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Use separate libusb contexts to avoid thread safety issues

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Unfortunately, it appears that using libusb's synchronous transfer API
from several threads causes nasty race conditions in event handling and
can lead to deadlocks, despite the fact that libusb's synchronous API
is documented to be perfectly fine to use from several threads (only
the manual polling functionality is supposed to require special
precautions).

Since usbdk was the only real reason for using a single libusb context
and since usbdk (currently) has so many issues with Dolphin, I think
dropping support for it in order to fix other backends is acceptable.
This commit is contained in:
Léo Lam
2019-06-25 17:31:35 +02:00
parent 769ba43abf
commit cf60a9a7f7
8 changed files with 16 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
Source/Core/InputCommon/GCAdapter.cpp
View File

@ -72,6 +72,8 @@ static bool s_libusb_hotplug_enabled = false;
static libusb_hotplug_callback_handle s_hotplug_handle;
#endif
static LibusbUtils::Context s_libusb_context;
static u8 s_endpoint_in = 0;
static u8 s_endpoint_out = 0;
@ -147,7 +149,6 @@ static int HotplugCallback(libusb_context* ctx, libusb_device* dev, libusb_hotpl
static void ScanThreadFunc()
{
auto& context = LibusbUtils::GetContext();
Common::SetCurrentThreadName("GC Adapter Scanning Thread");
NOTICE_LOG(SERIALINTERFACE, "GC Adapter scanning thread started");
@ -158,7 +159,7 @@ static void ScanThreadFunc()
if (s_libusb_hotplug_enabled)
{
if (libusb_hotplug_register_callback(
context,
s_libusb_context,
(libusb_hotplug_event)(LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED |
LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT),
LIBUSB_HOTPLUG_ENUMERATE, 0x057e, 0x0337, LIBUSB_HOTPLUG_MATCH_ANY, HotplugCallback,
@ -212,7 +213,7 @@ void StartScanThread()
{
if (s_adapter_detect_thread_running.IsSet())
return;
if (!LibusbUtils::GetContext().IsValid())
if (!s_libusb_context.IsValid())
return;
s_adapter_detect_thread_running.Set(true);
s_adapter_detect_thread = std::thread(ScanThreadFunc);
@ -240,7 +241,7 @@ static void Setup()
s_controller_rumble[i] = 0;
}
LibusbUtils::GetContext().GetDeviceList([](libusb_device* device) {
s_libusb_context.GetDeviceList([](libusb_device* device) {
if (CheckDeviceAccess(device))
{
// Only connect to a single adapter in case the user has multiple connected
@ -364,8 +365,8 @@ void Shutdown()
{
StopScanThread();
#if defined(LIBUSB_API_VERSION) && LIBUSB_API_VERSION >= 0x01000102
if (LibusbUtils::GetContext().IsValid() && s_libusb_hotplug_enabled)
libusb_hotplug_deregister_callback(LibusbUtils::GetContext(), s_hotplug_handle);
if (s_libusb_context.IsValid() && s_libusb_hotplug_enabled)
libusb_hotplug_deregister_callback(s_libusb_context, s_hotplug_handle);
#endif
Reset();