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 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /**
  * @file
  *
  * @brief Internal Support for POSIX Shared Memory
  */
 
 /*
  * Copyright (c) 2016 Gedare Bloom.
  *
  * 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.
  *
  * 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 _RTEMS_POSIX_SHM_H
 #define _RTEMS_POSIX_SHM_H
 
 #include <rtems/score/objectdata.h>
 #include <rtems/score/threadq.h>
 
 #include <sys/types.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /**
  * @defgroup POSIXShmPrivate POSIX Shared Memory Private Support
  *
  * @ingroup POSIXAPI
  *
  * Internal implementation support for POSIX shared memory.
  * @{
  */
 typedef struct POSIX_Shm_Object_operations POSIX_Shm_Object_operations;
 extern const POSIX_Shm_Object_operations _POSIX_Shm_Object_operations;
 
 /**
  * @brief Encapsulation for the storage and manipulation of shm objects.
  */
 typedef struct {
   /**
    * @brief The handle is private for finding object storage.
    */
   void                               *handle;
 
   /**
    * @brief The number of bytes allocated to the object. A size of 0 with
    * a handle of NULL means no object is allocated.
    */
   size_t                              size;
 
   /**
    * @brief Implementation-specific operations on shm objects.
    */
   const POSIX_Shm_Object_operations  *ops;
 } POSIX_Shm_Object;
 
 /**
  * @brief Operations on POSIX Shared Memory Objects.
  */
 struct POSIX_Shm_Object_operations {
   /**
    * @brief Allocates a new @a shm_obj with initial @a size.
    *
    * New shared memory is initialized to zeroes.
    *
    * Returns 0 for success.
    */
   int ( *object_create ) ( POSIX_Shm_Object *shm_obj, size_t size );
 
   /**
    * @brief Changes the @a shm_obj size to @a size.
    *
    * Zeroes out the portion of the shared memory object that shrinks or grows.
    *
    * Returns 0 for success.
    */
   int ( *object_resize ) ( POSIX_Shm_Object *shm_obj, size_t size );
 
   /**
    * @brief Deletes the @a shm_obj.
    *
    * Zeroes out the memory.
    *
    * Returns 0 for success.
    */
   int ( *object_delete ) ( POSIX_Shm_Object *shm_obj );
 
   /**
    * @brief Copies up to @count bytes of the @a shm_obj data into @a buf.
    *
    * Returns the number of bytes read (copied) into @a buf.
    */
   int ( *object_read ) ( POSIX_Shm_Object *shm_obj, void *buf, size_t count );
 
   /**
    * @brief Maps a shared memory object.
    *
    * Establishes a memory mapping between the shared memory object and the
    * caller.
    *
    * Returns the mapped address of the object.
    */
   void * ( *object_mmap ) ( POSIX_Shm_Object *shm_obj, size_t len, int prot, off_t off);
 };
 
 /**
  * @brief Control for a POSIX Shared Memory Object
  */
 typedef struct {
    Objects_Control      Object;
    Thread_queue_Control Wait_queue;
 
    int                  reference_count;
 
    POSIX_Shm_Object     shm_object;
 
    uid_t                uid;
    gid_t                gid;
    mode_t               mode;
    int                  oflag;
 
    time_t               atime;
    time_t               mtime;
    time_t               ctime;
 } POSIX_Shm_Control;
 
 /**
  * @brief The POSIX Shared Memory objects information.
  */
 extern Objects_Information _POSIX_Shm_Information;
 
 /**
  * @brief Macro to define the objects information for the POSIX Shared Memory
  * objects.
  *
  * This macro should only be used by <rtems/confdefs.h>.
  *
  * @param max The configured object maximum (the OBJECTS_UNLIMITED_OBJECTS flag
  * may be set).
  */
 #define POSIX_SHM_INFORMATION_DEFINE( max ) \
   OBJECTS_INFORMATION_DEFINE( \
     _POSIX_Shm, \
     OBJECTS_POSIX_API, \
     OBJECTS_POSIX_SHMS, \
     POSIX_Shm_Control, \
     max, \
     _POSIX_PATH_MAX, \
     NULL \
   )
 
 /**
  * @brief object_create operation for shm objects stored in RTEMS Workspace.
  */
 extern int _POSIX_Shm_Object_create_from_workspace(
   POSIX_Shm_Object *shm_obj,
   size_t size
 );
 
 /**
  * @brief object_delete operation for shm objects stored in RTEMS Workspace.
  */
 extern int _POSIX_Shm_Object_delete_from_workspace( POSIX_Shm_Object *shm_obj );
 
 /**
  * @brief object_resize operation for shm objects stored in RTEMS Workspace.
  */
 extern int _POSIX_Shm_Object_resize_from_workspace(
   POSIX_Shm_Object *shm_obj,
   size_t size
 );
 
 /**
  * @brief object_read operation for shm objects stored in RTEMS Workspace.
  */
 extern int _POSIX_Shm_Object_read_from_workspace(
   POSIX_Shm_Object *shm_obj,
   void *buf,
   size_t count
 );
 
 /**
  * @brief object_mmap operation for shm objects stored in RTEMS Workspace.
  */
 extern void * _POSIX_Shm_Object_mmap_from_workspace(
   POSIX_Shm_Object *shm_obj,
   size_t len,
   int prot,
   off_t off
 );
 
 /**
  * @brief object_create operation for shm objects stored in C program heap.
  */
 extern int _POSIX_Shm_Object_create_from_heap(
   POSIX_Shm_Object *shm_obj,
   size_t size
 );
 
 /**
  * @brief object_delete operation for shm objects stored in C program heap.
  */
 extern int _POSIX_Shm_Object_delete_from_heap( POSIX_Shm_Object *shm_obj );
 
 /**
  * @brief object_resize operation for shm objects stored in C program heap.
  */
 extern int _POSIX_Shm_Object_resize_from_heap(
   POSIX_Shm_Object *shm_obj,
   size_t size
 );
 
 /**
  * @brief object_read operation for shm objects stored in C program heap.
  */
 extern int _POSIX_Shm_Object_read_from_heap(
   POSIX_Shm_Object *shm_obj,
   void *buf,
   size_t count
 );
 
 /**
  * @brief object_mmap operation for shm objects stored in C program heap.
  */
 extern void * _POSIX_Shm_Object_mmap_from_heap(
   POSIX_Shm_Object *shm_obj,
   size_t len,
   int prot,
   off_t off
 );
 
 /** @} */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif

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