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Arnaud Le Blanc c13794cdcb
Adjust GC threshold if num_roots is higher than gc_threshold after collection (#13758)
This fixes an edge case causing the GC to be triggered repeatedly.

Destructors might add potential garbage to the buffer, so it may happen that num_root it higher than gc_threshold after collection, thus triggering a GC run almost immediately. This can happen by touching enough objects in a destructor, e.g. by iterating over an array. If this happens again in the new run, and the threshold is not updated, the GC may be triggered again.

The edge case requires specific conditions to be triggered and it must happen rarely in practice:

 * At least GC_THRESHOLD_TRIGGER (100) objects must be collected during each run for the threshold to not be updated
 * At least GC_G(gc_threshold) (initially 10k) objects must be touched (decref'ed to n>0) by any destructor during each run to fill the buffer

The fix is to increase the threshold if GC_G(num_roots) >= GC_G(gc_threshold) after GC. The threshold eventually reaches a point at which the second condition is not met anymore.

The included tests trigger more than 200 GC runs before the fix, and 2 after the fix (dtors always trigger a second run).

A related issue is that zend_gc_check_root_tmpvars() may add potential garbage before the threshold is adjusted, which may trigger GC and exhaust the stack. This is fixed by setting GC_G(active)=1 around zend_gc_check_root_tmpvars().
2024-03-25 16:17:54 +01:00
.circleci CircleCI: Increase no_output_timeout to 30m 2023-10-12 14:04:13 +02:00
.github Fix brew action (#13659) 2024-03-10 20:11:24 +05:30
appveyor Merge branch 'PHP-8.1' into PHP-8.2 2022-10-09 18:48:07 +02:00
build Fix AX_GCC_FUNC_ATTRIBUTE failure 2024-03-22 11:29:45 +01:00
docs Merge branch 'PHP-8.1' into PHP-8.2 2023-07-05 15:16:01 +02:00
ext Fix incorrect charset length in check_mb_eucjpms() 2024-03-22 11:31:36 +01:00
main Fix GH-13203: file_put_contents fail on strings over 4GB on Windows 2024-03-09 19:58:28 +00:00
pear [ci skip] Remove text editor modelines 2019-03-23 21:09:38 +01:00
sapi Fix incorrect check in fpm_shm_free() (#13797) 2024-03-24 13:57:08 +01:00
scripts Update year to 2024 2024-01-04 19:26:32 +01:00
tests Merge branch 'PHP-8.1' into PHP-8.2 2022-11-09 15:23:21 +01:00
travis Fix travis_wait 2023-11-29 10:35:09 +01:00
TSRM Fix GH-13727: macro generating invalid call test prototypes fixes. 2024-03-18 06:53:39 +00:00
win32 Merge branch 'PHP-8.1' into PHP-8.2 2023-02-17 16:38:53 +00:00
Zend Adjust GC threshold if num_roots is higher than gc_threshold after collection (#13758) 2024-03-25 16:17:54 +01:00
.cirrus.yml CI: update freebsd 13 image. 2024-03-19 22:34:56 +00:00
.editorconfig Fix JIT crash with large number of match/switch arms (#8961) 2022-07-18 12:34:20 +02:00
.gdbinit Fix dumping of zend_string.val in gdb 2024-01-23 12:55:24 +01:00
.gitattributes Fixed OSS fuzz issues #55589, #55599, and #55727 2023-02-10 13:03:47 +00:00
.gitignore Merge branch 'PHP-8.1' into PHP-8.2 2023-02-02 18:59:20 +01:00
.travis.yml Fix travis_wait 2023-11-29 10:35:09 +01:00
buildconf Remove build.mk usage 2019-07-21 11:40:23 +02:00
buildconf.bat Fix #79146: cscript can fail to run on some systems 2020-01-21 11:53:11 +01:00
CODING_STANDARDS.md Improve documentation for contributors 2021-06-17 06:29:38 +02:00
configure.ac Fix GH-13727: macro generating invalid call test prototypes fixes. 2024-03-18 06:53:39 +00:00
CONTRIBUTING.md Merge branch 'PHP-8.1' into PHP-8.2 2023-07-05 15:16:01 +02:00
EXTENSIONS [ci skip] Update EXTENSIONS and Author(s) in ext/random (#9074) 2022-07-21 17:53:32 +02:00
LICENSE Update year to 2024 2024-01-04 19:26:32 +01:00
NEWS [ci skip] NEWS 2024-03-24 13:58:09 +01:00
php.ini-development Remove mysqli.reconnect from php.ini files (#11836) 2023-08-19 22:54:21 +03:00
php.ini-production Remove mysqli.reconnect from php.ini files (#11836) 2023-08-19 22:54:21 +03:00
README.md Merge branch 'PHP-8.1' into PHP-8.2 2023-07-05 15:16:01 +02:00
README.REDIST.BINS [ci skip] Merge branch 'PHP-8.1' into PHP-8.2 2022-11-10 12:42:19 +01:00
run-tests.php Retry tests on deadlock 2023-11-16 16:02:20 +01:00
UPGRADING ext/gettext: dcgettext/dcngettext fix for stable branches. 2024-03-05 18:39:14 +00:00
UPGRADING.INTERNALS [skip ci] Document zend_enum_get_case_by_value() function 2022-10-20 11:08:57 +02:00

