#define _raw_spin_lock(lock) __LOCK(lock) __LOCK函数代码如下: #define __LOCK(lock) \ do { preempt_disable(); ___LOCK(lock); } while (0) 可以看出,首先禁止内核抢占。然后调用 #define ___LOCK(lock) \ do { __acquire(lock); (void)(lock); } while (0) 从上面的代码可以看出,单...
#define spin_lock(lock) _spin_lock(lock) linux-src/kernel/spinlock.c void __lockfunc _spin_lock(spinlock_t *lock) { preempt_disable(); LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); } linux-src/include/linux/spinlock.h # define _raw_spin_lock(lock) __raw_spin_lock(&(...
staticinlinevoiddo_raw_spin_lock(raw_spinlock_t*lock)__acquires(lock){__acquire(lock);arch_spin_lock(&lock->raw_lock);} arch_spin_lock函数的源代码: 代码语言:javascript 复制 static__always_inlinevoidarch_spin_lock(arch_spinlock_t*lock){register struct __raw_tickets inc={.tail=TICKET_LOC...
内核抢占锁加1spin_acquire(&lock->dep_map,0,0,_RET_IP_);#ifdef CONFIG_LOCKDEPLOCK_CONTENDED(l...
假设有两处代码(比如不同线程的两个函数 thread_P 和 thread_Q)都要获取两个锁(分别为 lockA 和 lockB),如果 thread_P 持有 lockA 后再去获取 lockB,而此时恰好由 thread_Q 持有 lockB 且它也正在尝试获取 lockA,那么此时就是处于死锁的状态,这是一个最简单的死锁例子,也即所谓的 AB-BA 死锁。
如果在代码中出现了不平衡的状况，那么在Sparse的检测中就会报警。如果要使用Sparse检测功能就需要安装sparse工具（参考相关安装方法），然后编译内核 make zImage C=1 (C=1，只检测新编译的文件，C=2是查所有文件)Sparse会定义__CHECKER__，如果你没有使用sparse工具，__acquire(lock)则定义为空 ...
do { __acquire(lock); (void)(lock); } while (0) # define __acquire(x) (void)0 SMP多核情况下,除了关抢占,还需要用到独占(原子)的汇编指令操作变量,如下: kernel\locking\spinlock.c include\linux\spinlock_api_smp.h #define raw_spin_lock(lock) _raw_spin_lock(lock) ...
1、spin_lock_init —— 初始化自旋锁,并把自旋锁的lock->raw_lock置为1(未锁) # define spin_lock_init(lock) / do { / static struct lock_class_key __key; / / __spin_lock_init((lock), #lock, &__key); / } while (0)
atomic_set(&lock->tail, OSQ_UNLOCKED_VAL); } 2.3 osq_lock()/osq_unlock() osq_lock()/osq_unlock()用于申请和释放MCS锁。 boolosq_lock(structoptimistic_spin_queue *lock) {structoptimistic_spin_node *node = this_cpu_ptr(&osq_node);---node指向当前CPU的struct optimistic_spin_node节点...
("Thread: Lock acquired successfully.\n");// 做一些需要锁保护的工作// 使用完锁后释放锁pthread_mutex_unlock(&mutex);}else{printf("Thread: Failed to acquire lock.\n");}pthread_exit(NULL);}intmain(){pthread_ttid;// 创建线程pthread_create(&tid,NULL,thread_function,NULL);// 等待线程结束...