Modification History:

 *** NOTE ***
 DO NOT UPDATE THIS FILE. UPDATE package.xml INSTEAD.
  This file contains the CHANGELOG for the initial release. For subsequent
  releases, the CHANGLELOG is maintained in the package.xml file itself.
  Please edit package.xml instead.
 ************

 03/02/2008   kannan, checkin xhprof_html/ and xhprof_lib/ directories.
              cjiang  [These contain PHP sources for the UI as well
                      as various supporting libraries to compute
                      "flat" info, diff reports, aggregate results
                      of multiple runs, typeahead support, etc.]
 02/20/2008   kannan  add basic sanity tests for the extension
 02/19/2008   kannan  register constants for optional profiler flags;
                      add xhprof.output_dir ini setting.
 01/22/2008   ps      port cpu affinity functions to FreeBSD
 01/15/2008   kannan  intercept builtins even if zend_execute_internal
                      were null to begin with
 01/14/2008   kannan  track builtins by default;
                      fix compiler warnings with fwd decls
 12/22/2008   cjiang  Further refactoring of the code for open sourcing:
                      (1). Remove level 1 profiling mode.
                      (2). Add xhprof_sample_enable, xhprof_sample_disable.
                      (3). Unifiy function and global variable prefix.
                      (4). Group relevant functions together.
                      (5). Migrate change history to CHANAGELOG file.
 12/19/2008   kannan  First step refactoring for open sourcing:
                      (1). Put basic direcotry structure
                      (2). Rename extension and function names
                      (3). Add LICENCE header.
 06/17/2008   veeve   use cycle_timer() for XHPROF_MODE_SAMPLED
 03/27/2008   cjiang  Add a 'hash-based' filter to reduce the number
                      of expensive call-stack tranversal on recursion
                      detection.
 03/17/2008   kannan  must not keep state on C stack to handle
                      exit (which causes _zend_bailout to longjmp
 02/25/2008   kannan  add xhprof_flags to toggle various metric
                      collections (buitins on/off, cpu metric on/off
                      memory stats on/off)
 02/14/2008   cjiang  Use cycle_timer based on 'rdtsc' instruction
                      on x86 machines to replace gettimeofday. rdtsc
                      is extremely cheap compared with gettimeofday
                      or getrusage.
 12/06/2007   veeve   bump version 1.1.2,
                      added hp_global_t
                      added mode callbacks, made modes extensible
                      added sampler mode
 12/05/2007   veeve   added doc; house cleaning
 11/28/2007   kannan  split include accounting into load/run_init
 11/09/2007   kannan  memory usage profiling
 10/27/2007   kannan  handle recursive calls, "include" operations
 10/20/2007   kannan  add hierarchical profiling; incl vs. exclusive
                      function times; browser based UI; diff and
                      aggregation support
 10/10/2007   hzhao   creation (flat function profiles)

Authors:
  Haiping Zhao           hzhao@facebook.com
  Kannan Muthukkaruppan  kannan@facebook.com
  Venkat Venkataramani   veeve@facebook.com
  Changhao Jiang         cjiang@facebook.com
