Patch from Gert-Jan Vons: create an event handle to go in the

OVERLAPPED structure in output threads, as we already do for input
threads. This apparently sorts out a hanging issue with serial ports
when trying to do simultaneous read and write, because (GJV says,
and it sounds plausible to me) in the absence of that event object
Windows signals the file handle itself to notify GetOverlappedResult
that it can return - and since the file handle might be being
signalled by a read operation instead, that leads to ambiguity.
Using an explicit event object in both directions means Windows
always knows which way the data is going.

Also a trivial fix in handle_output_new(), which was referencing the
wrong element of a union due to a copy and paste error. (Since the
result was address-taken and cast to void *, this wasn't a
functional error, but it was conceptually wrong.)

[originally from svn r8410]

diff --git a/windows/winhandl.c b/windows/winhandl.c
index f300962cb79f2d571ba4e1d6d005de6559bef79c..c0e8232d9dbab20a41de3a108a974d4240963256 100644 (file)
--- a/windows/winhandl.c
+++ b/windows/winhandl.c
@@ -262,12 +262,15 @@ static DWORD WINAPI handle_output_threadfunc(void *param)
 {
     struct handle_output *ctx = (struct handle_output *) param;
     OVERLAPPED ovl, *povl;
+    HANDLE oev;
     int writeret;
 
-    if (ctx->flags & HANDLE_FLAG_OVERLAPPED)
+    if (ctx->flags & HANDLE_FLAG_OVERLAPPED) {
        povl = &ovl;
-    else
+       oev = CreateEvent(NULL, TRUE, FALSE, NULL);
+    } else {
        povl = NULL;
+    }
 
     while (1) {
        WaitForSingleObject(ctx->ev_from_main, INFINITE);
@@ -275,8 +278,11 @@ static DWORD WINAPI handle_output_threadfunc(void *param)
            SetEvent(ctx->ev_to_main);
            break;
        }
-       if (povl)
+       if (povl) {
            memset(povl, 0, sizeof(OVERLAPPED));
+           povl->hEvent = oev;
+       }
+
        writeret = WriteFile(ctx->h, ctx->buffer, ctx->len,
                             &ctx->lenwritten, povl);
        if (!writeret)
@@ -297,6 +303,9 @@ static DWORD WINAPI handle_output_threadfunc(void *param)
            break;
     }
 
+    if (povl)
+       CloseHandle(oev);
+
     return 0;
 }
 
@@ -407,7 +416,7 @@ struct handle *handle_output_new(HANDLE handle, handle_outputfn_t sentdata,
     add234(handles_by_evtomain, h);
 
     CreateThread(NULL, 0, handle_output_threadfunc,
-                &h->u.i, 0, &out_threadid);
+                &h->u.o, 0, &out_threadid);
 
     return h;
 }