hidapi/libusb: allow building on Windows, using the SDL C runtime

Signed-off-by: Sam Lantinga <slouken@libsdl.org>

src/hidapi/SDL_hidapi_libusb.h

@@ -19,6 +19,28 @@
   3. This notice may not be removed or altered from any source distribution.
 */
 
+/* Define standard library functions in terms of SDL */
+#define HIDAPI_USING_SDL_RUNTIME
+#define free    SDL_free
+#define iconv_t         SDL_iconv_t
+#define ICONV_CONST
+#define iconv(a,b,c,d,e) SDL_iconv(a, (const char **)b, c, d, e)
+#define iconv_open      SDL_iconv_open
+#define iconv_close     SDL_iconv_close
+#define malloc          SDL_malloc
+#define realloc         SDL_realloc
+#define setlocale(X, Y) NULL
+#define snprintf        SDL_snprintf
+#define strcmp          SDL_strcmp
+#define strdup          SDL_strdup
+#define strncpy         SDL_strlcpy
+#ifdef tolower
+#undef tolower
+#endif
+#define tolower         SDL_tolower
+#define wcsdup          SDL_wcsdup
+
+
 #ifndef __FreeBSD__
 /* this is awkwardly inlined, so we need to re-implement it here
  * so we can override the libusb_control_transfer call */
@@ -32,5 +54,185 @@ static int SDL_libusb_get_string_descriptor(libusb_device_handle *dev,
 #define libusb_get_string_descriptor SDL_libusb_get_string_descriptor
 #endif /* __FreeBSD__ */
 
+#define HIDAPI_THREAD_STATE_DEFINED
+
+/* Barrier implementation because Android/Bionic don't have pthread_barrier.
+   This implementation came from Brent Priddy and was posted on
+   StackOverflow. It is used with his permission. */
+
+typedef struct _SDL_ThreadBarrier
+{
+    SDL_Mutex *mutex;
+    SDL_Condition *cond;
+    Uint32 count;
+    Uint32 trip_count;
+} SDL_ThreadBarrier;
+
+static int SDL_CreateThreadBarrier(SDL_ThreadBarrier *barrier, Uint32 count)
+{
+    SDL_assert(barrier != NULL);
+    SDL_assert(count != 0);
+
+    barrier->mutex = SDL_CreateMutex();
+    if (barrier->mutex == NULL) {
+        return -1; /* Error set by CreateMutex */
+    }
+    barrier->cond = SDL_CreateCondition();
+    if (barrier->cond == NULL) {
+        return -1; /* Error set by CreateCond */
+    }
+
+    barrier->trip_count = count;
+    barrier->count = 0;
+
+    return 0;
+}
+
+static void SDL_DestroyThreadBarrier(SDL_ThreadBarrier *barrier)
+{
+    SDL_DestroyCondition(barrier->cond);
+    SDL_DestroyMutex(barrier->mutex);
+}
+
+static int SDL_WaitThreadBarrier(SDL_ThreadBarrier *barrier)
+{
+    SDL_LockMutex(barrier->mutex);
+    barrier->count += 1;
+    if (barrier->count >= barrier->trip_count) {
+        barrier->count = 0;
+        SDL_BroadcastCondition(barrier->cond);
+        SDL_UnlockMutex(barrier->mutex);
+        return 1;
+    }
+    SDL_WaitCondition(barrier->cond, barrier->mutex);
+    SDL_UnlockMutex(barrier->mutex);
+    return 0;
+}
+
+#include "../thread/SDL_systhread.h"
+
+#define THREAD_STATE_WAIT_TIMED_OUT SDL_MUTEX_TIMEDOUT
+
+typedef struct
+{
+    SDL_Thread *thread;
+    SDL_Mutex *mutex; /* Protects input_reports */
+    SDL_Condition *condition;
+    SDL_ThreadBarrier barrier; /* Ensures correct startup sequence */
+
+} hid_device_thread_state;
+
+static void thread_state_init(hid_device_thread_state *state)
+{
+    state->mutex = SDL_CreateMutex();
+    state->condition = SDL_CreateCondition();
+    SDL_CreateThreadBarrier(&state->barrier, 2);
+}
+
+static void thread_state_free(hid_device_thread_state *state)
+{
+    SDL_DestroyThreadBarrier(&state->barrier);
+    SDL_DestroyCondition(state->condition);
+    SDL_DestroyMutex(state->mutex);
+}
+
+static void thread_state_push_cleanup(void (*routine)(void *), void *arg)
+{
+    /* There isn't an equivalent in SDL, and it's only useful for threads calling hid_read_timeout() */
+}
+
+static void thread_state_pop_cleanup(int execute)
+{
+}
+
+static void thread_state_lock(hid_device_thread_state *state)
+{
+    SDL_LockMutex(state->mutex);
+}
+
+static void thread_state_unlock(hid_device_thread_state *state)
+{
+    SDL_UnlockMutex(state->mutex);
+}
+
+static void thread_state_wait_condition(hid_device_thread_state *state)
+{
+    SDL_WaitCondition(state->condition, state->mutex);
+}
+
+static int thread_state_wait_condition_timeout(hid_device_thread_state *state, struct timespec *ts)
+{
+    Uint64 end_time;
+    Sint64 timeout_ns;
+    Sint32 timeout_ms;
+
+    end_time = ts->tv_sec;
+    end_time *= 1000000000L;
+    end_time += ts->tv_nsec;
+    timeout_ns = (Sint64)(end_time - SDL_GetTicksNS());
+    if (timeout_ns <= 0) {
+        timeout_ms = 0;
+    } else {
+        timeout_ms = (Sint32)SDL_NS_TO_MS(timeout_ns);
+    }
+    return SDL_WaitConditionTimeout(state->condition, state->mutex, timeout_ms);
+}
+
+static void thread_state_signal_condition(hid_device_thread_state *state)
+{
+    SDL_SignalCondition(state->condition);
+}
+
+static void thread_state_broadcast_condition(hid_device_thread_state *state)
+{
+    SDL_BroadcastCondition(state->condition);
+}
+
+static void thread_state_wait_barrier(hid_device_thread_state *state)
+{
+    SDL_WaitThreadBarrier(&state->barrier);
+}
+
+typedef struct
+{
+    void *(*func)(void*);
+    void *func_arg;
+
+} RunInputThreadParam;
+
+static int RunInputThread(void *param)
+{
+    RunInputThreadParam *data = (RunInputThreadParam *)param;
+    void *(*func)(void*) = data->func;
+    void *func_arg = data->func_arg;
+    SDL_free(data);
+    func(func_arg);
+    return 0;
+}
+
+static void thread_state_create_thread(hid_device_thread_state *state, void *(*func)(void*), void *func_arg)
+{
+    RunInputThreadParam *param = (RunInputThreadParam *)malloc(sizeof(*param));
+    /* Note that the hidapi code didn't check for thread creation failure.
+     * We'll crash if malloc() fails
+     */
+    param->func = func;
+    param->func_arg = func_arg;
+    state->thread = SDL_CreateThreadInternal(RunInputThread, "libusb", 0, param);
+}
+
+static void thread_state_join_thread(hid_device_thread_state *state)
+{
+    SDL_WaitThread(state->thread, NULL);
+}
+
+static void thread_state_get_current_time(struct timespec *ts)
+{
+    Uint64 ns = SDL_GetTicksNS();
+
+    ts->tv_sec = ns / 1000000000L;
+    ts->tv_nsec = ns % 1000000000L;
+}
+
 #undef HIDAPI_H__
 #include "libusb/hid.c"