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Diffstat (limited to 'utils/msg_q.h')
-rw-r--r-- | utils/msg_q.h | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/utils/msg_q.h b/utils/msg_q.h new file mode 100644 index 0000000..16df494 --- /dev/null +++ b/utils/msg_q.h @@ -0,0 +1,230 @@ +/* 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 <stdlib.h> + +/** 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_rmv + +DESCRIPTION + Remove 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_rmv(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__ */ |