diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/devices/timer.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/src/devices/timer.c b/src/devices/timer.c index 5b9e527..856a14e 100644 --- a/src/devices/timer.c +++ b/src/devices/timer.c @@ -110,13 +110,22 @@ timer_sleep (int64_t ticks) { int64_t start = timer_ticks (); - struct waiting_thread waiting_thread; - waiting_thread.tick_target = start + ticks; - - sema_init (&waiting_thread.sema, 0); - list_push_back (&waiting_threads, &waiting_thread.elem); + struct waiting_thread new_waiting_thread; + new_waiting_thread.tick_target = start + ticks; + sema_init (&new_waiting_thread.sema, 0); + + struct list_elem *before = list_begin (&waiting_threads); + while (before != list_end (&waiting_threads)) { + struct list_elem *next = list_next (before); + struct waiting_thread *waiting_thread = list_entry (before, struct waiting_thread, elem); + if (new_waiting_thread.tick_target < waiting_thread->tick_target) { + break; + } + before = next; + } + list_insert (before, &new_waiting_thread.elem); - sema_down (&waiting_thread.sema); + sema_down (&new_waiting_thread.sema); } /* Suspends execution for approximately MS milliseconds. */ @@ -161,8 +170,10 @@ timer_interrupt (struct intr_frame *args UNUSED) if (ticks >= waiting_thread->tick_target) { sema_up (&waiting_thread->sema); list_remove (e); + e = next; + } else { + break; } - e = next; } } |