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Diffstat (limited to 'nuttx/fs/mmap/fs_rammap.c')
| -rw-r--r-- | nuttx/fs/mmap/fs_rammap.c | 245 |
1 files changed, 0 insertions, 245 deletions
diff --git a/nuttx/fs/mmap/fs_rammap.c b/nuttx/fs/mmap/fs_rammap.c deleted file mode 100644 index f43541cc9..000000000 --- a/nuttx/fs/mmap/fs_rammap.c +++ /dev/null @@ -1,245 +0,0 @@ -/**************************************************************************** - * fs/mmap/fs_rammmap.c - * - * Copyright (C) 2011 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <gnutt@nuttx.org> - * - * 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. - * - ****************************************************************************/ - -/**************************************************************************** - * Included Files - ****************************************************************************/ - -#include <nuttx/config.h> - -#include <sys/types.h> -#include <sys/mman.h> - -#include <string.h> -#include <unistd.h> -#include <errno.h> -#include <debug.h> - -#include <nuttx/kmalloc.h> - -#include "fs_internal.h" -#include "fs_rammap.h" - -#ifdef CONFIG_FS_RAMMAP - -/**************************************************************************** - * Global Data - ****************************************************************************/ - -/* This is the list of all mapped files */ - -struct fs_allmaps_s g_rammaps; - -/**************************************************************************** - * Global Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: rammap_initialize - * - * Description: - * Verified that this capability has been initialized. - * - * Input Parameters: - * None - * - * Returned Value: - * None - * - ****************************************************************************/ - -void rammap_initialize(void) -{ - if (!g_rammaps.initialized) - { - sem_init(&g_rammaps.exclsem, 0, 1); - g_rammaps.initialized = true; - } -} - -/**************************************************************************** - * Name: rammmap - * - * Description: - * Support simulation of memory mapped files by copying files into RAM. - * - * Parameters: - * fd file descriptor of the backing file -- required. - * length The length of the mapping. For exception #1 above, this length - * ignored: The entire underlying media is always accessible. - * offset The offset into the file to map - * - * Returned Value: - * On success, rammmap() returns a pointer to the mapped area. On error, the - * value MAP_FAILED is returned, and errno is set appropriately. - * - * EBADF - * 'fd' is not a valid file descriptor. - * EINVAL - * 'length' or 'offset' are invalid - * ENOMEM - * Insufficient memory is available to map the file. - * - ****************************************************************************/ - -FAR void *rammap(int fd, size_t length, off_t offset) -{ - FAR struct fs_rammap_s *map; - FAR uint8_t *alloc; - FAR uint8_t *rdbuffer; - ssize_t nread; - off_t fpos; - int err; - int ret; - - /* There is a major design flaw that I have not yet thought of fix for: - * The goal is to have a single region of memory that represents a single - * file and can be shared by many threads. That is, given a filename a - * thread should be able to open the file, get a file descriptor, and - * call mmap() to get a memory region. Different file descriptors opened - * with the same file path should get the same memory region when mapped. - * - * The design flaw is that I don't have sufficient knowledge to know that - * these different file descriptors map to the same file. So, for the time - * being, a new memory region is created each time that rammap() is called. - * Not very useful! - */ - - /* Allocate a region of memory of the specified size */ - - alloc = (FAR uint8_t *)kmalloc(sizeof(struct fs_rammap_s) + length); - if (!alloc) - { - fdbg("Region allocation failed, length: %d\n", (int)length); - err = ENOMEM; - goto errout; - } - - /* Initialize the region */ - - map = (FAR struct fs_rammap_s *)alloc; - memset(map, 0, sizeof(struct fs_rammap_s)); - map->addr = alloc + sizeof(struct fs_rammap_s); - map->length = length; - map->offset = offset; - - /* Seek to the specified file offset */ - - fpos = lseek(fd, offset, SEEK_SET); - if (fpos == (off_t)-1) - { - /* Seek failed... errno has already been set, but EINVAL is probably - * the correct response. - */ - - fdbg("Seek to position %d failed\n", (int)offset); - err = EINVAL; - goto errout_with_region; - } - - /* Read the file data into the memory region */ - - rdbuffer = map->addr; - while (length > 0) - { - nread = read(fd, rdbuffer, length); - if (nread < 0) - { - /* Handle the special case where the read was interrupted by a - * signal. - */ - - err = get_errno(); - if (err != EINTR) - { - /* All other read errors are bad. errno is already set. - * (but maybe should be forced to EINVAL?). NOTE that if - * FS DEBUG is enabled, then the following fdbg() macro will - * destroy the errno value. - */ - - fdbg("Read failed: offset=%d errno=%d\n", (int)offset, err); -#ifdef CONFIG_DEBUG_FS - goto errout_with_region; -#else - goto errout_with_errno; -#endif - } - } - - /* Check for end of file. */ - - if (nread == 0) - { - break; - } - - /* Increment number of bytes read */ - - rdbuffer += nread; - length -= nread; - } - - /* Zero any memory beyond the amount read from the file */ - - memset(rdbuffer, 0, length); - - /* Add the buffer to the list of regions */ - - rammap_initialize(); - ret = sem_wait(&g_rammaps.exclsem); - if (ret < 0) - { - goto errout_with_errno; - } - - map->flink = g_rammaps.head; - g_rammaps.head = map; - - sem_post(&g_rammaps.exclsem); - return map->addr; - -errout_with_region: - kfree(alloc); -errout: - set_errno(err); - return MAP_FAILED; - -errout_with_errno: - kfree(alloc); - return MAP_FAILED; -} - -#endif /* CONFIG_FS_RAMMAP */ |