Adding use_system_libusb option for third_party/libusb

third_party/libusb/libusb/os/poll_windows.c

Index: third_party/libusb/libusb/os/poll_windows.c
diff --git a/third_party/libusb/libusb/os/poll_windows.c b/third_party/libusb/libusb/os/poll_windows.c
deleted file mode 100644
index c997c819c7f28bd4608adb82c4225d9fc31c8602..0000000000000000000000000000000000000000
--- a/third_party/libusb/libusb/os/poll_windows.c
+++ /dev/null
@@ -1,839 +0,0 @@
-/*
- * poll_windows: poll compatibility wrapper for Windows
- * Copyright (C) 2009-2010 Pete Batard <pbatard@gmail.com>
- * With contributions from Michael Plante, Orin Eman et al.
- * Parts of poll implementation from libusb-win32, by Stephan Meyer et al.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- */
-
-/*
- * poll() and pipe() Windows compatibility layer for libusb 1.0
- *
- * The way this layer works is by using OVERLAPPED with async I/O transfers, as
- * OVERLAPPED have an associated event which is flagged for I/O completion.
- *
- * For USB pollable async I/O, you would typically:
- * - obtain a Windows HANDLE to a file or device that has been opened in
- *   OVERLAPPED mode
- * - call usbi_create_fd with this handle to obtain a custom fd.
- *   Note that if you need simultaneous R/W access, you need to call create_fd
- *   twice, once in _O_RDONLY and once in _O_WRONLY mode to obtain 2 separate
- *   pollable fds
- * - leave the core functions call the poll routine and flag POLLIN/POLLOUT
- *
- * The pipe pollable synchronous I/O works using the overlapped event associated
- * with a fake pipe. The read/write functions are only meant to be used in that
- * context.
- */
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <io.h>
-
-#include <libusbi.h>
-
-// Uncomment to debug the polling layer
-//#define DEBUG_POLL_WINDOWS
-#if defined(DEBUG_POLL_WINDOWS)
-#define poll_dbg usbi_dbg
-#else
-// MSVC6 cannot use a variadic argument and non MSVC
-// compilers produce warnings if parenthesis are ommitted.
-#if defined(_MSC_VER)
-#define poll_dbg
-#else
-#define poll_dbg(...)
-#endif
-#endif
-
-#if defined(_PREFAST_)
-#pragma warning(disable:28719)
-#endif
-
-#if defined(__CYGWIN__)
-// cygwin produces a warning unless these prototypes are defined
-extern int _open(char* name, int flags);
-extern int _close(int fd);
-extern int _snprintf(char *buffer, size_t count, const char *format, ...);
-#define NUL_DEVICE "/dev/null"
-#else
-#define NUL_DEVICE "NUL"
-#endif
-
-#define CHECK_INIT_POLLING do {if(!is_polling_set) init_polling();} while(0)
-
-// public fd data
-const struct winfd INVALID_WINFD = {-1, INVALID_HANDLE_VALUE, NULL, RW_NONE};
-struct winfd poll_fd[MAX_FDS];
-// internal fd data
-struct {
-	CRITICAL_SECTION mutex; // lock for fds
-	// Additional variables for XP CancelIoEx partial emulation
-	HANDLE original_handle;
-	DWORD thread_id;
-} _poll_fd[MAX_FDS];
-
-// globals
-BOOLEAN is_polling_set = FALSE;
-#if defined(DYNAMIC_FDS)
-HANDLE fd_update = INVALID_HANDLE_VALUE;	// event to notify poll of fd update
-HANDLE new_fd[MAX_FDS];		// overlapped event handles for fds created since last poll
-unsigned nb_new_fds = 0;	// nb new fds created since last poll
-usbi_mutex_t new_fd_mutex;	// mutex required for the above
-#endif
-LONG pipe_number = 0;
-static volatile LONG compat_spinlock = 0;
-
-// CancelIoEx, available on Vista and later only, provides the ability to cancel
-// a single transfer (OVERLAPPED) when used. As it may not be part of any of the
-// platform headers, we hook into the Kernel32 system DLL directly to seek it.
