Linux: Dynamically load libudev.

third_party/libusb/src/libusb/os/linux_udev.c

Index: third_party/libusb/src/libusb/os/linux_udev.c
diff --git a/third_party/libusb/src/libusb/os/linux_udev.c b/third_party/libusb/src/libusb/os/linux_udev.c
deleted file mode 100644
index 99ac943410557de1a5cdd54082932db972040c2c..0000000000000000000000000000000000000000
--- a/third_party/libusb/src/libusb/os/linux_udev.c
+++ /dev/null
@@ -1,306 +0,0 @@
-/* -*- Mode: C; c-basic-offset:8 ; indent-tabs-mode:t -*- */
-/*
- * Linux usbfs backend for libusb
- * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
- * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
- * Copyright (c) 2012-2013 Nathan Hjelm <hjelmn@mac.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 <assert.h>
-#include <ctype.h>
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <poll.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/ioctl.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/utsname.h>
-#include <sys/socket.h>
-#include <unistd.h>
-#include <libudev.h>
-
-#include "libusb.h"
-#include "libusbi.h"
-#include "linux_usbfs.h"
-
-/* udev context */
-static struct udev *udev_ctx = NULL;
-static int udev_monitor_fd = -1;
-static int udev_control_pipe[2] = {-1, -1};
-static struct udev_monitor *udev_monitor = NULL;
-static pthread_t linux_event_thread;
-
-static void udev_hotplug_event(struct udev_device* udev_dev);
-static void *linux_udev_event_thread_main(void *arg);
-
-int linux_udev_start_event_monitor(void)
-{
-	int r;
-
-	assert(udev_ctx == NULL);
-	udev_ctx = udev_new();
-	if (!udev_ctx) {
-		usbi_err(NULL, "could not create udev context");
-		return LIBUSB_ERROR_OTHER;
-	}
-
-	udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
-	if (!udev_monitor) {
-		usbi_err(NULL, "could not initialize udev monitor");
-		goto err_free_ctx;
-	}
-
-	r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", 0);
-	if (r) {
-		usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
-		goto err_free_monitor;
-	}
-
-	if (udev_monitor_enable_receiving(udev_monitor)) {
-		usbi_err(NULL, "failed to enable the udev monitor");
-		goto err_free_monitor;
-	}
-
-	udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
-
-	/* Some older versions of udev are not non-blocking by default,
-	 * so make sure this is set */
-	r = fcntl(udev_monitor_fd, F_GETFL);
-	if (r == -1) {
-		usbi_err(NULL, "getting udev monitor fd flags (%d)", errno);
-		goto err_free_monitor;
-	}
-	r = fcntl(udev_monitor_fd, F_SETFL, r | O_NONBLOCK);
-	if (r) {
-		usbi_err(NULL, "setting udev monitor fd flags (%d)", errno);
-		goto err_free_monitor;
-	}
-
-	r = usbi_pipe(udev_control_pipe);
-	if (r) {
-		usbi_err(NULL, "could not create udev control pipe");
-		goto err_free_monitor;
-	}
-
-	r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
-	if (r) {
-		usbi_err(NULL, "creating hotplug event thread (%d)", r);
-		goto err_close_pipe;
-	}
-
-	return LIBUSB_SUCCESS;
-
-err_close_pipe:
-	close(udev_control_pipe[0]);
-	close(udev_control_pipe[1]);
-err_free_monitor:
-	udev_monitor_unref(udev_monitor);
-	udev_monitor = NULL;
-	udev_monitor_fd = -1;
-err_free_ctx:
-	udev_unref(udev_ctx);
-	udev_ctx = NULL;
-	return LIBUSB_ERROR_OTHER;
-}
-
-int linux_udev_stop_event_monitor(void)
-{
-	char dummy = 1;
-	int r;
-
-	assert(udev_ctx != NULL);
-	assert(udev_monitor != NULL);
-	assert(udev_monitor_fd != -1);
-
-	/* Write some dummy data to the control pipe and
-	 * wait for the thread to exit */
-	r = usbi_write(udev_control_pipe[1], &dummy, sizeof(dummy));
-	if (r <= 0) {
-		usbi_warn(NULL, "udev control pipe signal failed");
-	}
-	pthread_join(linux_event_thread, NULL);
-
-	/* Release the udev monitor */
-	udev_monitor_unref(udev_monitor);
-	udev_monitor = NULL;
-	udev_monitor_fd = -1;
-
-	/* Clean up the udev context */
-	udev_unref(udev_ctx);
-	udev_ctx = NULL;
-
