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rtx/TARGET_ARM7/rt_Mutex.c
- Committer:
- mbed_official
- Date:
- 2015-06-01
- Revision:
- 80:2dab120a94c2
File content as of revision 80:2dab120a94c2:
/*---------------------------------------------------------------------------- * RL-ARM - RTX *---------------------------------------------------------------------------- * Name: RT_MUTEX.C * Purpose: Implements mutex synchronization objects * Rev.: V4.60 *---------------------------------------------------------------------------- * * Copyright (c) 1999-2009 KEIL, 2009-2015 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_Conf.h" #include "rt_List.h" #include "rt_Task.h" #include "rt_Mutex.h" #include "rt_HAL_CM.h" /*---------------------------------------------------------------------------- * Functions *---------------------------------------------------------------------------*/ /*--------------------------- rt_mut_init -----------------------------------*/ void rt_mut_init (OS_ID mutex) { /* Initialize a mutex object */ P_MUCB p_MCB = mutex; p_MCB->cb_type = MUCB; p_MCB->prio = 0; p_MCB->level = 0; p_MCB->p_lnk = NULL; p_MCB->owner = NULL; } /*--------------------------- rt_mut_delete ---------------------------------*/ #ifdef __CMSIS_RTOS OS_RESULT rt_mut_delete (OS_ID mutex) { /* Delete a mutex object */ P_MUCB p_MCB = mutex; P_TCB p_TCB; /* Restore owner task's priority. */ if (p_MCB->level != 0) { p_MCB->owner->prio = p_MCB->prio; if (p_MCB->owner != os_tsk.run) { rt_resort_prio (p_MCB->owner); } } while (p_MCB->p_lnk != NULL) { /* A task is waiting for mutex. */ p_TCB = rt_get_first ((P_XCB)p_MCB); rt_ret_val(p_TCB, 0/*osOK*/); 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_MCB->cb_type = 0; return (OS_R_OK); } #endif /*--------------------------- rt_mut_release --------------------------------*/ OS_RESULT rt_mut_release (OS_ID mutex) { /* Release a mutex object */ P_MUCB p_MCB = mutex; P_TCB p_TCB; if (p_MCB->level == 0 || p_MCB->owner != os_tsk.run) { /* Unbalanced mutex release or task is not the owner */ return (OS_R_NOK); } if (--p_MCB->level != 0) { return (OS_R_OK); } /* Restore owner task's priority. */ os_tsk.run->prio = p_MCB->prio; if (p_MCB->p_lnk != NULL) { /* A task is waiting for mutex. */ 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_MUT); #endif rt_rmv_dly (p_TCB); /* A waiting task becomes the owner of this mutex. */ p_MCB->level = 1; p_MCB->owner = p_TCB; p_MCB->prio = p_TCB->prio; /* Priority inversion, check which task continues. */ if (os_tsk.run->prio >= rt_rdy_prio()) { rt_dispatch (p_TCB); } else { /* Ready task has higher priority than running task. */ rt_put_prio (&os_rdy, os_tsk.run); rt_put_prio (&os_rdy, p_TCB); os_tsk.run->state = READY; p_TCB->state = READY; rt_dispatch (NULL); } } else { /* Check if own priority raised by priority inversion. */ if (rt_rdy_prio() > os_tsk.run->prio) { rt_put_prio (&os_rdy, os_tsk.run); os_tsk.run->state = READY; rt_dispatch (NULL); } } return (OS_R_OK); } /*--------------------------- rt_mut_wait -----------------------------------*/ OS_RESULT rt_mut_wait (OS_ID mutex, U16 timeout) { /* Wait for a mutex, continue when mutex is free. */ P_MUCB p_MCB = mutex; if (p_MCB->level == 0) { p_MCB->owner = os_tsk.run; p_MCB->prio = os_tsk.run->prio; goto inc; } if (p_MCB->owner == os_tsk.run) { /* OK, running task is the owner of this mutex. */ inc:p_MCB->level++; return (OS_R_OK); } /* Mutex owned by another task, wait until released. */ if (timeout == 0) { return (OS_R_TMO); } /* Raise the owner task priority if lower than current priority. */ /* This priority inversion is called priority inheritance. */ if (p_MCB->prio < os_tsk.run->prio) { p_MCB->owner->prio = os_tsk.run->prio; rt_resort_prio (p_MCB->owner); } 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; } rt_block(timeout, WAIT_MUT); return (OS_R_TMO); } /*---------------------------------------------------------------------------- * end of file *---------------------------------------------------------------------------*/