-static BOOL (__stdcall *pCancelIoEx)(HANDLE, LPOVERLAPPED) = NULL;
-#define CancelIoEx_Available (pCancelIoEx != NULL)
-static __inline BOOL cancel_io(int _index)
-{
-	if ((_index < 0) || (_index >= MAX_FDS)) {
-		return FALSE;
-	}
-
-	if ( (poll_fd[_index].fd < 0) || (poll_fd[_index].handle == INVALID_HANDLE_VALUE)
-	  || (poll_fd[_index].handle == 0) || (poll_fd[_index].overlapped == NULL) ) {
-		return TRUE;
-	}
-	if (CancelIoEx_Available) {
-		return (*pCancelIoEx)(poll_fd[_index].handle, poll_fd[_index].overlapped);
-	}
-	if (_poll_fd[_index].thread_id == GetCurrentThreadId()) {
-		return CancelIo(poll_fd[_index].handle);
-	}
-	usbi_warn(NULL, "Unable to cancel I/O that was started from another thread");
-	return FALSE;
-}
-
-// Init
-void init_polling(void)
-{
-	int i;
-
-	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
-		SleepEx(0, TRUE);
-	}
-	if (!is_polling_set) {
-		pCancelIoEx = (BOOL (__stdcall *)(HANDLE,LPOVERLAPPED))
-			GetProcAddress(GetModuleHandleA("KERNEL32"), "CancelIoEx");
-		usbi_dbg("Will use CancelIo%s for I/O cancellation",
-			CancelIoEx_Available?"Ex":"");
-		for (i=0; i<MAX_FDS; i++) {
-			poll_fd[i] = INVALID_WINFD;
-			_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
-			_poll_fd[i].thread_id = 0;
-			InitializeCriticalSection(&_poll_fd[i].mutex);
-		}
-#if defined(DYNAMIC_FDS)
-		// We need to create an update event so that poll is warned when there
-		// are new/deleted fds during a timeout wait operation
-		fd_update = CreateEvent(NULL, TRUE, FALSE, NULL);
-		if (fd_update == NULL) {
-			usbi_err(NULL, "unable to create update event");
-		}
-		usbi_mutex_init(&new_fd_mutex, NULL);
-		nb_new_fds = 0;
-#endif
-		is_polling_set = TRUE;
-	}
-	compat_spinlock = 0;
-}
-
-// Internal function to retrieve the table index (and lock the fd mutex)
-int _fd_to_index_and_lock(int fd)
-{
-	int i;
-
-	if (fd <= 0)
-		return -1;
-
-	for (i=0; i<MAX_FDS; i++) {
-		if (poll_fd[i].fd == fd) {
-			EnterCriticalSection(&_poll_fd[i].mutex);
-			// fd might have changed before we got to critical
-			if (poll_fd[i].fd != fd) {
-				LeaveCriticalSection(&_poll_fd[i].mutex);
-				continue;
-			}
-			return i;
-		}
-	}
-	return -1;
-}
-
-OVERLAPPED *create_overlapped(void)
-{
-	OVERLAPPED *overlapped = calloc(1, sizeof(OVERLAPPED));
-	if (overlapped == NULL) {
-		return NULL;
-	}
-	overlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-	if(overlapped->hEvent == NULL) {
-		free (overlapped);
-		return NULL;
-	}
-	return overlapped;
-}
-
-void free_overlapped(OVERLAPPED *overlapped)
-{
-	if (overlapped == NULL)
-		return;
-
-	if ( (overlapped->hEvent != 0)
-	  && (overlapped->hEvent != INVALID_HANDLE_VALUE) ) {
-		CloseHandle(overlapped->hEvent);
-	}
-	free(overlapped);
-}
-
-void reset_overlapped(OVERLAPPED *overlapped)
-{
-	HANDLE event_handle;
-	if (overlapped == NULL)
-		return;
-
-	event_handle = overlapped->hEvent;
-	if (event_handle != NULL) {
-		ResetEvent(event_handle);
-	}
-	memset(overlapped, 0, sizeof(OVERLAPPED));
-	overlapped->hEvent = event_handle;
-}
-
-void exit_polling(void)
-{
-	int i;
-
-	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
-		SleepEx(0, TRUE);
