/* Copyright (c) 2011, The Linux Foundation. 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 The Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT * 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 __MSG_Q_H__ #define __MSG_Q_H__ #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ #include /** Linked List Return Codes */ typedef enum { eMSG_Q_SUCCESS = 0, /**< Request was successful. */ eMSG_Q_FAILURE_GENERAL = -1, /**< Failed because of a general failure. */ eMSG_Q_INVALID_PARAMETER = -2, /**< Failed because the request contained invalid parameters. */ eMSG_Q_INVALID_HANDLE = -3, /**< Failed because an invalid handle was specified. */ eMSG_Q_UNAVAILABLE_RESOURCE = -4, /**< Failed because an there were not enough resources. */ eMSG_Q_INSUFFICIENT_BUFFER = -5, /**< Failed because an the supplied buffer was too small. */ }msq_q_err_type; /*=========================================================================== FUNCTION msg_q_init DESCRIPTION Initializes internal structures for message queue. msg_q_data: pointer to an opaque Q handle to be returned; NULL if fails DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_init(void** msg_q_data); /*=========================================================================== FUNCTION msg_q_init2 DESCRIPTION Initializes internal structures for message queue. DEPENDENCIES N/A RETURN VALUE opaque handle to the Q created; NULL if create fails SIDE EFFECTS N/A ===========================================================================*/ const void* msg_q_init2(); /*=========================================================================== FUNCTION msg_q_destroy DESCRIPTION Releases internal structures for message queue. msg_q_data: State of message queue to be released. DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_destroy(void** msg_q_data); /*=========================================================================== FUNCTION msg_q_snd DESCRIPTION Sends data to the message queue. The passed in data pointer is not modified or freed. Passed in msg_obj is expected to live throughout the use of the msg_q (i.e. data is not allocated internally) msg_q_data: Message Queue to add the element to. msgp: Pointer to data to add into message queue. dealloc: Function used to deallocate memory for this element. Pass NULL if you do not want data deallocated during a flush operation DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_snd(void* msg_q_data, void* msg_obj, void (*dealloc)(void*)); /*=========================================================================== FUNCTION msg_q_rcv DESCRIPTION Retrieves data from the message queue. msg_obj is the oldest message received and pointer is simply removed from message queue. msg_q_data: Message Queue to copy data from into msgp. msg_obj: Pointer to space to copy msg_q contents to. DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_rcv(void* msg_q_data, void** msg_obj); /*=========================================================================== FUNCTION msg_q_flush DESCRIPTION Function removes all elements from the message queue. msg_q_data: Message Queue to remove elements from. DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_flush(void* msg_q_data); /*=========================================================================== FUNCTION msg_q_unblock DESCRIPTION This function will stop use of the message queue. All waiters will wake up and likely receive nothing from the queue resulting in a negative return value. The message queue can no longer be used until it is destroyed and initialized again after calling this function. msg_q_data: Message queue to unblock. DEPENDENCIES N/A RETURN VALUE Look at error codes above. SIDE EFFECTS N/A ===========================================================================*/ msq_q_err_type msg_q_unblock(void* msg_q_data); #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* __MSG_Q_H__ */