PHP内存泄漏分析定位

Fatal error: Allowed memory size of X bytes exhausted (tried to allocate Y bytes)

memory_get_usage()，这个函数的作用是获取目前PHP脚本所用的内存大小。
memory_get_peak_usage()，这个函数的作用返回当前脚本到目前位置所占用的内存峰值，这样就可能获取到目前的脚本的内存需求情况。

int memory_get_usage ([ bool $real_usage = false ] )

int memory_get_peak_usage ([ bool $real_usage = false ] )

php
ini_set(‘memory_limit‘, ‘128M‘);

$string = str_pad(‘1‘, 128 * 1024 * 1024);//str_pad函数的作用把字符串填充为新的长度

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 134217729 bytes) in /Users/zouyi/php-oom/bigfile.php on line 3

php
//php7 以下版本通过 composer 引入 paragonie/random_compat ，为了方便来生成一个随机名称的临时文件
require "vendor/autoload.php";
ini_set(‘memory_limit‘, ‘128M‘);
//生成临时文件存放大字符串
$fileName = ‘tmp‘.bin2hex(random_bytes(5)).‘.txt‘;
touch($fileName);
for ( $i = 0; $i <128; $i++ ) {
$string = str_pad(‘1‘, 1 * 1024 * 1024);
file_put_contents($fileName, $string, FILE_APPEND);
}
$handle = fopen($fileName, "r");
for ( $i = 0; $i <= filesize($fileName) / 1 * 1024 * 1024; $i++ ) {
//do something
$string = fread($handle, 1 * 1024 * 1024);
}
fclose($handle);
unlink($fileName);

php
ini_set("memory_limit",‘1M‘);
$string = str_pad(‘1‘, 1* 750 *1024);
$string2 = $string;
$string2 .= ‘1‘;

Fatal error: Allowed memory size of 1048576 bytes exhausted (tried to allocate 768001 bytes) in /Users/zouyi/php-oom/unset.php on line 8 Call Stack: 0.0004 235440 1. {main}() /Users/zouyi/php-oom/unset.php:0 zend_mm_heap corrupted

php
ini_set("memory_limit",‘1M‘);
$string = str_pad(‘1‘, 1* 750 *1024);
$string2 = $string;
unset($string);
$string2 .= ‘1‘;

php
ini_set("memory_limit",‘1M‘);
$string = str_pad(‘1‘, 1* 750 *1024);
$string2 = &$string;
$string2 .= ‘1‘;
unset($string2, $string);

$ php -i |grep memory memory_limit => 1024M => 1024M //php脚本执行最大可使用内存
$php -i |grep max max_execution_time => 0 => 0 //最大执行时间，脚本默认为0不限制，web请求默认30s
max_file_uploads => 20 => 20 //一个表单里最大上传文件数量max_input_nesting_level => 64 => 64 //一个表单里数据最大数组深度层数
max_input_time => -1 => -1 //php从接收请求开始处理数据后的超时时间
max_input_vars => 1000 => 1000 //一个表单（包括get、post、COOKIE的所有数据）最多提交1000个字段
post_max_size => 8M => 8M //一次post请求最多提交8M数据upload_max_filesize => 2M => 2M //一个可上传的文件最大不超过2M

pm = dynamic //仅dynamic模式下以下参数生效
pm.max_children = 10 //最大子进程数
pm.start_servers = 3 //启动时启动子进程数
pm.min_spare_servers = 2 //最小空闲进程数，不够了启动更多进程
pm.max_spare_servers = 5 //最大空闲进程数，超过了结束一些进程
pm.max_requests = 500 //最大请求数，注意这个参数是一个php-fpm如果处理了500个请求后会自己重启一下，可以避免一些三方扩展的内存泄露问题

$ulimit -a
-t: cpu time (seconds) unlimited
-f: file size (blocks) unlimited
-d: data seg size (kbytes) unlimited
-s: stack size (kbytes) 8192
-c: core file size (blocks) 0
-v: address space (kbytes) unlimited
-l: locked-in-memory size (kbytes) unlimited
-u: processes 1024
-n: file descriptors 1024

