code:setrun - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

2129

2130 /*

2131 * Set the process running;

2132 * arrange for it to be swapped in if necessary.

2133 */

2134 setrun(p)

2135 {

2136 register struct proc *rp;

2137

2138 rp = p;

2139 rp->p_wchan = 0;

2140 rp->p_stat = SRUN;

将睡眠原因置为0

将进程状态置为SRUN(就绪状态)

2141 if(rp->p_pri < curpri)

2142 runrun++;

若进程优先级比当前进程要高,则置runrun标志,以等待进程调度
参看进程调度#runrun

2143 if(runout != 0 && (rp->p_flag&SLOAD) == 0) {

2144 runout = 0;

2145 wakeup(&runout);

若runout已被置,且当前进程图象不在内存中
则清runout标志,并唤醒因runout睡眠的0#进程,以调用sched函数将进程图象调入内存

关于为何唤醒的是0#进程,参看进程调度之0#进程

2146 }

2147 }

2148 /* ------------------------- */

2149