料庫表時，也會因為資料庫表的可讀性不夠高，表欄位規則不統一，造成數據查詢，數據使用效率低的問題，所以有必要整理出一套合適的資料庫表欄位命名規範來解決優化這些問題。 本文是一篇包含了資料庫命名、數據 ...
  • [MYSQL筆記0]MYSQL的安裝
    mysql是一種關係型資料庫管理系統。以mysql5.7版本為例，安裝過程如下： 首先百度出mysql的官網，進入：（以下是自己安裝失敗的過程，直接下拉最後看大佬的安裝過程吧，就是那個紅紅的網址） 找到mysql的下載社區，找到對應的版本，這裡以mysql5.7為例： 這裡我們選擇zip格式安裝，對 ...
  • [20181130]如何猜測那些值存在hash衝突.txt
    [20181130]如何猜測那些值存在hash衝突.txt--//今年6月份開始kerrycode的1個帖子提到子查詢結果緩存在哈希表中情況:--//鏈接:http://www.cnblogs.com/kerrycode/p/9099507.html,摘要:通俗來將，當使用標量子查詢的時候，ORAC ...
  • [20181130]hash衝突導致查詢緩慢.txt
    [20181130]hash衝突導致查詢緩慢.txt--//昨天看了鏈接https://jonathanlewis.wordpress.com/2018/11/26/shrink-space-2/,演示了Shrink Space導致--//執行語句緩慢的情況,我自己重覆測試,實際上這樣發生的概率還是 ...
一周排行
    -Advertisement-
    Play Games
  • WPF 已知問題 監聽 WMI 事件導致觸摸失效
    示例項目結構 在 Visual Studio 中創建一個 WinForms 應用程式後，項目結構如下所示： MyWinFormsApp/ │ ├───Properties/ │ └───Settings.settings │ ├───bin/ │ ├───Debug/ │ └───Release/ ...
  • [STAThread]特性
    [STAThread] 特性用於需要與 COM 組件交互的應用程式，尤其是依賴單線程模型（如 Windows Forms 應用程式）的組件。在 STA 模式下，線程擁有自己的消息迴圈，這對於處理用戶界面和某些 COM 組件是必要的。 [STAThread] static void Main(stri ...
  • UWP WinUI3 傳入 AddHandler 的 RoutedEventHandler 類型與事件所需不匹配將拋出參數異常
    在WinForm中使用全局異常捕獲處理 在WinForm應用程式中，全局異常捕獲是確保程式穩定性的關鍵。通過在Program類的Main方法中設置全局異常處理，可以有效地捕獲並處理未預見的異常，從而避免程式崩潰。 註冊全局異常事件 [STAThread] static void Main() { / ...
  • .NET 多版本 WinForm 開源控制項庫 SunnyUI
    前言 給大家推薦一款開源的 Winform 控制項庫，可以幫助我們開發更加美觀、漂亮的 WinForm 界面。 項目介紹 SunnyUI.NET 是一個基於 .NET Framework 4.0+、.NET 6、.NET 7 和 .NET 8 的 WinForm 開源控制項庫，同時也提供了工具類庫、擴展 ...
  • .net core8 使用Swagger（附當前源碼）
    說明 該文章是屬於OverallAuth2.0系列文章，每周更新一篇該系列文章（從0到1完成系統開發）。 該系統文章，我會儘量說的非常詳細，做到不管新手、老手都能看懂。 說明：OverallAuth2.0 是一個簡單、易懂、功能強大的許可權+可視化流程管理系統。 有興趣的朋友，請關註我吧(*^▽^*) ...
  • WPF 什麼時候 VisualTreeHelper.GetDescendantBounds 將返回無窮大
    一、下載安裝 1.下載git 必須先下載並安裝git，再TortoiseGit下載安裝 git安裝參考教程：https://blog.csdn.net/mukes/article/details/115693833 2.TortoiseGit下載與安裝 TortoiseGit，Git客戶端，32/6 ...
  • C# 開源教程帶你輕鬆掌握數據結構與演算法
    前言 在項目開發過程中，理解數據結構和演算法如同掌握蓋房子的秘訣。演算法不僅能幫助我們編寫高效、優質的代碼，還能解決項目中遇到的各種難題。 給大家推薦一個支持C#的開源免費、新手友好的數據結構與演算法入門教程：Hello演算法。 項目介紹 《Hello Algo》是一本開源免費、新手友好的數據結構與演算法入門 ...
  • 第22篇 生成proto文件bat腳本
    1.生成單個Proto.bat內容 @rem Copyright 2016, Google Inc. @rem All rights reserved. @rem @rem Redistribution and use in source and binary forms, with or with ...
  • 記一次 .NET某上位機視覺程式 卡死分析
    一：背景 1. 講故事 前段時間有位朋友找到我，說他的窗體程式在客戶這邊出現了卡死，讓我幫忙看下怎麼回事？dump也生成了，既然有dump了那就上 windbg 分析吧。 二：WinDbg 分析 1. 為什麼會卡死 窗體程式的卡死，入口門檻很低，後續往下分析就不一定了，不管怎麼說先用 !clrsta ...
  • 醫學DICOM文件與PACS系統進行數據傳輸
    前言 人工智慧時代，人臉識別技術已成為安全驗證、身份識別和用戶交互的關鍵工具。 給大家推薦一款.NET 開源提供了強大的人臉識別 API，工具不僅易於集成，還具備高效處理能力。 本文將介紹一款如何利用這些API，為我們的項目添加智能識別的亮點。 項目介紹 GitHub 上擁有 1.2k 星標的 C# ...
所有分類