view src/os/unix/ngx_sunpro_x86.il @ 7784:8cc5b0365ee5

Improved maximum errno detection. Previously, systems without sys_nerr (or _sys_nerr) were handled with an assumption that errors start at 0 and continuous. This is, however, not something POSIX requires, and not true on some platforms. Notably, on Linux, where sys_nerr is no longer available for newly linked binaries starting with glibc 2.32, there are gaps in error list, which used to stop us from properly detecting maximum errno. Further, on GNU/Hurd errors start at 0x40000001. With this change, maximum errno detection is moved to the runtime code, now able to ignore gaps, and also detects the first error if needed. This fixes observed "Unknown error" messages as seen on Linux with glibc 2.32 and on GNU/Hurd.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 01 Mar 2021 20:00:43 +0300
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 on stack (%esp), 4(%esp), 8(%esp)

        .inline ngx_atomic_cmp_set,0
        movl      (%esp), %ecx
        movl      4(%esp), %eax
        movl      8(%esp), %edx
        lock
        cmpxchgl  %edx, (%ecx)
        setz      %al
        movzbl    %al, %eax
        .end


/ ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value,
/     ngx_atomic_int_t add);
/
/ the arguments are passed on stack (%esp), 4(%esp)

        .inline ngx_atomic_fetch_add,0
        movl      (%esp), %ecx
        movl      4(%esp), %eax
        lock
        xaddl     %eax, (%ecx)
        .end


/ ngx_cpu_pause()
/
/ the "rep; nop" is used instead of "pause" to avoid the "[ PAUSE ]" hardware
/ capability added by linker because Solaris/i386 does not know about it:
/
/ ld.so.1: nginx: fatal: hardware capability unsupported: 0x2000  [ PAUSE ]

        .inline ngx_cpu_pause,0
        rep; nop
        .end