PHPNG (next generation)

This page gives short information about development state of a new PHP branch based on refactored Zend Engine.

The phpng branch has been merged into master and has been used as the base for PHP 7.0

Some technical implementation details are available at phpng-int. Information for extension maintainers at phpng-upgrading.

Slides from a talk at ZendCon-2014 phpng-php7.pdf

Note: For anonymous checkout, use https://git.php.net/repository/php-src.git instead of git@git.php.net:php-src.git

mkdir ~/tmp
cd ~/tmp
git clone git@git.php.net:php-src.git
cd php-src
./buildconf
./configure \
    --prefix=$HOME/tmp/usr \
    --with-config-file-path=$HOME/tmp/usr/etc \
    --enable-mbstring \
    --enable-zip \
    --enable-bcmath \
    --enable-pcntl \
    --enable-ftp \
    --enable-exif \
    --enable-calendar \
    --enable-sysvmsg \
    --enable-sysvsem \
    --enable-sysvshm \
    --enable-wddx \
    --with-curl \
    --with-mcrypt \
    --with-iconv \
    --with-gmp \
    --with-pspell \
    --with-gd \
    --with-jpeg-dir=/usr \
    --with-png-dir=/usr \
    --with-zlib-dir=/usr \
    --with-xpm-dir=/usr \
    --with-freetype-dir=/usr \
    --with-t1lib=/usr \
    --enable-gd-native-ttf \
    --enable-gd-jis-conv \
    --with-openssl \
    --with-mysql=/usr \
    --with-pdo-mysql=/usr \
    --with-gettext=/usr \
    --with-zlib=/usr \
    --with-bz2=/usr \
    --with-recode=/usr \
    --with-mysqli=/usr/bin/mysql_config
make
make install
mkdir $HOME/tmp/usr/etc
vi $HOME/tmp/usr/etc/php.ini

max_execution_time=600
memory_limit=128M
error_reporting=0
display_errors=0
log_errors=0
user_ini.filename=
realpath_cache_size=2M
cgi.check_shebang_line=0

zend_extension=opcache.so
opcache.enable_cli=1
opcache.save_comments=0
opcache.fast_shutdown=1
opcache.validate_timestamps=1
opcache.revalidate_freq=60
opcache.use_cwd=1
opcache.max_accelerated_files=100000
opcache.max_wasted_percentage=5
opcache.memory_consumption=128
opcache.consistency_checks=0

Now PHP must be installed and configured. The final check.

$ sapi/cli/php -v
PHP 7.0.0-dev (cli) (built: Apr 28 2014 11:13:04) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.7.0-dev, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2014, by Zend Technologies

You may run synthetic benchmarks

$ sapi/cli/php Zend/bench.php
$ sapi/cli/php Zend/micro_bench.php

You may measure the performance of some web applications

$ sapi/cgi/php-cgi -T 1000 /var/www/html/wordpress/index.php > /dev/null''

You may do the same with callgrind profiler

$ valgrind --tool=callgrind --dump-instr=yes --separate-recs=1 sapi/cgi/php-cgi -T 100 /var/www/html/wordpress/index.php > /dev/null

Finally, you may run PHP as FastCGI server using CGI SAPI or FPM (it requires additional configuration)

$ PHP_FCGI_CHILDREN=4 PHP_FCGI_MAX_REQUESTS=0 sapi/cgi/php-cgi -b /tmp/fcgi-php

I would recommend build PHP from master and phpng branches and compare their performance

• cli
• cgi
• fpm
• apache (FastCGI and FPM might be significantly faster if mod_php is built as PIC)
• apache2handler

• bcmath
• bz2
• calendar
• com_dotnet
• ctype
• curl
• date
• dba
• dom
• enchant
• ereg
• exif
• fileinfo
• filter
• ftp
• gd
• gettext
• gmp
• hash
• iconv
• imap
• intl
• json
• ldap
• libxml
• mbstring
• mcrypt
• mysql
• mysqli
• mysqlnd
• odbc (tested with unixODBC and MySQL driver)
• openssl
• OPcache
• pcntl
• pcre
• PDO
• pdo_firebird
• pdo_mysql
• PDO_ODBC (tested with unixODBC and MySQL driver)
• pdo_pgsql
• pdo_sqlite
• pgsql
• Phar
• posix
• pspell
• readline
• recode
• Reflection
• session
• shmop
• SimpleXML
• snmp
• soap
• sockets
• SPL
• sqlite3
• standard
• sysvmsg
• sysvsem
• sysvshm
• tidy
• tokenizer
• wddx
• xml
• xmlreader
• xmlwriter
• xsl
• zip
• zlib

• interbase
• mssql
• oci8
• pdo_dblib
• pdo_oci
• sybase_ct

1. PHPNG doesn't keep original values of arguments passed to user functions, so func_get_arg() and func_get_args() will return current value of argument instead of the actually passed. The following code is going to be affected “function foo($x) { $x = 2; return func_get_arg(0);} var_dump(foo(1));”
   • tests/lang/func_get_arg.001.phpt
   • tests/lang/func_get_args.004.phpt
2. Function parameters with duplicate name are not allowed anymore. Definitions like “function foo($x,$x) {}” will lead to compile time error “Redefinition of parameter”
   • Zend/tests/bug54013.phpt
   • Zend/tests/bug64515.phpt
3. var_dump() may print recursive data structures differently
   • Zend/tests/closure_026.phpt
4. Passing scalars by reference may behave differently, because they don't have reference counters anymore