The PHP Interpreter

PHP is a popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world. PHP is distributed under the PHP License v3.01.

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Documentation

The PHP manual is available at php.net/docs.

Installation

Prebuilt packages and binaries

Prebuilt packages and binaries can be used to get up and running fast with PHP.

For Windows, the PHP binaries can be obtained from windows.php.net. After extracting the archive the *.exe files are ready to use.

For other systems, see the installation chapter.

Building PHP source code

For Windows, see Build your own PHP on Windows.

For a minimal PHP build from Git, you will need autoconf, bison, and re2c. For a default build, you will additionally need libxml2 and libsqlite3.

On Ubuntu, you can install these using:

sudo apt install -y pkg-config build-essential autoconf bison re2c \
                    libxml2-dev libsqlite3-dev

On Fedora, you can install these using:

sudo dnf install re2c bison autoconf make libtool ccache libxml2-devel sqlite-devel

Generate configure:

./buildconf

Configure your build. --enable-debug is recommended for development, see ./configure --help for a full list of options.

# For development
./configure --enable-debug
# For production
./configure

Build PHP. To speed up the build, specify the maximum number of jobs using -j:

make -j4

The number of jobs should usually match the number of available cores, which can be determined using nproc.

Testing PHP source code

PHP ships with an extensive test suite, the command make test is used after successful compilation of the sources to run this test suite.

It is possible to run tests using multiple cores by setting -jN in TEST_PHP_ARGS:

make TEST_PHP_ARGS=-j4 test

Shall run make test with a maximum of 4 concurrent jobs: Generally the maximum number of jobs should not exceed the number of cores available.

The qa.php.net site provides more detailed info about testing and quality assurance.

Installing PHP built from source

After a successful build (and test), PHP may be installed with:

make install

Depending on your permissions and prefix, make install may need super user permissions.

PHP extensions

Extensions provide additional functionality on top of PHP. PHP consists of many essential bundled extensions. Additional extensions can be found in the PHP Extension Community Library - PECL.

Contributing

The PHP source code is located in the Git repository at github.com/php/php-src. Contributions are most welcome by forking the repository and sending a pull request.

Discussions are done on GitHub, but depending on the topic can also be relayed to the official PHP developer mailing list internals@lists.php.net.

New features require an RFC and must be accepted by the developers. See Request for comments - RFC and Voting on PHP features for more information on the process.

Bug fixes don't require an RFC. If the bug has a GitHub issue, reference it in the commit message using GH-NNNNNN. Use #NNNNNN for tickets in the old bugs.php.net bug tracker.

Fix GH-7815: php_uname doesn't recognise latest Windows versions
Fix #55371: get_magic_quotes_gpc() throws deprecation warning

See Git workflow for details on how pull requests are merged.

Guidelines for contributors

See further documents in the repository for more information on how to contribute:

Credits

For the list of people who've put work into PHP, please see the PHP credits page.