tree db5dca310a1ec496fc7e519417d80dbcfa5253f9
parent 5382f96a3a0708c050ece38cf70ad8d6808b882c
author Yann Ylavic <ylavic@apache.org> 1657881384 +0000
committer Yann Ylavic <ylavic@apache.org> 1657881384 +0000

util_pcre: Add a thread local subpool cache for when stack does not suffice.

When AP_HAS_THREAD_LOCAL is available, use a thread-local match_thread_state to
save per-thread data in a subpool of the thread's pool.

If private_malloc() gets out of the stack buffer and the current thread has a
pool (i.e. ap_thread_current() != NULL), it will apr_palloc()ate and return
memory from the subpool.

When the match is complete and the match_data are freed, the thread subpool is
cleared thus giving back the memory to the allocator, which itself will give
back the memory or recycle it depending on its max_free setting.

* util_pcre.c:
  Restore POSIX_MALLOC_THRESHOLDsince this is part of the user API.

* util_pcre.c(match_data_pt):
  Type not used (explicitely) anymore, axe.
  
* util_pcre.c(struct match_data_state):
  Put the stack buffer there to simplify code (the state is allocated on
  stack anyway).
  If APREG_USE_THREAD_LOCAL, add the apr_thread_t* and match_thread_state*
  fields that track the thread local data for the match.

* util_pcre.c(alloc_match_data, free_match):
  Renamed to setup_state() and cleanup_state(), simplified (no stack buffer
  parameters anymore).
  cleanup_state() now clears the thread local subpool if used during the match.
  setup_state() set state->thd to ap_thread_current(), thus NULL if it's not a
  suitable thread for using thread local data.

* util_pcre.c(private_malloc):
  Fix a possible buf_used overflow (size <= avail < APR_ALIGN_DEFAULT(size)).
  Create the thread local subpool (once per thread) and allocate from there
  when stack space is missing and state->thd != NULL, otherwise fall back to
  malloc() still.

* util_pcre.c(private_free):
  Do nothing for thread local subpool memory, will be freed in cleanup_state
  eventually.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1902731 13f79535-47bb-0310-9956-ffa450edef68