本文基于Android 4.2.2从进程/文件的角度审视Android Camera子系统。

AndroidCamera子系统的整体架构分成客户端（Client）和服务器（Server）两个部分，它们建立在Android的进程间通讯机制Binder的基础之上。

查看进程

root@android:/# ps

USER  PID PPID VSIZE  RSS  WCHAN  PC    NAME

media 1012  1 37484 8740 ffffffff 4016bfe8 S/system/bin/mediaserver

u0_a142119 1010 162156 31244 ffffffff 4007cee4 S com.android.camera

查看线程

root@android:/# ps -t

USERPID PPID VSIZE RSS WCHAN PC NAME

media1012 1 37484 8740 ffffffff 4016bfe8 S /system/bin/mediaserver

media1191 1012 37484 8740 c0042004 4016d108 S AudioCommand

media1192 1012 37484 8740 c0042004 4016d108 S ApmCommand

media1208 1012 37484 8740 c0042004 4016d108 S AudioOut_2

media1209 1012 37484 8740 c02b2ffc 4016bfe8 S Binder_1

media1519 1012 37484 8740 c02b2ffc 4016bfe8 S Binder_2

media2055 1012 37484 8740 c02b2ffc 4016bfe8 S Binder_3

media2362 1012 37484 8740 c0042004 4016d108 S TimedEventQueue

media2363 1012 37484 8740 c0042004 4016d108 S .vorbis.decoder

media2364 1012 37484 8740 c0042004 4016d108 S OMXCallbackDisp

media2365 1012 37484 8740 c0042004 4016d108 S TimedEventQueue

media2366 1012 37484 8740 c0042004 4016d108 S .vorbis.decoder

media2367 1012 37484 8740 c0042004 4016d108 S OMXCallbackDisp

media2368 1012 37484 8740 00000000 4016d6a4 R CameraPreviewTh

media2369 1012 37484 8740 c0042004 4016d108 S CameraAutoFocus

u0_a142119 1010 162156 31244 ffffffff 4007cee4 S com.android.camera

u0_a142122 2119 162156 31244 c0042004 4007d108 S GC

u0_a142124 2119 162156 31244 c0026658 4007c9c8 S Signal Catcher

u0_a142125 2119 162156 31244 c0364f54 4007cbd0 S JDWP

u0_a142126 2119 162156 31244 c0042004 4007d108 S Compiler

u0_a142127 2119 162156 31244 c0042004 4007d108 S ReferenceQueueD

u0_a142128 2119 162156 31244 c0042004 4007d108 S FinalizerDaemon

u0_a142129 2119 162156 31244 c0042004 4007d108 S FinalizerWatchd

u0_a142130 2119 162156 31244 c02b2ffc 4007bfe8 S Binder_1

u0_a142131 2119 162156 31244 c02b2ffc 4007bfe8 S Binder_2

u0_a142134 2119 162156 31244 c0042004 4007d108 S pool-1-thread-1

u0_a142136 2119 162156 31244 c00a5004 4007cee4 S CameraHolder

u0_a142152 2119 162156 31244 c02b2ffc 4007bfe8 S Binder_3

u0_a142375 2119 162156 31244 c0042004 4007d108 S SoundPool

u0_a142376 2119 162156 31244 c0042004 4007d108 S SoundPoolThread

u0_a142377 2119 162156 31244 c0042004 4007d108 S Thread-123

列出binder service

root@android:/# service list

63media.audio_policy: [android.media.IAudioPolicyService]

64media.camera: [android.hardware.ICameraService]

65media.player: [android.media.IMediaPlayerService]

66media.audio_flinger: [android.media.IAudioFlinger]

