Lisp SBCL&x27;s statistic profiler不会为每个调用的函数显示一个条目
我正在使用SBCL的统计分析器分析这些功能:Lisp SBCL&x27;s statistic profiler不会为每个调用的函数显示一个条目,lisp,common-lisp,profiler,sbcl,Lisp,Common Lisp,Profiler,Sbcl,我正在使用SBCL的统计分析器分析这些功能: (defun fact-rec (n) (if (zerop n) 1 (* n (fact-rec (1- n))))) (defun fact-call (n) (fact-rec n)) (defun fact-iter (n) (loop :with accu = 1 :for i :upfrom 2 :to n :doing (setf accu (* i accu)) :fi
(defun fact-rec (n)
(if (zerop n)
1
(* n (fact-rec (1- n)))))
(defun fact-call (n)
(fact-rec n))
(defun fact-iter (n)
(loop :with accu = 1
:for i :upfrom 2 :to n
:doing (setf accu (* i accu))
:finally (return accu)))
(defun fact-opti-iter (n)
(let ((accu 1))
(tagbody
loop
(unless (zerop n)
(setf accu (* n accu))
(decf n)
(go loop)))
accu))
为了评估递归版本的权重,我定义了一个函数fact call
,它位于所有fact rec
调用下面的堆栈上,以便能够正确地监视它。以下是我的分析代码:
(sb-sprof:profile-call-counts 'fact-rec 'fact-call 'fact-iter 'fact-opti-iter)
(sb-sprof:with-profiling (:max-samples 1000
:loop nil
:report :flat)
(dotimes (i 1500)
(fact-call i)
(fact-iter i)
(fact-opti-iter i)))
这样做可以确保从不直接调用事实记录
,因此,如果它出现在探查器的报告中,那么它必然被事实记录
调用。但我得到的报告如下:
Profiler sample vector full (70 traces / 10000 samples), doubling the size
Profiler sample vector full (133 traces / 20000 samples), doubling the size
Number of samples: 195
Sample interval: 0.01 seconds
Total sampling time: 1.9499999 seconds
Number of cycles: 0
Sampled threads:
#
Self Total Cumul
Nr Count % Count % Count % Calls Function
------------------------------------------------------------------------
1 193 99.0 193 99.0 193 99.0 - SB-BIGNUM:MULTIPLY-BIGNUM-AND-FIXNUM
2 1 0.5 195 100.0 194 99.5 - SB-KERNEL:TWO-ARG-*
3 1 0.5 1 0.5 195 100.0 - SB-BIGNUM::%NORMALIZE-BIGNUM
4 0 0.0 195 100.0 195 100.0 - "Unknown component: #x100317AB30"
5 0 0.0 195 100.0 195 100.0 - SB-INT:SIMPLE-EVAL-IN-LEXENV
6 0 0.0 195 100.0 195 100.0 - EVAL
7 0 0.0 195 100.0 195 100.0 - SWANK::EVAL-REGION
8 0 0.0 195 100.0 195 100.0 - (LAMBDA NIL :IN SWANK-REPL::REPL-EVAL)
9 0 0.0 195 100.0 195 100.0 - SWANK-REPL::TRACK-PACKAGE
10 0 0.0 195 100.0 195 100.0 - SWANK::CALL-WITH-RETRY-RESTART
11 0 0.0 195 100.0 195 100.0 - SWANK::CALL-WITH-BUFFER-SYNTAX
12 0 0.0 195 100.0 195 100.0 - SWANK-REPL::REPL-EVAL
13 0 0.0 195 100.0 195 100.0 - SWANK:EVAL-FOR-EMACS
14 0 0.0 195 100.0 195 100.0 - SWANK::PROCESS-REQUESTS
15 0 0.0 195 100.0 195 100.0 - (LAMBDA NIL :IN SWANK::HANDLE-REQUESTS)
16 0 0.0 195 100.0 195 100.0 - SWANK/SBCL::CALL-WITH-BREAK-HOOK
17 0 0.0 195 100.0 195 100.0 - (FLET SWANK/BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/Users/vleo/quicklisp/dists/quicklisp/software/slime-v2.19/swank/sbcl.lisp")
18 0 0.0 195 100.0 195 100.0 - SWANK::CALL-WITH-BINDINGS
19 0 0.0 195 100.0 195 100.0 - SWANK::HANDLE-REQUESTS
20 0 0.0 195 100.0 195 100.0 - (LABELS SWANK/SBCL::RUN :IN SWANK/BACKEND:ADD-FD-HANDLER)
21 0 0.0 195 100.0 195 100.0 - SB-IMPL::SUB-SUB-SERVE-EVENT
22 0 0.0 195 100.0 195 100.0 - SB-IMPL::SUB-SERVE-EVENT
23 0 0.0 195 100.0 195 100.0 - SB-SYS:WAIT-UNTIL-FD-USABLE
24 0 0.0 195 100.0 195 100.0 - SB-IMPL::REFILL-INPUT-BUFFER
25 0 0.0 195 100.0 195 100.0 - SB-IMPL::INPUT-CHAR/UTF-8