DB::listen(function ($query) {
// $query->sql
// $query->bindings
// $query->time
});

模块初始化（MINIT）-> 请求初始化（RINIT）-> 请求处理 -> 请求结束（RSHUTDOWN） -> 请求初始化（RINIT）-> 请求处理 -> 请求结束（RSHUTDOWN）……. 请求初始化（RINIT）-> 请求处理 -> 请求结束（RSHUTDOWN）-> 模块关闭（MSHUTDOWN）。

$ export USE_ZEND_ALLOC=0 # 设置环境变量关闭内存管理 $ valgrind --tool=memcheck --num-callers=30 --log-file=php.log /Users/zouyi/Downloads/php-5.6.31/sapi/cli/php leak.php

==12075== Memcheck, a memory error detector
==12075== Copyright (C) 2002-2017, and GNU GPL‘d, by Julian Seward et al.
==12075== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==12075== Command: /Users/zouyi/Downloads/php-5.6.31/sapi/cli/php leak.php
==12075== Parent PID: 42043
==12075==
==12075== Syscall param msg->desc.port.name points to uninitialised byte(s)
==12075== at 0x10121F34A: mach_msg_trap (in /usr/lib/system/libsystem_kernel.dylib)
==12075== by 0x10121E796: mach_msg (in /usr/lib/system/libsystem_kernel.dylib)
==12075== by 0x101218485: task_set_special_port (in /usr/lib/system/libsystem_kernel.dylib)
==12075== by 0x1013B410E: _os_trace_create_debug_control_port (in /usr/lib/system/libsystem_trace.dylib)
==12075== by 0x1013B4458: _libtrace_init (in /usr/lib/system/libsystem_trace.dylib)
==12075== by 0x100DF09DF: libSystem_initializer (in /usr/lib/libSystem.B.dylib)
==12075== by 0x100C37A1A: ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) (in /usr/lib/dyld)
==12075== by 0x100C37C1D: ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) (in /usr/lib/dyld)
==12075== by 0x100C334A9: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld)
==12075== by 0x100C33440: ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld)
==12075== by 0x100C32523: ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) (in /usr/lib/dyld)
==12075== by 0x100C325B8: ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) (in /usr/lib/dyld) ==12075== by 0x100C24433: dyld::initializeMainExecutable() (in /usr/lib/dyld)
==12075== by 0x100C288C5: dyld::_main(macho_header const*, unsigned long, int, char const**, char const**, char const**, unsigned long*) (in /usr/lib/dyld)
==12075== by 0x100C23248: dyldbootstrap::start(macho_header const*, int, char const**, long, macho_header const*, unsigned long*) (in /usr/lib/dyld) ==12075== by 0x100C23035: _dyld_start (in /usr/lib/dyld)
==12075== by 0x1: ???
==12075== by 0x1054AC862: ???
==12075== by 0x1054AC891: ???
==12075== Address 0x1054aa98c is on thread 1‘s stack
==12075== in frame #2, created by task_set_special_port (???:)
==12075==
--12075-- UNKNOWN mach_msg unhandled MACH_SEND_TRAILER option
--12075-- UNKNOWN mach_msg unhandled MACH_SEND_TRAILER option (repeated 2 times)
--12075-- UNKNOWN mach_msg unhandled MACH_SEND_TRAILER option (repeated 4 times)
==12075==
==12075== HEAP SUMMARY:
==12075== in use at exit: 125,805 bytes in 185 blocks
==12075== total heap usage: 14,686 allocs, 14,501 frees, 3,261,322 bytes allocated
==12075==
==12075== LEAK SUMMARY:
==12075== definitely lost: 3 bytes in 1 blocks
==12075== indirectly lost: 0 bytes in 0 blocks
==12075== possibly lost: 72 bytes in 3 blocks
==12075== still reachable: 107,582 bytes in 23 blocks
==12075== suppressed: 18,148 bytes in 158 blocks
==12075== Rerun with --leak-check=full to see details of leaked memory
==12075==
==12075== For counts of detected and suppressed errors, rerun with: -v
==12075== Use --track-origins=yes to see where uninitialised values come from
==12075== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 1 from 1)