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Diffstat (limited to 'cpukit/include/rtems/score/coremsg.h')
| -rw-r--r-- | cpukit/include/rtems/score/coremsg.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/cpukit/include/rtems/score/coremsg.h b/cpukit/include/rtems/score/coremsg.h new file mode 100644 index 0000000000..8d25529fdc --- /dev/null +++ b/cpukit/include/rtems/score/coremsg.h @@ -0,0 +1,185 @@ +/** + * @file rtems/score/coremsg.h + * + * @brief Constants and Structures Associated with the Message Queue Handler. + * + * This include file contains all the constants and structures associated + * with the Message queue Handler. + */ + +/* + * COPYRIGHT (c) 1989-2009. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef _RTEMS_SCORE_COREMSG_H +#define _RTEMS_SCORE_COREMSG_H + +#include <rtems/score/chain.h> +#include <rtems/score/isrlock.h> +#include <rtems/score/threadq.h> +#include <rtems/score/watchdog.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @defgroup ScoreMessageQueue Message Queue Handler + * + * @ingroup Score + * + * This handler encapsulates functionality which provides the foundation + * Message Queue services used in all of the APIs supported by RTEMS. + */ +/**@{*/ + +#if defined(RTEMS_POSIX_API) + /** + * This macro is defined when an API is enabled that requires that the + * Message Queue Handler include support for priority based enqueuing + * of messages. + */ + #define RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY +#endif + +#if defined(RTEMS_POSIX_API) + /** + * This macro is defined when an API is enabled that requires that the + * Message Queue Handler include support for notification of enqueuing + * a message. + */ + #define RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION +#endif + +#if defined(RTEMS_POSIX_API) + /** + * This macro is defined when an API is enabled that requires the + * Message Queue Handler include support for blocking send operations. + */ + #define RTEMS_SCORE_COREMSG_ENABLE_BLOCKING_SEND +#endif + +typedef struct CORE_message_queue_Control CORE_message_queue_Control; + +/** + * @brief Data types needed to manipulate the contents of message buffers. + * + * The following defines the data types needed to manipulate + * the contents of message buffers. + * + * @note The buffer field is normally longer than a single uint32_t + * but since messages are variable length we just make a ptr to 1. + */ +typedef struct { + /** This field is the size of this message. */ + size_t size; + /** This field contains the actual message. */ + uint32_t buffer[1]; +} CORE_message_queue_Buffer; + +/** + * @brief The organization of a message buffer. + * + * The following records define the organization of a message + * buffer. + */ +typedef struct { + /** This element allows this structure to be placed on chains. */ + Chain_Node Node; + #if defined(RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY) + /** This field is the priority of this message. */ + int priority; + #endif + /** This field points to the contents of the message. */ + CORE_message_queue_Buffer Contents; +} CORE_message_queue_Buffer_control; + +/** + * @brief The possible blocking disciplines for a message queue. + * + * This enumerated types defines the possible blocking disciplines + * for a message queue. + */ +typedef enum { + /** This value indicates that blocking tasks are in FIFO order. */ + CORE_MESSAGE_QUEUE_DISCIPLINES_FIFO, + /** This value indicates that blocking tasks are in priority order. */ + CORE_MESSAGE_QUEUE_DISCIPLINES_PRIORITY +} CORE_message_queue_Disciplines; + +#if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION) + /** + * @brief Type for a notification handler. + * + * The following defines the type for a Notification handler. A + * notification handler is invoked when the message queue makes a + * 0->1 transition on pending messages. + */ + typedef void (*CORE_message_queue_Notify_Handler)( + CORE_message_queue_Control *, + Thread_queue_Context * + ); +#endif + +/** + * @brief Control block used to manage each message queue. + * + * The following defines the control block used to manage each + * Message Queue. + */ +struct CORE_message_queue_Control { + /** This field is the Waiting Queue used to manage the set of tasks + * which are blocked waiting to receive a message from this queue. + */ + Thread_queue_Control Wait_queue; + + /** + * @brief The thread queue operations according to the blocking discipline. + */ + const Thread_queue_Operations *operations; + + /** This element is maximum number of messages which may be pending + * at any given time. + */ + uint32_t maximum_pending_messages; + /** This element is the number of messages which are currently pending. + */ + uint32_t number_of_pending_messages; + /** This is the size in bytes of the largest message which may be + * sent via this queue. + */ + size_t maximum_message_size; + /** This chain is the set of pending messages. It may be ordered by + * message priority or in FIFO order. + */ + Chain_Control Pending_messages; + /** This is the address of the memory allocated for message buffers. + * It is allocated are part of message queue initialization and freed + * as part of destroying it. + */ + CORE_message_queue_Buffer *message_buffers; + #if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION) + /** This is the routine invoked when the message queue transitions + * from zero (0) messages pending to one (1) message pending. + */ + CORE_message_queue_Notify_Handler notify_handler; + #endif + /** This chain is the set of inactive messages. A message is inactive + * when it does not contain a pending message. + */ + Chain_Control Inactive_messages; +}; + +/**@}*/ + +#ifdef __cplusplus +} +#endif + +#endif +/* end of include file */ |