-	}
-	if (is_polling_set) {
-		is_polling_set = FALSE;
-
-		for (i=0; i<MAX_FDS; i++) {
-			// Cancel any async I/O (handle can be invalid)
-			cancel_io(i);
-			// If anything was pending on that I/O, it should be
-			// terminating, and we should be able to access the fd
-			// mutex lock before too long
-			EnterCriticalSection(&_poll_fd[i].mutex);
-			if ( (poll_fd[i].fd > 0) && (poll_fd[i].handle != INVALID_HANDLE_VALUE) && (poll_fd[i].handle != 0)
-			  && (GetFileType(poll_fd[i].handle) == FILE_TYPE_UNKNOWN) ) {
-				_close(poll_fd[i].fd);
-			}
-			free_overlapped(poll_fd[i].overlapped);
-			if (!CancelIoEx_Available) {
-				// Close duplicate handle
-				if (_poll_fd[i].original_handle != INVALID_HANDLE_VALUE) {
-					CloseHandle(poll_fd[i].handle);
-				}
-			}
-			poll_fd[i] = INVALID_WINFD;
-#if defined(DYNAMIC_FDS)
-			usbi_mutex_destroy(&new_fd_mutex);
-			CloseHandle(fd_update);
-			fd_update = INVALID_HANDLE_VALUE;
-#endif
-			LeaveCriticalSection(&_poll_fd[i].mutex);
-			DeleteCriticalSection(&_poll_fd[i].mutex);
-		}
-	}
-	compat_spinlock = 0;
-}
-
-/*
- * 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 = calloc(1, sizeof(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;
-
-	// Read end of the "pipe"
-	filedes[0] = _open(NUL_DEVICE, _O_WRONLY);
-	if (filedes[0] < 0) {
-		usbi_err(NULL, "could not create pipe: errno %d", errno);
-		goto out1;
-	}
-	// We can use the same handle for both ends
-	filedes[1] = filedes[0];
-	poll_dbg("pipe filedes = %d", filedes[0]);
-
-	// Note: manual reset must be true (second param) as the reset occurs in read
-	overlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-	if(!overlapped->hEvent) {
-		goto out2;
-	}
-
-	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;
-			}
-
-			poll_fd[i].fd = 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;
-		}
-	}
-
-	CloseHandle(overlapped->hEvent);
-out2:
-	_close(filedes[0]);
-out1:
-	free(overlapped);
-	return -1;
-}
-
-/*
- * 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);
-#if defined(DYNAMIC_FDS)
-			usbi_mutex_lock(&new_fd_mutex);
-			new_fd[nb_new_fds++] = overlapped->hEvent;
-			usbi_mutex_unlock(&new_fd_mutex);
-			// Notify poll that fds have been updated
-			SetEvent(fd_update);
-#endif
-			return wfd;
-		}
-	}
-	free_overlapped(overlapped);
-	_close(fd);
-	return INVALID_WINFD;
-}
-
-void _free_index(int _index)
-{
-	// Cancel any async IO (Don't care about the validity of our handles for this)
-	cancel_io(_index);
-	// close fake handle for devices
-	if ( (poll_fd[_index].handle != INVALID_HANDLE_VALUE) && (poll_fd[_index].handle != 0)
-	  && (GetFileType(poll_fd[_index].handle) == FILE_TYPE_UNKNOWN) ) {
-		_close(poll_fd[_index].fd);
-	}
-	// close the duplicate handle (if we have an actual duplicate)
-	if (!CancelIoEx_Available) {
-		if (_poll_fd[_index].original_handle != INVALID_HANDLE_VALUE) {
-			CloseHandle(poll_fd[_index].handle);
-		}
-		_poll_fd[_index].original_handle = INVALID_HANDLE_VALUE;
-		_poll_fd[_index].thread_id = 0;
-	}
-	free_overlapped(poll_fd[_index].overlapped);
-	poll_fd[_index] = INVALID_WINFD;
-}
-
-/*
- * Release a pollable file descriptor.
