Synchronization Primitives Lock Semaphore Barriers Thread 1: Thread 2: void foo(){ void bar( sem.lock(); sem.lock(; X++; y++; y=X X++ sem.unlockO; sem.unlockO;Synchronization Primitives Semaphore Barriers Lock Thread 1: void foo() { sem.lock(); x++; y = x; sem.unlock(); } Thread 2: void bar() { sem.lock(); y++; x++; sem.unlock(); }