view src/os/unix/ngx_sunpro_amd64.il @ 9143:48691bab4474

QUIC: fixed probe-congestion deadlock. When probe timeout expired while congestion window was exhausted, probe PINGs could not be sent. As a result, lost packets could not be declared lost and congestion window could not be freed for new packets. This deadlock continued until connection idle timeout expiration. Now PINGs are sent separately from the frame queue without congestion control, as specified by RFC 9002, Section 7: An endpoint MUST NOT send a packet if it would cause bytes_in_flight (see Appendix B.2) to be larger than the congestion window, unless the packet is sent on a PTO timer expiration (see Section 6.2) or when entering recovery (see Section 7.3.2).
author Roman Arutyunyan <arut@nginx.com>
date Mon, 14 Aug 2023 08:28:30 +0400
parents 2cd019520210
children
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/
/ Copyright (C) Igor Sysoev
/ Copyright (C) Nginx, Inc.
/

/ ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
/     ngx_atomic_uint_t old, ngx_atomic_uint_t set);
/
/ the arguments are passed in %rdi, %rsi, %rdx
/ the result is returned in the %rax

        .inline ngx_atomic_cmp_set,0
        movq      %rsi, %rax
        lock
        cmpxchgq  %rdx, (%rdi)
        setz      %al
        movzbq    %al, %rax
        .end


/ ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value,
/     ngx_atomic_int_t add);
/
/ the arguments are passed in %rdi, %rsi
/ the result is returned in the %rax

        .inline ngx_atomic_fetch_add,0
        movq      %rsi, %rax
        lock
        xaddq     %rax, (%rdi)
        .end


/ ngx_cpu_pause()
/
/ the "rep; nop" is used instead of "pause" to avoid the "[ PAUSE ]" hardware
/ capability added by linker because Solaris/amd64 does not know about it:
/
/ ld.so.1: nginx: fatal: hardware capability unsupported: 0x2000 [ PAUSE ]

        .inline ngx_cpu_pause,0
        rep; nop
        .end