565 lines
15 KiB
C
565 lines
15 KiB
C
/*
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* author : prife (goprife@gmail.com)
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* date : 2013/01/14 01:18:50
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* version: v 0.2.0
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*/
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#include <rtthread.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <signal.h>
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#include <unistd.h>
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#include <semaphore.h>
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#include <time.h>
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#include <sys/time.h>
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//#define TRACE printf
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#define TRACE(...)
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typedef struct _thread
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{
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pthread_t pthread;
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void (*task)(void *);
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void *para;
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void (*exit)(void);
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sem_t sem;
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rt_thread_t rtthread;
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int status;
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void *data;
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} thread_t;
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#define THREAD_T(thread) ((thread_t *)thread)
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#define MSG_SUSPEND SIGUSR1 /* 10 */
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#define MSG_RESUME SIGUSR2
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#define MSG_TICK SIGALRM /* 14 */
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#define TIMER_TYPE ITIMER_REAL
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#define MAX_INTERRUPT_NUM ((unsigned int)sizeof(unsigned int) * 8)
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#define INTERRUPT_ENABLE 0
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#define INTERRUPT_DISABLE 1
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/* 线程挂起状态，共两种取值 */
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#define SUSPEND_LOCK 0
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#define SUSPEND_SIGWAIT 1
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#define THREAD_RUNNING 2
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/* interrupt flag, if 1, disable, if 0, enable */
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static long interrupt_disable_flag;
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//static int systick_signal_flag;
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/* flag in interrupt handling */
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rt_ubase_t rt_interrupt_from_thread, rt_interrupt_to_thread;
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rt_ubase_t rt_thread_switch_interrupt_flag;
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/* interrupt event mutex */
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static pthread_mutex_t *ptr_int_mutex;
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static pthread_cond_t cond_int_hit; /* interrupt occured! */
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static volatile unsigned int cpu_pending_interrupts;
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static int (* cpu_isr_table[MAX_INTERRUPT_NUM])(void) = {0};
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static pthread_t mainthread_pid;
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/* function definition */
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static void start_sys_timer(void);
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static int tick_interrupt_isr(void);
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static void mthread_signal_tick(int sig);
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static int mainthread_scheduler(void);
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int signal_install(int sig, void (*func)(int))
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{
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struct sigaction act;
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/* set the signal handler */
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act.sa_handler = func ;
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sigemptyset(&act.sa_mask);
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act.sa_flags = 0;
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sigaction(sig, &act, 0);
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}
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int signal_mask(void)
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{
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sigset_t sigmask, oldmask;
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/* set signal mask */
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sigemptyset(&sigmask);
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sigaddset(&sigmask, SIGALRM);
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pthread_sigmask(SIG_BLOCK, &sigmask, &oldmask);
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}
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static void thread_suspend_signal_handler(int sig)
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{
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sigset_t sigmask;
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pthread_t pid = pthread_self();
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thread_t *thread_from;
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thread_t *thread_to;
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rt_thread_t tid;
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if (sig != MSG_SUSPEND)
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{
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printf("get an unexpected signal <%d>, exit\n", sig);
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exit(EXIT_FAILURE);
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}
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thread_from = (thread_t *) rt_interrupt_from_thread;
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thread_to = (thread_t *) rt_interrupt_to_thread;
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/* 注意！此时 rt_thread_self的值是to线程的值！ */
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tid = rt_thread_self();
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/* FIXME RT_ASSERT(thread_from->pthread == pid); */
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RT_ASSERT((thread_t *)(tid->sp) == thread_to);
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TRACE("signal: SIGSUSPEND suspend <%s>\n", thread_from->rtthread->name);
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/* 使用sigwait或者sigsuspend来挂起from线程 */
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//sem_wait(&thread_from->sem);
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sigemptyset(&sigmask);
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sigaddset(&sigmask, MSG_RESUME);
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/* Beginnig Linux Programming上说，当信号处理函数运行中，此信号就会被屏蔽，
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* 以防止重复执行信号处理函数
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*/
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thread_from->status = SUSPEND_SIGWAIT;
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if (sigwait(&sigmask, &sig) != 0)
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{
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printf("sigwait faild, %d\n", sig);
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}
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thread_to = (thread_t *) rt_interrupt_to_thread;
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RT_ASSERT(thread_to == thread_from);
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thread_to->status = THREAD_RUNNING;
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TRACE("signal: SIGSUSPEND resume <%s>\n", thread_from->rtthread->name);
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}
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static void thread_resume_signal_handler(int sig)
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{
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sigset_t sigmask;
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pthread_t pid = pthread_self();
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thread_t *thread_from;
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thread_t *thread_to;
