skeleton for lab1
Dependencies: AvailableMemory mbed-rtos mbed
Fork of helloaabbc by
mbed-rtos/rtx/rt_Mailbox.c
- Committer:
- y7jin
- Date:
- 2014-04-03
- Revision:
- 0:1c8f2727e9f5
File content as of revision 0:1c8f2727e9f5:
/*---------------------------------------------------------------------------- * RL-ARM - RTX *---------------------------------------------------------------------------- * Name: RT_MAILBOX.C * Purpose: Implements waits and wake-ups for mailbox messages * Rev.: V4.60 *---------------------------------------------------------------------------- * * Copyright (c) 1999-2009 KEIL, 2009-2012 ARM Germany GmbH * All rights reserved. * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - Neither the name of ARM nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. *---------------------------------------------------------------------------*/ #include "rt_TypeDef.h" #include "RTX_Config.h" #include "rt_System.h" #include "rt_List.h" #include "rt_Mailbox.h" #include "rt_MemBox.h" #include "rt_Task.h" #include "rt_HAL_CM.h" /*---------------------------------------------------------------------------- * Functions *---------------------------------------------------------------------------*/ /*--------------------------- rt_mbx_init -----------------------------------*/ void rt_mbx_init (OS_ID mailbox, U16 mbx_size) { /* Initialize a mailbox */ P_MCB p_MCB = mailbox; p_MCB->cb_type = MCB; p_MCB->state = 0; p_MCB->isr_st = 0; p_MCB->p_lnk = NULL; p_MCB->first = 0; p_MCB->last = 0; p_MCB->count = 0; p_MCB->size = (mbx_size + sizeof(void *) - sizeof(struct OS_MCB)) / (U32)sizeof (void *); } /*--------------------------- rt_mbx_send -----------------------------------*/ OS_RESULT rt_mbx_send (OS_ID mailbox, void *p_msg, U16 timeout) { /* Send message to a mailbox */ P_MCB p_MCB = mailbox; P_TCB p_TCB; if ((p_MCB->p_lnk != NULL) && (p_MCB->state == 1)) { /* A task is waiting for message */ p_TCB = rt_get_first ((P_XCB)p_MCB); #ifdef __CMSIS_RTOS rt_ret_val2(p_TCB, 0x10/*osEventMessage*/, (U32)p_msg); #else *p_TCB->msg = p_msg; rt_ret_val (p_TCB, OS_R_MBX); #endif rt_rmv_dly (p_TCB); rt_dispatch (p_TCB); } else { /* Store message in mailbox queue */ if (p_MCB->count == p_MCB->size) { /* No free message entry, wait for one. If message queue is full, */ /* then no task is waiting for message. The 'p_MCB->p_lnk' list */ /* pointer can now be reused for send message waits task list. */ if (timeout == 0) { return (OS_R_TMO); } if (p_MCB->p_lnk != NULL) { rt_put_prio ((P_XCB)p_MCB, os_tsk.run); } else { p_MCB->p_lnk = os_tsk.run; os_tsk.run->p_lnk = NULL; os_tsk.run->p_rlnk = (P_TCB)p_MCB; /* Task is waiting to send a message */ p_MCB->state = 2; } os_tsk.run->msg = p_msg; rt_block (timeout, WAIT_MBX); return (OS_R_TMO); } /* Yes, there is a free entry in a mailbox. */ p_MCB->msg[p_MCB->first] = p_msg; rt_inc (&p_MCB->count); if (++p_MCB->first == p_MCB->size) { p_MCB->first = 0; } } return (OS_R_OK); } /*--------------------------- rt_mbx_wait -----------------------------------*/ OS_RESULT rt_mbx_wait (OS_ID mailbox, void **message, U16 timeout) { /* Receive a message; possibly wait for it */ P_MCB p_MCB = mailbox; P_TCB p_TCB; /* If a message is available in the fifo buffer */ /* remove it from the fifo buffer and return. */ if (p_MCB->count) { *message = p_MCB->msg[p_MCB->last]; if (++p_MCB->last == p_MCB->size) { p_MCB->last = 0; } if ((p_MCB->p_lnk != NULL) && (p_MCB->state == 2)) { /* A task is waiting to send message */ p_TCB = rt_get_first ((P_XCB)p_MCB); #ifdef __CMSIS_RTOS rt_ret_val(p_TCB, 0/*osOK*/); #else rt_ret_val(p_TCB, OS_R_OK); #endif