On 09/11/13 17:32, Hans Leidekker wrote:
On Wed, 2013-09-11 at 16:38 +0200, Jacek Caban wrote:
Hi Hans,
On 09/11/13 13:50, Hans Leidekker wrote:
static DWORD chunked_get_avail_data(data_stream_t *stream, http_request_t *req) {
- /* Allow reading only from read buffer */
- chunked_stream_t *chunked_stream = (chunked_stream_t*)stream;
- DWORD res;
- if(!chunked_stream->chunk_size || chunked_stream->chunk_size == ~0u) {
res = start_next_chunk(chunked_stream, req);if(res != ERROR_SUCCESS)return 0;- }
start_next_chunk may block and we don't want chunked_get_avail_data to block.
We can't avoid that. If this is the first chunk or if the current chunk has been consumed we need to read a couple of bytes to find out how much we can expect.
The first chunk will be received by HTTP_ReceiveRequestData in both HTTP_HttpSendRequest and HTTP_HttpEndRequest. Subsequent chunks are also avoidable, just like they didn't block without your patch. We really can't block in InternetQueryDataAvailable for async request.
Network traces tell me that native also performs a read on the first call to InternetQueryDataAvailable.
Are you sure it's not an asynchronous read from a separated thread that is ordered by InternetQueryDataAvailable if no data is available?
Jacek