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rt_thread_t tid;
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thread_from = (thread_t *) rt_interrupt_from_thread;
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thread_to = (thread_t *) rt_interrupt_to_thread;
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/* 注意！此时 rt_thread_self的值是to线程的值！ */
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tid = rt_thread_self();
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RT_ASSERT((thread_t *)(tid->sp) == thread_to);
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TRACE("signal: SIGRESUME resume <%s>\n", thread_to->rtthread->name);
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}
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static void *thread_run(void *parameter)
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{
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rt_thread_t tid;
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thread_t *thread;
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thread = THREAD_T(parameter);
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int res;
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/* set signal mask, mask the timer! */
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signal_mask();
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thread->status = SUSPEND_LOCK;
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TRACE("pid <%08x> stop on sem...\n", (unsigned int)(thread->pthread));
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sem_wait(&thread->sem);
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tid = rt_thread_self();
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TRACE("pid <%08x> tid <%s> starts...\n", (unsigned int)(thread->pthread),
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tid->parent.name);
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thread->rtthread = tid;
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thread->task(thread->para);
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TRACE("pid <%08x> tid <%s> exit...\n", (unsigned int)(thread->pthread),
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tid->parent.name);
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thread->exit();
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/*TODO:
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* 最后一行的pthread_exit永远没有机会执行，这是因为在threead->exit函数中
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* 会发生线程切换，并永久将此pthread线程挂起，所以更完美的解决方案是在这
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* 里发送信号给主线程，主线程中再次唤醒此线程令其自动退出。
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*/
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//sem_destroy(&thread->sem);
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pthread_exit(NULL);
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}
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static int thread_create(
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thread_t *thread, void *task, void *parameter, void *pexit)
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{
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int res;
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pthread_attr_t attr;
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thread->task = task;
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thread->para = parameter;
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thread->exit = pexit;
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if (sem_init(&thread->sem, 0, 0) != 0)
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{
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printf("init thread->sem failed, exit \n");
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exit(EXIT_FAILURE);
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}
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/* No need to join the threads. */
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pthread_attr_init(&attr);
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pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
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/* create a posix thread */
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res = pthread_create(&thread->pthread, &attr, &thread_run, (void *)thread);
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if (res)
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{
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printf("pthread create faild, <%d>\n", res);
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exit(EXIT_FAILURE);
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}
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return 0;
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}
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/* resume the thread */
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static int thread_resume(thread_t *thread)
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{
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sem_post(& thread->sem);
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}
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rt_uint8_t *rt_hw_stack_init(
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void *pEntry,
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void *pParam,
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rt_uint8_t *pStackAddr,
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void *pExit)
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{
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thread_t *thread;
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thread = (thread_t *)(pStackAddr - sizeof(thread_t));
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/* set the filed to zero */
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memset(thread, 0x00, sizeof(thread_t));
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thread_create(thread, pEntry, pParam, pExit);
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//TRACE("thread %x created\n", (unsigned int)thread_table[t].pthread);
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return (rt_uint8_t *) thread;
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}
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rt_base_t rt_hw_interrupt_disable(void)
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{
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long back;
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if (ptr_int_mutex == NULL)
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{
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return 0;
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}
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pthread_mutex_lock(ptr_int_mutex);
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back = interrupt_disable_flag;
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interrupt_disable_flag = INTERRUPT_DISABLE;
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/*TODO: It may need to unmask the signal */
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return back;
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}
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void rt_hw_interrupt_enable(rt_base_t level)
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{
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struct rt_thread * tid;
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pthread_t pid;
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thread_t *thread_from;
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thread_t *thread_to;
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if (ptr_int_mutex == NULL)
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return;
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interrupt_disable_flag = level;
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pthread_mutex_unlock(ptr_int_mutex);
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/* 如果已经中断仍然关闭 */
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if (interrupt_disable_flag)
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{
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return;
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}
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/* 表示当前中断打开, 检查是否有挂起的中断 */
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pthread_mutex_lock(ptr_int_mutex);
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if (!cpu_pending_interrupts)
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{
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pthread_mutex_unlock(ptr_int_mutex);
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return;
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}
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thread_from = (thread_t *) rt_interrupt_from_thread;
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thread_to = (thread_t *) rt_interrupt_to_thread;
