diff options
Diffstat (limited to 'proc.c')
| -rw-r--r-- | proc.c | 28 |
1 files changed, 27 insertions, 1 deletions
@@ -7,6 +7,7 @@ struct proc proc[NPROC]; struct proc *curproc; +int next_pid = 1; /* * set up a process's task state and segment descriptors @@ -54,6 +55,8 @@ newproc() if(np >= &proc[NPROC]) return 0; + np->pid = next_pid++; + np->ppid = curproc->pid; np->sz = curproc->sz; np->mem = kalloc(curproc->sz); if(np->mem == 0) @@ -111,7 +114,12 @@ swtch() // XXX callee-saved registers? - // XXX probably ought to lgdt on trap return too + // h/w sets busy bit in TSS descriptor sometimes, and faults + // if it's set in LTR. so clear tss descriptor busy bit. + curproc->gdt[SEG_TSS].sd_type = STS_T32A; + + // XXX probably ought to lgdt on trap return too, in case + // a system call has moved a program or changed its size. asm volatile("lgdt %0" : : "g" (np->gdt_pd.pd_lim)); ltr(SEG_TSS << 3); @@ -122,3 +130,21 @@ swtch() asm volatile("movl %0, %%esp" : : "g" (np->esp)); asm volatile("movl %0, %%ebp" : : "g" (np->ebp)); } + +void +sleep(void *chan) +{ + curproc->chan = chan; + curproc->state = WAITING; + swtch(); +} + +void +wakeup(void *chan) +{ + struct proc *p; + + for(p = proc; p < &proc[NPROC]; p++) + if(p->state == WAITING && p->chan == chan) + p->state = RUNNABLE; +} |