X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftime.lisp;h=fb35b183eb50ab97e4033e56d80dca7c7e1e130f;hb=c7de1989d006e0b3a4f26143b7a81c9bdb754101;hp=4781333814d5a6cb138d573441669a91953e0580;hpb=31361af9eb64344f521abbb245ea784c76c746e5;p=sbcl.git diff --git a/src/code/time.lisp b/src/code/time.lisp index 4781333..fb35b18 100644 --- a/src/code/time.lisp +++ b/src/code/time.lisp @@ -11,13 +11,13 @@ (in-package "SB!IMPL") -(defconstant internal-time-units-per-second 100 +(defconstant sb!xc:internal-time-units-per-second 1000 #!+sb-doc "The number of internal time units that fit into a second. See GET-INTERNAL-REAL-TIME and GET-INTERNAL-RUN-TIME.") (defconstant micro-seconds-per-internal-time-unit - (/ 1000000 internal-time-units-per-second)) + (/ 1000000 sb!xc:internal-time-units-per-second)) ;;; The base number of seconds for our internal "epoch". We initialize ;;; this to the time of the first call to GET-INTERNAL-REAL-TIME, and @@ -27,10 +27,8 @@ (defun get-internal-real-time () #!+sb-doc - "Return the real time in the internal time format. This is useful for - finding elapsed time. See INTERNAL-TIME-UNITS-PER-SECOND." - ;; FIXME: See comment on OPTIMIZE declaration in GET-INTERNAL-RUN-TIME. - (declare (optimize (speed 3) (safety 3))) + "Return the real time in the internal time format. (See + INTERNAL-TIME-UNITS-PER-SECOND.) This is useful for finding elapsed time." (multiple-value-bind (ignore seconds useconds) (sb!unix:unix-gettimeofday) (declare (ignore ignore) (type (unsigned-byte 32) seconds useconds)) (let ((base *internal-real-time-base-seconds*) @@ -41,7 +39,7 @@ (truly-the (unsigned-byte 32) (+ (the (unsigned-byte 32) (* (the (unsigned-byte 32) (- seconds base)) - internal-time-units-per-second)) + sb!xc:internal-time-units-per-second)) uint))) (t (setq *internal-real-time-base-seconds* seconds) @@ -49,15 +47,9 @@ (defun get-internal-run-time () #!+sb-doc - "Return the run time in the internal time format. This is useful for - finding CPU usage." + "Return the run time in the internal time format. (See + INTERNAL-TIME-UNITS-PER-SECOND.) This is useful for finding CPU usage." (declare (values (unsigned-byte 32))) - ;; FIXME: In CMU CL this was (SPEED 3) (SAFETY 0), and perhaps - ;; someday it should be again, since overhead here is annoying. But - ;; it's even more annoying to worry about this function returning - ;; out-of-range values, so while debugging the profiling code, - ;; I set it to (SAFETY 3) for now. - (declare (optimize (speed 3) (safety 3))) (multiple-value-bind (ignore utime-sec utime-usec stime-sec stime-usec) (sb!unix:unix-fast-getrusage sb!unix:rusage_self) (declare (ignore ignore) @@ -67,10 +59,9 @@ ;; documented anywhere and the observed behavior is to ;; sometimes return 1000000 exactly.) (type (integer 0 1000000) utime-usec stime-usec)) - (let ((result (+ (the (unsigned-byte 32) (* (the (unsigned-byte 32) (+ utime-sec stime-sec)) - internal-time-units-per-second)) + sb!xc:internal-time-units-per-second)) (floor (+ utime-usec stime-usec (floor micro-seconds-per-internal-time-unit 2)) @@ -79,13 +70,42 @@ ;;;; Encode and decode universal times. -;;; Returns two values: -;;; - the minutes west of GMT. -;;; - T if daylight savings is in effect, NIL if not. -(sb!alien:def-alien-routine get-timezone sb!c-call:void - (when sb!c-call:long :in) - (minutes-west sb!c-call:int :out) - (daylight-savings-p sb!alien:boolean :out)) +;;; In August 2003, work was done in this file for more plausible +;;; timezone handling after the unix timezone database runs out in +;;; 2038. We assume that timezone rules are trending sane rather than +;;; insane, so for all years after the end of time_t we apply the +;;; rules for 2035/2036 instead of the