Import libusb 1.0.9-rc3 into third_party

third_party/libusb/libusb/os/threads_windows.c

Index: third_party/libusb/libusb/os/threads_windows.c
diff --git a/third_party/libusb/libusb/os/threads_windows.c b/third_party/libusb/libusb/os/threads_windows.c
new file mode 100644
index 0000000000000000000000000000000000000000..8a2992035f967c6c05c7fda5a3fdf08c6383c857
--- /dev/null
+++ b/third_party/libusb/libusb/os/threads_windows.c
@@ -0,0 +1,208 @@
+/*
+ * libusb synchronization on Microsoft Windows
+ *
+ * Copyright (C) 2010 Michael Plante <michael.plante@gmail.com>
+ *
+ * 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
+ */
+
+#include <config.h>
+#include <objbase.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "libusbi.h"
+
+
+int usbi_mutex_init(usbi_mutex_t *mutex,
+					const usbi_mutexattr_t *attr) {
+	if(! mutex) return ((errno=EINVAL));
+	*mutex = CreateMutex(NULL, FALSE, NULL);
+	if(!*mutex) return ((errno=ENOMEM));
+	return 0;
+}
+int usbi_mutex_destroy(usbi_mutex_t *mutex) {
+	// It is not clear if CloseHandle failure is due to failure to unlock.
+	//   If so, this should be errno=EBUSY.
+	if(!mutex || !CloseHandle(*mutex)) return ((errno=EINVAL));
+	*mutex = NULL;
+	return 0;
+}
+int usbi_mutex_trylock(usbi_mutex_t *mutex) {
+	DWORD result;
+	if(!mutex) return ((errno=EINVAL));
+	result = WaitForSingleObject(*mutex, 0);
+	if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+		return 0; // acquired (ToDo: check that abandoned is ok)
+	if(result == WAIT_TIMEOUT)
+		return ((errno=EBUSY));
+	return ((errno=EINVAL)); // don't know how this would happen
+							 //   so don't know proper errno
+}
+int usbi_mutex_lock(usbi_mutex_t *mutex) {
+	DWORD result;
+	if(!mutex) return ((errno=EINVAL));
+	result = WaitForSingleObject(*mutex, INFINITE);
+	if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+		return 0; // acquired (ToDo: check that abandoned is ok)
+	return ((errno=EINVAL)); // don't know how this would happen
+							 //   so don't know proper errno
+}
+int usbi_mutex_unlock(usbi_mutex_t *mutex) {
+	if(!mutex)                return ((errno=EINVAL));
+	if(!ReleaseMutex(*mutex)) return ((errno=EPERM ));
+	return 0;
+}
+
+int usbi_mutex_static_lock(usbi_mutex_static_t *mutex) {
+	if(!mutex)               return ((errno=EINVAL));
+	while (InterlockedExchange((LONG *)mutex, 1) == 1) {
+		SleepEx(0, TRUE);
+	}
+	return 0;
+}
+int usbi_mutex_static_unlock(usbi_mutex_static_t *mutex) {
+	if(!mutex)               return ((errno=EINVAL));
+	*mutex = 0;
+	return 0;
+}
+
+
+
+int usbi_cond_init(usbi_cond_t *cond,
+				   const usbi_condattr_t *attr) {
+	if(!cond)           return ((errno=EINVAL));
+	list_init(&cond->waiters    );
+	list_init(&cond->not_waiting);
+	return 0;
+}
+int usbi_cond_destroy(usbi_cond_t *cond) {
+	// This assumes no one is using this anymore.  The check MAY NOT BE safe.
+	struct usbi_cond_perthread *pos, *prev_pos = NULL;
+	if(!cond) return ((errno=EINVAL));
+	if(!list_empty(&cond->waiters)) return ((errno=EBUSY )); // (!see above!)
+	list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+		free(prev_pos);
+		list_del(&pos->list);
+		prev_pos = pos;
+	}
+	free(prev_pos);
+	prev_pos = pos = NULL;
+
+	return 0;
+}
+
+int usbi_cond_broadcast(usbi_cond_t *cond) {
+	// Assumes mutex is locked; this is not in keeping with POSIX spec, but
+	//   libusb does this anyway, so we simplify by not adding more sync
+	//   primitives to the CV definition!
