714 lines
16 KiB
C
714 lines
16 KiB
C
/* semaphore kernel services */
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/*
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* Copyright (c) 1997-2010, 2012-2015 Wind River Systems, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1) Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2) Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3) Neither the name of Wind River Systems nor the names of its contributors
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* may be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/* includes */
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#include <microkernel.h>
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#include <toolchain.h>
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#include <sections.h>
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#include <minik.h>
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/*******************************************************************************
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*
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* signal_semaphore - common code for signaling a semaphore
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*
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* RETURNS: N/A
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*/
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static void signal_semaphore(int n, struct sem_struct *S)
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{
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struct k_args *A, *X, *Y;
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#ifdef CONFIG_OBJECT_MONITOR
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S->Count += n;
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#endif
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S->Level += n;
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A = S->Waiters;
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Y = NULL;
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while (A && S->Level) {
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X = A->Forw;
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Comm == WAITSREQ || A->Comm == WAITSTMO)
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#else
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if (A->Comm == WAITSREQ)
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#endif
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{
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S->Level--;
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if (Y) {
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Y->Forw = X;
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} else {
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S->Waiters = X;
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}
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.timer) {
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force_timeout(A);
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A->Comm = WAITSRPL;
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} else {
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#endif
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A->Time.rcode = RC_OK;
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reset_state_bit(A->Ctxt.proc, TF_SEMA);
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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}
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#endif
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} else if (A->Comm == WAITMREQ) {
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S->Level--;
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A->Comm = WAITMRDY;
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GETARGS(Y);
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*Y = *A;
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SENDARGS(Y);
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Y = A;
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} else {
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Y = A;
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}
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A = X;
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}
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait - finish handling incomplete waits on semaphores
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait(struct k_args *R)
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{
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struct k_args *A = R->Ctxt.args;
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FREEARGS(R);
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if (--(A->Args.s1.nsem) == 0) {
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reset_state_bit(A->Ctxt.proc, TF_LIST);
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}
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait_cancel - handle cancellation of a semaphore involved in a
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* semaphore group wait request
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*
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* This routine only applies to semaphore group wait requests. It is invoked
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* for each semaphore in the semaphore group that "lost" the semaphore group
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* wait request.
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait_cancel(struct k_args *A)
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{
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struct sem_struct *S = _k_sem_list + OBJ_INDEX(A->Args.s1.sema);
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struct k_args *X = S->Waiters;
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struct k_args *Y = NULL;
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while (X && (X->Prio <= A->Prio)) {
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if (X->Ctxt.args == A->Ctxt.args) {
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if (Y) {
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Y->Forw = X->Forw;
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} else {
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S->Waiters = X->Forw;
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}
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if (X->Comm == WAITMREQ || X->Comm == WAITMRDY) {
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if (X->Comm == WAITMRDY) {
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/* obtain struct k_args of waiting task */
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struct k_args *waitTaskArgs = X->Ctxt.args;
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/*
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* Determine if the wait cancellation request is being
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* processed after the state of the 'Waiters' packet state
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* has been updated to WAITMRDY, but before the WAITMRDY
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* packet has been processed. This will occur if a WAITMTMO
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* timer expiry occurs between the update of the packet state
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* and the processing of the WAITMRDY packet.
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*/
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if (unlikely(waitTaskArgs->Args.s1.sema ==
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ENDLIST)) {
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waitTaskArgs->Args.s1.sema = A->Args.s1.sema;
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} else {
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signal_semaphore(1, S);
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}
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}
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_k_sem_group_wait(X);
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} else {
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FREEARGS(X); /* ERROR */
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}
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FREEARGS(A);
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return;
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} else {
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Y = X;
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X = X->Forw;
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}
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}
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A->Forw = X;
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if (Y) {
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Y->Forw = A;
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} else {
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S->Waiters = A;
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}
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait_accept - handle acceptance of the ready semaphore request
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*
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* This routine only applies to semaphore group wait requests. It handles
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* the request for the one semaphore in the group that "wins" the semaphore
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* group wait request.
