Core Dudes: Critical #20274 needs your input View as Markdown

Problem:

Solaris libc cannot fopen()/fdopen() more than 255 files. Additionally,
it cannot handle file descriptors larger than 255.
Although streams now avoids FILE* as much as possible, ZE1 requires
FILE* in its flex scanners.

Symptom:

PHP SAPI implementations based on threads or that recycle processes
may fail to open php scripts.
If thread/process has already opened a number of files (such as log
files opened for the web server), or has served previous requests, PHP
can fail to open even the primary script file.

Possible Solutions:

1. Backport my ZE-stream patch from ZE2. This would eliminate the
   problem entirely, as the ZE will no longer depend on the libc stdio
   implementation. However, this would cause a binary compatibility issue:
   in particular, the zend file handle structure needs to be memset to 0
   before use; encoders and caches would probably need to have their source
   code patched for this to work nicely.

2. Do nothing to the PHP_4_3 code but:

a) Suggest that people using PHP under Solaris use an alternative SAPI,
such as CGI/Fast-CGI. Performance will not be as good, but at least
the scripts will work reliably.
-> http://www.thetaphi.de/php-ressources/

b) Suggest that they build apache + mod_php against glibc for Solaris
if they really need better performance. The drawback here is that
any libraries that they intend to use with apache/php also need to
be compiled against glibc (== lots of compiling for them).

3. Is there another alternative that does not require a large amount of
   hacking in 4.3.x ?

IMO, 1.) is the nicest fix, but it is probably too big a change to make
in the 4.3.x series (especially with its impact on binary
compatibility), so I'm -1 on doing this.

It is worth noting that the perl guys have this same problem, and that
even with the changes I made to ZE2, any code in PHP that uses FILE* is
still affected by this issue.

This means that we should make an effort to replace VCWD_FOPEN macro
calls with either VCWD_OPEN, php_stream_open_wrapper or php_stream_fopen
where possible in PHP5.

Opinions please; we need to have an official resolution before 4.3.2 is
released. ("Solaris sucks, use <insert_name_of_not_so_broken_os_here>
instead")

--Wez.

PS: Thanks to Uwe for doing the legwork/research on the cause of this
problem.