51操作系统学习uCOS 2.52版本

/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * EVENT FLAG MANAGEMENT * * (c) Copyright 2001, Jean J. Labrosse, Weston, FL * All Rights Reserved * * File : OS_FLAG.C * By : Jean J. Labrosse ********************************************************************************************************* */ #ifndef OS_MASTER_FILE #include "source\includes.h" #endif #if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0) /* ********************************************************************************************************* * LOCAL PROTOTYPES ********************************************************************************************************* */ static void OS_FlagBlock(OS_FLAG_GRP *pgrp, OS_FLAG_NODE *pnode, OS_FLAGS flags, INT8U wait_type, INT16U timeout) reentrant; static BOOLEAN OS_FlagTaskRdy(OS_FLAG_NODE *pnode, OS_FLAGS flags_rdy) reentrant; /*$PAGE*/ /* ********************************************************************************************************* * CHECK THE STATUS OF FLAGS IN AN EVENT FLAG GROUP * * Description: This function is called to check the status of a combination of bits to be set or cleared * in an event flag group. Your application can check for ANY bit to be set/cleared or ALL * bits to be set/cleared. * * This call does not block if the desired flags are not present. * * Arguments : pgrp is a pointer to the desired event flag group. * * flags Is a bit pattern indicating which bit(s) (i.e. flags) you wish to check. * The bits you want are specified by setting the corresponding bits in * 'flags'. e.g. if your application wants to wait for bits 0 and 1 then * 'flags' would contain 0x03. * * wait_type specifies whether you want ALL bits to be set/cleared or ANY of the bits * to be set/cleared. * You can specify the following argument: * * OS_FLAG_WAIT_CLR_ALL You will check ALL bits in 'flags' to be clear (0) * OS_FLAG_WAIT_CLR_ANY You will check ANY bit in 'flags' to be clear (0) * OS_FLAG_WAIT_SET_ALL You will check ALL bits in 'flags' to be set (1) * OS_FLAG_WAIT_SET_ANY You will check ANY bit in 'flags' to be set (1) * * NOTE: Add OS_FLAG_CONSUME if you want the event flag to be 'consumed' by * the call. Example, to wait for any flag in a group AND then clear * the flags that are present, set 'wait_type' to: * * OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME * * err is a pointer to an error code and can be: * OS_NO_ERR No error * OS_ERR_EVENT_TYPE You are not pointing to an event flag group * OS_FLAG_ERR_WAIT_TYPE You didn't specify a proper 'wait_type' argument. * OS_FLAG_INVALID_PGRP You passed a NULL pointer instead of the event flag * group handle. * OS_FLAG_ERR_NOT_RDY The desired flags you are waiting for are not * available. * * Returns : The state of the flags in the event flag group. * * Called from: Task or ISR ********************************************************************************************************* */ #if OS_FLAG_ACCEPT_EN > 0 OS_FLAGS OSFlagAccept (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U wait_type, INT8U *err) reentrant { #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr; #endif OS_FLAGS flags_cur; OS_FLAGS flags_rdy; BOOLEAN consume; #if OS_ARG_CHK_EN > 0 if (pgrp == (OS_FLAG_GRP *)0) { /* Validate 'pgrp' */ *err = OS_FLAG_INVALID_PGRP; return ((OS_FLAGS)0); } if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) { /* Validate event block type */ *err = OS_ERR_EVENT_TYPE; return ((OS_FLAGS)0); } #endif if (wait_type & OS_FLAG_CONSUME) { /* See if we need to consume the flags */ wait_type &= ~OS_FLAG_CONSUME; consume = TRUE; } else { consume = FALSE; } /*$PAGE*/ *err = OS_NO_ERR; /* Assume NO error until proven otherwise. */ OS_ENTER_CRITICAL(); switch (wait_type) { case OS_FLAG_WAIT_SET_ALL: /* See if all required flags are set */ flags_rdy = pgrp->OSFlagFlags & flags; /* Extract only the bits we want */ if (flags_rdy == flags) { /* Must match ALL the bits that we want */ if (consume == TRUE) { /* See if we need to consume the flags */ pgrp->OSFlagFlags &= ~flags_rdy; /* Clear ONLY the flags that we wanted */ } } else { *err = OS_FLAG_ERR_NOT_RDY; } flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */ OS_EXIT_CRITICAL(); break; case OS_FLAG_WAIT_SET_ANY: flags_rdy = pgrp->OSFlagFlags & flags; /* Extract only the bits we want */ if (flags_rdy != (OS_FLAGS)0) { /* See if any flag set */ if (consume == TRUE) { /* See if we need to consume the flags */ pgrp->OSFlagFlags &= ~flags_rdy; /* Clear ONLY the flags that we got */ } } else { *err = OS_FLAG_ERR_NOT_RDY; } flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */ OS_EXIT_CRITICAL(); break; #if OS_FLAG_WAIT_CLR_EN > 0 case OS_FLAG_WAIT_CLR_ALL: /* See if all required flags are cleared */ flags_rdy = ~pgrp->OSFlagFlags & flags; /* Extract only the bits we want */ if (flags_rdy == flags) { /* Must match ALL the bits that we want */ if (consume == TRUE) { /* See if we need to consume the flags */ pgrp->OSFlagFlags |= flags_rdy; /* Set ONLY the flags that we wanted */ } } else { *err = OS_FLAG_ERR_NOT_RDY; } flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */ OS_EXIT_CRITICAL(); break; case OS_FLAG_WAIT_CLR_ANY: flags_rdy = ~pgrp->OSFlagFlags & flags; /* Extract only the bits we want */ if (flags_rdy != (OS_FLAGS)0) { /* See if any flag cleared */ if (consume == TRUE) { /* See if we need to consume