1 / 5

Too Much Milk With Locks

Both threads: struct lock l; ... l ock_acquire (&l); if (milk == 0) { buy_milk (); } lock_release (& l);. Too Much Milk With Locks. char buffer[SIZE]; int count = 0; int head = 0, tail = 0; struct lock l; lock_init (&l); void put(char c) { lock_acquire (&l); count++;

iram
Download Presentation

Too Much Milk With Locks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Both threads: struct lock l; ... lock_acquire(&l); if (milk == 0) { buy_milk(); } lock_release(&l); Too Much Milk With Locks CS 140 Lecture Notes: Concurrency

  2. char buffer[SIZE]; int count = 0; int head = 0, tail = 0; struct lock l; lock_init(&l); void put(char c) { lock_acquire(&l); count++; buffer[head] = c; head++; if (head == SIZE) { head = 0; } lock_release(&l); } char get() { char c; lock_acquire(&l); count--; c = buffer[tail]; tail++; if (tail == SIZE) { tail = 0; } lock_release(&l); return c; } Producer/Consumer, v1 CS 140 Lecture Notes: Locks

  3. char buffer[SIZE]; int count = 0; int head = 0, tail = 0; struct lock l; lock_init(&l); void put(char c) { lock_acquire(&l); while (count == SIZE) { lock_release(&l); lock_acquire(&l); } count++; buffer[head] = c; head++; if (head == SIZE) { head = 0; } lock_release(&l); } char get() { char c; lock_acquire(&l); while (count == 0) { lock_release(&l); lock_acquire(&l); } count--; c = buffer[tail]; tail++; if (tail == SIZE) { tail = 0; } lock_release(&l); return c; } Producer/Consumer v2 CS 140 Lecture Notes: Locks

  4. char buffer[SIZE]; int count = 0; int head = 0, tail = 0; struct lock l; struct condition dataAvailable; struct condition spaceAvailable; lock_init(&l); cond_init(&dataAvailable); cond_init(&spaceAvailable); void put(char c) { lock_acquire(&l); while (count == SIZE) { cond_wait(&spaceAvailable, &l); } count++; buffer[head] = c; head++; if (head == SIZE) { head = 0; } cond_signal(&dataAvailable, &l); lock_release(&l); } char get() { char c; lock_acquire(&l); while (count == 0) { cond_wait(&dataAvailable, &l); } count--; c = buffer[tail]; tail++; if (tail == SIZE) { tail = 0; } cond_signal(&spaceAvailable, &l); lock_release(&l); return c; } Producer/Consumer v3 T1 T2 T3 CS 140 Lecture Notes: Locks

  5. CS 140 Lecture Notes: Locks

More Related