diff options
| -rw-r--r-- | kernel/pipe.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/kernel/pipe.c b/kernel/pipe.c index 7ed402d..b6eefb9 100644 --- a/kernel/pipe.c +++ b/kernel/pipe.c @@ -76,26 +76,29 @@ pipeclose(struct pipe *pi, int writable) int pipewrite(struct pipe *pi, uint64 addr, int n) { - int i; - char ch; + int i = 0; struct proc *pr = myproc(); acquire(&pi->lock); - for(i = 0; i < n; i++){ - while(pi->nwrite == pi->nread + PIPESIZE){ //DOC: pipewrite-full - if(pi->readopen == 0 || pr->killed){ - release(&pi->lock); - return -1; - } + while(i < n){ + if(pi->readopen == 0 || pr->killed){ + release(&pi->lock); + return -1; + } + if(pi->nwrite == pi->nread + PIPESIZE){ //DOC: pipewrite-full wakeup(&pi->nread); sleep(&pi->nwrite, &pi->lock); + } else { + char ch; + if(copyin(pr->pagetable, &ch, addr + i, 1) == -1) + break; + pi->data[pi->nwrite++ % PIPESIZE] = ch; + i++; } - if(copyin(pr->pagetable, &ch, addr + i, 1) == -1) - break; - pi->data[pi->nwrite++ % PIPESIZE] = ch; } wakeup(&pi->nread); release(&pi->lock); + return i; } |