函数sched_lock实现 禁用调度,函数sched_unlock实现关闭禁用调度。 sched_lock函数实现流程如下: 当前任务tcb不为NULL; 当前任务没有处于中断处理中; tcb->lockcount++; 结束 sched_unlock函数实现流程如下: 获取当前任务的tcb块; 当前任务tcb不为NULL且当前任务没有处于中断处理中; tcb->lockcount--; 当tcb->...
信号量是 NuttX 中同步和互斥的基础,尽管sched_lock()和sched_unlock()接口也能实现这个功能,但是这两个接口还是会在系统中带来一些副作用,因为sched_lock()会同时禁止高优先级任务的运行。使用信号量机制就可以避免,但是信号量机制也会带来一些其他的问题: 优先级反转的问题。比如: Ø 低优先级任务Task C,获取...
信号量是获得对资源独占访问的首选机制,尽管sched_lock()和sched_unlock()接口也能实现这个功能,但是这两个接口还是会在系统中带来一些副作用,sched_lock()会同时禁止高优先级任务的运行,这些任务不依赖于信号量管理的资源,这会对系统的相应时间产生负面影响。 优先级反转 正确使用信号量可以避免sched_lock()的问题,...
1. 环境搭建 2. Nuttx任务 3. 系统构建模式 4. 系统架构 5. 系统调用 6. 创建任务 7. 任务首次调度 8. pthread线程首次调度 9. 创建pthread线程 10. 激活任务引发的调度流程 11. 定时器中断触发的调度 12. sched_lock/sched_unlock导致的调度 13. 内存布局 14. 内核启动 15. usleep/sleep...
Summary purpose: 1 sched_lock is very time-consuming, and reducing its invocations can improve performance. 2 sched_lock is prone to misuse, and narrowing its scope of use is to prevent people from...
queue */ sched_lock(); msgq = mqdes->msgq; /* Allocate a message structure: * - Immediately if we are called from an interrupt handler. * - Immediately if the messagequeue is not full, or * - After successfullywaiting for the message queue to become * non-FULL. This would fail...
sched_lock(); /* Create the siginfo structure */ info.si_signo = signo; info.si_ = SI_USER; info.si_errno = EINTR;info.si_value.sival_ptr = NULL;#ifdef CONFIG_SCHED_HAVE_PARENT info.si_pid = rtcb->pid; info.si_status = OK;#endif /* Send the signal */ ret = sig_dispatch...
Summary The critical section does not prevent task scheduling If the critical section is in sched_lock, there is no need to check, scheduling is not going to happen If sched_lock is in the critica...
sched / sched / sched.h sched.h16.83 KB 一键复制编辑原始数据按行查看历史 Masayuki Ishikawa提交于4年前.sched: sched: Remove sched_tasklistlock.c for SMP /*** * sched/sched/sched.h * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor...
If you enable the generic, built-in math library, then that math library will expect your toolchain to provide the standardfloat.hheader file. The float.h header file defines the properties of your floating point implementation. It would always be best to use your toolchain'sfloat.hheader fil...