From 5685a395be4bbbf8363a19a5c380f6c35e075474 Mon Sep 17 00:00:00 2001 From: prife Date: Mon, 14 Jan 2013 01:23:08 +0800 Subject: [PATCH] add some comments and clean code in cpu_port.c --- libcpu/sim/posix/cpu_port.c | 121 ++++++++++++++++++------------------ 1 file changed, 59 insertions(+), 62 deletions(-) mode change 100755 => 100644 libcpu/sim/posix/cpu_port.c diff --git a/libcpu/sim/posix/cpu_port.c b/libcpu/sim/posix/cpu_port.c old mode 100755 new mode 100644 index 919abc5209..ca25747c5a --- a/libcpu/sim/posix/cpu_port.c +++ b/libcpu/sim/posix/cpu_port.c @@ -1,3 +1,8 @@ +/* + * author : prife (goprife@gmail.com) + * date : 2013/01/14 01:18:50 + * version: v 0.1.0 + */ #include #include #include @@ -10,7 +15,6 @@ //#define TRACE printf #define TRACE(...) -#define _DEBUG typedef struct _thread { @@ -31,10 +35,11 @@ typedef struct _thread #define TIMER_TYPE ITIMER_REAL #define MAX_INTERRUPT_NUM ((unsigned int)sizeof(unsigned int) * 8) +#define INTERRUPT_ENABLE 0 +#define INTERRUPT_DISABLE 1 +/* interrupt flag, if 1, disable, if 0, enable */ +static long interrupt_disable_flag; -/* #define INT_ENABLE 0 - * #define INT_DISABLE 1 - */ /* flag in interrupt handling */ rt_uint32_t rt_interrupt_from_thread, rt_interrupt_to_thread; rt_uint32_t rt_thread_switch_interrupt_flag; @@ -181,29 +186,28 @@ rt_uint8_t *rt_hw_stack_init( return (rt_uint8_t *) thread; } +static int dis_count; +static int en_count; -/* interrupt contex switch hit, value 1 or 0 */ -static long int_cs_hit; - +/* TODO: 此函数还没有真正实现 */ rt_base_t rt_hw_interrupt_disable(void) { - if (ptr_int_mutex != NULL) - { -// pthread_mutex_lock(ptr_int_mutex); //FIXME - } + long back; - /*TODO: It may need to mask the signal */ - return 0; + back = interrupt_disable_flag; + interrupt_disable_flag = INTERRUPT_DISABLE; + + /*TODO: It may need to unmask the signal */ + dis_count++; + return back; } +/* TODO: 此函数还没有真正实现 */ void rt_hw_interrupt_enable(rt_base_t level) { - level = level; + interrupt_disable_flag = level; - if (ptr_int_mutex != NULL) - { -// pthread_mutex_unlock(ptr_int_mutex); //FIXME - } + en_count++; /*TODO: It may need to unmask the signal */ } @@ -224,6 +228,7 @@ void rt_hw_context_switch(rt_uint32_t from, RT_ASSERT(from != to); #if 0 + //TODO: 还需要考虑嵌套切换的情况 if (rt_thread_switch_interrupt_flag != 1) { rt_thread_switch_interrupt_flag = 1; @@ -242,19 +247,32 @@ void rt_hw_context_switch(rt_uint32_t from, tid = rt_thread_self(); pid = pthread_self(); - /* 注意，只有两种可可能，一种是线程函数中调用此函数，一种是在中断中调用 - * 而在中断调用是在主线程的信号处理函数中实现（目前只有tick中断）。 - * 即, 只有如下两种可能: - * 1)普通RTT线程间接调用，如rt_thread_delay函数 - * 2)或者主线程信号处理函数,如rt_tick_increase中调用 - */ + /* + * FIXME: 这段代码应该删除，因为rt_schedule函数中是先关闭中断，然后再开启的 + * 开启就会出发PendSV（以stm32为例）中断，cpu_port.c的win32版本可以模拟这种 + * 情形，因为它的中断是在主线程代码实现的，而本设计中，切换分为两种情况， + * 1) 普通rtt线程调用rt_thread_delay/rt_sem_take等主动挂起时，即刻实现切换 + * 2) 当rt_thread_delay定时到期时，主线程的SIGALRM信号处理函数中实现线程切换 + * + * 在第一种情况下，如果添加打开如下代码，由于if中语句为真，会导致失败退出。 + * + if (interrupt_disable_flag != 0) + { + printf("dis_count=%d, en_count=%d\n", dis_count, en_count); + printf("interrupt_disable_flag = %d\n", interrupt_disable_flag); + printf("bug! interrupt is disabled! You may forget enable interrupt\n"); + exit(EXIT_FAILURE); + } + */ + if (pid != mainthread_pid) { + /* FIXME: 注意这段代码是在RTT普通线程函数总函数中执行的， + * from线程就是当前rtt线程 */ TRACE("conswitch: P in pid<%x> ,suspend <%s>, resume <%s>!