Fix infinite loop in post-relay flush when peer stops reading#598
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renaudallard wants to merge 1 commit intotinyproxy:masterfrom
Open
Fix infinite loop in post-relay flush when peer stops reading#598renaudallard wants to merge 1 commit intotinyproxy:masterfrom
renaudallard wants to merge 1 commit intotinyproxy:masterfrom
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write_buffer() returns 0 on EAGAIN/EWOULDBLOCK (from SO_SNDTIMEO timeout), but the flush loops after relay_connection() only broke on return < 0. This caused an infinite retry loop when the peer stopped accepting data: send() would block for idletimeout seconds, return EAGAIN, write_buffer would return 0, and the loop would retry forever. Each stuck thread consumes a maxclients slot. Once all slots are exhausted, the proxy stops accepting new connections entirely. Fix: break on write_buffer() <= 0 in both client and server flush loops. These are best-effort flushes after the main relay loop already delivered the bulk of the data.
Contributor
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nice debugging work here. but imo your PR doesn't go far enough, that's why i opened #599 . would you mind testing my PR and confirming whether it fixes the issues you encountered ? |
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write_buffer() returns 0 on EAGAIN/EWOULDBLOCK (from SO_SNDTIMEO timeout), but the flush loops after relay_connection() only broke on return < 0. This caused an infinite retry loop when the peer stopped accepting data: send() would block for idletimeout seconds, return EAGAIN, write_buffer would return 0, and the loop would retry forever.
Each stuck thread consumes a maxclients slot. Once all slots are exhausted, the proxy stops accepting new connections entirely.
Fix: break on write_buffer() <= 0 in both client and server flush loops. These are best-effort flushes after the main relay loop already delivered the bulk of the data.