embeded_timer.rar_embeded c++_嵌入式超时

/* * timer/timer.c * * Copyright (C) SGS-THOMSON Microelectronics Ltd. 1997 * * Generic time handling functions for external timers */ #include <stddef.h> #include <os20.h> #include <os20i.h> #include <task.h> #include <c1timeri.h> #include <c1timer.h> #include <element.h> #include <assert.h> #include <debug.h> #define FIXOFFSET(s) ((char *) s-offsetof(tdesc_t,tdesc_tlink)) list_t timer_queue; static void timer_enable_int(void) { (*timer_enable_int_ptr)(); } static void timer_raise_int(void) { (*timer_raise_int_ptr)(); } static void timer_disable_int(void) { (*timer_disable_int_ptr)(); } static void timer_set(int p ) { (*timer_set_ptr)(p); } static int timer_read(void) { return ((*timer_read_ptr)()); } static __inline void timer_queue_add(int Time) { tdesc_t* t; tdesc_t* tdesc; element_t* elem; __optasm { ldtdesc; stl tdesc; } tdesc->tdesc_tdelay = Time; elem = HEAD(&timer_queue); if (is_empty(&timer_queue)) { add_head(&timer_queue,(element_t*) &(tdesc->tdesc_tlink)); timer_set(Time); } else { while((elem != (element_t *) &timer_queue)) { t = (tdesc_t *) FIXOFFSET(elem); if (time_after( t->tdesc_tdelay, Time )) { if (HEAD(&timer_queue) == elem) { add_head(&timer_queue,(element_t *) &tdesc->tdesc_tlink); timer_set(Time); } else { element_t *e = (element_t *) &tdesc->tdesc_tlink; NEXT(PREV(elem)) = e; PREV(e) = PREV(elem); PREV(elem) = e; NEXT(e) = elem; } return; } else { elem = NEXT(elem); } } /* end of list */ add_tail(&timer_queue,(element_t *) &tdesc->tdesc_tlink); } return; } static __inline void timer_enable(void) { tdesc_t* tdesc; __optasm { ldtdesc; stl tdesc; } timer_enable_int(); /* enable interrupt or timer */ if (tdesc->tdesc_tstate == ENABLING_P) if (time_after(timer_read(),tdesc->tdesc_tdelay)) timer_raise_int(); } void timer_wait(const clock_t *timeout) { tdesc_t *tdesc; INTERRUPT_DECLARE; /* if the timeout is not infinate we must setup an expiry time */ if (TIMEOUT_INFINITY != timeout) { /* enqueue the tdesc onto the timer queue */ INTERRUPT_LOCK(); timer_queue_add(*timeout); INTERRUPT_UNLOCK(); /* enable the timer plugins timer interrupt (and check that the timer * is not already due) */ timer_enable(); } __optasm { ldtdesc; stl tdesc; } /* block the task unless the timer has already elapsed or the semaphore * has already been signaled. * * this mimics the ST20-C2 behaviour since waiting for a time in the * past or very near future does not guarantee a deschedule. */ INTERRUPT_LOCK(); if (tdesc->tdesc_tstate == ENABLING_P) { tdesc->tdesc_tstate = WAITING_P; TIMESLICE_UNLOCK(); __optasm { stop; } } INTERRUPT_UNLOCK(); } static void _task_delay_until(unsigned int Time) { tdesc_t* tdesc; __optasm { ldtdesc; stl tdesc; } tdesc->tdesc_tstate = ENABLING_P; timer_wait(&Time); } static void _task_delay(unsigned int Delay) { _task_delay_until(timer_read()+Delay); } void timer_interrupt(void) { tdesc_t* tdesc; element_t* elem, *next; FATAL_ERROR_IF(task_context_interrupt != task_context(NULL, NULL), "illegal operation *not* from interrupt"); elem = HEAD(&timer_queue); while(elem!=(element_t *) &timer_queue) { tdesc = (tdesc_t *) FIXOFFSET(elem); next = (element_t*)tdesc->tdesc_tlink; if ( time_after( timer_read(),tdesc->tdesc_tdelay)) { rem_element(elem); if (tdesc->tdesc_tstate == WAITING_P) { __optasm { ldl tdesc; run; } } else { tdesc->tdesc_tstate = READY_P; } elem = next; } else { timer_set(tdesc->tdesc_tdelay); if (!time_after(timer_read(),tdesc->tdesc_tdelay)) { return; } } } if (is_empty(&timer_queue)) timer_disable_int(); return; } void timer_initialize(timer_api_t *api) { FATAL_ERROR_IF_NOT_TASK(); FATAL_ERROR_IF_LOCKED(); init_list((list_t *) &timer_queue); time_now_ptr = api->timer_read; task_delay_ptr = &_task_delay; task_delay_until_ptr = &_task_delay_until; timer_set_ptr = api->timer_set; timer_read_ptr = api->timer_read; timer_enable_int_ptr = api->timer_enable_int; timer_disable_int_ptr = api->timer_disable_int; timer_raise_int_ptr = api->timer_raise_int; }