/*
* Create a fake pipe.
* As libusb only uses pipes for signaling, all we need from a pipe is an
* event. To that extent, we create a single wfd and overlapped as a means
* to access that event.
*/
int usbi_pipe(int filedes[2])
{
int i;
OVERLAPPED* overlapped;
CHECK_INIT_POLLING;
overlapped = create_overlapped();
if (overlapped == NULL) {
return -1;
}
// The overlapped must have status pending for signaling to work in poll
overlapped->Internal = STATUS_PENDING;
overlapped->InternalHigh = 0;
for (i=0; i<MAX_FDS; i++) {
if (poll_fd[i].fd < 0) {
EnterCriticalSection(&_poll_fd[i].mutex);
// fd might have been allocated before we got to critical
if (poll_fd[i].fd >= 0) {
LeaveCriticalSection(&_poll_fd[i].mutex);
continue;
}
// Use index as the unique fd number
poll_fd[i].fd = i;
// Read end of the "pipe"
filedes[0] = poll_fd[i].fd;
// We can use the same handle for both ends
filedes[1] = filedes[0];
poll_fd[i].handle = DUMMY_HANDLE;
poll_fd[i].overlapped = overlapped;
// There's no polling on the write end, so we just use READ for our needs
poll_fd[i].rw = RW_READ;
_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
LeaveCriticalSection(&_poll_fd[i].mutex);
return 0;
}
}
free_overlapped(overlapped);
return -1;
}
struct winfd usbi_create_fd(HANDLE handle, int access_mode)
{
int i, fd;
struct winfd wfd = INVALID_WINFD;
OVERLAPPED* overlapped = NULL;
CHECK_INIT_POLLING;
if ((handle == 0) || (handle == INVALID_HANDLE_VALUE)) {
return INVALID_WINFD;
}
if ((access_mode != _O_RDONLY) && (access_mode != _O_WRONLY)) {
usbi_warn(NULL, "only one of _O_RDONLY or _O_WRONLY are supported.\n"
"If you want to poll for R/W simultaneously, create multiple fds from the same handle.");
return INVALID_WINFD;
}
if (access_mode == _O_RDONLY) {
wfd.rw = RW_READ;
} else {
wfd.rw = RW_WRITE;
}
fd = _open(NUL_DEVICE, _O_WRONLY);
if (fd < 0) {
return INVALID_WINFD;
}
overlapped = create_overlapped();
if(overlapped == NULL) {
_close(fd);
return INVALID_WINFD;
}
for (i=0; i<MAX_FDS; i++) {
if (poll_fd[i].fd < 0) {
EnterCriticalSection(&_poll_fd[i].mutex);
if (poll_fd[i].fd >= 0) {
LeaveCriticalSection(&_poll_fd[i].mutex);
continue;
}
wfd.fd = fd;
if (!CancelIoEx_Available) {
_poll_fd[i].thread_id = GetCurrentThreadId();
if (!DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(),
&wfd.handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
usbi_dbg("could not duplicate handle for CancelIo - using original one");
wfd.handle = handle;
_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
} else {
_poll_fd[i].original_handle = handle;
}
} else {
wfd.handle = handle;
}
wfd.overlapped = overlapped;
memcpy(&poll_fd[i], &wfd, sizeof(struct winfd));
LeaveCriticalSection(&_poll_fd[i].mutex);
return wfd;
}
}
free_overlapped(overlapped);
_close(fd);
return INVALID_WINFD;
}
/*
* Create both an fd and an OVERLAPPED from an open Windows handle, so that
* it can be used with our polling function
* The handle MUST support overlapped transfers (usually requires CreateFile
* with FILE_FLAG_OVERLAPPED)
* Return a pollable file descriptor struct, or INVALID_WINFD on error
*
* Note that the fd returned by this function is a per-transfer fd, rather
* than a per-session fd and cannot be used for anything else but our
* custom functions (the fd itself points to the NUL: device)
* if you plan to do R/W on the same handle, you MUST create 2 fds: one for
* read and one for write. Using a single R/W fd is unsupported and will
* produce unexpected results
*/
struct winfd usbi_create_fd(HANDLE handle, int access_mode)
{
int i, fd;
struct winfd wfd = INVALID_WINFD;
OVERLAPPED* overlapped = NULL;
CHECK_INIT_POLLING;
if ((handle == 0) || (handle == INVALID_HANDLE_VALUE)) {
return INVALID_WINFD;
}
if ((access_mode != _O_RDONLY) && (access_mode != _O_WRONLY)) {
usbi_warn(NULL, "only one of _O_RDONLY or _O_WRONLY are supported.\n"
"If you want to poll for R/W simultaneously, create multiple fds from the same handle.");
