Windows: Fix I/O completion port thread behavior on error
The GetQueuedCompletionStatus() returns FALSE when the I/O operation
itself does not complete successfully. The I/O completion thread should
therefore not exit on this condition. Adjust the check to verify that an
OVERLAPPED structure was provided and use an explicit completion key
value in the exit path to disambiguate receiving a valid NULL OVERLAPPED
pointer.
Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
diff --git a/libusb/os/windows_common.c b/libusb/os/windows_common.c
index 9406632..2f79928 100644
--- a/libusb/os/windows_common.c
+++ b/libusb/os/windows_common.c
@@ -418,13 +418,18 @@
usbi_dbg("I/O completion thread started");
while (true) {
- if (!GetQueuedCompletionStatus(iocp, &num_bytes, &completion_key, &overlapped, INFINITE)) {
+ overlapped = NULL;
+ if (!GetQueuedCompletionStatus(iocp, &num_bytes, &completion_key, &overlapped, INFINITE) && (overlapped == NULL)) {
usbi_err(ctx, "GetQueuedCompletionStatus failed: %s", windows_error_str(0));
break;
}
- if (overlapped == NULL)
- break; // Signal to quit
+ if (overlapped == NULL) {
+ // Signal to quit
+ if (completion_key != (ULONG_PTR)ctx)
+ usbi_err(ctx, "program assertion failed - overlapped is NULL");
+ break;
+ }
transfer_priv = container_of(overlapped, struct windows_transfer_priv, overlapped);
itransfer = (struct usbi_transfer *)((unsigned char *)transfer_priv + PTR_ALIGN(sizeof(*transfer_priv)));
@@ -556,7 +561,7 @@
}
// A NULL completion status will indicate to the thread that it is time to exit
- if (!PostQueuedCompletionStatus(priv->completion_port, 0, 0, NULL))
+ if (!PostQueuedCompletionStatus(priv->completion_port, 0, (ULONG_PTR)ctx, NULL))
usbi_err(ctx, "failed to post I/O completion: %s", windows_error_str(0));
if (WaitForSingleObject(priv->completion_port_thread, INFINITE) == WAIT_FAILED)
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index bee4117..dfaf221 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11537
+#define LIBUSB_NANO 11538