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait_accept(struct k_args *A)
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{
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struct sem_struct *S = _k_sem_list + OBJ_INDEX(A->Args.s1.sema);
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struct k_args *X = S->Waiters;
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struct k_args *Y = NULL;
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while (X && (X->Prio <= A->Prio)) {
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if (X->Ctxt.args == A->Ctxt.args) {
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if (Y) {
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Y->Forw = X->Forw;
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} else {
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S->Waiters = X->Forw;
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}
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if (X->Comm == WAITMRDY) {
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_k_sem_group_wait(X);
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} else {
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FREEARGS(X); /* ERROR */
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}
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FREEARGS(A);
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return;
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} else {
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Y = X;
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X = X->Forw;
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}
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}
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/* ERROR */
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait_timeout - handle semaphore group timeout request
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait_timeout(struct k_args *A)
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{
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ksem_t *L;
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.timer) {
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FREETIMER(A->Time.timer);
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}
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#endif
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L = A->Args.s1.list;
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while (*L != ENDLIST) {
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struct k_args *R;
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GETARGS(R);
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R->Prio = A->Prio;
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R->Comm =
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(K_COMM)((*L == A->Args.s1.sema) ? WAITMACC : WAITMCAN);
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R->Ctxt.args = A;
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R->Args.s1.sema = *L++;
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SENDARGS(R);
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}
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}
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/*******************************************************************************
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*
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* _k_sem_group_ready - handle semaphore ready request
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*
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* This routine only applies to semaphore group wait requests. It identifies
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* the one semaphore in the group that "won" the semaphore group wait request
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* before triggering the semaphore group timeout handler.
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_ready(struct k_args *R)
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{
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struct k_args *A = R->Ctxt.args;
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if (A->Args.s1.sema == ENDLIST) {
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A->Args.s1.sema = R->Args.s1.sema;
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A->Comm = WAITMTMO;
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.timer) {
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force_timeout(A);
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} else
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#endif
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_k_sem_group_wait_timeout(A);
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}
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FREEARGS(R);
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}
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/*******************************************************************************
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*
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* _k_sem_wait_reply - reply to a semaphore wait request
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*
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* RETURNS: N/A
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*/
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void _k_sem_wait_reply(struct k_args *A)
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{
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.timer) {
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FREETIMER(A->Time.timer);
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}
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if (A->Comm == WAITSTMO) {
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REMOVE_ELM(A);
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A->Time.rcode = RC_TIME;
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} else
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#endif
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A->Time.rcode = RC_OK;
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reset_state_bit(A->Ctxt.proc, TF_SEMA);
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait_request - handle internal wait request on a semaphore involved in a
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* semaphore group wait request
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait_request(struct k_args *A)
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{
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struct sem_struct *S = _k_sem_list + OBJ_INDEX(A->Args.s1.sema);
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struct k_args *X = S->Waiters;
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struct k_args *Y = NULL;
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while (X && (X->Prio <= A->Prio)) {
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if (X->Ctxt.args == A->Ctxt.args) {
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if (Y) {
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Y->Forw = X->Forw;
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} else {
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S->Waiters = X->Forw;
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}
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if (X->Comm == WAITMCAN) {
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_k_sem_group_wait(X);
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} else {
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FREEARGS(X); /* ERROR */
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}
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FREEARGS(A);
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return;
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} else {
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Y = X;
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X = X->Forw;
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}
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}
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A->Forw = X;
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if (Y) {
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Y->Forw = A;
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} else {
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S->Waiters = A;
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}
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signal_semaphore(0, S);
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}
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/*******************************************************************************
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*
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* _k_sem_group_wait_any - handle semaphore group wait request
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*
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* This routine splits the single semaphore group wait request into several
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* internal wait requests--one for each semaphore in the group.