+	int fail = 0;
+	struct usbi_cond_perthread *pos;
+	if(!cond)                      return ((errno=EINVAL));
+	list_for_each_entry(pos, &cond->waiters, list, struct usbi_cond_perthread) {
+		if(!SetEvent(pos->event))
+			fail = 1;
+	}
+	// The wait function will remove its respective item from the list.
+	return fail ? ((errno=EINVAL)) : 0;
+}
+int usbi_cond_signal(usbi_cond_t *cond) {
+	// Assumes mutex is locked; this is not in keeping with POSIX spec, but
+	//   libusb does this anyway, so we simplify by not adding more sync
+	//   primitives to the CV definition!
+	struct usbi_cond_perthread *pos;
+	if(!cond)                      return ((errno=EINVAL));
+	if(list_empty(&cond->waiters)) return 0; // no one to wakeup.
+	pos = list_entry(&cond->waiters.next, struct usbi_cond_perthread, list);
+	// The wait function will remove its respective item from the list.
+	return SetEvent(pos->event) ? 0 : ((errno=EINVAL));
+}
+static int __inline usbi_cond_intwait(usbi_cond_t *cond,
+									  usbi_mutex_t *mutex,
+									  DWORD timeout_ms) {
+	struct usbi_cond_perthread *pos;
+	int found = 0, r;
+	DWORD r2,tid = GetCurrentThreadId();
+	if(!cond || !mutex) return ((errno=EINVAL));
+	list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+		if(tid == pos->tid) {
+			found = 1;
+			break;
+		}
+	}
+	if(!found) {
+		pos      = malloc(sizeof(struct usbi_cond_perthread));
+		if(!pos) return ((errno=ENOMEM)); // This errno is not POSIX-allowed.
+		pos->tid = tid;
+		pos->event = CreateEvent(NULL, FALSE, FALSE, NULL); // auto-reset.
+		if(!pos->event) {
+			free(pos);
+			return      ((errno=ENOMEM));
+		}
+		list_add(&pos->list, &cond->not_waiting);
+	}
+
+	list_del(&pos->list); // remove from not_waiting list.
+	list_add(&pos->list, &cond->waiters);
+
+	r  = usbi_mutex_unlock(mutex);
+	if(r) return r;
+	r2 = WaitForSingleObject(pos->event, timeout_ms);
+	r  = usbi_mutex_lock(mutex);
+	if(r) return r;
+
+	list_del(&pos->list);
+	list_add(&pos->list, &cond->not_waiting);
+
+	if(r2 == WAIT_TIMEOUT) return ((errno=ETIMEDOUT));
+
+	return 0;
+}
+// N.B.: usbi_cond_*wait() can also return ENOMEM, even though pthread_cond_*wait cannot!
+int usbi_cond_wait(usbi_cond_t *cond, usbi_mutex_t *mutex) {
+	return usbi_cond_intwait(cond, mutex, INFINITE);
+}
+int usbi_cond_timedwait(usbi_cond_t *cond,
+						usbi_mutex_t *mutex,
+						const struct timespec *abstime) {
+	FILETIME filetime;
+	ULARGE_INTEGER rtime;
+	struct timeval targ_time, cur_time, delta_time;
+	struct timespec cur_time_ns;
+	DWORD millis;
+	extern const uint64_t epoch_time;
+
+	GetSystemTimeAsFileTime(&filetime);
+	rtime.LowPart   = filetime.dwLowDateTime;
+	rtime.HighPart  = filetime.dwHighDateTime;
+	rtime.QuadPart -= epoch_time;
+	cur_time_ns.tv_sec = (long)(rtime.QuadPart / 10000000);
+	cur_time_ns.tv_nsec = (long)((rtime.QuadPart % 10000000)*100);
+	TIMESPEC_TO_TIMEVAL(&cur_time, &cur_time_ns);
+
+	TIMESPEC_TO_TIMEVAL(&targ_time, abstime);
+	timersub(&targ_time, &cur_time, &delta_time);
+	if(delta_time.tv_sec < 0) // abstime already passed?
+		millis = 0;
+	else {
+		millis  = delta_time.tv_usec/1000;
+		millis += delta_time.tv_sec *1000;
+		if (delta_time.tv_usec % 1000) // round up to next millisecond
+			millis++;
+	}
+
+	return usbi_cond_intwait(cond, mutex, millis);
+}
+