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tid = rt_thread_self();
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pid = pthread_self();
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//pid != mainthread_pid &&
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if (thread_from->pthread == pid)
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{
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/* 注意这段代码是在RTT普通线程函数总函数中执行的，
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* from线程就是当前rtt线程 */
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/* 需要检查是否有挂起的中断需要处理 */
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TRACE("conswitch: P in pid<%x> ,suspend <%s>, resume <%s>!\n",
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(unsigned int)pid,
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thread_from->rtthread->name,
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thread_to->rtthread->name);
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cpu_pending_interrupts --;
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thread_from->status = SUSPEND_LOCK;
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pthread_mutex_unlock(ptr_int_mutex);
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/* 唤醒被挂起的线程 */
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if (thread_to->status == SUSPEND_SIGWAIT)
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{
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pthread_kill(thread_to->pthread, MSG_RESUME);
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}
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else if (thread_to->status == SUSPEND_LOCK)
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{
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sem_post(& thread_to->sem);
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}
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else
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{
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printf("conswitch: should not be here! %d\n", __LINE__);
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exit(EXIT_FAILURE);
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}
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/* 挂起当前的线程 */
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sem_wait(& thread_from->sem);
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pthread_mutex_lock(ptr_int_mutex);
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thread_from->status = THREAD_RUNNING;
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pthread_mutex_unlock(ptr_int_mutex);
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}
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else
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{
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/* 注意这段代码可能在多种情况下运行：
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* 1. 在system tick中执行， 即主线程的SIGALRM信号处理函数中执行
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* 2. 其他线程中调用，比如用于获取按键输入的线程中调用
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*/
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TRACE("conswitch: S in pid<%x> ,suspend <%s>, resume <%s>!\n",
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(unsigned int)pid,
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thread_from->rtthread->name,
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thread_to->rtthread->name);
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cpu_pending_interrupts --;
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/* 需要把解锁函数放在前面,以防止死锁？？ */
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pthread_mutex_unlock(ptr_int_mutex);
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/* 挂起from线程 */
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pthread_kill(thread_from->pthread, MSG_SUSPEND);
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/* 注意：这里需要确保线程被挂起了, 否则312行就很可能就会报错退出
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* 因为这里挂起线程是通过信号实现的，所以一定要确保线程挂起才行 */
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while (thread_from->status != SUSPEND_SIGWAIT)
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{
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sched_yield();
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}
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/* 唤醒to线程 */
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if (thread_to->status == SUSPEND_SIGWAIT)
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{
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pthread_kill(thread_to->pthread, MSG_RESUME);
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}
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else if (thread_to->status == SUSPEND_LOCK)
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{
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sem_post(& thread_to->sem);
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}
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else
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{
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printf("conswitch: should not be here! %d\n", __LINE__);
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exit(EXIT_FAILURE);
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}
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}
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/*TODO: It may need to unmask the signal */
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}
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void rt_hw_context_switch(rt_ubase_t from,
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rt_ubase_t to)
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{
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struct rt_thread * tid;
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pthread_t pid;
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thread_t *thread_from;
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thread_t *thread_to;
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RT_ASSERT(from != to);
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#if 0
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//TODO: 可能还需要考虑嵌套切换的情况
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if (rt_thread_switch_interrupt_flag != 1)
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{
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rt_thread_switch_interrupt_flag = 1;
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// set rt_interrupt_from_thread
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rt_interrupt_from_thread = *((rt_ubase_t *)from);
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}
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#endif
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pthread_mutex_lock(ptr_int_mutex);
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rt_interrupt_from_thread = *((rt_ubase_t *)from);
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rt_interrupt_to_thread = *((rt_ubase_t *)to);
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/* 这个函数只是并不会真正执行中断处理函数，而只是简单的
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* 设置一下中断挂起标志位
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*/
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cpu_pending_interrupts ++;
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pthread_mutex_unlock(ptr_int_mutex);
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}
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void rt_hw_context_switch_interrupt(rt_ubase_t from,
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rt_ubase_t to)
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{
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rt_hw_context_switch(from, to);
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}
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void rt_hw_context_switch_to(rt_ubase_t to)
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{
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//set to thread
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rt_interrupt_to_thread = *((rt_ubase_t *)(to));
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//clear from thread
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rt_interrupt_from_thread = 0;
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//set interrupt to 1
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rt_thread_switch_interrupt_flag = 0; //TODO: 还需要考虑这个嵌套切换的情况
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/* enable interrupt
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* note: NOW, there are only one interrupt in simposix: system tick */
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rt_hw_interrupt_enable(0);
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//start the main thread scheduler
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mainthread_scheduler();
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//never reach here!
