http/client: handle early server response during streaming body write#3410
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levenon wants to merge 1 commit into
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http/client: handle early server response during streaming body write#3410levenon wants to merge 1 commit into
levenon wants to merge 1 commit into
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When using body_writer for streaming uploads (e.g., chunked transfer), the server may send an error response and close the connection before the client finishes writing the body. Previously, do_make_request() serialized write_body and recv_reply, meaning the client could not detect the server's early response until write_body completed — which may never happen for long-lived streams, as writes continue to succeed into kernel/userspace buffers even after the remote end has closed. Fix this by running write_body and recv_reply concurrently via when_all(). If recv_reply completes first (server responded early), shutdown_output() is called to immediately abort the in-progress write. If write_body completes first (normal flow), recv_reply proceeds as before without shutdown. This resolves a hang where streaming HTTP clients would remain stuck in write_body indefinitely after the server had already rejected the request.
xemul
reviewed
May 29, 2026
| return _write_buf.flush().then([this] { | ||
| return recv_reply(); | ||
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| return do_with(false, [this, &req](bool& write_done) { |
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For short bodies (those without body writer function set) this can be avoided
xemul
reviewed
May 29, 2026
| } | ||
| return make_ready_future<reply_ptr>(std::move(rep)); | ||
| }) | ||
| ).then([](auto joined) { |
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Good fit for .then_unpack() sugar
Contributor
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Test that reproduces the issue is needed badly |
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When using body_writer for streaming uploads (e.g., chunked transfer), the server may send an error response and close the connection before the client finishes writing the body. Previously, do_make_request() serialized write_body and recv_reply, meaning the client could not detect the server's early response until write_body completed — which may never happen for long-lived streams, as writes continue to succeed into kernel/userspace buffers even after the remote end has closed.
Fix this by running write_body and recv_reply concurrently via when_all(). If recv_reply completes first (server responded early), shutdown_output() is called to immediately abort the in-progress write. If write_body completes first (normal flow), recv_reply proceeds as before without shutdown.
This resolves a hang where streaming HTTP clients would remain stuck in write_body indefinitely after the server had already rejected the request.