actual date asked for. Making +;;; the same assumption about the early 1900s would be less +;;; reasonable, however, so please note that we're still broken for +;;; local time between 1900-1-1 and 1901-12-13 + +;;; It should be noted that 64 bit machines don't actually fix this +;;; problem, at least as of 2003, because the Unix zonefiles are +;;; specified in terms of 32 bit fields even on, say, the Alpha. So, +;;; references to the range of time_t elsewhere in this file should +;;; rightly be read as shorthand for the range of an signed 32 bit +;;; number of seconds since 1970-01-01 + +;;; I'm obliged to Erik Naggum's "Long, Painful History of Time" paper +;;; for the choice of epoch +;;; here. By starting the year in March, we avoid having to test the month +;;; whenever deciding whether to account for a leap day. 2000 is especially +;;; special, because it's disvisible by 400, hence the start of a 400 year +;;; leap year cycle + +;;; If a universal-time is after time_t runs out, we find its offset +;;; from 1st March of whichever year it falls in, then add that to +;;; 2035-3-1. This date has two relevant properties: (1) somewhere +;;; near the end of time_t, and (2) preceding a leap year. Thus a +;;; date which is e.g. 365.5 days from March 1st in its year will be +;;; treated for timezone lookup as if it were Feb 29th 2036 + +;;; This epoch is used only for fixing the timezones-outside-time_t +;;; problem. Someday it would be nice to come back to this code and +;;; see if the rest of the file and its references to Spice Lisp +;;; history (Perq time base?) could be cleaned up any on this basis. +;;; -- dan, 2003-08-08 + ;;; Subtract from the returned Internal-Time to get the universal ;;; time. The offset between our time base and the Perq one is 2145 @@ -102,7 +122,7 @@ (defun get-universal-time () #!+sb-doc - "Returns a single integer for the current time of + "Return a single integer for the current time of day in universal time format." (multiple-value-bind (res secs) (sb!unix:unix-gettimeofday) (declare (ignore res)) @@ -110,11 +130,40 @@ (defun get-decoded-time () #!+sb-doc - "Returns nine values specifying the current time as follows: + "Return nine values specifying the current time as follows: second, minute, hour, date, month, year, day of week (0 = Monday), T (daylight savings times) or NIL (standard time), and timezone." (decode-universal-time (get-universal-time))) +(defconstant +mar-1-2000+ #.(encode-universal-time 0 0 0 1 3 2000 0)) +(defconstant +mar-1-2035+ #.(encode-universal-time 0 0 0 1 3 2035 0)) + +(defun years-since-mar-2000 (utime) + "Returns number of complete years since March 1st 2000, and remainder in seconds" + (let* ((days-in-year (* 86400 365)) + (days-in-4year (+ (* 4 days-in-year) 86400)) + (days-in-100year (- (* 25 days-in-4year) 86400)) + (days-in-400year (+ (* 4 days-in-100year) 86400)) + (offset (- utime +mar-1-2000+)) + (year 0)) + (labels ((whole-num (x y inc max) + (let ((w (truncate x y))) + (when (and max (> w max)) (setf w max)) + (incf year (* w inc)) + (* w y)))) + (decf offset (whole-num offset days-in-400year 400 nil)) + (decf offset (whole-num offset days-in-100year 100 3)) + (decf offset (whole-num offset days-in-4year 4 25)) + (decf offset (whole-num offset days-in-year 1 3)) + (values year offset)))) + +(defun truncate-to-unix-range (utime) + (let ((unix-time (- utime unix-to-universal-time))) + (if (< unix-time (ash 1 31)) + unix-time + (multiple-value-bind (year offset) (years-since-mar-2000 utime) + (+ +mar-1-2035+ (- unix-to-universal-time) offset))))) + (defun decode-universal-time (universal-time &optional time-zone) #!