PowerPoint

Process, Thread, IO Model #1

Why? / low level

CGI mod_php, mod_python ? DBMS apache server pool DB Connection pool web ?

(lesstif@gmail.com)http://lesstif.com, https:/github.com/lesstif 5 http://wikibook.co.kr/laravel-5-programming/ https://github.com/lesstif/web-service-hardening

Program - OS

5

Program - gcc o a.out a.c a.out

6

Process OS

7

Process - Process ID, process group ID, user ID, and group ID Environment, Working directory Stack, Heap File descriptors Signal handler Shared libraries Inter-process communication tools (message queues, pipes, semaphores, shared memory).

8

9

10

Process - - #1

fork system call

11

Process - - #2 fork fork OS COW(Copy on write)

12

Process - - #3 fork (Ex: DBMS) fork

13

Process - IPC(Inter Process Communication), Socket, Pipe ipcs IPC . ( ) Process Context switching

14

Process FAQ - #1 ? init daemon(PID: 1) . (orphan process) Kernel init

15

Process FAQ - #2 ? SIGCHLD wait wait process table zombie, defunct process

16

A1. cgi mod_php cgi php httpd -> fork -> exec() php php fork httpd mod_php php httpd . fork

17

Thread thread Multi Thread

18

Thread (Data, Text, Heap) ( ) ( ) context switching

19

Thread -> ( ) ( )

20

Process ( ) DBMS

21

A2 DBMS DBMS Multi Process Shared Memory (SGA ) (Kernel IPC )

22

- 2 #1 93 SUN Micro Systems Solaris IO library Sparc machine 6 2

23

- 2 #2 x==2; = C if (x = 2) ( ) ( )

24

- 2 #3 (X) (O)

25

-2 #4 2 (Ex: PHP === )

26

Thread ( ) POSIX pthread_create !

27

Thread Mutex #1 ? (critical section) Mutex(mutual exclusion) POSIX pthread_mutex_lock mutex

28

Thread Mutex #2 mutex ? mutex blocking mutex (mutex )

29

Thread Mutex #3 mutex blocking ?pthread_mutex_trylock mutex (Non-Blocking)mutex CPU

30

Thread Cond Var mutex ?mutex_lock, trylock mutex POSIX POSIX Condition variable mutex phread_cond_wait pthread_cond_signal

31

Thread Cond Var mutex ?mutex_lock, trylock mutex POSIX POSIX Condition variable mutex phread_cond_wait pthread_cond_signal

32

Thread - thread suspend, resume, stop, kill suspend mutex lock deadlock Java .NET deprecated

33

Thread - mutex condition variable , , ( )

34

Server Pool - #1 Pool Thread Thread pool, Server Pool

35

Server Pool - #2 apache httpd, php-fpm (Ex: ) (StartServers) idle (MaxSpareServers ) idle (MinSpareServers)

MaxSpareServers - - 36

DB Connection Pool - #1 DBMS DBMS (connection , DBMS ) WAS DB Connection Pool app Pool app pool

MaxSpareServers - - 37

PHP DB Connection Pool PHP DB Connection Pool (SQLRelay ?) MySQL connect/close DBMS pool

38

DB Pool Manager ? DB Pool / . Mutex lock Pool (DB Connection) ? (Pool Manager or App ?) DBMS db pool dummy

39

DB Pool Manager ? Pool / Pool Pool 30 3 Pool 10

40

Multi Thread safety #1 PHP Zend ZTS None ZTS 2 ?ZTS(Zend Thread Safety) PHP (Thread safety) (http://sunyzero.tistory.com/97)

41

Multi Thread safety #2 ? (atomic) , static, global XPOSIX.1-2008 (http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_09_01) (gcc -pthreads)

42

(Reentrant ) + _r asctime_r, ctime_r

43

& QNAAdvanced Programming in the Unix EnvironmentUnix network programingExpert C Programming: Deep C SecretsProgramming with POSIX Threads (http://sunyzero.tistory.com/)

Q&A

.

.