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Windows Mobile 6.5 메모리 관리
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• URL : http://cafe.naver.com/wincepro• Since : 2006. 4. 23• Members : about 20,000• Staff : about 15• Manager : [email protected]• Contents :
– - Windows Embedded CE– - Windows Mobile
Windows CE 5.0 Memory Model
Virtual Memory Map- 2GB 커널영역- 2GB 의 모든 Processes 들의 영역
-각 Slot 당 32MB
32 개 Process 제한- 유저 영역의 상위 절반 (1GB)- Process 에 의해 읽기 / 쓰기
공유 메모리 (Shared memory)- 유저 영역의 상위 절반 (1GB)- Process 에 의해 읽기 / 쓰기
가상메모리 관리 단위- 64KB alignment
Windows CE 5.0 Memory Model
::
Shared Memory
Kernel
32 Slots for Processes
Single2 GB VMfor allProcesses
Execution Slot and
Shared DLL SlotSlot 0 – ExecutionSlot 1 – ROM DLLsSlot 2 – NK.exeSlot 3 – Filesys.exeSlot 4 – Device.exeSlot 5 – GWES.exe
Slot 31Slot 32
Slot 7 – Services.exe
2 GBKernelSpace
Slot 7
Application Memory Map
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COREDLL.DLL
0000 00000001 0000
Read only data
03FF FFFF
Code
Read write data
reserved
Other ROM DLLs
Resources
Stack (reserved space) Heap (reserved space)
Free virtual space
Application Specific Space
: 프로세스의 실행 영역
ROM DLL space
0200 0000
DLL Space (Con-stant for all appli-
cations): 프로세스의 보관 영역
RAM based DLLs
문제점과 원인
증상- RAM 에 있는 DLL, Driver 는 load/unload 하면서 실패- 시스템은 RAM 이 비어 있다고 reporting - 그러나 ! 메모리 할당 불가
원인- 가상 메모리 쪼개짐- 가상 메모리 영역을 벗어남
VM Exhaustion
App1 DLL A 로드
App2 실행
App1 DLL B 로드 + more Heap
App2 DLL Z 로드
App2 DLL X 로드
App1 DLL C 로드 실패 !
Thread 2
Reserved
APP 1
Slot 0 System DLLs
Main Thread
Process Heap
DLL A
Reserved
APP 2
Slot 0 System DLLs
Main Thread
Process Heap
DLL A
DLL B DLL B
2nd Heap
DLL ZDLL Z
DLL X
DLL X
DLL C
효과적인 방법
DLL 을 FILES SECTION 또는 STORAGE 에 위치
클라이언트 / 플러그인 드라이버PCMCIAUSBSDIOBluetoothetc…
어플리케이션이 DLL 실행
효과적인 방법
DLL 을 FILES SECTION 또는 STORAGE 에 위치
클라이언트 / 플러그인 드라이버PCMCIAUSBSDIOBluetoothetc…
어플리케이션이 DLL 실행
10
Windows Mobile 6
Slot 63 :: Resource-Only DLLs
Slot 0 :: Alias of Active Process from Other SlotsOverflow DLLs Reduce VM Space for All Processes
Slots 2-32 :: Application Processes
Slots 33-611 GB Large Memory Area
Memory-Mapped Files
2 G
B ::
Use
r Spa
ce
FILE DLLs are loaded into every slot which decreases VM space
to all slots
DLL Overflow Causes Instabil-
ity
Slot 62 :: Shared Heaps
Slot 1 :: ROM FILE DLLs + MODULE DLLs
Slot Fill Or-der
FILE DLLs MODULE DLLs
0 1, 0
MODULE DLLs are
4K page-aligned in-
stead of 64K due to
ARM architecture
saving 9MB of VM
11
Windows Mobile 6.1
Slot 63 :: Resource-Only DLLs
Slot 1 :: ROM FILE DLLs + MODULE DLLs
Slots 2-32 :: Application Processes
Slots 33-58 :: Large Memory AreaMemory-Mapped Files
2 G
B ::
Use
r Spa
ce
Slot 62 :: Shared Heap Area
Slot 61 :: Read-Only FILE DLLs
Slot 60 :: Read-Only FILE DLLs
Slot 59 :: Device.exe Thread Stacks
Extra 64 MB of VM
