libaltos: use PurgeComm in Windows altos_close to abort in-progress ops

Instead of manually signalling the related events, use PurgeComm which
can then abort the operations itself. Also make sure all of the
relevant handles are set to INVALID before closing them to avoid race conditions.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/libaltos/libaltos.c b/libaltos/libaltos.c
index fc949c70..4a6363ed 100644
--- a/libaltos/libaltos.c
+++ b/libaltos/libaltos.c
@@ -994,6 +994,11 @@ log_message(char *fmt, ...)
 	if (!log)
 		log = fopen("\\temp\\altos.txt", "w");
 	if (log) {
+		SYSTEMTIME time;
+		GetLocalTime(&time);
+		fprintf (log, "%4d-%02d-%02d %2d:%02d:%02d. ", 
+			 time.wYear, time.wMonth, time.wDay,
+			 time.wHour, time.wMinute, time.wSecond);
 		va_start(a, fmt);
 		vfprintf(log, fmt, a);
 		va_end(a);
@@ -1339,6 +1344,7 @@ altos_open(struct altos_device *device)
 		file->handle = open_serial(full_name);
 		if (file->handle != INVALID_HANDLE_VALUE)
 			break;
+		altos_set_last_windows_error();
 		Sleep(100);
 	}
 	
@@ -1373,13 +1379,19 @@ altos_open(struct altos_device *device)
 PUBLIC void
 altos_close(struct altos_file *file)
 {
-	if (file->handle != INVALID_HANDLE_VALUE) {
-		CloseHandle(file->handle);
+	HANDLE	handle = file->handle;
+	if (handle != INVALID_HANDLE_VALUE) {
+		HANDLE	ov_read = file->ov_read.hEvent;
+		HANDLE	ov_write = file->ov_write.hEvent;
+		file->handle = INVALID_HANDLE_VALUE;
+		file->ov_read.hEvent = INVALID_HANDLE_VALUE;
+		file->ov_write.hEvent = INVALID_HANDLE_VALUE;
+		PurgeComm(handle, PURGE_RXABORT|PURGE_RXCLEAR|PURGE_TXABORT|PURGE_TXCLEAR);
+		Sleep(100);
+		CloseHandle(handle);
 		file->handle = INVALID_HANDLE_VALUE;
-		SetEvent(file->ov_read.hEvent);
-		SetEvent(file->ov_write.hEvent);
-		CloseHandle(file->ov_read.hEvent);
-		CloseHandle(file->ov_write.hEvent);
+		CloseHandle(ov_read);
+		CloseHandle(ov_write);
 	}
 }