[php kernel bug] Extensions compiled with dynamic linking, expanding the global space dtor causes core dump_PHP tutorial

author: goosman.lei(Lei Guoguo)

blog: http://blog.csdn.net/lgg201

mail: lgg860911@yahoo.com.cn

Related codes can be found in Chapter 12 of the book , section "Extension Globals".

The global space code to register the extension is as follows:

#ifdef ZTS

ts_allocate_id(&sample_globals_id, sizeof(zend_sample_globals), (ts_allocate_ctor)ZEND_MODULE_GLOBALS_CTOR_N(sample), (ts_allocate_dtor)ZEND_MODULE_GLOBALS_DTOR_N(sample));

#else

sample_globals_ctor(&sample_globals TSRMLS_CC);

#endif

In the ts_allocate_id() function call, a record is written to the resource_types_table array.

In the process of tsrm_shutdown(), the registered dtor callback function will be called.

But after I finish coding according to the book, there will be coredump when running the test code.

After tracking, it was found that during the calling process of zend_shutdown(), DL_UNLOAD(module->handle); had been called on the module, causing the handle (dtor) registered at that time to be inaccessible when executing tsrm_shutdown().

At the same time, I saw that this registration method is also used in ext/standard/file.c in the standard extension. However, it should be statically compiled so there is no problem. My extension is compiled.so and dynamically linked.

The following is the calling path that traces zend_shutdown() to DL_UNLOAD().

zend_shutdown() => zend_desctroy_modules() => zend_hash_graceful_reverse_destroy() =>

http://www.bkjia.com/PHPjc/477806.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/477806.htmlTechArticleauthor: goosman.lei (Lei Guo) blog: http://blog.csdn.net/lgg201 mail : lgg860911@yahoo.com.cn For relevant code, please refer to Chapter 12 of the book php extending and embedding, section Extension Globals...