From: Daniel Drake <dsd@gentoo.org>
Date: Fri, 18 Apr 2008 22:42:40 +0000 (+0100)
Subject: mutex protection for device and handle lists
X-Git-Tag: upstream/1.0.21~1100
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0efd2efa65d5513e5754d717d522b2c5c45332e2;p=platform%2Fupstream%2Flibusb.git

mutex protection for device and handle lists
---

diff --git a/libusb/core.c b/libusb/core.c
index f90ea06..3bce9a1 100644
--- a/libusb/core.c
+++ b/libusb/core.c
@@ -37,7 +37,10 @@ const struct usbi_os_backend * const usbi_backend = &linux_usbfs_backend;
 #endif
 
 static struct list_head usb_devs;
+static pthread_mutex_t usb_devs_lock = PTHREAD_MUTEX_INITIALIZER;
+
 struct list_head usbi_open_devs;
+pthread_mutex_t usbi_open_devs_lock = PTHREAD_MUTEX_INITIALIZER;
 
 /**
  * \mainpage libusb-1.0 API Reference
@@ -237,20 +240,28 @@ struct libusb_device *usbi_alloc_device(unsigned long session_id)
 
 	dev->refcnt = 1;
 	dev->session_data = session_id;
-	list_add(&dev->list, &usb_devs);
 	memset(&dev->os_priv, 0, priv_size);
+
+	pthread_mutex_lock(&usb_devs_lock);
+	list_add(&dev->list, &usb_devs);
+	pthread_mutex_unlock(&usb_devs_lock);
 	return dev;
 }
 
 struct libusb_device *usbi_get_device_by_session_id(unsigned long session_id)
 {
 	struct libusb_device *dev;
+	struct libusb_device *ret = NULL;
 
+	pthread_mutex_lock(&usb_devs_lock);
 	list_for_each_entry(dev, &usb_devs, list)
-		if (dev->session_data == session_id)
-			return dev;
+		if (dev->session_data == session_id) {
+			ret = dev;
+			break;
+		}
+	pthread_mutex_unlock(&usb_devs_lock);
 
-	return NULL;
+	return ret;
 }
 
 /** @ingroup dev
@@ -354,7 +365,10 @@ API_EXPORTED void libusb_device_unref(struct libusb_device *dev)
 		if (usbi_backend->destroy_device)
 			usbi_backend->destroy_device(dev);
 
+		pthread_mutex_lock(&usb_devs_lock);
 		list_del(&dev->list);
+		pthread_mutex_unlock(&usb_devs_lock);
+
 		if (dev->config)
 			free(dev->config);
 		free(dev);
@@ -392,7 +406,9 @@ API_EXPORTED struct libusb_device_handle *libusb_open(struct libusb_device *dev)
 		return NULL;
 	}
 
+	pthread_mutex_lock(&usbi_open_devs_lock);
 	list_add(&handle->list, &usbi_open_devs);
+	pthread_mutex_unlock(&usbi_open_devs_lock);
 	return handle;
 }
 
@@ -460,7 +476,10 @@ API_EXPORTED void libusb_close(struct libusb_device_handle *dev_handle)
 		return;
 	usbi_dbg("");
 
+	pthread_mutex_lock(&usbi_open_devs_lock);
 	list_del(&dev_handle->list);
+	pthread_mutex_unlock(&usbi_open_devs_lock);
+
 	do_close(dev_handle);
 	free(dev_handle);
 }
@@ -545,12 +564,16 @@ API_EXPORTED void libusb_exit(void)
 {
 	struct libusb_device_handle *devh;
 	usbi_dbg("");
+
+	pthread_mutex_lock(&usbi_open_devs_lock);
 	if (!list_empty(&usbi_open_devs)) {
 		usbi_dbg("naughty app left some devices open!\n");
 		list_for_each_entry(devh, &usbi_open_devs, list)
 			do_close(devh);
 		/* FIXME where do the open handles get freed? */
 	}
+	pthread_mutex_unlock(&usbi_open_devs_lock);
+
 	if (usbi_backend->exit)
 		usbi_backend->exit();
 }
diff --git a/libusb/io.c b/libusb/io.c
index 5e0e92f..18ab594 100644
--- a/libusb/io.c
+++ b/libusb/io.c
@@ -624,12 +624,14 @@ out:
 
 static int submit_transfer(struct usbi_transfer *itransfer)
 {
-	int r = usbi_backend->submit_transfer(itransfer);
+	int r;
+	
+	add_to_flying_list(itransfer);
+	r = usbi_backend->submit_transfer(itransfer);
 	if (r < 0)
-		return r;
+		list_del(&itransfer->list);
 
-	add_to_flying_list(itransfer);
-	return 0;
+	return r;
 }
 
 /** \ingroup asyncio
diff --git a/libusb/libusbi.h b/libusb/libusbi.h
index c589ef6..19b28b6 100644
--- a/libusb/libusbi.h
+++ b/libusb/libusbi.h
@@ -24,6 +24,7 @@
 #include <config.h>
 
 #include <endian.h>
+#include <pthread.h>
 #include <stddef.h>
 #include <sys/select.h>
 #include <time.h>
@@ -206,6 +207,7 @@ struct usb_descriptor_header {
 /* shared data and functions */
 
 extern struct list_head usbi_open_devs;
+extern pthread_mutex_t usbi_open_devs_lock;
 
 void usbi_io_init(void);
 
diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
index 550fa08..2504fea 100644
--- a/libusb/os/linux_usbfs.c
+++ b/libusb/os/linux_usbfs.c
@@ -23,6 +23,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -1036,8 +1037,9 @@ static int reap_for_handle(struct libusb_device_handle *handle)
 static int op_handle_events(fd_set *readfds, fd_set *writefds)
 {
 	struct libusb_device_handle *handle;
-	int r;
+	int r = 0;
 
+	pthread_mutex_lock(&usbi_open_devs_lock);
 	list_for_each_entry(handle, &usbi_open_devs, list) {
 		struct linux_device_handle_priv *hpriv = __device_handle_priv(handle);
 		if (!FD_ISSET(hpriv->fd, writefds))
@@ -1046,10 +1048,13 @@ static int op_handle_events(fd_set *readfds, fd_set *writefds)
 		if (r == -1 && errno == EAGAIN)
 			continue;
 		if (r < 0)
-			return r;
+			goto out;
 	}
 
-	return 0;
+	r = 0;
+out:
+	pthread_mutex_unlock(&usbi_open_devs_lock);
+	return r;
 }
 
 const struct usbi_os_backend linux_usbfs_backend = {