• foreach may behave differently
  • tests/lang/foreachLoop.013.phpt
  • tests/lang/foreachLoop.014.phpt
  • tests/lang/foreachLoop.015.phpt
  • ext/standard/tests/serialize/serialization_arrays_005.phpt
• user code in error handler may cause destruction of array, element of which is currently processed
  • Zend/tests/bug54265.phpt
• _toString() may behave differently
  • Zend/tests/bug60825.phpt (it was a bogus behavior in php5.6 and below)
• Internal object constructors can't set $this to NULL
  • ext/fileinfo/tests/bug61173.phpt
  • ext/fileinfo/tests/finfo_open_error.phpt
  • ext/pdo_mysql/tests/pdo_mysql_construct.phpt
  • ext/pdo_mysql/tests/pdo_mysql_construct_options.phpt
  • ext/intl/tests/breakiter_construct_error.phpt
  • ext/intl/tests/bug62017.phpt
  • ext/intl/tests/dateformat_construct_bad_tz_cal.phpt
  • ext/intl/tests/formatter_format2.phpt
  • ext/intl/tests/gregoriancalendar_construct_error.phpt
  • ext/intl/tests/resourcebundle_create.phpt
• Internal object constructors can't set $this to NULL when called indirectly - parent::__construct()
  • ext/date/tests/bug67118.phpt
  • ext/date/tests/bug67118_2.phpt
• PDP Persistent connection handling
  • ext/pdo_mysql/tests/bug63176.phpt
  • ext/pdo_mysql/tests/pdo_mysql_pconnect.phpt
  • ext/pdo_sqlite/tests/bug43831.phpt
• Passing scalars by reference may behave differently, because they don't have reference counters anymore
  • Zend/tests/bug35393.phpt
  • ext/pdo_firebird/tests/pdo_005.phpt
  • ext/pdo_mysql/tests/pdo_005.phpt
  • ext/pdo_odbc/tests/pdo_005.phpt
  • ext/pdo_pgsql/tests/pdo_005.phpt
  • ext/pdo_sqlite/tests/pdo_005.phpt
• We can't catch situations when argument passed to internal function was modified by callback
  • ext/standard/tests/array/unexpected_array_mod_bug.phpt
  • ext/standard/tests/strings/bug55871.phpt (it was a bogus behavior in php5.6 and below)
• Memory or resource leaks
  • ext/standard/tests/http/bug60570.phpt
• Inconsistent reference behaviour <?php $a['x'] = 'foo'; $a['x'] = &$a; $a = array(); $a['x'] = $a; var_dump($a); ?>
  • ext/wddx/tests/bug48562.phpt
• Bug in GC
  • Zend/tests/bug63635.phpt (visible with valgrind)
• GC doesn't destroy inner-loops
  • ext/standard/tests/array/compact_variation1.phpt
• Improper resource destruction
  • ext/standard/tests/streams/bug61115.phpt (visible with valgrind)
• Arrays are not allowed in class constants
  • Zend/tests/bug67368.phpt
  • Zend/tests/constant_expressions_self_referencing_array.phpt
• Improperly detected resource leaks during pharcmd build
• Memory leak if pdo persistent dbh lost connection to server
• call_user_func accepts some arguments for by-ref params that it did not previously. Reproduce code: $i = 1; $a = array(4, 3, 2, $i); var_dump(call_user_func("sort", $a));

• Split IS_BOOL into IS_FALSE and IS_TRUE.
• Introduce immutable arrays. They don't need to be copied and might be used directly from opcache shared memory. They might be also useful for APCU.
• Bundle libpcre with JIT support. ext/pcre must use it out of the box.
• Think about parameter passing/receiving. Currently parameters passed to user functions are copied twice. First by SEND and then by RECV.
• Refactor zend_parse_parameters() API (It's slow like a hell. for ord() function it takes 90% of CPU time). See PHP RFC: Fast Parameter Parsing API
• Convert some simple and often used internal functions into more efficient opcodes - e.g. defined(), strlen(), is_array()...
• Replace Zend Memory Manager with xx_malloc (it must give us at least additional 2% improvement)
• Use interned zend_strings for often used strings in C code.
• arg_info->name should be zend_string*, but we have to initialize it from C code.
• Think about CALL/RETURN related optimizations. Function call/return code is the main consumer of CPU time now.
• Try to optimize VM instructions dispatching. May be use global register for “execute_data”. May be also keep “opline” in CPU register?
• move zend_op.lineno into a separate compressed debug_info table.
• Try to reduce amount of data copied from OPCache SHM into process memory on each request
• Try to replace ext/json with pecl/jsond

We constantly measure the performance evaluation using the following 4 tests

• bench.php (sec) - time taken to execute Zend/bench.php

sapi/cli/php ../Zend/bench.php

• bench.php (instr) - number of CPU instructions for Zend/bench.php execution

valgrind --tool=callgrind sapi/cli/php ../Zend/bench.php

• WordPress (sec) - time taken to perform 1000 requests to wordpress-3.6.0 home page

sapi/cgi/php-cgi -T 1000 /var/www/html/bench/wordpress-3.6/index.php > /dev/null

• WordPress (instr) - number of CPU instructions for 100 requests to wordpress-3.6.0 home page

valgrind --tool=callgrind sapi/cgi/php-cgi -T 100 /var/www/html/bench/wordpress-3.6/index.php > /dev/null

more benchmarks