/**************************************************************************** * include/nuttx/mqueue.h * * Copyright (C) 2007, 2009, 2011, 2014-2016 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. Neither the name NuttX 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 THE * COPYRIGHT OWNER OR 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. * ****************************************************************************/ #ifndef ___INCLUDE_NUTTX_MQUEUE_H #define ___INCLUDE_NUTTX_MQUEUE_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #if CONFIG_MQ_MAXMSGSIZE > 0 /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Public Type Declarations ****************************************************************************/ /* This structure defines a message queue */ struct mq_des; /* forward reference */ struct mqueue_inode_s { FAR struct inode *inode; /* Containing inode */ sq_queue_t msglist; /* Prioritized message list */ int16_t maxmsgs; /* Maximum number of messages in the queue */ int16_t nmsgs; /* Number of message in the queue */ int16_t nwaitnotfull; /* Number tasks waiting for not full */ int16_t nwaitnotempty; /* Number tasks waiting for not empty */ #if CONFIG_MQ_MAXMSGSIZE < 256 uint8_t maxmsgsize; /* Max size of message in message queue */ #else uint16_t maxmsgsize; /* Max size of message in message queue */ #endif #ifndef CONFIG_DISABLE_SIGNALS FAR struct mq_des *ntmqdes; /* Notification: Owning mqdes (NULL if none) */ pid_t ntpid; /* Notification: Receiving Task's PID */ struct sigevent ntevent; /* Notification description */ #endif }; /* This describes the message queue descriptor that is held in the * task's TCB */ struct mq_des { FAR struct mq_des *flink; /* Forward link to next message descriptor */ FAR struct mqueue_inode_s *msgq; /* Pointer to associated message queue */ int oflags; /* Flags set when message queue was opened */ }; /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Public Function Prototypes ****************************************************************************/ #ifdef __cplusplus #define EXTERN extern "C" extern "C" { #else #define EXTERN extern #endif struct mq_attr; /* Forward reference */ struct tcb_s; /* Forward reference */ struct task_group_s; /* Forward reference */ /**************************************************************************** * Name: mq_msgqfree * * Description: * This function deallocates an initialized message queue structure. * First, it deallocates all of the queued messages in the message * queue. It is assumed that this message is fully unlinked and * closed so that no thread will attempt access it while it is being * deleted. * * Inputs: * msgq - Named essage queue to be freed * * Return Value: * None * ****************************************************************************/ void mq_msgqfree(FAR struct mqueue_inode_s *msgq); /**************************************************************************** * Name: mq_msgqalloc * * Description: * This function implements a part of the POSIX message queue open logic. * It allocates and initializes a structu mqueue_inode_s structure. * * Parameters: * mode - mode_t value is ignored * attr - The mq_maxmsg attribute is used at the time that the message * queue is created to determine the maximum number of * messages that may be placed in the message queue. * * Return Value: * The allocated and initalized message queue structure or NULL in the * event of a failure. * ****************************************************************************/ FAR struct mqueue_inode_s *mq_msgqalloc(mode_t mode, FAR struct mq_attr *attr); /**************************************************************************** * Name: mq_descreate * * Description: * Create a message queue descriptor for the specified TCB * * Inputs: * TCB - task that needs the descriptor. * msgq - Named message queue containing the message * oflags - access rights for the descriptor * * Return Value: * On success, the message queue descriptor is returned. NULL is returned * on a failure to allocate. * ****************************************************************************/ mqd_t mq_descreate(FAR struct tcb_s *mtcb, FAR struct mqueue_inode_s *msgq, int oflags); /**************************************************************************** * Name: mq_close_group * * Description: * This function is used to indicate that all threads in the group are * finished with the specified message queue mqdes. The mq_close_group() * deallocates any system resources allocated by the system for use by * this task for its message queue. * * Parameters: * mqdes - Message queue descriptor. * group - Group that has the open descriptor. * * Return Value: * 0 (OK) if the message queue is closed successfully, * otherwise, -1 (ERROR). * ****************************************************************************/ int mq_close_group(mqd_t mqdes, FAR struct task_group_s *group); /**************************************************************************** * Name: mq_desclose_group * * Description: * This function performs the portion of the mq_close operation related * to freeing resource used by the message queue descriptor itself. * * Parameters: * mqdes - Message queue descriptor. * group - Group that has the open descriptor. * * Return Value: * None. * * Assumptions: * - Called only from mq_close() with the scheduler locked. * ****************************************************************************/ void mq_desclose_group(mqd_t mqdes, FAR struct task_group_s *group); #undef EXTERN #ifdef __cplusplus } #endif #endif /* CONFIG_MQ_MAXMSGSIZE > 0 */ #endif /* ___INCLUDE_NUTTX_MQUEUE_H */