- *
- * Note that the associated Windows handle is not closed by this call
- */
-void usbi_free_fd(int fd)
-{
-	int _index;
-
-	CHECK_INIT_POLLING;
-
-	_index = _fd_to_index_and_lock(fd);
-	if (_index < 0) {
-		return;
-	}
-	_free_index(_index);
-	LeaveCriticalSection(&_poll_fd[_index].mutex);
-}
-
-/*
- * The functions below perform various conversions between fd, handle and OVERLAPPED
- */
-struct winfd fd_to_winfd(int fd)
-{
-	int i;
-	struct winfd wfd;
-
-	CHECK_INIT_POLLING;
-
-	if (fd <= 0)
-		return INVALID_WINFD;
-
-	for (i=0; i<MAX_FDS; i++) {
-		if (poll_fd[i].fd == fd) {
-			EnterCriticalSection(&_poll_fd[i].mutex);
-			// fd might have been deleted before we got to critical
-			if (poll_fd[i].fd != fd) {
-				LeaveCriticalSection(&_poll_fd[i].mutex);
-				continue;
-			}
-			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
-			LeaveCriticalSection(&_poll_fd[i].mutex);
-			return wfd;
-		}
-	}
-	return INVALID_WINFD;
-}
-
-struct winfd handle_to_winfd(HANDLE handle)
-{
-	int i;
-	struct winfd wfd;
-
-	CHECK_INIT_POLLING;
-
-	if ((handle == 0) || (handle == INVALID_HANDLE_VALUE))
-		return INVALID_WINFD;
-
-	for (i=0; i<MAX_FDS; i++) {
-		if (poll_fd[i].handle == handle) {
-			EnterCriticalSection(&_poll_fd[i].mutex);
-			// fd might have been deleted before we got to critical
-			if (poll_fd[i].handle != handle) {
-				LeaveCriticalSection(&_poll_fd[i].mutex);
-				continue;
-			}
-			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
-			LeaveCriticalSection(&_poll_fd[i].mutex);
-			return wfd;
-		}
-	}
-	return INVALID_WINFD;
-}
-
-struct winfd overlapped_to_winfd(OVERLAPPED* overlapped)
-{
-	int i;
-	struct winfd wfd;
-
-	CHECK_INIT_POLLING;
-
-	if (overlapped == NULL)
-		return INVALID_WINFD;
-
-	for (i=0; i<MAX_FDS; i++) {
-		if (poll_fd[i].overlapped == overlapped) {
-			EnterCriticalSection(&_poll_fd[i].mutex);
-			// fd might have been deleted before we got to critical
-			if (poll_fd[i].overlapped != overlapped) {
-				LeaveCriticalSection(&_poll_fd[i].mutex);
-				continue;
-			}
-			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
-			LeaveCriticalSection(&_poll_fd[i].mutex);
-			return wfd;
-		}
-	}
-	return INVALID_WINFD;
-}
-
-/*
- * POSIX poll equivalent, using Windows OVERLAPPED
- * Currently, this function only accepts one of POLLIN or POLLOUT per fd
- * (but you can create multiple fds from the same handle for read and write)
- */
-int usbi_poll(struct pollfd *fds, unsigned int nfds, int timeout)
-{
-	unsigned i;
-	int _index, object_index, triggered;
-	HANDLE *handles_to_wait_on;
-	int *handle_to_index;
-	DWORD nb_handles_to_wait_on = 0;
-	DWORD ret;
-
-#if defined(DYNAMIC_FDS)
-	DWORD nb_extra_handles = 0;
-	unsigned j;
-
-	// To address the possibility of missing new fds between the time the new
-	// pollable fd set is assembled, and the ResetEvent() call below, an
-	// additional new_fd[] HANDLE table is used for any new fd that was created
-	// since the last call to poll (see below)
-	ResetEvent(fd_update);
-
-	// At this stage, any new fd creation will be detected through the fd_update
-	// event notification, and any previous creation that we may have missed
-	// will be picked up through the existing new_fd[] table.
