嵌入式Linux中文站收集整理Linux0.11版本內(nèi)核學(xué)習(xí)筆記，本文分析了Linux進(jìn)程控制模塊的數(shù)據(jù)結(jié)構(gòu)。

struct?task_struct?{??

long?state??

//任務(wù)的運(yùn)行狀態(tài)(-1?不可運(yùn)行,0?可運(yùn)行(就緒),>0?已停止)。??

long?counter??

//?任務(wù)運(yùn)行時(shí)間計(jì)數(shù)(遞減)(滴答數(shù)),運(yùn)行時(shí)間片。??

long?priority??

//?運(yùn)行優(yōu)先數(shù)。??

任務(wù)開始運(yùn)行時(shí)?counter=priority,??

越大運(yùn)行越長。??

long?signal??

//?信號(hào)。是位圖,每個(gè)比特位代表一種信號(hào),信號(hào)值=位偏移值+1。??

struct?sigaction?sigaction[32]?//?信號(hào)執(zhí)行屬性結(jié)構(gòu),對應(yīng)信號(hào)將要執(zhí)行的操作和標(biāo)志信息。??

long?blocked??

//?進(jìn)程信號(hào)屏蔽碼(對應(yīng)信號(hào)位圖)。??

int?exit_code??

//?任務(wù)執(zhí)行停止的退出碼,其父進(jìn)程會(huì)取。??

//?代碼段地址。??

unsigned?long?start_code??

unsigned?long?end_code??

//?代碼長度(字節(jié)數(shù))。??

unsigned?long?end_data??

//?代碼長度?+?數(shù)據(jù)長度(字節(jié)數(shù))。??

unsigned?long?brk??

//?總長度(字節(jié)數(shù))。??

unsigned?long?start_stack??

//?堆棧段地址。??

long?pid??

//?進(jìn)程標(biāo)識(shí)號(hào)(進(jìn)程號(hào))。??

long?father??

//?父進(jìn)程號(hào)。??

long?pgrp??

//?父進(jìn)程組號(hào)。??

long?session??

//?會(huì)話號(hào)。??

long?leader??

//?會(huì)話首領(lǐng)。??

unsigned?short?uid??

//?用戶標(biāo)識(shí)號(hào)(用戶?id)。??

unsigned?short?euid??

//?有效用戶?id。??

unsigned?short?suid??

//?保存的用戶?id。??

unsigned?short?gid??

//?組標(biāo)識(shí)號(hào)(組?id)。??

unsigned?short?egid??

//?有效組?id。??

unsigned?short?sgid??

//?保存的組?id。??

long?alarm??

//?報(bào)警定時(shí)值(滴答數(shù))。??

long?utime??

//?用戶態(tài)運(yùn)行時(shí)間(滴答數(shù))。??

long?stime??

//?系統(tǒng)態(tài)運(yùn)行時(shí)間(滴答數(shù))。??

long?cutime??

//?子進(jìn)程用戶態(tài)運(yùn)行時(shí)間。??

long?cstime??

//?子進(jìn)程系統(tǒng)態(tài)運(yùn)行時(shí)間。??

long?start_time??

//?進(jìn)程開始運(yùn)行時(shí)刻。??

unsigned?short?used_math??

//?標(biāo)志:是否使用了協(xié)處理器。??

int?tty??

//?進(jìn)程使用?tty?的子設(shè)備號(hào)。-1?表示沒有使用。??

unsigned?short?umask??

//?文件創(chuàng)建屬性屏蔽位。??

struct?m_inode?*?pwd??

//?當(dāng)前工作目錄?i?節(jié)點(diǎn)結(jié)構(gòu)。??

struct?m_inode?*?root??

//?根目錄?i?節(jié)點(diǎn)結(jié)構(gòu)。??

struct?m_inode?*?executable?//?執(zhí)行文件?i?節(jié)點(diǎn)結(jié)構(gòu)。??

unsigned?long?close_on_exec?//?執(zhí)行時(shí)關(guān)閉文件句柄位圖標(biāo)志。(參見?include/fcntl.h)??

struct?file?*?filp[NR_OPEN]?//?文件結(jié)構(gòu)指針表,最多?32?項(xiàng)。表項(xiàng)號(hào)即是文件描述符的值。??

struct?desc_struct?ldt[3]?//?任務(wù)局部描述符表。0-空,1-代碼段?cs,2-數(shù)據(jù)和堆棧段?ds&ss。??

struct?tss_struct?tss??

//?進(jìn)程的任務(wù)狀態(tài)段信息結(jié)構(gòu)。??