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_wait_any(struct k_args *A)
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{
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ksem_t *L;
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L = A->Args.s1.list;
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A->Args.s1.sema = ENDLIST;
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A->Args.s1.nsem = 0;
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if (*L == ENDLIST) {
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return;
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}
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while (*L != ENDLIST) {
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struct k_args *R;
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GETARGS(R);
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R->Prio = _k_current_task->Prio;
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R->Comm = WAITMREQ;
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R->Ctxt.args = A;
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R->Args.s1.sema = *L++;
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SENDARGS(R);
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(A->Args.s1.nsem)++;
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}
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A->Ctxt.proc = _k_current_task;
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set_state_bit(_k_current_task, TF_LIST);
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.ticks != TICKS_NONE) {
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if (A->Time.ticks == TICKS_UNLIMITED) {
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A->Time.timer = NULL;
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} else {
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A->Comm = WAITMTMO;
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enlist_timeout(A);
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}
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}
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#endif
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}
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/*******************************************************************************
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*
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* _k_sem_wait_request - handle semaphore test and wait request
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*
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* RETURNS: N/A
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*/
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void _k_sem_wait_request(struct k_args *A)
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{
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struct sem_struct *S;
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uint32_t Sid;
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Sid = A->Args.s1.sema;
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S = _k_sem_list + OBJ_INDEX(Sid);
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if (S->Level) {
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S->Level--;
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A->Time.rcode = RC_OK;
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} else if (A->Time.ticks != TICKS_NONE) {
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A->Ctxt.proc = _k_current_task;
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A->Prio = _k_current_task->Prio;
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set_state_bit(_k_current_task, TF_SEMA);
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INSERT_ELM(S->Waiters, A);
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#ifdef CONFIG_SYS_CLOCK_EXISTS
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if (A->Time.ticks == TICKS_UNLIMITED) {
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A->Time.timer = NULL;
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} else {
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A->Comm = WAITSTMO;
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enlist_timeout(A);
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}
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#endif
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return;
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} else {
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A->Time.rcode = RC_FAIL;
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}
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}
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/*******************************************************************************
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*
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* _task_sem_take - test a semaphore
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*
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* This routine tests a semaphore to see if it has been signaled. If the signal
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* count is greater than zero, it is decremented.
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*
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* @param sema Semaphore to test.
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* @param time Maximum number of ticks to wait.
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*
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* RETURNS: RC_OK, RC_FAIL, RC_TIME on success, failure, timeout respectively
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*/
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int _task_sem_take(ksem_t sema, int32_t time)
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{
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struct k_args A;
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A.Comm = WAITSREQ;
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A.Time.ticks = time;
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A.Args.s1.sema = sema;
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KERNEL_ENTRY(&A);
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return A.Time.rcode;
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}
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/*******************************************************************************
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*
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* _task_sem_group_take - test multiple semaphores
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*
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* This routine tests a group of semaphores. A semaphore group is an array of
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* semaphore names terminated by the predefined constant ENDLIST.
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*
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* It returns the ID of the first semaphore in the group whose signal count is
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* greater than zero, and decrements the signal count.
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*
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* @param group Group of semaphores to test.
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* @param time Maximum number of ticks to wait.
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*
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* RETURNS: N/A
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*/
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ksem_t _task_sem_group_take(ksemg_t group, int32_t time)
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{
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struct k_args A;
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A.Comm = WAITMANY;
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A.Prio = _k_current_task->Prio;
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A.Time.ticks = time;
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A.Args.s1.list = group;
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KERNEL_ENTRY(&A);
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return A.Args.s1.sema;
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}
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/*******************************************************************************
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*
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* _k_sem_signal - handle semaphore signal request
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*
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* RETURNS: N/A
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*/
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void _k_sem_signal(struct k_args *A)
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{
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uint32_t Sid = A->Args.s1.sema;
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signal_semaphore(1, _k_sem_list + OBJ_INDEX(Sid));
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}
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/*******************************************************************************
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*
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* _k_sem_group_signal - handle signal semaphore group request
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*
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* RETURNS: N/A
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*/
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void _k_sem_group_signal(struct k_args *A)
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{
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ksem_t *L = A->Args.s1.list;
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while ((A->Args.s1.sema = *L++) != ENDLIST) {
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_k_sem_signal(A);
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}
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}
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/*******************************************************************************
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*
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* task_sem_give - signal a semaphore
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*
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* This routine signals the specified semaphore.
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*
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* @param sema Semaphore to signal.
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*
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* RETURNS: N/A
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*/
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void task_sem_give(ksem_t sema)
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{
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struct k_args A;
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A.Comm = SIGNALS;
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A.Args.s1.sema = sema;
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KERNEL_ENTRY(&A);
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}
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/*******************************************************************************
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*
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* task_sem_group_give - signal a group of semaphores
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*
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* This routine signals a group of semaphores. A semaphore group is an array of
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* semaphore names terminated by the predefined constant ENDLIST.
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*
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* If the semaphore list of waiting tasks is empty, the signal count is
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* incremented, otherwise the highest priority waiting task is released.
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*
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* Using task_sem_group_give() is faster than using multiple single signals,
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* and ensures all signals take place before other tasks run.
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*
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* @param group Group of semaphores to signal.
