Diff: source/rtos/rt_Semaphore.c

Revision:

0:01f31e923fe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/rtos/rt_Semaphore.c	Tue Apr 07 12:55:42 2020 +0200
@@ -0,0 +1,131 @@
+/**
+ * @file    rt_Semaphore.c
+ * @brief   
+ *
+ * DAPLink Interface Firmware
+ * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "rt_TypeDef.h"
+#include "RTX_Config.h"
+#include "rt_System.h"
+#include "rt_List.h"
+#include "rt_Task.h"
+#include "rt_Semaphore.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_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);
+    p_TCB->ret_val = OS_R_SEM;
+    rt_rmv_dly (p_TCB);
+    rt_dispatch (p_TCB);
+    os_tsk.run->ret_val = OS_R_OK;
+  }
+  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;
+    p_TCB->ret_val = OS_R_SEM;
+    rt_put_prio (&os_rdy, p_TCB);
+  }
+  else {
+    /* Store token */
+    p_CB->tokens++;
+  }
+}
+
+/*----------------------------------------------------------------------------
+ * end of file
+ *---------------------------------------------------------------------------*/
+