nginx 0.7.66 *) Security: now nginx/Windows ignores default file stream name. Thanks to Jose Antonio Vazquez Gonzalez. *) Change: now the charset filter runs before the SSI filter. *) Change: now no message is written in an error log if a variable is not found by $r->variable() method. *) Change: now keepalive connections after POST requests are not disabled for MSIE 7.0+. Thanks to Adam Lounds. *) Feature: the "proxy_no_cache" and "fastcgi_no_cache" directives. *) Feature: now the "rewrite" directive does a redirect automatically if the $scheme variable is used. Thanks to Piotr Sikora. *) Feature: the "chunked_transfer_encoding" directive. *) Feature: the $geoip_city_continent_code, $geoip_latitude, and $geoip_longitude variables. Thanks to Arvind Sundararajan. *) Feature: now the ngx_http_image_filter_module deletes always EXIF and other application specific data if the data consume more than 5% of a JPEG file. *) Feature: now the "msie_padding" directive works for Chrome too. *) Workaround: now keepalive connections are disabled for Safari. Thanks to Joshua Sierles. *) Bugfix: nginx ignored the "private" and "no-store" values in the "Cache-Control" backend response header line. *) Bugfix: an "&" character was not escaped when it was copied in arguments part in a rewrite rule. *) Bugfix: nginx might be terminated abnormally while a signal processing or if the directive "timer_resolution" was used on platforms which do not support kqueue or eventport notification methods. Thanks to George Xie and Maxim Dounin. *) Bugfix: if temporary files and permanent storage area resided at different file systems, then permanent file modification times were incorrect. Thanks to Maxim Dounin. *) Bugfix: ngx_http_memcached_module might issue the error message "memcached sent invalid trailer". Thanks to Maxim Dounin. *) Bugfix: nginx could not built zlib-1.2.4 library using the library sources. Thanks to Maxim Dounin. *) Bugfix: values of the $query_string, $arg_..., etc. variables cached in main request were used by the SSI module in subrequests. *) Bugfix: nginx did not support HTTPS referrers. *) Bugfix: nginx/Windows might not find file if path in configuration was given in other character case; the bug had appeared in 0.7.65. *) Bugfix: the $date_local variable has an incorrect value, if the "%s" format was used. Thanks to Maxim Dounin. *) Bugfix: nginx did not support all ciphers and digests used in client certificates. Thanks to Innocenty Enikeew. *) Bugfix: if ssl_session_cache was not set or was set to "none", then during client certificate verify the error "session id context uninitialized" might occur; the bug had appeared in 0.7.1. *) Bugfix: OpenSSL-1.0.0 compatibility on 64-bit Linux. Thanks to Maxim Dounin. *) Bugfix: a geo range returned default value if the range included two or more /16 networks and did not begin at /16 network boundary. *) Bugfix: the $uid_got variable might not be used in the SSI and perl modules. *) Bugfix: a worker process hung if a FIFO file was requested. Thanks to Vicente Aguilar and Maxim Dounin. *) Bugfix: a variable value was repeatedly encoded after each an "echo" SSI-command output; the bug had appeared in 0.6.14. *) Bugfix: a "stub" parameter of an "include" SSI directive was not used, if empty response has 200 status code. *) Bugfix: a block used in a "stub" parameter of an "include" SSI directive was output with "text/plain" MIME type. *) Bugfix: if a proxied or FastCGI request was internally redirected to another proxied or FastCGI location, then a segmentation fault might occur in a worker process; the bug had appeared in 0.7.65. Thanks to Yichun Zhang. *) Bugfix: IMAP connections may hang until they timed out while talking to Zimbra server. Thanks to Alan Batie. *) Bugfix: nginx did not support chunked transfer encoding for 201 responses. Thanks to Julian Reich.

/*
 * Copyright (C) Igor Sysoev
 */


#if (NGX_SMP)
#define NGX_SMP_LOCK  "lock;"
#else
#define NGX_SMP_LOCK
#endif


/*
 * "cmpxchgq  r, [m]":
 *
 *     if (rax == [m]) {
 *         zf = 1;
 *         [m] = r;
 *     } else {
 *         zf = 0;
 *         rax = [m];
 *     }
 *
 *
 * The "r" is any register, %rax (%r0) - %r16.
 * The "=a" and "a" are the %rax register.
 * Although we can return result in any register, we use "a" because it is
 * used in cmpxchgq anyway.  The result is actually in %al but not in $rax,
 * however as the code is inlined gcc can test %al as well as %rax.
 *
 * The "cc" means that flags were changed.
 */

static ngx_inline ngx_atomic_uint_t
ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old,
    ngx_atomic_uint_t set)
{
    u_char  res;

    __asm__ volatile (

         NGX_SMP_LOCK
    "    cmpxchgq  %3, %1;   "
    "    sete      %0;       "

    : "=a" (res) : "m" (*lock), "a" (old), "r" (set) : "cc", "memory");

    return res;
}


/*
 * "xaddq  r, [m]":
 *
 *     temp = [m];
 *     [m] += r;
 *     r = temp;
 *
 *
 * The "+r" is any register, %rax (%r0) - %r16.
 * The "cc" means that flags were changed.
 */

static ngx_inline ngx_atomic_int_t
ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add)
{
    __asm__ volatile (

         NGX_SMP_LOCK
    "    xaddq  %0, %1;   "

    : "+r" (add) : "m" (*value) : "cc", "memory");

    return add;
}


#define ngx_memory_barrier()    __asm__ volatile ("" ::: "memory")

#define ngx_cpu_pause()         __asm__ ("pause")