commit 412fbe9f177f742e0e56df612f44261f6771973a Author: Alexander Færøy ahf@torproject.org Date: Thu Dec 20 13:11:24 2018 +0100

Make example CancelIoEx() code use CancelIo().

This patch changes the CancelIoEx() example code to use CancelIo(), which is available for older versions of Windows too. I still think the kernel handles this nicely by sending broken pipes if either side closes the pipe while I/O operations are pending.

See: https://bugs.torproject.org/28179 --- src/lib/process/process_win32.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/lib/process/process_win32.c b/src/lib/process/process_win32.c index 3b4373f42..641af2bb0 100644 --- a/src/lib/process/process_win32.c +++ b/src/lib/process/process_win32.c @@ -720,31 +720,24 @@ process_win32_cleanup_handle(process_win32_handle_t *handle) tor_assert(handle);

#if 0 - /* FIXME(ahf): My compiler does not set _WIN32_WINNT to a high enough value - * for this code to be available. Should we force it? CancelIoEx() is - * available from Windows 7 and above. If we decide to require this, we need - * to update the checks in all the three I/O completion callbacks to handle - * the ERROR_OPERATION_ABORTED as well as ERROR_BROKEN_PIPE. */ - -#if _WIN32_WINNT >= 0x0600 - /* This code is only supported from Windows 7 and onwards. */ BOOL ret; DWORD error_code;

- /* Cancel any pending I/O requests. */ - ret = CancelIoEx(handle->pipe, &handle->overlapped); + /* Cancel any pending I/O requests: This means that instead of getting + * ERROR_BROKEN_PIPE we get ERROR_OPERATION_ABORTED, but it doesn't seem + * like this is needed. */ + ret = CancelIo(handle->pipe);

if (! ret) { error_code = GetLastError();

/* There was no pending I/O requests for our handle. */ if (error_code != ERROR_NOT_FOUND) { - log_warn(LD_PROCESS, "CancelIoEx() failed: %s", + log_warn(LD_PROCESS, "CancelIo() failed: %s", format_win32_error(error_code)); } } #endif -#endif

/* Close our handle. */ if (handle->pipe != INVALID_HANDLE_VALUE) {