5.3.1 What is semaphore? (7/10 Binary Semaphore(二元信号量) a binary semaphore is initialized to 1 PO waits until the value is 1 · Then set it to0 VO sets the value to 1 Wakes up a thread waiting at PO, if any5.3.1 What is semaphore?(7/10） • Binary Semaphore(二元信号量) • A binary semaphore is initialized to 1 • P() waits until the value is 1 • Then set it to 0 • V() sets the value to 1 • Wakes up a thread waiting at P(), if any 10