Mercurial > hg > nginx-quic

view src/os/unix/ngx_sunpro_amd64.il @ 8751:555533169506

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
HTTP/2: fixed "task already active" with sendfile in threads. With sendfile in threads, "task already active" alerts might appear in logs if a write event happens on the main HTTP/2 connection, triggering a sendfile in threads while another thread operation is already running. Observed with "aio threads; aio_write on; sendfile on;" and with thread event handlers modified to post a write event to the main HTTP/2 connection (though can happen without any modifications). Similarly, sendfile() with AIO preloading on FreeBSD can trigger duplicate aio operation, resulting in "second aio post" alerts. This is, however, harder to reproduce, especially on modern FreeBSD systems, since sendfile() usually does not return EBUSY. Fix is to avoid starting a sendfile operation if other thread operation is active by checking r->aio in the thread handler (and, similarly, in aio preload handler). The added check also makes duplicate calls protection redundant, so it is removed.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 25 Nov 2021 22:02:05 +0300
parents 2cd019520210
children
line wrap: on
line source

/
/ 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