};??

struct task_struct {long state//任務(wù)的運(yùn)行狀態(tài)(-1 不可運(yùn)行,0 可運(yùn)行(就緒),>0 已停止)。long counter// 任務(wù)運(yùn)行時(shí)間計(jì)數(shù)(遞減)(滴答數(shù)),運(yùn)行時(shí)間片。long priority// 運(yùn)行優(yōu)先數(shù)。任務(wù)開始運(yùn)行時(shí) counter=priority,越大運(yùn)行越長。long signal// 信號(hào)。是位圖,每個(gè)比特位代表一種信號(hào),信號(hào)值=位偏移值+1。struct sigaction sigaction[32] // 信號(hào)執(zhí)行屬性結(jié)構(gòu),對應(yīng)信號(hào)將要執(zhí)行的操作和標(biāo)志信息。long blocked// 進(jìn)程信號(hào)屏蔽碼(對應(yīng)信號(hào)位圖)。int exit_code// 任務(wù)執(zhí)行停止的退出碼,其父進(jìn)程會(huì)取。// 代碼段地址。unsigned long start_codeunsigned long end_code// 代碼長度(字節(jié)數(shù))。unsigned long end_data// 代碼長度 + 數(shù)據(jù)長度(字節(jié)數(shù))。unsigned long brk// 總長度(字節(jié)數(shù))。unsigned long start_stack// 堆棧段地址。long pid// 進(jìn)程標(biāo)識(shí)號(hào)(進(jìn)程號(hào))。long father// 父進(jìn)程號(hào)。long pgrp// 父進(jìn)程組號(hào)。long session// 會(huì)話號(hào)。long leader// 會(huì)話首領(lǐng)。unsigned short uid// 用戶標(biāo)識(shí)號(hào)(用戶 id)。unsigned short euid// 有效用戶 id。unsigned short suid// 保存的用戶 id。unsigned short gid// 組標(biāo)識(shí)號(hào)(組 id)。unsigned short egid// 有效組 id。unsigned short sgid// 保存的組 id。long alarm// 報(bào)警定時(shí)值(滴答數(shù))。long utime// 用戶態(tài)運(yùn)行時(shí)間(滴答數(shù))。long stime// 系統(tǒng)態(tài)運(yùn)行時(shí)間(滴答數(shù))。long cutime// 子進(jìn)程用戶態(tài)運(yùn)行時(shí)間。long cstime// 子進(jìn)程系統(tǒng)態(tài)運(yùn)行時(shí)間。long start_time// 進(jìn)程開始運(yùn)行時(shí)刻。unsigned short used_math// 標(biāo)志:是否使用了協(xié)處理器。int tty// 進(jìn)程使用 tty 的子設(shè)備號(hào)。-1 表示沒有使用。unsigned short umask// 文件創(chuàng)建屬性屏蔽位。struct m_inode * pwd// 當(dāng)前工作目錄 i 節(jié)點(diǎn)結(jié)構(gòu)。struct m_inode * root// 根目錄 i 節(jié)點(diǎn)結(jié)構(gòu)。struct m_inode * executable // 執(zhí)行文件 i 節(jié)點(diǎn)結(jié)構(gòu)。unsigned long close_on_exec // 執(zhí)行時(shí)關(guān)閉文件句柄位圖標(biāo)志。(參見 include/fcntl.h)struct file * filp[NR_OPEN] // 文件結(jié)構(gòu)指針表,最多 32 項(xiàng)。表項(xiàng)號(hào)即是文件描述符的值。struct desc_struct ldt[3] // 任務(wù)局部描述符表。0-空,1-代碼段 cs,2-數(shù)據(jù)和堆棧段 ds&ss。struct tss_struct tss// 進(jìn)程的任務(wù)狀態(tài)段信息結(jié)構(gòu)。};?

其中的 m_inode數(shù)據(jù)結(jié)構(gòu)如下

struct?m_inode?{??

unsigned?short?i_mode;??

unsigned?short?i_uid;??

unsigned?long?i_size;??

unsigned?long?i_mtime;??

unsigned?char?i_gid;??

unsigned?char?i_nlinks;??

unsigned?short?i_zone[9];??

/*?these?are?in?memory?also?*/??

struct?task_struct?*?i_wait;??

unsigned?long?i_atime;??

unsigned?long?i_ctime;??

unsigned?short?i_dev;??

unsigned?short?i_num;??

unsigned?short?i_count;??

unsigned?char?i_lock;??

unsigned?char?i_dirt;??

unsigned?char?i_pipe;??

unsigned?char?i_mount;??

unsigned?char?i_seek;??

unsigned?char?i_update;??

};??

struct m_inode {unsigned short i_mode;unsigned short i_uid;unsigned long i_size;unsigned long i_mtime;unsigned char i_gid;unsigned char i_nlinks;unsigned short i_zone[9];/* these are in memory also */struct task_struct * i_wait;unsigned long i_atime;unsigned long i_ctime;unsigned short i_dev;unsigned short i_num;unsigned short i_count;unsigned char i_lock;unsigned char i_dirt;unsigned char i_pipe;unsigned char i_mount;unsigned char i_seek;unsigned char i_update;};?

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