When configured, an individual listen socket on a given address is
created for each worker process. This allows to reduce in-kernel lock
contention on configurations with high accept rates, resulting in better
performance. As of now it works on Linux and DragonFly BSD.
Note that on Linux incoming connection requests are currently tied up
to a specific listen socket, and if some sockets are closed, connection
requests will be reset, see https://lwn.net/Articles/542629/. With
nginx, this may happen if the number of worker processes is reduced.
There is no such problem on DragonFly BSD.
Based on previous work by Sepherosa Ziehau and Yingqi Lu.
The code tried to use suffixes for "long" and "long long" types, but
it never worked as intended due to the bug in the shell code. Also,
the max value for any 64-bit type other than "long long" on platforms
with 32-bit "long" would be incorrect if the bug was fixed.
So instead of fixing the bug in the shell code, always use the "int"
constant for 32-bit types, and "long long" constant for 64-bit types.
It appeared that the NGX_HAVE_AIO_SENDFILE macro was defined regardless of
the "--with-file-aio" configure option and the NGX_HAVE_FILE_AIO macro.
Now they are related.
Additionally, fixed one macro.
Previous workaround to avoid warnings on OS X due to deprecated system
OpenSSL library (introduced in a3870ea96ccd) no longer works, as
the MAC_OS_X_VERSION_MIN_REQUIRED macro is ignored on OS X 10.9
if a compiler used supports __attribute__(availability).
This fixes --with-file-aio support on systems that lack eventfd()
syscall, notably aarch64 Linux.
The syscall(SYS_eventfd) may still be necessary on systems that
have eventfd() syscall in the kernel but lack it in glibc, e.g.
as seen in the current CentOS 5 release.
Client address specified in the PROXY protocol header is now
saved in the $proxy_protocol_addr variable and can be used in
the realip module.
This is currently not implemented for mail.
Modern clang versions seem to no longer produce warnings for
system headers on Linux (at least clang 3.3 works), hence the
change. For older versions --with-cc-opt="-Wno-error" can be
used as a workaround.
Several warnings silenced, notably (ngx_socket_t) -1 is now checked
on socket operations instead of -1, as ngx_socket_t is unsigned on win32
and gcc complains on comparison.
With this patch, it's now possible to compile nginx using mingw gcc,
with options we normally compile on win32.
Several false positive warnings silenced, notably W8012 "Comparing
signed and unsigned" (due to u_short values promoted to int), and
W8072 "Suspicious pointer arithmetic" (due to large type values added
to pointers).
With this patch, it's now again possible to compile nginx using bcc32,
with options we normally compile on win32 minus ipv6 and ssl.
Precompiled headers are disabled as they lead to internal compiler errors
with long configure lines. Couple of false positive warnings silenced.
Various win32 typedefs are adjusted to work with Open Watcom C 1.9 headers.
With this patch, it's now again possible to compile nginx using owc386,
with options we normally compile on win32 minus ipv6 and ssl.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
As of PCRE 8.33, config.h.generic no longer contains boolean macros. Two
of them (SUPPORT_PCRE8 and HAVE_MEMMOVE) were added to appropriate makefiles.
This allows PCRE 8.33 to compile and don't change anything for previous
versions.
