source: trunk/kernel/syscalls/sys_close.c

/*
 * sys_close.c  kernel function implementing the <close> syscall
 * 
 * Author       Alain Greiner (2016,2017,2018,2019,2020)
 *
 * Copyright (c) UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <kernel_config.h>
#include <hal_kernel_types.h>
#include <hal_special.h>
#include <vfs.h>
#include <process.h>
#include <thread.h>
#include <ksocket.h>
#include <printk.h>

#include <syscalls.h>

///////////////////////////////
int sys_close ( uint32_t fdid )
{
    error_t            error;
    xptr_t             file_xp;
    cxy_t              file_cxy;
    vfs_file_t       * file_ptr;
    vfs_file_type_t   file_type;

        thread_t  * this    = CURRENT_THREAD;
        process_t * process = this->process;

#if DEBUG_SYS_CLOSE || DEBUG_SYSCALLS_ERROR || CONFIG_INSTRUMENTATION_SYSCALLS
uint64_t     tm_start = hal_get_cycles();
#endif

#if DEBUG_SYS_CLOSE
if( DEBUG_SYS_CLOSE < (uint32_t)tm_start )
printk("\n[%s] thread[%x,%x] enter / fdid %d / cycle %d\n",
__FUNCTION__, process->pid, this->trdid, fdid, (uint32_t)tm_start );
#endif
 
    // check fdid argument
        if( fdid >= CONFIG_PROCESS_FILE_MAX_NR )
        {

#if DEBUG_SYSCALLS_ERROR
if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
printk("\n[ERROR] in %s : thread[%x,%x] / illegal file descriptor index = %d\n",
__FUNCTION__ , process->pid , this->trdid , fdid );
#endif
                this->errno = EBADFD;
                return -1;
        }

    // get extended pointer on remote file descriptor
    file_xp = process_fd_get_xptr_from_local( process , fdid );

    if( file_xp == XPTR_NULL )
    {

#if DEBUG_SYSCALLS_ERROR
if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
printk("\n[ERROR] in %s : thread[%x,%x] / undefined file descriptor %d\n",
__FUNCTION__ , process->pid , this->trdid , fdid );
#endif
        this->errno = EBADFD;
                return -1;
    }

    // get file type
    file_cxy  = GET_CXY( file_xp );
    file_ptr  = GET_PTR( file_xp );
    file_type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );

    if( file_type == FILE_TYPE_DIR ) 
        {

#if DEBUG_SYSCALLS_ERROR
if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
printk("\n[ERROR] in %s : thread[%x,%x] / file descriptor %d is a directory\n",
__FUNCTION__ , process->pid , this->trdid , fdid );
#endif
                this->errno = EBADFD;
                return -1;
        }
    else if( file_type == FILE_TYPE_SOCK )
    {
        // call the relevant socket function
        error = socket_close( file_xp , fdid );
    }
    else if( (file_type == FILE_TYPE_REG) ||
             (file_type == FILE_TYPE_FIFO) )
    {
        // call the relevant VFS function
            error = vfs_close( file_xp , fdid );
    }
    else 
    {
           
#if DEBUG_SYSCALLS_ERROR
if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
printk("\n[WARNING] in %s : thread[%x,%x] / file_type (%s) unsupported / fdid %d\n",
__FUNCTION__ , process->pid , this->trdid , vfs_inode_type_str(file_type) , fdid );
#endif
        error = 0;        
    }

        if( error )
        {

#if DEBUG_SYSCALLS_ERROR
if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
printk("\n[ERROR] in %s : thread[%x,%x] cannot close file descriptor %d\n",
__FUNCTION__ , process->pid , this->trdid , fdid );
#endif
                this->errno = error;
                return -1;
        }

        hal_fence();

#if (DEBUG_SYS_CLOSE || CONFIG_INSTRUMENTATION_SYSCALLS)
uint64_t     tm_end = hal_get_cycles();
#endif

#if DEBUG_SYS_CLOSE
tm_end = hal_get_cycles();
if( DEBUG_SYS_CLOSE < tm_start )
printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
#endif
 
#if CONFIG_INSTRUMENTATION_SYSCALLS
hal_atomic_add( &syscalls_cumul_cost[SYS_CLOSE] , tm_end - tm_start );
hal_atomic_add( &syscalls_occurences[SYS_CLOSE] , 1 );
#endif

        return 0;
}