Set FD_CLOEXEC in a little convenience function that does the right thing

[sgt/putty] / windows / winhandl.c

diff --git a/windows/winhandl.c b/windows/winhandl.c
index fc64181..b5f0b85 100644 (file)
--- a/windows/winhandl.c
+++ b/windows/winhandl.c
@@ -16,6 +16,17 @@
  * write; so the output thread waits for an event object notifying
  * it to _attempt_ a write, and then it sets an event in return
  * when one completes.
+ * 
+ * (It's terribly annoying having to spawn a subthread for each
+ * direction of each handle. Technically it isn't necessary for
+ * serial ports, since we could use overlapped I/O within the main
+ * thread and wait directly on the event objects in the OVERLAPPED
+ * structures. However, we can't use this trick for some types of
+ * file handle at all - for some reason Windows restricts use of
+ * OVERLAPPED to files which were opened with the overlapped flag -
+ * and so we must use threads for those. This being the case, it's
+ * simplest just to use threads for everything rather than trying
+ * to keep track of multiple completely separate mechanisms.)
  */
 
 #include <assert.h>
@@ -101,19 +112,32 @@ static DWORD WINAPI handle_input_threadfunc(void *param)
 {
     struct handle_input *ctx = (struct handle_input *) param;
     OVERLAPPED ovl, *povl;
+    HANDLE oev;
+    int readlen;
 
-    if (ctx->flags & HANDLE_FLAG_OVERLAPPED)
+    if (ctx->flags & HANDLE_FLAG_OVERLAPPED) {
        povl = &ovl;
-    else
+       oev = CreateEvent(NULL, TRUE, FALSE, NULL);
+    } else {
        povl = NULL;
+    }
+
+    if (ctx->flags & HANDLE_FLAG_UNITBUFFER)
+       readlen = 1;
+    else
+       readlen = sizeof(ctx->buffer);
 
     while (1) {
-       if (povl)
+       if (povl) {
            memset(povl, 0, sizeof(OVERLAPPED));
-       ctx->readret = ReadFile(ctx->h, ctx->buffer, sizeof(ctx->buffer),
+           povl->hEvent = oev;
+       }
+       ctx->readret = ReadFile(ctx->h, ctx->buffer, readlen,
                                &ctx->len, povl);
-       if (povl && !ctx->readret && GetLastError() == ERROR_IO_PENDING)
-           ctx->readret = GetOverlappedResult(ctx->h, povl, &ctx->len, TRUE);
+       if (povl && !ctx->readret && GetLastError() == ERROR_IO_PENDING) {
+           WaitForSingleObject(povl->hEvent, INFINITE);
+           ctx->readret = GetOverlappedResult(ctx->h, povl, &ctx->len, FALSE);
+       }
 
        if (!ctx->readret)
            ctx->len = 0;
@@ -132,6 +156,9 @@ static DWORD WINAPI handle_input_threadfunc(void *param)
            break;                     /* main thread told us to shut down */
     }
 
+    if (povl)
+       CloseHandle(oev);
+
     return 0;
 }