Revert "Use a single libusb context"

This reverts commit c8a6dc6c23.

libusb on Windows isn't really safe to use from different threads
with a single context.

Source/Core/Core/IOS/USB/Bluetooth/BTReal.cpp

@@ -15,7 +15,6 @@
 
 #include "Common/Assert.h"
 #include "Common/ChunkFile.h"
-#include "Common/LibusbContext.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
 #include "Common/Network.h"
@@ -60,7 +59,11 @@ namespace Device
 BluetoothReal::BluetoothReal(u32 device_id, const std::string& device_name)
     : BluetoothBase(device_id, device_name)
 {
-  m_libusb_context = LibusbContext::Get();
+  const int ret = libusb_init(&m_libusb_context);
+  if (ret < 0)
+  {
+    PanicAlertT("Couldn't initialise libusb for Bluetooth passthrough: %s", libusb_error_name(ret));
+  }
   LoadLinkKeys();
 }
 
@@ -77,6 +80,7 @@ BluetoothReal::~BluetoothReal()
     libusb_unref_device(m_device);
   }
 
+  libusb_exit(m_libusb_context);
   SaveLinkKeys();
 }
 
@@ -86,7 +90,7 @@ ReturnCode BluetoothReal::Open(const OpenRequest& request)
     return IPC_EACCES;
 
   libusb_device** list;
-  const ssize_t cnt = libusb_get_device_list(m_libusb_context.get(), &list);
+  const ssize_t cnt = libusb_get_device_list(m_libusb_context, &list);
   if (cnt < 0)
   {
     ERROR_LOG(IOS_WIIMOTE, "Couldn't get device list: %s",
@@ -607,7 +611,7 @@ void BluetoothReal::TransferThread()
   Common::SetCurrentThreadName("BT USB Thread");
   while (m_thread_running.IsSet())
   {
-    libusb_handle_events_completed(m_libusb_context.get(), nullptr);
+    libusb_handle_events_completed(m_libusb_context, nullptr);
   }
 }
 

Source/Core/Core/IOS/USB/Bluetooth/BTReal.h

@@ -76,7 +76,7 @@ private:
 
   libusb_device* m_device = nullptr;
   libusb_device_handle* m_handle = nullptr;
-  std::shared_ptr<libusb_context> m_libusb_context;
+  libusb_context* m_libusb_context = nullptr;
 
   Common::Flag m_thread_running;
   std::thread m_thread;

Source/Core/Core/IOS/USB/Host.cpp

@@ -13,7 +13,6 @@
 #include "Common/Assert.h"
 #include "Common/ChunkFile.h"
 #include "Common/CommonTypes.h"
-#include "Common/LibusbContext.h"
 #include "Common/Logging/Log.h"
 #include "Common/Thread.h"
 #include "Core/ConfigManager.h"
@@ -30,6 +29,18 @@ namespace Device
 {
 USBHost::USBHost(u32 device_id, const std::string& device_name) : Device(device_id, device_name)
 {
+#ifdef __LIBUSB__
+  const int ret = libusb_init(&m_libusb_context);
+  _dbg_assert_msg_(IOS_USB, ret == 0, "Failed to init libusb for USB passthrough.");
+#endif
+}
+
+USBHost::~USBHost()
+{
+#ifdef __LIBUSB__
+  if (m_libusb_context)
+    libusb_exit(m_libusb_context);
+#endif
 }
 
 ReturnCode USBHost::Open(const OpenRequest& request)
@@ -116,11 +127,10 @@ bool USBHost::AddNewDevices(std::set<u64>& new_devices, DeviceChangeHooks& hooks
   if (SConfig::GetInstance().m_usb_passthrough_devices.empty())
     return true;
 
-  auto libusb_context = LibusbContext::Get();
-  if (libusb_context)
+  if (m_libusb_context)
   {
     libusb_device** list;
-    const ssize_t count = libusb_get_device_list(libusb_context.get(), &list);
+    const ssize_t count = libusb_get_device_list(m_libusb_context, &list);
     if (count < 0)
     {
       WARN_LOG(IOS_USB, "Failed to get device list: %s",
@@ -200,12 +210,11 @@ void USBHost::StartThreads()
   }
 
 #ifdef __LIBUSB__
-  if (!m_event_thread_running.IsSet())
+  if (!m_event_thread_running.IsSet() && m_libusb_context)
   {
     m_event_thread_running.Set();
     m_event_thread = std::thread([this] {
       Common::SetCurrentThreadName("USB Passthrough Thread");
-      std::shared_ptr<libusb_context> context;
       while (m_event_thread_running.IsSet())
       {
         if (SConfig::GetInstance().m_usb_passthrough_devices.empty())
@@ -214,15 +223,8 @@ void USBHost::StartThreads()
           continue;
         }
 
-        if (!context)
-          context = LibusbContext::Get();
-
-        // If we failed to get a libusb context, stop the thread.
-        if (!context)
-          return;
-
         static timeval tv = {0, 50000};
-        libusb_handle_events_timeout_completed(context.get(), &tv, nullptr);
+        libusb_handle_events_timeout_completed(m_libusb_context, &tv, nullptr);
       }
     });
   }

Source/Core/Core/IOS/USB/Host.h

@@ -34,7 +34,7 @@ class USBHost : public Device
 {
 public:
   USBHost(u32 device_id, const std::string& device_name);
-  virtual ~USBHost() = default;
+  virtual ~USBHost();
 
   ReturnCode Open(const OpenRequest& request) override;
 
@@ -71,6 +71,8 @@ private:
   void DispatchHooks(const DeviceChangeHooks& hooks);
 
 #ifdef __LIBUSB__
+  libusb_context* m_libusb_context = nullptr;
+
   // Event thread for libusb
   Common::Flag m_event_thread_running;
   std::thread m_event_thread;