Hi All,
 
I’ve recently discovered a strange Cygwin bug on Windows 8. Calling 
SetupDiGetDeviceRegistryProperty() from a Cygwin thread created with 
pthread_create() causes it fail unconditionally. This actually breaks libusb 
for any program that uses it outside the main thread. 
The bug can be reproduced with a small program below. 
Could anyone please advise me if this could be fixed in one of the next Cygwin 
releases?
 
Best regards,
Ivan Shcherbakov
 
Repro case (g ++ thread_repro.cpp -o thread_repro.exe -lsetupapi && 
./thread_repro):
 
#include <windows.h>
#include <SetupAPI.h>
#include <pthread.h>
#include <stdio.h>
 
void list_devices(int maxCount)
{
                HDEVINFO hDevInfo = SetupDiGetClassDevs(NULL, NULL, NULL, 
DIGCF_PRESENT | DIGCF_ALLCLASSES);
                SP_DEVINFO_DATA devinfo = { sizeof(devinfo) };
                for (int i = 0; i < maxCount && SetupDiEnumDeviceInfo(hDevInfo, 
i, &devinfo); i++)
                {
                               DWORD dataType = 0;
                               char szData[1024] = { 0, };
                               if (SetupDiGetDeviceRegistryPropertyA(hDevInfo, 
&devinfo, SPDRP_HARDWAREID, &dataType, (BYTE *) szData, sizeof(szData), NULL))
                                               printf("%d: %s\n", i, szData);
                               else
                                               printf("%d - error %d\n", i, 
GetLastError());
 
                               devinfo.cbSize = sizeof(devinfo);
                }
                SetupDiDestroyDeviceInfoList(hDevInfo);
}
 
void* thread_body(void *)
{
                printf("Listing devices from a pthread\n");
                list_devices(10);
                return 0;
}
 
int main()
{
                printf("Listing devices from the main thread\n");
                list_devices(10);
 
                pthread_t t;
                pthread_create(&t, NULL, thread_body, 0);
                pthread_join(t, NULL);
 
                return 0;
}

The output on Windows 8:

Listing devices from the main thread
0: USB\VID_0E0F&PID_0007&REV_0100
1: ACPI\VEN_PNP&DEV_0100
2: STORAGE\Volume
3: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
4: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
5: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
6: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
7: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
8: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
9: PCI\VEN_15AD&DEV_07A0&SUBSYS_07A015AD&REV_01
Listing devices from a pthread
0 - error 13
1 - error 13
2 - error 13
3 - error 13
4 - error 13
5 - error 13
6 - error 13
7 - error 13
8 - error 13
9 - error 13


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