return INVALID_WINFD;
}
if (access_mode == _O_RDONLY) {
wfd.rw = RW_READ;
} else {
wfd.rw = RW_WRITE;
}
// Ensure that we get a non system conflicting unique fd, using
// the same fd attribution system as the pipe ends
fd = _open(NUL_DEVICE, _O_WRONLY);
if (fd < 0) {
return INVALID_WINFD;
}
overlapped = create_overlapped();
if(overlapped == NULL) {
_close(fd);
return INVALID_WINFD;
}
for (i=0; i<MAX_FDS; i++) {
if (poll_fd[i].fd < 0) {
EnterCriticalSection(&_poll_fd[i].mutex);
// fd might have been removed before we got to critical
if (poll_fd[i].fd >= 0) {
LeaveCriticalSection(&_poll_fd[i].mutex);
continue;
}
wfd.fd = fd;
// Attempt to emulate some of the CancelIoEx behaviour on platforms
// that don't have it
if (!CancelIoEx_Available) {
_poll_fd[i].thread_id = GetCurrentThreadId();
if (!DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(),
&wfd.handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
usbi_dbg("could not duplicate handle for CancelIo - using original one");
wfd.handle = handle;
// Make sure we won't close the original handle on fd deletion then
_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
} else {
_poll_fd[i].original_handle = handle;
}
} else {
wfd.handle = handle;
}
wfd.overlapped = overlapped;
memcpy(&poll_fd[i], &wfd, sizeof(struct winfd));
LeaveCriticalSection(&_poll_fd[i].mutex);
return wfd;
}
}
free_overlapped(overlapped);
_close(fd);
return INVALID_WINFD;
}
/*
* Create both an fd and an OVERLAPPED from an open Windows handle, so that
* it can be used with our polling function
* The handle MUST support overlapped transfers (usually requires CreateFile
* with FILE_FLAG_OVERLAPPED)
* Return a pollable file descriptor struct, or INVALID_WINFD on error
*
* Note that the fd returned by this function is a per-transfer fd, rather
* than a per-session fd and cannot be used for anything else but our
* custom functions (the fd itself points to the NUL: device)
* if you plan to do R/W on the same handle, you MUST create 2 fds: one for
* read and one for write. Using a single R/W fd is unsupported and will
* produce unexpected results
*/
struct winfd usbi_create_fd(HANDLE handle, int access_mode, struct usbi_transfer *itransfer, cancel_transfer *cancel_fn)
{
int i;
struct winfd wfd = INVALID_WINFD;
OVERLAPPED* overlapped = NULL;
CHECK_INIT_POLLING;
if ((handle == 0) || (handle == INVALID_HANDLE_VALUE)) {
return INVALID_WINFD;
}
wfd.itransfer = itransfer;
wfd.cancel_fn = cancel_fn;
if ((access_mode != RW_READ) && (access_mode != RW_WRITE)) {
usbi_warn(NULL, "only one of RW_READ or RW_WRITE are supported.\n"
"If you want to poll for R/W simultaneously, create multiple fds from the same handle.");
return INVALID_WINFD;
}
if (access_mode == RW_READ) {
wfd.rw = RW_READ;
} else {
wfd.rw = RW_WRITE;
}
overlapped = create_overlapped();
if(overlapped == NULL) {
return INVALID_WINFD;
}
for (i=0; i<MAX_FDS; i++) {
if (poll_fd[i].fd < 0) {
EnterCriticalSection(&_poll_fd[i].mutex);
// fd might have been removed before we got to critical
if (poll_fd[i].fd >= 0) {
LeaveCriticalSection(&_poll_fd[i].mutex);
continue;
}
// Use index as the unique fd number
wfd.fd = i;
// Attempt to emulate some of the CancelIoEx behaviour on platforms
// that don't have it
if (Use_Duplicate_Handles) {
_poll_fd[i].thread_id = GetCurrentThreadId();
if (!DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(),
&wfd.handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
usbi_dbg("could not duplicate handle for CancelIo - using original one");
wfd.handle = handle;
// Make sure we won't close the original handle on fd deletion then
_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
} else {
_poll_fd[i].original_handle = handle;
}
} else {
wfd.handle = handle;
}
wfd.overlapped = overlapped;
memcpy(&poll_fd[i], &wfd, sizeof(struct winfd));
LeaveCriticalSection(&_poll_fd[i].mutex);
return wfd;
}
}
free_overlapped(overlapped);
return INVALID_WINFD;
}
