From 3fa5fbdfd1ab257028f272fbc32759b39608ddaf Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Tue, 11 Sep 2012 23:04:19 -0700
Subject: [PATCH] Clean up Windows event handles on com port close

This avoids having to wait for the receiver to timeout before we can
open the same com port again.

This patch also adds a bit more debugging -- it prints Windows error
messages to stdout along with the file/line where the error was generated.

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 altosui/libaltos/libaltos.c | 33 +++++++++++++--------------------
 1 file changed, 13 insertions(+), 20 deletions(-)

diff --git a/altosui/libaltos/libaltos.c b/altosui/libaltos/libaltos.c
index 515432f9..ab6ca878 100644
--- a/altosui/libaltos/libaltos.c
+++ b/altosui/libaltos/libaltos.c
@@ -941,7 +941,7 @@ struct altos_file {
 };
 
 static void
-altos_set_last_windows_error(void)
+_altos_set_last_windows_error(char *file, int line)
 {
 	DWORD	error = GetLastError();
 	TCHAR	message[1024];
@@ -952,9 +952,13 @@ altos_set_last_windows_error(void)
 		      message,
 		      sizeof (message) / sizeof (TCHAR),
 		      NULL);
+	if (error != ERROR_SUCCESS)
+		printf ("%s:%d %s\n", file, line, message);
 	altos_set_last_error(error, message);
 }
 
+#define altos_set_last_windows_error() _altos_set_last_windows_error(__FILE__, __LINE__)
+
 PUBLIC struct altos_list *
 altos_list_start(void)
 {
@@ -1161,6 +1165,7 @@ altos_flush(struct altos_file *file)
 		if (!WriteFile(file->handle, data, used, &put, &file->ov_write)) {
 			if (GetLastError() != ERROR_IO_PENDING) {
 				altos_set_last_windows_error();
+				printf ("\tflush write error\n");
 				return LIBALTOS_ERROR;
 			}
 			ret = WaitForSingleObject(file->ov_write.hEvent, INFINITE);
@@ -1168,11 +1173,13 @@ altos_flush(struct altos_file *file)
 			case WAIT_OBJECT_0:
 				if (!GetOverlappedResult(file->handle, &file->ov_write, &put, FALSE)) {
 					altos_set_last_windows_error();
+					printf ("\tflush result error\n");
 					return LIBALTOS_ERROR;
 				}
 				break;
 			default:
 				altos_set_last_windows_error();
+				printf ("\tflush wait error\n");
 				return LIBALTOS_ERROR;
 			}
 		}
@@ -1188,7 +1195,6 @@ altos_open(struct altos_device *device)
 {
 	struct altos_file	*file = calloc (1, sizeof (struct altos_file));
 	char	full_name[64];
-	DCB dcbSerialParams = {0};
 	COMMTIMEOUTS timeouts;
 
 	if (!file)
@@ -1201,6 +1207,7 @@ altos_open(struct altos_device *device)
 				  FILE_FLAG_OVERLAPPED, NULL);
 	if (file->handle == INVALID_HANDLE_VALUE) {
 		altos_set_last_windows_error();
+		printf ("cannot open %s\n", full_name);
 		free(file);
 		return NULL;
 	}
@@ -1214,24 +1221,6 @@ altos_open(struct altos_device *device)
 	timeouts.WriteTotalTimeoutConstant = 0;
 	SetCommTimeouts(file->handle, &timeouts);
 
-	dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
-	if (!GetCommState(file->handle, &dcbSerialParams)) {
-		altos_set_last_windows_error();
-		CloseHandle(file->handle);
-		free(file);
-		return NULL;
-	}
-	dcbSerialParams.BaudRate = CBR_9600;
-	dcbSerialParams.ByteSize = 8;
-	dcbSerialParams.StopBits = ONESTOPBIT;
-	dcbSerialParams.Parity = NOPARITY;
-	if (!SetCommState(file->handle, &dcbSerialParams)) {
-		altos_set_last_windows_error();
-		CloseHandle(file->handle);
-		free(file);
-		return NULL;
-	}
-
 	return file;
 }
 
@@ -1241,6 +1230,10 @@ altos_close(struct altos_file *file)
 	if (file->handle != INVALID_HANDLE_VALUE) {
 		CloseHandle(file->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);
 	}
 }
 
-- 
2.30.2