For each request, the worker calls the php_execute_script function
from libphp that changes to the script directory before doing its
work and then restores the process directory before returning. The
chdir(2) calls it performs are unnecessary in Unit design. In simple
benchmarks, profiling shows that the chdir syscall code path (syscall,
FS walk, etc.) is where the CPU spends most of its time.
PHP SAPI semantics requires the script to be run from the script
directory. In Unit's PHP implementation, we have two use cases:
- script
- arbitrary path
The "script" configuration doesn't have much need for a working
directory change: it can be changed once at module initialization.
The module needs to chdir again only if the user's PHP script also
calls chdir to switch to another directory during execution.
If "script" is not used in Unit configuration, we must ensure the
script is run from its directory (thus calling chdir before exec),
but there's no need to restore the working directory later.
Our implementation disables mandatory chdir calls with the SAPI
option SAPI_OPTION_NO_CHDIR, instead calling chdir only when needed.
To detect the user's calls to chdir, a simple "unit" extension is
added that hooks the built-in chdir() PHP call.
Currently almost all Unit object files depends on generated nxt_version.h.
This patch adds missing dependence and fixes running make with multiple
jobs.
This closes#318 issue on GitHub.
Since PHP 7, a zend_signal_startup() call is required if the interpreter
was built with ZEND_SIGNALS defined; such a call was added in 3fd76e4ce70a.
However, the zend_signal_startup() export is missing from the PHP library;
as the result, dlopen() fails with the 'Undefined symbol "zend_signal_startup"'
error while loading the PHP module.
Meanwhile, if PHP is built without ZTS, the zend_signal_startup() call can
be omitted; otherwise, the missing call causes segmentation fault.
The PHP fix already was committed to upstream, but we still have to deal
with numerous unpatched versions remaining at large.
See the related PHP bug: https://bugs.php.net/bug.php?id=71041
Configuration and building example:
./configure
./configure python
./configure php
./configure go
make all
or
./configure
make nginext
./configure python
make python
./configure php
make php
./configure go
make go
Modules configuration options and building examples:
./configure python --module=python2 --config=python2.7-config
make python2
./configure php --module=php7 --config=php7.0-config
--lib-path=/usr/local/php7.0
make php7
./configure go --go=go1.6 --go-path=${HOME}/go1.6
make go1.6
Valentin Bartenev