file_hlock.c

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/* low-level lock and unlock functions */

#include "../fb.h"
#include <fcntl.h>

static int do_lock(FILE *f, int lock, fb_off_t inipos, fb_off_t size)
{
        struct flock lck;
        int fd;

        fd = fileno( f );

        if( lock ) {
                if( fcntl( fd, F_GETFL ) & O_RDONLY )
                        lck.l_type = F_RDLCK;
                else
                        lck.l_type = F_WRLCK;
        } else {
                lck.l_type = F_UNLCK;
        }

        lck.l_whence = SEEK_SET;
        lck.l_start = inipos;
        lck.l_len = size;

        return fb_ErrorSetNum( fcntl( fd, F_SETLKW, &lck ) ? FB_RTERROR_FILEIO : FB_RTERROR_OK );
}

int fb_hFileLock( FILE *f, fb_off_t inipos, fb_off_t size )
{
        return do_lock(f, TRUE, inipos, size);
}

int fb_hFileUnlock( FILE *f, fb_off_t inipos, fb_off_t size )
{
        return do_lock(f, FALSE, inipos, size);
}