Diff: rtx/rt_Mailbox.c

Revision:

6:350b53afb889

Child:

11:db1fc233faa9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtx/rt_Mailbox.c	Fri Nov 23 09:57:31 2012 +0000
@@ -0,0 +1,292 @@
+/*----------------------------------------------------------------------------
+ *      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
+ *---------------------------------------------------------------------------*/
+