-#endif
-
-	CHECK_INIT_POLLING;
-
-	triggered = 0;
-	handles_to_wait_on = malloc((nfds+1)*sizeof(HANDLE));	// +1 for fd_update
-	handle_to_index = malloc(nfds*sizeof(int));
-	if ((handles_to_wait_on == NULL) || (handle_to_index == NULL)) {
-		errno = ENOMEM;
-		triggered = -1;
-		goto poll_exit;
-	}
-
-	for (i = 0; i < nfds; ++i) {
-		fds[i].revents = 0;
-
-		// Only one of POLLIN or POLLOUT can be selected with this version of poll (not both)
-		if ((fds[i].events & ~POLLIN) && (!(fds[i].events & POLLOUT))) {
-			fds[i].revents |= POLLERR;
-			errno = EACCES;
-			usbi_warn(NULL, "unsupported set of events");
-			triggered = -1;
-			goto poll_exit;
-		}
-
-		_index = _fd_to_index_and_lock(fds[i].fd);
-		poll_dbg("fd[%d]=%d: (overlapped=%p) got events %04X", i, poll_fd[_index].fd, poll_fd[_index].overlapped, fds[i].events);
-
-		if ( (_index < 0) || (poll_fd[_index].handle == INVALID_HANDLE_VALUE)
-		  || (poll_fd[_index].handle == 0) || (poll_fd[_index].overlapped == NULL)) {
-			fds[i].revents |= POLLNVAL | POLLERR;
-			errno = EBADF;
-			if (_index >= 0) {
-				LeaveCriticalSection(&_poll_fd[_index].mutex);
-			}
-			usbi_warn(NULL, "invalid fd");
-			triggered = -1;
-			goto poll_exit;
-		}
-
-		// IN or OUT must match our fd direction
-		if ((fds[i].events & POLLIN) && (poll_fd[_index].rw != RW_READ)) {
-			fds[i].revents |= POLLNVAL | POLLERR;
-			errno = EBADF;
-			usbi_warn(NULL, "attempted POLLIN on fd without READ access");
-			LeaveCriticalSection(&_poll_fd[_index].mutex);
-			triggered = -1;
-			goto poll_exit;
-		}
-
-		if ((fds[i].events & POLLOUT) && (poll_fd[_index].rw != RW_WRITE)) {
-			fds[i].revents |= POLLNVAL | POLLERR;
-			errno = EBADF;
-			usbi_warn(NULL, "attempted POLLOUT on fd without WRITE access");
-			LeaveCriticalSection(&_poll_fd[_index].mutex);
-			triggered = -1;
-			goto poll_exit;
-		}
-
-		// The following macro only works if overlapped I/O was reported pending
-		if ( (HasOverlappedIoCompleted(poll_fd[_index].overlapped))
-		  || (HasOverlappedIoCompletedSync(poll_fd[_index].overlapped)) ) {
-			poll_dbg("  completed");
-			// checks above should ensure this works:
-			fds[i].revents = fds[i].events;
-			triggered++;
-		} else {
-			handles_to_wait_on[nb_handles_to_wait_on] = poll_fd[_index].overlapped->hEvent;
-			handle_to_index[nb_handles_to_wait_on] = i;
-#if defined(DYNAMIC_FDS)
-			// If this fd from the poll set is also part of the new_fd event handle table, remove it
-			usbi_mutex_lock(&new_fd_mutex);
-			for (j=0; j<nb_new_fds; j++) {
-				if (handles_to_wait_on[nb_handles_to_wait_on] == new_fd[j]) {
-					new_fd[j] = INVALID_HANDLE_VALUE;
-					break;
-				}
-			}
-			usbi_mutex_unlock(&new_fd_mutex);
-#endif
-			nb_handles_to_wait_on++;
-		}
-		LeaveCriticalSection(&_poll_fd[_index].mutex);
-	}
-#if defined(DYNAMIC_FDS)
-	// At this stage, new_fd[] should only contain events from fds that
-	// have been added since the last call to poll, but are not (yet) part
-	// of the pollable fd set. Typically, these would be from fds that have
-	// been created between the construction of the fd set and the calling
-	// of poll.