+sb-doc "Converts a universal-time to decoded time format returning the following @@ -133,15 +182,16 @@ (year NIL) (day NIL) (daylight NIL) - (timezone (if (null time-zone) - (multiple-value-bind - (ignore minwest dst) - (get-timezone (- universal-time - unix-to-universal-time)) - (declare (ignore ignore)) - (setf daylight dst) - minwest) - (* time-zone 60)))) + (timezone (cond + ((null time-zone) + (multiple-value-bind (ignore minwest dst) + (sb!unix::get-timezone + (truncate-to-unix-range universal-time)) + (declare (ignore ignore)) + (declare (fixnum minwest)) + (setf daylight dst) + minwest)) + (t (* time-zone 60))))) (declare (fixnum timezone)) (multiple-value-bind (t1 seconds) (truncate secs 60) (setq second seconds) @@ -195,6 +245,7 @@ (incf sum days-in-month)) (coerce (nreverse reversed-result) 'simple-vector))) + (defun encode-universal-time (second minute hour date month year &optional time-zone) #!+sb-doc @@ -219,39 +270,36 @@ (hours (+ hour (* days 24)))) (if time-zone (+ second (* (+ minute (* (+ hours time-zone) 60)) 60)) - (let* ((minwest-guess - (nth-value 1 - (get-timezone (- (* hours 60 60) - unix-to-universal-time)))) - (guess (+ minute (* hours 60) minwest-guess)) - (minwest - (nth-value 1 - (get-timezone (- (* guess 60) - unix-to-universal-time))))) - (+ second (* (+ guess (- minwest minwest-guess)) 60)))))) + ;; can't ask unix for times after 2037: this is only a problem + ;; if we need to query the system timezone + (if (> year 2037) + (labels ((leap-year-p (year) + (cond ((zerop (mod year 400)) t) + ((zerop (mod year 100)) t) + ((zerop (mod year 4)) t) + (t nil)))) + (let* ((fake-year (if (leap-year-p year) 2036 2037)) + (fake-time (encode-universal-time second minute hour + date month fake-year))) + (+ fake-time + (* 86400 (+ (* 365 (- year fake-year)) + (- (leap-years-before year) + (leap-years-before fake-year))))))) + (let* ((minwest-guess + (sb!unix::unix-get-minutes-west + (- (* hours 60 60) unix-to-universal-time))) + (guess (+ minute (* hours 60) minwest-guess)) + (minwest + (sb!unix::unix-get-minutes-west + (- (* guess 60) unix-to-universal-time)))) + (+ second (* (+ guess (- minwest minwest-guess)) 60))))))) ;;;; TIME (defmacro time (form) #!+sb-doc - "Evaluates the Form and prints timing information on *Trace-Output*." - `(%time #'(lambda () ,form))) - -;;; Try to compile the closure arg to %TIME if it is interpreted. -(defun massage-time-function (fun) - (cond - #!+sb-interpreter - ((sb!eval:interpreted-function-p fun) - (multiple-value-bind (def env-p) (function-lambda-expression fun) - (declare (ignore def)) - (cond - (env-p - (warn "non-null environment for TIME form, forced to interpret.~@ - Compiling the entire form will produce more accurate times.") - fun) - (t - (compile nil fun))))) - (t fun))) + "Execute FORM and print timing information on *TRACE-OUTPUT*." + `(%time (lambda () ,form))) ;;; Return all the data that we want TIME to report. (defun time-get-sys-info () @@ -261,8 +309,8 @@ ;;; The guts of the TIME macro. Compute overheads, run the (compiled) ;;; function, report the times. (defun %time (fun) - (let ((fun (massage-time-function fun)) - old-run-utime + (declare (type function fun)) + (let (old-run-utime new-run-utime old-run-stime new-run-stime @@ -319,12 +367,12 @@ ~S page fault~:P and~% ~ ~S bytes consed.~%" (max (/ (- new-real-time old-real-time) - (float internal-time-units-per-second)) + (float sb!xc:internal-time-units-per-second)) 0.0) (max (/ (- new-run-utime old-run-utime) 1000000.0) 0.0) (max (/ (- new-run-stime old-run-stime) 1000000.0) 0.0) (unless (zerop gc-run-time) (/ (float gc-run-time) - (float internal-time-units-per-second))) + (float sb!xc:internal-time-units-per-second))) (max (- new-page-faults old-page-faults) 0) (max (- new-bytes-consed old-bytes-consed) 0)))))))