Diff: mbed-rtos/rtx/rt_Semaphore.c

Revision:

0:0ed2a7c7190c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-rtos/rtx/rt_Semaphore.c	Fri May 31 04:09:54 2013 +0000
@@ -0,0 +1,171 @@
+/*----------------------------------------------------------------------------
+ *      RL-ARM - RTX
+ *----------------------------------------------------------------------------
+ *      Name:    RT_SEMAPHORE.C
+ *      Purpose: Implements binary and counting semaphores
+ *      Rev.:    V4.50
+ *----------------------------------------------------------------------------
+ *
+ * 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_Task.h"
+#include "rt_Semaphore.h"
+#include "rt_HAL_CM.h"
+
+
+/*----------------------------------------------------------------------------
+ *      Functions
+ *---------------------------------------------------------------------------*/
+
+
+/*--------------------------- rt_sem_init -----------------------------------*/
+
+void rt_sem_init (OS_ID semaphore, U16 token_count) {
+  /* Initialize a semaphore */
+  P_SCB p_SCB = semaphore;
+
+  p_SCB->cb_type = SCB;
+  p_SCB->p_lnk  = NULL;
+  p_SCB->tokens = token_count;
+}
+
+
+/*--------------------------- rt_sem_delete ---------------------------------*/
+OS_RESULT rt_sem_delete (OS_ID semaphore) {
+  /* Delete semaphore */
+  P_SCB p_SCB = semaphore;
+  P_TCB p_TCB;
+
+  while (p_SCB->p_lnk != NULL) {
+    /* A task is waiting for token */
+    p_TCB = rt_get_first ((P_XCB)p_SCB);
+    rt_ret_val(p_TCB, 0);
+    rt_rmv_dly(p_TCB);
+    p_TCB->state = READY;
+    rt_put_prio (&os_rdy, p_TCB);
+  }
+
+  if (os_rdy.p_lnk && (os_rdy.p_lnk->prio > os_tsk.run->prio)) {
+    /* preempt running task */
+    rt_put_prio (&os_rdy, os_tsk.run);
+    os_tsk.run->state = READY;
+    rt_dispatch (NULL);
+  }
+
+  p_SCB->cb_type = 0;
+
+  return (OS_R_OK);
+}
+
+/*--------------------------- rt_sem_send -----------------------------------*/
+
+OS_RESULT rt_sem_send (OS_ID semaphore) {
+  /* Return a token to semaphore */
+  P_SCB p_SCB = semaphore;
+  P_TCB p_TCB;
+
+  if (p_SCB->p_lnk != NULL) {
+    /* A task is waiting for token */
+    p_TCB = rt_get_first ((P_XCB)p_SCB);
+    rt_ret_val(p_TCB, 1);
+    rt_rmv_dly (p_TCB);
+    rt_dispatch (p_TCB);
+  }
+  else {
+    /* Store token. */
+    p_SCB->tokens++;
+  }
+  return (OS_R_OK);
+}
+
+
+/*--------------------------- rt_sem_wait -----------------------------------*/
+
+OS_RESULT rt_sem_wait (OS_ID semaphore, U16 timeout) {
+  /* Obtain a token; possibly wait for it */
+  P_SCB p_SCB = semaphore;
+
+  if (p_SCB->tokens) {
+    p_SCB->tokens--;
+    return (OS_R_OK);
+  }
+  /* No token available: wait for one */
+  if (timeout == 0) {
+    return (OS_R_TMO);
+  }
+  if (p_SCB->p_lnk != NULL) {
+    rt_put_prio ((P_XCB)p_SCB, os_tsk.run);
+  }
+  else {
+    p_SCB->p_lnk = os_tsk.run;
+    os_tsk.run->p_lnk = NULL;
+    os_tsk.run->p_rlnk = (P_TCB)p_SCB;
+  }
+  rt_block(timeout, WAIT_SEM);
+  return (OS_R_TMO);
+}
+
+
+/*--------------------------- isr_sem_send ----------------------------------*/
+
+void isr_sem_send (OS_ID semaphore) {
+  /* Same function as "os_sem"send", but to be called by ISRs */
+  P_SCB p_SCB = semaphore;
+
+  rt_psq_enq (p_SCB, 0);
+  rt_psh_req ();
+}
+
+
+/*--------------------------- rt_sem_psh ------------------------------------*/
+
+void rt_sem_psh (P_SCB p_CB) {
+  /* Check if task has to be waken up */
+  P_TCB p_TCB;
+
+  if (p_CB->p_lnk != NULL) {
+    /* A task is waiting for token */
+    p_TCB = rt_get_first ((P_XCB)p_CB);
+    rt_rmv_dly (p_TCB);
+    p_TCB->state   = READY;
+    rt_ret_val(p_TCB, 1);
+    rt_put_prio (&os_rdy, p_TCB);
+  }
+  else {
+    /* Store token */
+    p_CB->tokens++;
+  }
+}
+
+/*----------------------------------------------------------------------------
+ * end of file
+ *---------------------------------------------------------------------------*/
+