Extra 8 MB of VM for Device Drivers
Slot 0 :: Alias of Active Process from Other SlotsOverflow DLLs Reduce VM Space for All Processes
Convert mshtml.dll to
FILE DLL to free 6 MB of VM
DLLs used ex-clusively by one process don’t take space from other pro-
cesses
Slot Fill Or-der
FILE DLLs MODULES
60, 61, 0 1, 0
Windows Mobile 6.5
Slot 63 :: Resource-Only DLLs
Slot 1 :: ROM FILE DLLs + MODULE DLLs
Slots 2-32 :: Application Processes
Slots 33-58 :: Large Memory AreaMemory-Mapped Files
2 G
B ::
Use
r Spa
ce
Slot 62 :: Shared Heaps
Slot 61 :: FILE + MODULE DLLs
Slot 60 :: FILE + MODULE DLLs
Slot 59 :: Device.exe Thread Stacks
Slot 0 :: Alias of Active Process from Other SlotsOverflow DLLs Reduce VM Space for All Processes
Faster MODULE DLLs whose VM is allocated at build time instead of runtime can go ev-erywhere!
Process Threshold
of 28
Slot Fill Or-der
FILE DLLs MODULE DLLs
60, 61, 0 1, 61, 60, 0
Windows Mobile 6.5Faster Performance
JPEG images decode faster by aligning buffer size to 128-byte boundary needed by hardware
Glyph Cache jumps from 8KB to 72KB for English and 128KB for Asian builds to boost font rendering speed
GDI used to draw text one character at a time; now draws the entire string in one shot
Switching Today screens and backgrounds repeatedly does not degrade device performance
Paging Pool is set to a minimum of 15 MB to boost application load performance
Minimum devices specs include a 400 MHz processor, 128 MB of RAM and 256 MB of ROM
14
Application Verifier
• 응용프로그램의 안정성 평가 Tool
• 개발 중 실수 할 수 있는 Leak 을 감지– Memory Leaks– Handle Leaks– GDI Leaks
• 응용프로그램은 물론 드라이버도 가능• http://www.microsoft.com/downloads/details.aspx?FamilyId=D
275348A-D937-4D88-AE25-28702C78748D&displaylang=en
15
Application Leak(1)
• AppVerifer 실행
16
Application Leak(2)
• AppVerifer 클릭 “ Connect…”• Device Connection Windows 클릭
“ Settings…”
17
Application Leak(3)
• CE Platform Manager– 클릭 “ Add Device”– 이름을 변경– Properties
18
Application Leak(4)
• Device Properties 에서– CESH Server…– “OK”
19
Application Leak(5)
• Device Connection 에서– 클릭 “ Connect…”– KITL 을 선택 “ OK”
20
Application Leak(6)
• AppVerifer “Add…”• Add Application LeakApp.exe “Open”
21
Application Leak(7)
• AppVerifer 에서– “LeakApp.exe”– “Heap Verifier” 체크 – “Run”
22
Application Leak(8)
• LeakApp 에서– Leak Memory– “Exit”
23
Application Leak(9)
• AppVerifer – “Get Logs…”– “View Exported Log…”– “Open”
24
Application Leak(10)
• Exported Log– “Potention Leak: 3 items (3072 bytes)…”– 메모리 누수가 생긴 부분의 API 나 함수 노출
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Application Leak(11)
• Source Code
void Create_MemoryLeak( HWND hWnd ){
MessageBox(hWnd, _T("Create 1 KB (1024 bytes) memory leak"), _T("Leak App"),MB_OK);
// LPBYTE p = (LPBYTE)LocalAlloc(LPTR, 1024);////LocalFree((HLOCAL)p);
}
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Question?
