2005-04-27 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

2005-04-27 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	Add wall-clock timing statistics to 'show thread cpu' output.
	* thread.h: Define struct rusage_t to contain wall-clock time
	  and cpu time.  Change GETRUSAGE macro to collect both pieces
	  of data.  Make appropriate changes to struct cpu_thread_history
	  to track CPU time and real time.  Change proto for
	  thread_consumed_time to return real and cpu time elapsed.
	  And declare a new global variable 'struct timeval recent_time'.
	* thread.c (struct timeval recent_time): New global timestamp variable.
	  (timeval_adjust): If timeout is negative, set to 0 (not 10
	  microseconds).  And remove upper bound of 1,000,000 seconds, since
	  this does not seem to make any sense (and it breaks
	  funcname_thread_add_timer_timeval).
	  (timeval_cmp): Should return long, not int.
	  (vty_out_cpu_thread_history): Show CPU time and real time.
	  (cpu_record_hash_print): Calculate totals for CPU and real time.
	  (cpu_record_print): Change 'show thread cpu' title to show CPU and
	  real time.
	  (thread_timer_remain_second): Put current time in global recent_time.
	  (funcname_thread_add_timer_timeval): Fix assert.  Replace 2-case
	  switch assignment with a ternary expression.  Use global recent_time
	  variable.  Fix use of timeval_adjust (previously, the value was not
	  actually being adjusted).
	  (thread_cancel): Add missing "break" statement in case
	  THREAD_BACKGROUND.
	  (thread_timer_wait): Use global recent_time value instead of calling
	  gettimeofday.  And there's no need to check for negative timeouts,
	  since timeval_subtract already sets these to zero.
	  (thread_timer_process): Timers are sorted, so bail out once we
	  encounter a timer that has not yet popped.  And remove some
	  extraneous asserts.
	  (thread_fetch): Do not process foreground timers before calling
	  select.  Instead, add them to the ready list just after the select.
	  Also, no need to maintain a count of the number of ready threads,
	  since we don't care how many there are, just whether there's
	  one at the head of the ready list (which is easily checked).
	  Stick current time in global variable recent_time to reduce
	  the number of calls to gettimeofday.  Tighten logic for
	  calculating the select timeout.
	  (thread_consumed_time): Now returns real time and puts the elapsed
	  cpu time in an additional argument.
	  (thread_should_yield): Use real (wall-clock) time to decide whether
	  to yield.
	  (thread_call): Maintain CPU and real time statistics.
	* vty.c (vty_command): For slow commands, show real and cpu time.