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*
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* RETURNS: N/A
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*/
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void task_sem_group_give(ksemg_t group)
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{
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struct k_args A;
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A.Comm = SIGNALM;
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A.Args.s1.list = group;
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KERNEL_ENTRY(&A);
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}
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/*******************************************************************************
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|
*
|
|
* fiber_sem_give - signal a semaphore from a fiber
|
|
*
|
|
* This routine (to only be called from a fiber) signals a semaphore. It
|
|
* requires a statically allocated command packet (from a command packet set)
|
|
* that is implicitly released once the command packet has been processed.
|
|
* To signal a semaphore from a task, task_sem_give() should be used instead.
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
FUNC_ALIAS(isr_sem_give, fiber_sem_give, void);
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* isr_sem_give - signal a semaphore from an ISR
|
|
*
|
|
* This routine (to only be called from an ISR) signals a semaphore. It
|
|
* requires a statically allocated command packet (from a command packet set)
|
|
* that is implicitly released once the command packet has been processed.
|
|
* To signal a semaphore from a task, task_sem_give() should be used instead.
|
|
*
|
|
* @param sema Semaphore to signal.
|
|
* @param pSet Pointer to command packet set.
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void isr_sem_give(ksem_t sema, struct cmd_pkt_set *pSet)
|
|
{
|
|
struct k_args *pCommand; /* ptr to command packet */
|
|
|
|
/*
|
|
* The cmdPkt_t data structure was designed to work seamlessly with the
|
|
* struct k_args data structure and it is thus safe (and expected) to typecast
|
|
* the return value of _cmd_pkt_get() to "struct k_args *".
|
|
*/
|
|
|
|
pCommand = (struct k_args *)_cmd_pkt_get(pSet);
|
|
pCommand->Comm = SIGNALS;
|
|
pCommand->Args.s1.sema = sema;
|
|
|
|
nano_isr_stack_push(&_k_command_stack, (uint32_t)pCommand);
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* _k_sem_reset - handle semaphore reset request
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void _k_sem_reset(struct k_args *A)
|
|
{
|
|
uint32_t Sid = A->Args.s1.sema;
|
|
|
|
_k_sem_list[OBJ_INDEX(Sid)].Level = 0;
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* _k_sem_group_reset - handle semaphore group reset request
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void _k_sem_group_reset(struct k_args *A)
|
|
{
|
|
ksem_t *L = A->Args.s1.list;
|
|
|
|
while ((A->Args.s1.sema = *L++) != ENDLIST) {
|
|
_k_sem_reset(A);
|
|
}
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* task_sem_reset - reset semaphore count to zero
|
|
*
|
|
* This routine resets the signal count of the specified semaphore to zero.
|
|
*
|
|
* @param sema Semaphore to reset.
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void task_sem_reset(ksem_t sema)
|
|
{
|
|
struct k_args A;
|
|
|
|
A.Comm = RESETS;
|
|
A.Args.s1.sema = sema;
|
|
KERNEL_ENTRY(&A);
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* task_sem_group_reset - reset a group of semaphores
|
|
*
|
|
* This routine resets the signal count for a group of semaphores. A semaphore
|
|
* group is an array of semaphore names terminated by the predefined constant
|
|
* ENDLIST.
|
|
*
|
|
* @param group Group of semaphores to reset.
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void task_sem_group_reset(ksemg_t group)
|
|
{
|
|
struct k_args A;
|
|
|
|
A.Comm = RESETM;
|
|
A.Args.s1.list = group;
|
|
KERNEL_ENTRY(&A);
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* _k_sem_inquiry - handle semaphore inquiry request
|
|
*
|
|
* RETURNS: N/A
|
|
*/
|
|
|
|
void _k_sem_inquiry(struct k_args *A)
|
|
{
|
|
struct sem_struct *S;
|
|
uint32_t Sid;
|
|
|
|
Sid = A->Args.s1.sema;
|
|
S = _k_sem_list + OBJ_INDEX(Sid);
|
|
A->Time.rcode = S->Level;
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* task_sem_count_get - read the semaphore signal count
|
|
*
|
|
* This routine reads the signal count of the specified semaphore.
|
|
*
|
|
* @param sema Semaphore to query.
|
|
*
|
|
* RETURNS: signal count
|
|
*/
|
|
|
|
int task_sem_count_get(ksem_t sema)
|
|
{
|
|
struct k_args A;
|
|
|
|
A.Comm = INQSEMA;
|
|
A.Args.s1.sema = sema;
|
|
KERNEL_ENTRY(&A);
|
|
return A.Time.rcode;
|
|
}
|