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Diffstat (limited to 'nuttx/lib/lib_init.c')
| -rw-r--r-- | nuttx/lib/lib_init.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/nuttx/lib/lib_init.c b/nuttx/lib/lib_init.c new file mode 100644 index 0000000000..216f7b780a --- /dev/null +++ b/nuttx/lib/lib_init.c @@ -0,0 +1,203 @@ +/************************************************************ + * lib_init.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 Gregory Nutt 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 <stdio.h> +#include <string.h> +#include <errno.h> +#include <nuttx/kmalloc.h> +#include <nuttx/fs.h> +#include <nuttx/os_external.h> +#include "lib_internal.h" + +/************************************************************ + * Definitions + ************************************************************/ + +/************************************************************ + * Private Variables + ************************************************************/ + +/************************************************************ + * Private Functions + ************************************************************/ + +static void _lib_semtake(struct streamlist *list) +{ + /* Take the semaphore (perhaps waiting) */ + + while (sem_wait(&list->sl_sem) != 0) + { + /* The only case that an error should occr here is if + * the wait was awakened by a signal. + */ + + ASSERT(*get_errno_ptr() == EINTR); + } +} + +static inline void _lib_semgive(struct streamlist *list) +{ + sem_post(&list->sl_sem); +} + +/************************************************************ + * Public Functions + ************************************************************/ + +/************************************************************ + * lib_initialize + ************************************************************/ + +/* General library initialization hook */ + +void weak_const_function lib_initialize(void) +{ +} + +#if CONFIG_NFILE_STREAMS > 0 +/* The following function is called when a new TCB is allocated. It + * creates the streamlist instance that is stored in the TCB. + */ + +struct streamlist *lib_alloclist(void) +{ + struct streamlist *list; + list = (struct streamlist*)kzmalloc(sizeof(struct streamlist)); + if (list) + { + int i; + + /* Start with a reference count of one */ + + list->sl_crefs = 1; + + /* Initialize the list access mutex */ + + (void)sem_init(&list->sl_sem, 0, 1); + + /* Initialize each FILE structure */ + + for (i = 0; i < CONFIG_NFILE_STREAMS; i++) + { + /* Clear the IOB */ + + memset(&list->sl_streams[i], 0, sizeof(FILE)); + + /* Indicate not opened */ + + list->sl_streams[i].fs_filedes = -1; + + /* Initialize the stream semaphore to one to support one-at- + * a-time access to private data sets. + */ + + lib_sem_initialize(&list->sl_streams[i]); + } + } + return list; + +} + +/* This function is called when a TCB is closed (such as with + * pthread_create(). It increases the reference count on the stream + * list. + */ + +void lib_addreflist(struct streamlist *list) +{ + if (list) + { + /* Increment the reference count on the list */ + + _lib_semtake(list); + list->sl_crefs++; + _lib_semgive(list); + } +} + +/* this function is called when a TCB is destroyed. Note that is + * does not close the file by release this inode. This happens + * separately when the file descriptor list is freed. + */ + +void lib_releaselist(struct streamlist *list) +{ + int crefs; + if (list) + { + /* Decrement the reference count */ + + _lib_semtake(list); + crefs = --list->sl_crefs; + _lib_semgive(list); + + /* If the count decrements to zero, then there is no reference + * to the structure and it should be deallocated. + */ + + if (crefs <= 0) + { + int i; + + /* Destroy the semaphore and release the filelist */ + + (void)sem_destroy(&list->sl_sem); + sched_free(list); + + /* Initialize each FILE structure */ + + for (i = 0; i < CONFIG_NFILE_STREAMS; i++) + { + /* Destroy the semaphore that protects the IO buffer */ + + (void)sem_destroy(&list->sl_streams[i].fs_sem); + + /* Release the IO buffer */ + if (&list->sl_streams[i].fs_bufstart) + { + free(list->sl_streams[i].fs_bufstart); + } + } + } + } +} + +#endif /* CONFIG_NFILE_STREAMS */ + + |