-	// Event if we won't be able to return usable poll data on these events,
-	// make sure we monitor them to return an EINTR code
-	usbi_mutex_lock(&new_fd_mutex); // We could probably do without
-	for (i=0; i<nb_new_fds; i++) {
-		if (new_fd[i] != INVALID_HANDLE_VALUE) {
-			handles_to_wait_on[nb_handles_to_wait_on++] = new_fd[i];
-			nb_extra_handles++;
-		}
-	}
-	usbi_mutex_unlock(&new_fd_mutex);
-	poll_dbg("dynamic_fds: added %d extra handles", nb_extra_handles);
-#endif
-
-	// If nothing was triggered, wait on all fds that require it
-	if ((timeout != 0) && (triggered == 0) && (nb_handles_to_wait_on != 0)) {
-#if defined(DYNAMIC_FDS)
-		// Register for fd update notifications
-		handles_to_wait_on[nb_handles_to_wait_on++] = fd_update;
-		nb_extra_handles++;
-#endif
-		if (timeout < 0) {
-			poll_dbg("starting infinite wait for %d handles...", (int)nb_handles_to_wait_on);
-		} else {
-			poll_dbg("starting %d ms wait for %d handles...", timeout, (int)nb_handles_to_wait_on);
-		}
-		ret = WaitForMultipleObjects(nb_handles_to_wait_on, handles_to_wait_on,
-			FALSE, (timeout<0)?INFINITE:(DWORD)timeout);
-		object_index = ret-WAIT_OBJECT_0;
-		if ((object_index >= 0) && ((DWORD)object_index < nb_handles_to_wait_on)) {
-#if defined(DYNAMIC_FDS)
-			if ((DWORD)object_index >= (nb_handles_to_wait_on-nb_extra_handles)) {
-				// Detected fd update => flag a poll interruption
-				if ((DWORD)object_index == (nb_handles_to_wait_on-1))
-					poll_dbg("  dynamic_fds: fd_update event");
-				else
-					poll_dbg("  dynamic_fds: new fd I/O event");
-				errno = EINTR;
-				triggered = -1;
-				goto poll_exit;
-			}
-#endif
-			poll_dbg("  completed after wait");
-			i = handle_to_index[object_index];
-			_index = _fd_to_index_and_lock(fds[i].fd);
-			fds[i].revents = fds[i].events;
-			triggered++;
-			if (_index >= 0) {
-				LeaveCriticalSection(&_poll_fd[_index].mutex);
-			}
-		} else if (ret == WAIT_TIMEOUT) {
-			poll_dbg("  timed out");
-			triggered = 0;	// 0 = timeout
-		} else {
-			errno = EIO;
-			triggered = -1;	// error
-		}
-	}
-
-poll_exit:
-	if (handles_to_wait_on != NULL) {
-		free(handles_to_wait_on);
-	}
-	if (handle_to_index != NULL) {
-		free(handle_to_index);
-	}
-#if defined(DYNAMIC_FDS)
-	usbi_mutex_lock(&new_fd_mutex);
-	nb_new_fds = 0;
-	usbi_mutex_unlock(&new_fd_mutex);
-#endif
-	return triggered;
-}
-
-/*
- * close a fake pipe fd
- */
-int usbi_close(int fd)
-{
-	int _index;
-	int r = -1;
-
-	CHECK_INIT_POLLING;
-
