Eliminate contention between HIDAPI controller reads and writes

Rumble can often take a long time, and it is theoretically safe to simultaneously read and write hidapi devices on all platforms.

Fixes https://github.com/libsdl-org/SDL/issues/9441
This commit is contained in:
Sam Lantinga
2026-02-09 21:17:24 -08:00
parent 31404a9dcb
commit 71f4af7322
4 changed files with 11 additions and 51 deletions

View File

@@ -77,14 +77,12 @@ static int SDLCALL SDL_HIDAPI_RumbleThread(void *data)
SDL_UnlockMutex(SDL_HIDAPI_rumble_lock);
if (request) {
SDL_LockMutex(request->device->dev_lock);
if (request->device->dev) {
#ifdef DEBUG_RUMBLE
HIDAPI_DumpPacket("Rumble packet: size = %d", request->data, request->size);
#endif
SDL_hid_write(request->device->dev, request->data, request->size);
}
SDL_UnlockMutex(request->device->dev_lock);
if (request->callback) {
request->callback(request->userdata);
}

View File

@@ -2726,17 +2726,7 @@ static void HandleFullControllerState(SDL_Joystick *joystick, SDL_DriverSwitch_C
Uint64 now = SDL_GetTicks();
if (now >= (ctx->m_ulLastIMUReset + IMU_RESET_DELAY_MS)) {
SDL_HIDAPI_Device *device = ctx->device;
if (device->updating) {
SDL_UnlockMutex(device->dev_lock);
}
SetIMUEnabled(ctx, true);
if (device->updating) {
SDL_LockMutex(device->dev_lock);
}
ctx->m_ulLastIMUReset = now;
}

View File

@@ -72,7 +72,7 @@ static SDL_HIDAPI_DeviceDriver *SDL_HIDAPI_drivers[] = {
#endif
#ifdef SDL_JOYSTICK_HIDAPI_STEAMDECK
&SDL_HIDAPI_DriverSteamTriton,
#endif
#endif
#ifdef SDL_JOYSTICK_HIDAPI_SWITCH
&SDL_HIDAPI_DriverNintendoClassic,
&SDL_HIDAPI_DriverJoyCons,
@@ -439,19 +439,15 @@ static void HIDAPI_CleanupDeviceDriver(SDL_HIDAPI_Device *device)
device->driver->FreeDevice(device);
device->driver = NULL;
SDL_LockMutex(device->dev_lock);
{
if (device->dev) {
SDL_hid_close(device->dev);
device->dev = NULL;
}
if (device->context) {
SDL_free(device->context);
device->context = NULL;
}
if (device->dev) {
SDL_hid_close(device->dev);
device->dev = NULL;
}
if (device->context) {
SDL_free(device->context);
device->context = NULL;
}
SDL_UnlockMutex(device->dev_lock);
}
static void HIDAPI_SetupDeviceDriver(SDL_HIDAPI_Device *device, bool *removed) SDL_NO_THREAD_SAFETY_ANALYSIS // We unlock the joystick lock to be able to open the HID device on Android
@@ -916,7 +912,6 @@ static SDL_HIDAPI_Device *HIDAPI_AddDevice(const struct SDL_hid_device_info *inf
device->usage_page = info->usage_page;
device->usage = info->usage;
device->is_bluetooth = (info->bus_type == SDL_HID_API_BUS_BLUETOOTH);
device->dev_lock = SDL_CreateMutex();
// Need the device name before getting the driver to know whether to ignore this device
{
@@ -1013,7 +1008,6 @@ static void HIDAPI_DelDevice(SDL_HIDAPI_Device *device)
}
SDL_SetObjectValid(device, SDL_OBJECT_TYPE_HIDAPI_JOYSTICK, false);
SDL_DestroyMutex(device->dev_lock);
SDL_free(device->manufacturer_string);
SDL_free(device->product_string);
SDL_free(device->serial);
@@ -1434,12 +1428,7 @@ void HIDAPI_UpdateDevices(void)
continue;
}
if (device->driver) {
if (SDL_TryLockMutex(device->dev_lock)) {
device->updating = true;
device->driver->UpdateDevice(device);
device->updating = false;
SDL_UnlockMutex(device->dev_lock);
}
device->driver->UpdateDevice(device);
}
}
HIDAPI_FinishUpdatingDevices();
@@ -1552,11 +1541,7 @@ static bool HIDAPI_JoystickOpen(SDL_Joystick *joystick, int device_index)
hwdata->device = device;
// Process any pending reports before opening the device
SDL_LockMutex(device->dev_lock);
device->updating = true;
device->driver->UpdateDevice(device);
device->updating = false;
SDL_UnlockMutex(device->dev_lock);
// UpdateDevice() may have called HIDAPI_JoystickDisconnected() if the device went away
if (device->num_joysticks == 0) {
@@ -1682,22 +1667,13 @@ static void HIDAPI_JoystickClose(SDL_Joystick *joystick) SDL_NO_THREAD_SAFETY_AN
if (joystick->hwdata) {
SDL_HIDAPI_Device *device = joystick->hwdata->device;
int i;
// Wait up to 30 ms for pending rumble to complete
if (device->updating) {
// Unlock the device so rumble can complete
SDL_UnlockMutex(device->dev_lock);
}
for (i = 0; i < 3; ++i) {
for (int i = 0; i < 3; ++i) {
if (SDL_GetAtomicInt(&device->rumble_pending) > 0) {
SDL_Delay(10);
}
}
if (device->updating) {
// Relock the device
SDL_LockMutex(device->dev_lock);
}
device->driver->CloseJoystick(device, joystick);

View File

@@ -100,7 +100,6 @@ typedef struct SDL_HIDAPI_Device
struct SDL_HIDAPI_DeviceDriver *driver;
void *context;
SDL_Mutex *dev_lock;
SDL_hid_device *dev;
SDL_AtomicInt rumble_pending;
int num_joysticks;
@@ -109,9 +108,6 @@ typedef struct SDL_HIDAPI_Device
// Used during scanning for device changes
bool seen;
// Used to flag that the device is being updated
bool updating;
// Used to flag devices that failed open
// This can happen on Windows with Bluetooth devices that have turned off
bool broken;