static void wince_exit(void)
{
HANDLE semaphore;
TCHAR sem_name[11 + 8 + 1]; // strlen("libusb_init") + (32-bit hex PID) + '\0'
_stprintf(sem_name, _T("libusb_init%08X"), (unsigned int)(GetCurrentProcessId() & 0xFFFFFFFF));
semaphore = CreateSemaphore(NULL, 1, 1, sem_name);
if (semaphore == NULL)
return;
// A successful wait brings our semaphore count to 0 (unsignaled)
// => any concurent wait stalls until the semaphore release
if (WaitForSingleObject(semaphore, INFINITE) != WAIT_OBJECT_0) {
CloseHandle(semaphore);
return;
}
// Only works if exits and inits are balanced exactly
if (--concurrent_usage < 0) { // Last exit
exit_dllimports();
exit_polling();
if (driver_handle != INVALID_HANDLE_VALUE) {
UkwCloseDriver(driver_handle);
driver_handle = INVALID_HANDLE_VALUE;
}
}
ReleaseSemaphore(semaphore, 1, NULL); // increase count back to 1
CloseHandle(semaphore);
}
static int usbdk_init(struct libusb_context *ctx)
{
int r;
if (++concurrent_usage == 0) { // First init?
r = load_usbdk_helper_dll(ctx);
if (r)
goto init_exit;
init_polling();
r = windows_common_init(ctx);
if (r)
goto init_exit;
}
// At this stage, either we went through full init successfully, or didn't need to
r = LIBUSB_SUCCESS;
init_exit:
if (!concurrent_usage && r != LIBUSB_SUCCESS) { // First init failed?
exit_polling();
windows_common_exit();
unload_usbdk_helper_dll();
}
if (r != LIBUSB_SUCCESS)
--concurrent_usage; // Not expected to call libusb_exit if we failed.
return r;
}
static void usbdk_exit(void)
{
if (--concurrent_usage < 0) {
windows_common_exit();
exit_polling();
unload_usbdk_helper_dll();
}
}
static void wince_exit(void)
{
int i;
HANDLE semaphore;
TCHAR sem_name[11+1+8]; // strlen(libusb_init)+'\0'+(32-bit hex PID)
_stprintf(sem_name, _T("libusb_init%08X"), (unsigned int)GetCurrentProcessId()&0xFFFFFFFF);
semaphore = CreateSemaphore(NULL, 1, 1, sem_name);
if (semaphore == NULL) {
return;
}
// A successful wait brings our semaphore count to 0 (unsignaled)
// => any concurent wait stalls until the semaphore release
if (WaitForSingleObject(semaphore, INFINITE) != WAIT_OBJECT_0) {
CloseHandle(semaphore);
return;
}
// Only works if exits and inits are balanced exactly
if (--concurrent_usage < 0) { // Last exit
exit_polling();
if (timer_thread) {
SetEvent(timer_request[1]); // actually the signal to quit the thread.
if (WAIT_OBJECT_0 != WaitForSingleObject(timer_thread, INFINITE)) {
usbi_dbg("could not wait for timer thread to quit");
TerminateThread(timer_thread, 1);
}
CloseHandle(timer_thread);
timer_thread = NULL;
}
for (i = 0; i < 2; i++) {
if (timer_request[i]) {
CloseHandle(timer_request[i]);
timer_request[i] = NULL;
}
}
if (timer_response) {
CloseHandle(timer_response);
timer_response = NULL;
}
if (timer_mutex) {
CloseHandle(timer_mutex);
timer_mutex = NULL;
}
if (driver_handle != INVALID_HANDLE_VALUE) {
UkwCloseDriver(driver_handle);
driver_handle = INVALID_HANDLE_VALUE;
}
}
ReleaseSemaphore(semaphore, 1, NULL); // increase count back to 1
CloseHandle(semaphore);
}
// Internal API functions
static int wince_init(struct libusb_context *ctx)
{
int r = LIBUSB_ERROR_OTHER;
HANDLE semaphore;
LARGE_INTEGER li_frequency;
TCHAR sem_name[11 + 8 + 1]; // strlen("libusb_init") + (32-bit hex PID) + '\0'
_stprintf(sem_name, _T("libusb_init%08X"), (unsigned int)(GetCurrentProcessId() & 0xFFFFFFFF));
semaphore = CreateSemaphore(NULL, 1, 1, sem_name);
if (semaphore == NULL) {
usbi_err(ctx, "could not create semaphore: %s", windows_error_str(0));
return LIBUSB_ERROR_NO_MEM;
}
// A successful wait brings our semaphore count to 0 (unsignaled)
// => any concurent wait stalls until the semaphore's release
if (WaitForSingleObject(semaphore, INFINITE) != WAIT_OBJECT_0) {
usbi_err(ctx, "failure to access semaphore: %s", windows_error_str(0));
CloseHandle(semaphore);
return LIBUSB_ERROR_NO_MEM;
}
// NB: concurrent usage supposes that init calls are equally balanced with
// exit calls. If init is called more than exit, we will not exit properly
if ( ++concurrent_usage == 0 ) { // First init?
// Initialize pollable file descriptors
init_polling();
// Load DLL imports
if (init_dllimports() != LIBUSB_SUCCESS) {
usbi_err(ctx, "could not resolve DLL functions");
r = LIBUSB_ERROR_NOT_SUPPORTED;
goto init_exit;
}
// try to open a handle to the driver
driver_handle = UkwOpenDriver();
if (driver_handle == INVALID_HANDLE_VALUE) {
usbi_err(ctx, "could not connect to driver");
r = LIBUSB_ERROR_NOT_SUPPORTED;
goto init_exit;
}
// find out if we have access to a monotonic (hires) timer
if (QueryPerformanceFrequency(&li_frequency)) {
hires_frequency = li_frequency.QuadPart;
// The hires frequency can go as high as 4 GHz, so we'll use a conversion
// to picoseconds to compute the tv_nsecs part in clock_gettime
hires_ticks_to_ps = UINT64_C(1000000000000) / hires_frequency;
usbi_dbg("hires timer available (Frequency: %"PRIu64" Hz)", hires_frequency);
} else {
usbi_dbg("no hires timer available on this platform");
hires_frequency = 0;
hires_ticks_to_ps = UINT64_C(0);
}
}
// At this stage, either we went through full init successfully, or didn't need to
r = LIBUSB_SUCCESS;
init_exit: // Holds semaphore here.
if (!concurrent_usage && r != LIBUSB_SUCCESS) { // First init failed?
exit_dllimports();
exit_polling();
if (driver_handle != INVALID_HANDLE_VALUE) {
UkwCloseDriver(driver_handle);
driver_handle = INVALID_HANDLE_VALUE;
}
}
if (r != LIBUSB_SUCCESS)
--concurrent_usage; // Not expected to call libusb_exit if we failed.
ReleaseSemaphore(semaphore, 1, NULL); // increase count back to 1
CloseHandle(semaphore);
return r;
}
