Device.cxx

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#include "Devtab.hxx"
 
#include <fcntl.h>
#include <unistd.h>
 
#ifdef TARGET_LPC11Cxx
#define NUM_OPEN_FILES     4
#else
#define NUM_OPEN_FILES     20 //12
#endif
 
Device *Device::first = NULL;
 
Device::Device(const char *name)
    : FileIO(name)
{
    mutex.lock();
    next = first;
    first = this;
    prev = NULL;
    if (next)
    {
        next->prev = this;
    }
    mutex.unlock();
}
 
Device::~Device()
{
    mutex.lock();
    if (first == this)
    {
        first = next;
    }
    else
    {
        prev->next = next;
    }
    if (next)
    {
        next->prev = prev;
    }
    mutex.unlock();
}
 
int Device::open(struct _reent *reent, const char *path, int flags, int mode)
{
    mutex.lock();
    int fd = fd_alloc();
    mutex.unlock();
    if (fd < 0)
    {
        errno = EMFILE;
        return -1;
    }
    files[fd].flags = flags;
    for (Device *dev = first; dev != NULL; dev = dev->next)
    {
        if (dev->name)
        {
            if (!strcmp(dev->name, path))
            {
                files[fd].dev = dev;
                files[fd].device = true;
                int result = files[fd].dev->open(&files[fd], path, flags, mode);
                if (result < 0)
                {
                    fd_free(fd);
                    errno = -result;
                    return -1;
                }
                return fd;
            }
        }
    }
    // No device found.
    fd_free(fd);
    errno = ENODEV;
    return -1;
}
 
int Device::close(struct _reent *reent, int fd)
{
    File* f = file_lookup(fd);
    if (!f) 
    {
        /* errno should already be set appropriately */
        return -1;
    }
    if (fd >=0 && fd <= 2)
    {
        // stdin, stdout, and stderr never get closed
        return 0;
    }
    files[fd].inshdn = true;
    int result = f->dev->close(f);
    if (result < 0)
    {
        files[fd].inshdn = false;
        errno = -result;
        return -1;
    }
    fd_free(fd);
    return 0;
}
 
int Device::stat(struct _reent *reent, const char *path, struct stat *stat)
{
    for (Device *dev = first; dev != NULL; dev = dev->next)
    {
        if (dev->name)
        {
            if (!strcmp(dev->name, path))
            {
                memset(stat, 0, sizeof(*stat));
                stat->st_mode = dev->get_mode();
                return 0;
            }
        }
    }
 
    errno = ENOENT;
    return -1;
}