-	/* close and reset control pipe */
-	close(udev_control_pipe[0]);
-	close(udev_control_pipe[1]);
-	udev_control_pipe[0] = -1;
-	udev_control_pipe[1] = -1;
-
-	return LIBUSB_SUCCESS;
-}
-
-static void *linux_udev_event_thread_main(void *arg)
-{
-	char dummy;
-	int r;
-	struct udev_device* udev_dev;
-	struct pollfd fds[] = {
-		{.fd = udev_control_pipe[0],
-		 .events = POLLIN},
-		{.fd = udev_monitor_fd,
-		 .events = POLLIN},
-	};
-
-	usbi_dbg("udev event thread entering.");
-
-	while (poll(fds, 2, -1) >= 0) {
-		if (fds[0].revents & POLLIN) {
-			/* activity on control pipe, read the byte and exit */
-			r = usbi_read(udev_control_pipe[0], &dummy, sizeof(dummy));
-			if (r <= 0) {
-				usbi_warn(NULL, "udev control pipe read failed");
-			}
-			break;
-		}
-		if (fds[1].revents & POLLIN) {
-			usbi_mutex_static_lock(&linux_hotplug_lock);
-			udev_dev = udev_monitor_receive_device(udev_monitor);
-			if (udev_dev)
-				udev_hotplug_event(udev_dev);
-			usbi_mutex_static_unlock(&linux_hotplug_lock);
-		}
-	}
-
-	usbi_dbg("udev event thread exiting");
-
-	return NULL;
-}
-
-static int udev_device_info(struct libusb_context *ctx, int detached,
-			    struct udev_device *udev_dev, uint8_t *busnum,
-			    uint8_t *devaddr, const char **sys_name) {
-	const char *dev_node;
-
-	dev_node = udev_device_get_devnode(udev_dev);
-	if (!dev_node) {
-		return LIBUSB_ERROR_OTHER;
-	}
-
-	*sys_name = udev_device_get_sysname(udev_dev);
-	if (!*sys_name) {
-		return LIBUSB_ERROR_OTHER;
-	}
-
-	return linux_get_device_address(ctx, detached, busnum, devaddr,
-					dev_node, *sys_name);
-}
-
-static void udev_hotplug_event(struct udev_device* udev_dev)
-{
-	const char* udev_action;
-	const char* sys_name = NULL;
-	uint8_t busnum = 0, devaddr = 0;
-	int detached;
-	int r;
-
-	do {
-		udev_action = udev_device_get_action(udev_dev);
-		if (!udev_action) {
-			break;
-		}
-
-		detached = !strncmp(udev_action, "remove", 6);
-
-		r = udev_device_info(NULL, detached, udev_dev, &busnum, &devaddr, &sys_name);
-		if (LIBUSB_SUCCESS != r) {
-			break;
-		}
-
-		usbi_dbg("udev hotplug event. action: %s.", udev_action);
-
-		if (strncmp(udev_action, "add", 3) == 0) {
-			linux_hotplug_enumerate(busnum, devaddr, sys_name);
-		} else if (detached) {
-			linux_device_disconnected(busnum, devaddr, sys_name);
-		} else {
-			usbi_err(NULL, "ignoring udev action %s", udev_action);
-		}
-	} while (0);
-
-	udev_device_unref(udev_dev);
-}
-
-int linux_udev_scan_devices(struct libusb_context *ctx)
-{
-	struct udev_enumerate *enumerator;
-	struct udev_list_entry *devices, *entry;
-	struct udev_device *udev_dev;
-	const char *sys_name;
-	int r;
-
-	assert(udev_ctx != NULL);
-
-	enumerator = udev_enumerate_new(udev_ctx);
-	if (NULL == enumerator) {
-		usbi_err(ctx, "error creating udev enumerator");
-		return LIBUSB_ERROR_OTHER;
-	}
-
-	udev_enumerate_add_match_subsystem(enumerator, "usb");
-	udev_enumerate_scan_devices(enumerator);
-	devices = udev_enumerate_get_list_entry(enumerator);
-
-	udev_list_entry_foreach(entry, devices) {
-		const char *path = udev_list_entry_get_name(entry);
-		uint8_t busnum = 0, devaddr = 0;
-
-		udev_dev = udev_device_new_from_syspath(udev_ctx, path);
-
-		r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
-		if (r) {
-			udev_device_unref(udev_dev);
-			continue;
-		}
-
-		linux_enumerate_device(ctx, busnum, devaddr, sys_name);
-		udev_device_unref(udev_dev);
-	}
-
-	udev_enumerate_unref(enumerator);
-
-	return LIBUSB_SUCCESS;
-}
-
-void linux_udev_hotplug_poll(void)
-{
-	struct udev_device* udev_dev;
-
-	usbi_mutex_static_lock(&linux_hotplug_lock);
-	do {
-		udev_dev = udev_monitor_receive_device(udev_monitor);
-		if (udev_dev) {
-			usbi_dbg("Handling hotplug event from hotplug_poll");
-			udev_hotplug_event(udev_dev);
-		}
-	} while (udev_dev);
-	usbi_mutex_static_unlock(&linux_hotplug_lock);
-}