max_execution_time and async signal handling in apache2handler

Hi, I got a bug report on the Japanese PHP user's list that states free() aborts within the timer signal handler due to reentrance to the function when max_execution_time takes effect and the signal occurs within the same libc function. The reporter also states he uses apache2handler, which doesn't provide block_interruptions nor unblock_interruptions SAPI handlers in contrast to the apache1 handler. Whilst I doubt this happens quite frequently because PHP has its own memory pool and it's far more rare that the libc's allocators get called than the emalloc() and efree(), this should be addressed somehow. A proposed fix is attached but note this greatly compromises overall performance due to excessive system calls. Regards, Moriyoshi

Attachment: [text/x-patch] php-apache2-sigblock-20090316.patch.diff