\n", (unsigned int)pid, thread_from->rtthread->name, thread_to->rtthread->name); - /* from线程就是当前rtt线程 */ /* 确定一下，这两个值一定是相等的！ */ RT_ASSERT(thread_from->pthread == pid); @@ -263,14 +281,14 @@ void rt_hw_context_switch(rt_uint32_t from, sem_post(& thread_to->sem); /* 挂起from线程, 既然from线程就是当前线程，所以应该直接 - * 挂起在这里 - */ + * 挂起在这里 */ sem_wait(& thread_from->sem); } else { /* FIXME: 注意这段代码是在system tick 函数中执行的， - * 即此时位于主线程的SIGALRM信号处理函数中 */ + * 即此时位于主线程的SIGALRM信号处理函数中 + */ TRACE("conswitch: S in pid<%x> ,suspend <%s>, resume <%s>!\n", (unsigned int)pid, thread_from->rtthread->name, @@ -293,7 +311,11 @@ void rt_hw_context_switch_to(rt_uint32_t to) rt_interrupt_from_thread = 0; //set interrupt to 1 - rt_thread_switch_interrupt_flag = 0; //<------ + rt_thread_switch_interrupt_flag = 0; //TODO: 还需要考虑这个嵌套切换的情况 + + /* enable interrupt + * note: NOW, there are only one interrupt in simposix: system tick */ + rt_hw_interrupt_enable(0); //start the main thread scheduler mainthread_scheduler(); @@ -315,21 +337,19 @@ static int mainthread_scheduler(void) mainthread_pid = pthread_self(); TRACE("pid <%08x> mainthread\n", (unsigned int)(mainthread_pid)); - /* register interrupts which is simulated for yield and systick */ - //register_interrupt(CPU_INTERRUPT_YIELD, yield_interrupt_isr); - //register_interrupt(CPU_INTERRUPT_TICK, tick_interrupt_isr); - /* install signal handler of system tick */ signal_install(SIGALRM, mthread_signal_tick); /* install signal handler used to suspend itself */ signal_install(MSG_SUSPEND, thread_switch_handler); +#if 0 /* create a mutex and condition val, used to indicate interrupts occrue */ ptr_int_mutex = &mutex; pthread_mutexattr_init(&mutexattr); pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE); pthread_mutex_init(ptr_int_mutex, &mutexattr); pthread_cond_init(&cond_int_hit, NULL); +#endif /* start timer */ start_sys_timer(); @@ -341,18 +361,6 @@ static int mainthread_scheduler(void) for (;;) { -#if 0 - pthread_mutex_lock(ptr_int_mutex); - /*Lock mutex and wait for signal. Note that the pthread_cond_wait - *routine will automatically and atomically unlock mutex while it waits. - */ - TRACE("mthread: wait cond val!\n"); - pthread_cond_wait(&cond_int_hit, ptr_int_mutex); - TRACE("mthread: got cond val!\n"); - - pthread_mutex_unlock(ptr_int_mutex); -#endif - //printf("main thread...\n"); sleep(1); } @@ -402,7 +410,13 @@ static void mthread_signal_tick(int sig) if (sig == SIGALRM) { TRACE("pid <%x> signal: SIGALRM enter!\n", (unsigned int)pid); + + /* FIXME: 下面这条语句不能打开，打开就会导致失败tick_interrupt_isry + * 永远无法执行 + */ + /* if (! interrupt_disable_flag) */ tick_interrupt_isr(); + TRACE("pid <%x> signal: SIGALRM leave!\n", (unsigned int)pid); } else @@ -428,20 +442,3 @@ static int tick_interrupt_isr(void) return 0; } -#if 0 - -static void trigger_interrupt(int index) -{ - if ((index < MAX_INTERRUPT_NUM) && ptr_int_mutex != NULL) - { - pthread_mutex_lock(ptr_int_mutex); - cpu_pending_interrupts |= (1 << index); - - /* signal the condition val */ - pthread_cond_signal(&cond_int_hit); - - pthread_mutex_unlock(ptr_int_mutex); - } -} -#endif -