查看进程虚拟地址空间

media 1012  1 37484 8740 ffffffff 4016bfe8 S/system/bin/mediaserver

root@android:/# cat /proc/1012/maps

401f7000-40215000r-xp 00000000 00:11 637 /system/lib/libbinder.so

40215000-4021a000r--p 0001d000 00:11 637 /system/lib/libbinder.so

4021a000-4021b000rw-p 00022000 00:11 637 /system/lib/libbinder.so

4025a000-4025b000r-xp 00000000 00:11 524 /system/lib/libhardware.so

4025b000-4025c000r--p 00000000 00:11 524 /system/lib/libhardware.so

4025c000-4025d000rw-p 00001000 00:11 524 /system/lib/libhardware.so

40451000-40467000r-xp 00000000 00:11 585 /system/lib/libcamera_client.so

40467000-40468000---p 00000000 00:00 0

40468000-4046d000r--p 00016000 00:11 585 /system/lib/libcamera_client.so

4046d000-4046e000rw-p 0001b000 00:11 585 /system/lib/libcamera_client.so

40581000-40586000r-xp 00000000 00:11 636 /system/lib/libhardware_legacy.so

40586000-40587000r--p 00004000 00:11 636 /system/lib/libhardware_legacy.so

40587000-40588000rw-p 00005000 00:11 636 /system/lib/libhardware_legacy.so

4059c000-405d4000r-xp 00000000 00:11 655 /system/lib/libcameraservice.so

405d4000-405d8000r--p 00037000 00:11 655 /system/lib/libcameraservice.so

405d8000-405d9000rw-p 0003b000 00:11 655 /system/lib/libcameraservice.so

405d9000-405dc000r-xp 00000000 00:11 582 /system/lib/libcamera_metadata.so

405dc000-405dd000r--p 00002000 00:11 582 /system/lib/libcamera_metadata.so

405dd000-405de000rw-p 00003000 00:11 582 /system/lib/libcamera_metadata.so

40b12000-40b1f000r-xp 00000000 00:11 569 /system/lib/hw/camera.sama5d3-ek.so

40b1f000-40b20000r--p 0000c000 00:11 569 /system/lib/hw/camera.sama5d3-ek.so

40b20000-40b21000rw-p 0000d000 00:11 569 /system/lib/hw/camera.sama5d3-ek.so

41eb5000-41eb7000r-xp 00000000 00:11 565 /system/lib/hw/gralloc.sama5d3-ek.so

41eb7000-41eb8000r--p 00001000 00:11 565 /system/lib/hw/gralloc.sama5d3-ek.so

41eb8000-41eb9000rw-p 00002000 00:11 565 /system/lib/hw/gralloc.sama5d3-ek.so

42264000-42426000rw-s 3f200000 00:0b 554 /dev/video1

u0_a142119 1010 162156 31244 ffffffff 4007cee4 S com.android.camera

root@android:/# cat /proc/2119/maps

40130000-4014e000r-xp 00000000 00:11 637 /system/lib/libbinder.so

4014e000-40153000r--p 0001d000 00:11 637 /system/lib/libbinder.so

40153000-40154000rw-p 00022000 00:11 637 /system/lib/libbinder.so

40154000-401e5000r-xp 00000000 00:11 598 /system/lib/libandroid_runtime.so

401e5000-401e6000---p 00000000 00:00 0

401e6000-401ea000r--p 00091000 00:11 598 /system/lib/libandroid_runtime.so

401ea000-401f0000rw-p 00095000 00:11 598 /system/lib/libandroid_runtime.so

404e9000-404ff000r-xp 00000000 00:11 585 /system/lib/libcamera_client.so

404ff000-40500000---p 00000000 00:00 0

40500000-40505000r--p 00016000 00:11 585 /system/lib/libcamera_client.so

40505000-40506000rw-p 0001b000 00:11 585 /system/lib/libcamera_client.so

44cfe000-44cff000r--s 003c4000 00:11 160 /system/framework/framework.jar

44cff000-456f2000r--p 00000000 00:12 107/data/dalvik-cache/system@framework@framework.jar@classes.dex

456f2000-457b3000rw-p 00000000 00:04 1203 /dev/ashmem/dalvik-aux-structure (deleted)

4939a000-493a2000r--s 0010c000 00:11 195 /system/app/LegacyCamera.apk

493a2000-493ef000r--s 000bc000 00:11 195 /system/app/LegacyCamera.apk

493ef000-493f7000r--s 0010c000 00:11 195 /system/app/LegacyCamera.apk

493f7000-49447000r--p 00000000 00:12 485/data/dalvik-cache/system@app@LegacyCamera.apk@classes.dex

49447000-49450000rw-p 00000000 00:04 3819 /dev/ashmem/dalvik-aux-structure (deleted)