p_MCB->msg[p_MCB->first] = p_TCB->msg; if (++p_MCB->first == p_MCB->size) { p_MCB->first = 0; } rt_rmv_dly (p_TCB); rt_dispatch (p_TCB); } else { rt_dec (&p_MCB->count); } return (OS_R_OK); } /* No message available: wait for one */ if (timeout == 0) { return (OS_R_TMO); } if (p_MCB->p_lnk != NULL) { rt_put_prio ((P_XCB)p_MCB, os_tsk.run); } else { p_MCB->p_lnk = os_tsk.run; os_tsk.run->p_lnk = NULL; os_tsk.run->p_rlnk = (P_TCB)p_MCB; /* Task is waiting to receive a message */ p_MCB->state = 1; } rt_block(timeout, WAIT_MBX); #ifndef __CMSIS_RTOS os_tsk.run->msg = message; #endif return (OS_R_TMO); } /*--------------------------- rt_mbx_check ----------------------------------*/ OS_RESULT rt_mbx_check (OS_ID mailbox) { /* Check for free space in a mailbox. Returns the number of messages */ /* that can be stored to a mailbox. It returns 0 when mailbox is full. */ P_MCB p_MCB = mailbox; return (p_MCB->size - p_MCB->count); } /*--------------------------- isr_mbx_send ----------------------------------*/ void isr_mbx_send (OS_ID mailbox, void *p_msg) { /* Same function as "os_mbx_send", but to be called by ISRs. */ P_MCB p_MCB = mailbox; rt_psq_enq (p_MCB, (U32)p_msg); rt_psh_req (); } /*--------------------------- isr_mbx_receive -------------------------------*/ OS_RESULT isr_mbx_receive (OS_ID mailbox, void **message) { /* Receive a message in the interrupt function. The interrupt function */ /* should not wait for a message since this would block the rtx os. */ P_MCB p_MCB = mailbox; if (p_MCB->count) { /* A message is available in the fifo buffer. */ *message = p_MCB->msg[p_MCB->last]; if (p_MCB->state == 2) { /* A task is locked waiting to send message */ rt_psq_enq (p_MCB, 0); rt_psh_req (); } rt_dec (&p_MCB->count); if (++p_MCB->last == p_MCB->size) { p_MCB->last = 0; } return (OS_R_MBX); } return (OS_R_OK); } /*--------------------------- rt_mbx_psh ------------------------------------*/ void rt_mbx_psh (P_MCB p_CB, void *p_msg) { /* Store the message to the mailbox queue or pass it to task directly. */ P_TCB p_TCB; void *mem; if (p_CB->p_lnk != NULL) switch (p_CB->state) { #ifdef __CMSIS_RTOS case 3: /* Task is waiting to allocate memory, remove it from the waiting list */ mem = rt_alloc_box(p_msg); if (mem == NULL) break; p_TCB = rt_get_first ((P_XCB)p_CB); rt_ret_val(p_TCB, (U32)mem); p_TCB->state = READY; rt_rmv_dly (p_TCB); rt_put_prio (&os_rdy, p_TCB); break; #endif case 2: /* Task is waiting to send a message, remove it from the waiting list */ p_TCB = rt_get_first ((P_XCB)p_CB); #ifdef __CMSIS_RTOS rt_ret_val(p_TCB, 0/*osOK*/); #else rt_ret_val(p_TCB, OS_R_OK); #endif p_CB->msg[p_CB->first] = p_TCB->msg; rt_inc (&p_CB->count); if (++p_CB->first == p_CB->size) { p_CB->first = 0; } p_TCB->state = READY; rt_rmv_dly (p_TCB); rt_put_prio (&os_rdy, p_TCB); break; case 1: /* Task is waiting for a message, pass the message to the task directly */ p_TCB = rt_get_first ((P_XCB)p_CB); #ifdef __CMSIS_RTOS rt_ret_val2(p_TCB, 0x10/*osEventMessage*/, (U32)p_msg); #else *p_TCB->msg = p_msg; rt_ret_val (p_TCB, OS_R_MBX); #endif p_TCB->state = READY; rt_rmv_dly (p_TCB); rt_put_prio (&os_rdy, p_TCB); break; } else { /* No task is waiting for a message, store it to the mailbox queue */ if (p_CB->count < p_CB->size) { p_CB->msg[p_CB->first] = p_msg; rt_inc (&p_CB->count); if (++p_CB->first == p_CB->size) { p_CB->first = 0; } } else { os_error (OS_ERR_MBX_OVF); } } } /*---------------------------------------------------------------------------- * end of file *---------------------------------------------------------------------------*/