diff options
Diffstat (limited to 'cpukit/libcsupport/src/libio.c')
| -rw-r--r-- | cpukit/libcsupport/src/libio.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/libio.c b/cpukit/libcsupport/src/libio.c new file mode 100644 index 0000000000..d080d01596 --- /dev/null +++ b/cpukit/libcsupport/src/libio.c @@ -0,0 +1,278 @@ +/* + * This file contains the support infrastructure used to manage the + * table of integer style file descriptors used by the low level + * POSIX system calls like open(), read, fstat(), etc. + * + * COPYRIGHT (c) 1989-1999. + * 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.com/license/LICENSE. + * + * $Id$ + */ + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <rtems.h> +#include <rtems/libio_.h> +#include <rtems/assoc.h> + +/* define this to alias O_NDELAY to O_NONBLOCK, i.e., + * O_NDELAY is accepted on input but fcntl(F_GETFL) returns + * O_NONBLOCK. This is because rtems has no distinction + * between the two (but some systems have). + * Note that accepting this alias creates a problem: + * an application trying to clear the non-blocking flag + * using a + * + * fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NDELAY); + * + * does (silently) ignore the operation. + */ +#undef ACCEPT_O_NDELAY_ALIAS + +/* + * rtems_libio_fcntl_flags + * + * Convert UNIX fnctl(2) flags to ones that RTEMS drivers understand + */ + +const rtems_assoc_t access_modes_assoc[] = { + { "READ", LIBIO_FLAGS_READ, O_RDONLY }, + { "WRITE", LIBIO_FLAGS_WRITE, O_WRONLY }, + { "READ/WRITE", LIBIO_FLAGS_READ_WRITE, O_RDWR }, + { 0, 0, 0 }, +}; + +const rtems_assoc_t status_flags_assoc[] = { +#ifdef ACCEPT_O_NDELAY_ALIAS + { "NO DELAY", LIBIO_FLAGS_NO_DELAY, O_NDELAY }, +#endif + { "NONBLOCK", LIBIO_FLAGS_NO_DELAY, O_NONBLOCK }, + { "APPEND", LIBIO_FLAGS_APPEND, O_APPEND }, + { "CREATE", LIBIO_FLAGS_CREATE, O_CREAT }, + { 0, 0, 0 }, +}; + +uint32_t rtems_libio_fcntl_flags( + uint32_t fcntl_flags +) +{ + uint32_t flags = 0; + uint32_t access_modes; + + /* + * Access mode is a small integer + */ + + access_modes = fcntl_flags & O_ACCMODE; + fcntl_flags &= ~O_ACCMODE; + flags = rtems_assoc_local_by_remote( access_modes_assoc, access_modes ); + + /* + * Everything else is single bits + */ + + flags |= + rtems_assoc_local_by_remote_bitfield(status_flags_assoc, fcntl_flags); + return flags; +} + +/* + * rtems_libio_to_fcntl_flags + * + * Convert RTEMS internal flags to UNIX fnctl(2) flags + */ + +uint32_t rtems_libio_to_fcntl_flags( + uint32_t flags +) +{ + uint32_t fcntl_flags = 0; + + if ( (flags & LIBIO_FLAGS_READ_WRITE) == LIBIO_FLAGS_READ_WRITE ) { + fcntl_flags |= O_RDWR; + } else if ( (flags & LIBIO_FLAGS_READ) == LIBIO_FLAGS_READ) { + fcntl_flags |= O_RDONLY; + } else if ( (flags & LIBIO_FLAGS_WRITE) == LIBIO_FLAGS_WRITE) { + fcntl_flags |= O_WRONLY; + } + + if ( (flags & LIBIO_FLAGS_NO_DELAY) == LIBIO_FLAGS_NO_DELAY ) { + fcntl_flags |= O_NONBLOCK; + } + + if ( (flags & LIBIO_FLAGS_APPEND) == LIBIO_FLAGS_APPEND ) { + fcntl_flags |= O_APPEND; + } + + if ( (flags & LIBIO_FLAGS_CREATE) == LIBIO_FLAGS_CREATE ) { + fcntl_flags |= O_CREAT; + } + + return fcntl_flags; +} + +/* + * rtems_libio_allocate + * + * This routine searches the IOP Table for an unused entry. If it + * finds one, it returns it. Otherwise, it returns NULL. + */ + +rtems_libio_t *rtems_libio_allocate( void ) +{ + rtems_libio_t *iop, *next; + rtems_status_code rc; + rtems_id sema; + + rtems_libio_lock(); + + if (rtems_libio_iop_freelist) { + rc = rtems_semaphore_create( + RTEMS_LIBIO_IOP_SEM(rtems_libio_iop_freelist - rtems_libio_iops), + 1, + RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY, + 0, + &sema + ); + if (rc != RTEMS_SUCCESSFUL) + goto failed; + iop = rtems_libio_iop_freelist; + next = iop->data1; + (void) memset( iop, 0, sizeof(rtems_libio_t) ); + iop->flags = LIBIO_FLAGS_OPEN; + iop->sem = sema; + rtems_libio_iop_freelist = next; + goto done; + } + +failed: + iop = 0; + +done: + rtems_libio_unlock(); + return iop; +} + +/* + * rtems_libio_free + * + * This routine frees the resources associated with an IOP (file descriptor) + * and clears the slot in the IOP Table. + */ + +void rtems_libio_free( + rtems_libio_t *iop +) +{ + rtems_libio_lock(); + + if (iop->sem) + rtems_semaphore_delete(iop->sem); + + iop->flags &= ~LIBIO_FLAGS_OPEN; + iop->data1 = rtems_libio_iop_freelist; + rtems_libio_iop_freelist = iop; + + rtems_libio_unlock(); +} + +/* + * rtems_libio_is_open_files_in_fs + * + * This routine scans the entire file descriptor table to determine if the + * are any active file descriptors that refer to the at least one node in the + * file system that we are trying to dismount. + * + * If there is at least one node in the file system referenced by the mount + * table entry a 1 is returned, otherwise a 0 is returned. + */ + +int rtems_libio_is_open_files_in_fs( + rtems_filesystem_mount_table_entry_t * fs_mt_entry +) +{ + rtems_libio_t *iop; + int result = 0; + uint32_t i; + + rtems_libio_lock(); + + /* + * Look for any active file descriptor entry. + */ + + for (iop=rtems_libio_iops,i=0; i < rtems_libio_number_iops; iop++, i++){ + + if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) { + + /* + * Check if this node is under the file system that we + * are trying to dismount. + */ + + if ( iop->pathinfo.mt_entry == fs_mt_entry ) { + result = 1; + break; + } + } + } + + rtems_libio_unlock(); + + return result; +} + +/* + * rtems_libio_is_file_open + * + * This routine scans the entire file descriptor table to determine if the + * given file refers to an active file descriptor. + * + * If the given file is open a 1 is returned, otherwise a 0 is returned. + */ + +int rtems_libio_is_file_open( + void *node_access +) +{ + rtems_libio_t *iop; + int result=0; + uint32_t i; + + rtems_libio_lock(); + + /* + * Look for any active file descriptor entry. + */ + + for (iop=rtems_libio_iops,i=0; i < rtems_libio_number_iops; iop++, i++){ + if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) { + + /* + * Check if this node is under the file system that we + * are trying to dismount. + */ + + if ( iop->pathinfo.node_access == node_access ) { + result = 1; + break; + } + } + } + + rtems_libio_unlock(); + + return result; +} |