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return;
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}
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static int mainthread_scheduler(void)
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{
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int i, res, sig;
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thread_t *thread_from;
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thread_t *thread_to;
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pthread_mutex_t mutex;
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pthread_mutexattr_t mutexattr;
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sigset_t sigmask, oldmask;
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/* save the main thread id */
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mainthread_pid = pthread_self();
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TRACE("pid <%08x> mainthread\n", (unsigned int)(mainthread_pid));
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/* 屏蔽suspend信号和resume信号 */
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sigemptyset(&sigmask);
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sigaddset(&sigmask, MSG_SUSPEND);
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sigaddset(&sigmask, MSG_RESUME);
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pthread_sigmask(SIG_BLOCK, &sigmask, &oldmask);
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sigemptyset(&sigmask);
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sigaddset(&sigmask, SIGALRM);
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/* install signal handler of system tick */
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signal_install(SIGALRM, mthread_signal_tick);
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/* install signal handler used to suspend/resume threads */
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signal_install(MSG_SUSPEND, thread_suspend_signal_handler);
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signal_install(MSG_RESUME, thread_resume_signal_handler);
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/* create a mutex and condition val, used to indicate interrupts occrue */
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ptr_int_mutex = &mutex;
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pthread_mutexattr_init(&mutexattr);
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pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE_NP);
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pthread_mutex_init(ptr_int_mutex, &mutexattr);
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/* start timer */
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start_sys_timer();
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thread_to = (thread_t *) rt_interrupt_to_thread;
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thread_resume(thread_to);
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for (;;)
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{
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#if 1
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if (sigwait(&sigmask, &sig) != 0)
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{
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printf("mthread: sigwait get unexpected sig %d\n", sig);
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}
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#else
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pause();
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#endif
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TRACE("mthread:got sig %d\n", sig);
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/* signal mask sigalrm 屏蔽SIGALRM信号 */
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pthread_sigmask(SIG_BLOCK, &sigmask, &oldmask);
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// if (systick_signal_flag != 0)
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if (pthread_mutex_trylock(ptr_int_mutex) == 0)
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{
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tick_interrupt_isr();
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// systick_signal_flag = 0;
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pthread_mutex_unlock(ptr_int_mutex);
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}
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else
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{
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TRACE("try lock failed.\n");
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}
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/* 开启SIGALRM信号 */
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pthread_sigmask(SIG_UNBLOCK, &sigmask, &oldmask);
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}
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return 0;
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}
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/*
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* Setup the systick timer to generate the tick interrupts at the required
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* frequency.
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*/
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static void start_sys_timer(void)
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{
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struct itimerval itimer, oitimer;
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int us;
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us = 1000000 / RT_TICK_PER_SECOND - 1;
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TRACE("start system tick!\n");
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/* Initialise the structure with the current timer information. */
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if (0 != getitimer(TIMER_TYPE, &itimer))
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{
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TRACE("get timer failed.\n");
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exit(EXIT_FAILURE);
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}
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/* Set the interval between timer events. */
|
||
itimer.it_interval.tv_sec = 0;
|
||
itimer.it_interval.tv_usec = us;
|
||
/* Set the current count-down. */
|
||
itimer.it_value.tv_sec = 0;
|
||
itimer.it_value.tv_usec = us;
|
||
|
||
/* Set-up the timer interrupt. */
|
||
if (0 != setitimer(TIMER_TYPE, &itimer, &oitimer))
|
||
{
|
||
TRACE("set timer failed.\n");
|
||
exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
static void mthread_signal_tick(int sig)
|
||
{
|
||
int res;
|
||
pthread_t pid = pthread_self();
|
||
|
||
if (sig == SIGALRM)
|
||
{
|
||
TRACE("pid <%x> signal: SIGALRM enter!\n", (unsigned int)pid);
|
||
//systick_signal_flag = 1;
|
||
TRACE("pid <%x> signal: SIGALRM leave!\n", (unsigned int)pid);
|
||
}
|
||
else
|
||
{
|
||
TRACE("got an unexpected signal <%d>\n", sig);
|
||
exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
/* isr return value: 1, should not be masked, if 0, can be masked */
|
||
static int tick_interrupt_isr(void)
|
||
{
|
||
TRACE("isr: systick enter!\n");
|
||
/* enter interrupt */
|
||
rt_interrupt_enter();
|
||
|
||
rt_tick_increase();
|
||
|
||
/* leave interrupt */
|
||
rt_interrupt_leave();
|
||
|
||
TRACE("isr: systick leave!\n");
|
||
return 0;
|
||
}
|
||
|