-	_index = _fd_to_index_and_lock(fd);
-
-	if (_index < 0) {
-		errno = EBADF;
-	} else {
-		if (poll_fd[_index].overlapped != NULL) {
-			// Must be a different event for each end of the pipe
-			CloseHandle(poll_fd[_index].overlapped->hEvent);
-			free(poll_fd[_index].overlapped);
-		}
-		r = _close(poll_fd[_index].fd);
-		if (r != 0) {
-			errno = EIO;
-		}
-		poll_fd[_index] = INVALID_WINFD;
-		LeaveCriticalSection(&_poll_fd[_index].mutex);
-	}
-	return r;
-}
-
-/*
- * synchronous write for fake "pipe" signaling
- */
-ssize_t usbi_write(int fd, const void *buf, size_t count)
-{
-	int _index;
-
-	CHECK_INIT_POLLING;
-
-	if (count != sizeof(unsigned char)) {
-		usbi_err(NULL, "this function should only used for signaling");
-		return -1;
-	}
-
-	_index = _fd_to_index_and_lock(fd);
-
-	if ( (_index < 0) || (poll_fd[_index].overlapped == NULL) ) {
-		errno = EBADF;
-		if (_index >= 0) {
-			LeaveCriticalSection(&_poll_fd[_index].mutex);
-		}
-		return -1;
-	}
-
-	poll_dbg("set pipe event (fd = %d, thread = %08X)", _index, GetCurrentThreadId());
-	SetEvent(poll_fd[_index].overlapped->hEvent);
-	poll_fd[_index].overlapped->Internal = STATUS_WAIT_0;
-	// If two threads write on the pipe at the same time, we need to
-	// process two separate reads => use the overlapped as a counter
-	poll_fd[_index].overlapped->InternalHigh++;
-
-	LeaveCriticalSection(&_poll_fd[_index].mutex);
-	return sizeof(unsigned char);
-}
-
-/*
- * synchronous read for fake "pipe" signaling
- */
-ssize_t usbi_read(int fd, void *buf, size_t count)
-{
-	int _index;
-	ssize_t r = -1;
-
-	CHECK_INIT_POLLING;
-
-	if (count != sizeof(unsigned char)) {
-		usbi_err(NULL, "this function should only used for signaling");
-		return -1;
-	}
-
-	_index = _fd_to_index_and_lock(fd);
-
-	if (_index < 0) {
-		errno = EBADF;
-		return -1;
-	}
-
-	if (WaitForSingleObject(poll_fd[_index].overlapped->hEvent, INFINITE) != WAIT_OBJECT_0) {
-		usbi_warn(NULL, "waiting for event failed: %d", (int)GetLastError());
-		errno = EIO;
-		goto out;
-	}
-
-	poll_dbg("clr pipe event (fd = %d, thread = %08X)", _index, GetCurrentThreadId());
-	poll_fd[_index].overlapped->InternalHigh--;
-	// Don't reset unless we don't have any more events to process
-	if (poll_fd[_index].overlapped->InternalHigh <= 0) {
-		ResetEvent(poll_fd[_index].overlapped->hEvent);
-		poll_fd[_index].overlapped->Internal = STATUS_PENDING;
-	}
-
-	r = sizeof(unsigned char);
-
-out:
-	LeaveCriticalSection(&_poll_fd[_index].mutex);
-	return r;
-}