dependency hell kth 2

PC ? (== ?)debug 10 2~3

dll

dll dll ?

dll dll ?dll = dynamic linking library = (=) (=)

compileclass foo { private int _bar; private int *_pBar; private static int _s_bar1=7; private static int[100000000] _s_bar2;

public int foobar(value bar) { int local_bar=0; _pBar = malloc(10000000*sizeof(int)); } public static staticFoobar() { }}

compile ( )

.. -> ? ??

compileclass foo { private int _bar; private int *_pBar; private static int _s_bar1=7; private static int[100000000] _s_bar2;

public int foobar(value bar) { int local_bar=0; _pBar = malloc(10000000*sizeof(int)); } public static staticFoobar() { }}

sizeof(int) 4bytes compile time !!_s_bar1 4bytes_s_bar2 4*100000000bytes

compile time !! x = new foo(); memory

compile0000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 0111

_s_bar1 4bytes0000 00f00000 00ff ( )

compile0000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 0111???? ???? ???? ???? ???? ???? ???? ???? ???????? ???? ???? ???? ???? ???? ???? ???? ???????? ???? ???? ???? ???? ???? ???? ???? ???????? ???? ???? ???? ???? ???? ???? ???? ????

_s_bar1 4bytes ( )

_s_bar2 100Mbytes

100Mbytes ?0000 00f00000 00ff

compile0000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 0111

_s_bar1 4bytes ( )_s_bar2

100Mbytes _s_bar2 . ???? ???? ???? ???? ???? ???? ???? ???? ????

0000 00f00000 00ff

compile0000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 0111

_s_bar1 4bytes ( )_s_bar2 ???? ???? ???? ???? ???? ???? ???? ???? ????

0000 00f00000 00fffoo@foobar(value) foo@staticFoobar() class , method call

compiledata section ( )bss section0000 00f00000 00ffcode section

compile (= foo.o file )

link .. ?

link

foo.o

foo2.o+ +a+=executable image(= foo.exe foo.lib foo.dll)(xx.lib xx.dll)

link

foo.o

foo2.o

( ) offset foo.exe foo.lib foo.dlloffset ( )offset + 1offset + 2offset + 3

static link foo.exe foo.lib 400Mb

foo.lib

object file bss( )

static link

foo.lib

foo2.o+=

foo2.exe

foo.lib

foo3.o+=

foo3.exe

foo.lib ?

program size 400mb

program size 400mb

dynamic linkfoo.dll load . dll

foo2.o+=

foo2.exe

foo.dll

foo3.o+=

foo3.exe

foo.dll

foo.dll

runtimeclass foo { private int _bar; private int *_pBar; private static int _s_bar1=7; private static int[100000000] _s_bar2;

public int foobar(value bar) { int local_bar=0; _pBar = malloc(10000000*sizeof(int)); } public static staticFoobar() { }}

sizeof(int) 4bytes _pBar , 400mb memory .

local_bar , foobar()

runtimebssdatacodefoo.exe process stackheapstackheapnew foo() , malloc(xxx) foo->foobar() method call foobar() call stack local_bar foobar() ,(=return) local_bar

stack

dynamic linked library

heap

data

code

static linked library

Run time AreaDesign time Area

stack

dynamic linked library

heap

data

code

static linked library

Run time AreaDesign time Area

DLL

dll class foo { private int _bar; private int *_pBar; private static int _s_bar1=7; private static int[777777777] _s_bar2;

public int foobar(value bar) { int local_bar=0; _pBar = malloc(777777777*sizeof(int)); } public static staticFoobar() { }}

_s_bar2

_pBar foo.dll v2.0 / foo.dll v1.0

dll foo.dll system memory load memory load foo.dll v1.0foo.dll v2.0 foo3.exe !!!

foo2.exefoo.dll (v1.0)

foo3.exefoo.dll (v2.0)

system memoryfoo.dll (v1.0)

dll system directory dll case1 : system library case2 : system library

MS Windows shared library

winsock.dllc:\windows\system\msvcrt.dllwindows.dll.

dll main / library -> library ?-> .

linux shared library

libc.so/usr/liblibpthread.soglib.so.

libc.so/usr/local/liblibpthread.soglib.so.

jar program jar !! dll !!

java class path

/path/Afoo.jar (old)

/path/Bfoo.jar (new)

dependency ?PEBKAC(http://en.wikipedia.org/wiki/User_error)

library metadata / / build/package manager library virtual environment library

build/package managermavenbiicodepip / setuptoolsnpmyum / apt-get

virtual environmentvirtualenvdocker

Q & A ?