26 0 0.0 195 100.0 195 100.0 - (LAMBDA (&REST REST) :IN SB-IMPL::GET-EXTERNAL-FORMAT)
27 0 0.0 195 100.0 195 100.0 - READ-CHAR
28 0 0.0 195 100.0 195 100.0 - SB-IMPL::%READ-PRESERVING-WHITESPACE
29 0 0.0 195 100.0 195 100.0 - READ
30 0 0.0 195 100.0 195 100.0 - SB-IMPL::REPL-READ-FORM-FUN
31 0 0.0 195 100.0 195 100.0 - SB-IMPL::REPL-FUN
32 0 0.0 195 100.0 195 100.0 - (LAMBDA NIL :IN SB-IMPL::TOPLEVEL-REPL)
33 0 0.0 195 100.0 195 100.0 - SB-IMPL::%WITH-REBOUND-IO-SYNTAX
34 0 0.0 195 100.0 195 100.0 - SB-IMPL::TOPLEVEL-REPL
35 0 0.0 195 100.0 195 100.0 - SB-IMPL::TOPLEVEL-INIT
36 0 0.0 195 100.0 195 100.0 - (FLET #:WITHOUT-INTERRUPTS-BODY-74 :IN SAVE-LISP-AND-DIE)
37 0 0.0 195 100.0 195 100.0 - (LABELS SB-IMPL::RESTART-LISP :IN SAVE-LISP-AND-DIE)
38 0 0.0 69 35.4 195 100.0 1500 FACT-OPTI-ITER
39 0 0.0 65 33.3 195 100.0 1125750 FACT-REC
40 0 0.0 61 31.3 195 100.0 1500 FACT-ITER
------------------------------------------------------------------------
0 0.0 elsewhere
探查器样本向量已满(70道/10000个样本),大小加倍
探查器样本向量已满(133道/20000个样本),大小加倍
样本数目:195
采样间隔:0.01秒
总采样时间:1.949999秒
循环次数:0
采样线程:
#
自总积云
Nr Count%Count%Count%调用函数
------------------------------------------------------------------------
119399.019399.019399.019399.0-SB-BIGNUM:MULTIPLY-BIGNUM-AND-FIXNUM
21 0.5 195 100.0 194 99.5-SB-KERNEL:TWO-ARG-*
3 1 0.5 1 0.5 195 100.0-SB-BIGNUM::%NORMALIZE-BIGNUM
4 0 0.0 195 100.0 195 100.0-“未知部件:#x100317AB30”
5 0 0.0 195 100.0 195 100.0-SB-INT:SIMPLE-EVAL-IN-lexev
6 0 0.0 195 100.0 195 100.0-评估
7 0 0.0 195 100.0 195 100.0-SWANK::EVAL-REGION
8 0 0.0 195 100.0 195 100.0-(λ零:在SWANK-REPL::REPL-EVAL中)
9 0 0.0 195 100.0 195 100.0-SWANK-REPL::TRACK-PACKAGE
10 0 0.0 195 100.0 195 100.0-SWANK::CALL-WITH-RETRY-RESTART
11 0 0.0 195 100.0 195 100.0-SWANK::CALL-WITH-BUFFER-SYNTAX
12 0 0.0 195 100.0 195 100.0-SWANK-REPL::REPL-EVAL
13 0 0.0 195 100.0 195 100.0-SWANK:EVAL-FOR-EMACS
14 0 0.0 195 100.0 195 100.0-SWANK::PROCESS-REQUESTS
15 0 0.0 195 100.0 195 100.0-(LAMBDA NIL:IN-SWANK::HANDLE-REQUESTS)
16 0 0.0 195 100.0 195 100.0-SWANK/SBCL::带断钩呼叫
17 0 0.0 195 100.0 195 100.0-(FLET-SWANK/后端:CALL-WITH-DEBUGGER-HOOK:IN”/Users/vleo/quicklisp/dists/quicklisp/software/slime-v2.19/SWANK/sbcl.lisp)
18 0 0.0 195 100.0 195 100.0-SWANK::带绑定的调用
19 0 0.0 195 100.0 195 100.0-SWANK::HANDLE-REQUESTS
20 0 0.0 195 100.0 195 100.0-(标签SWANK/SBCL::RUN:IN SWANK/BACKEND:ADD-FD-HANDLER)
21 0 0.0 195 100.0 195 100.0-SB-IMPL::SUB-SUB-SERVE-EVENT
22 0 0.0 195 100.0 195 100.0-SB-IMPL::SUB-SERVE-EVENT
23 0 0.0 195 100.0 195 100.0-SB-SYS:WAIT-UNTIL-FD-Available
24 0 0.0 195 100.0 195 100.0-SB-IMPL::重新填充输入缓冲区
25 0 0.0 195 100.0 195 100.0-SB-IMPL::INPUT-CHAR/UTF-8
26 0 0.0 195 100.0 195 100.0-(LAMBDA(&REST):在SB-IMPL::GET-EXTERNAL-FORMAT中)
27 0 0.0 195 100.0 195 100.0-可读字符
28 0 0.0 195 100.0 195 100.0-SB-IMPL::%保留读取的空白
29 0 0.0 195 100.0 195 100.0-读取
30 0 0.0 195 100.0 195 100.0-SB-IMPL::REPL-READ-FORM-FUN
31 0 0.0 195 100.0 195 100.0-SB-IMPL::REPL-FUN
32 0 0.0 195 100.0 195 100.0-(LAMBDA NIL:在SB-IMPL::TOPLEVEL-REPL中)
33 0 0.0 195 100.0 195 100.0-SB-IMPL::%带-response-IO-SYNTAX
34 0 0.0 195 100.0 195 100.0-SB-IMPL::TOPLEVEL-REPL
35 0 0.0 195 100.0 195 100.0-SB-IMPL::TOPLEVEL-INIT
36 0 0.0 195 100.0 195 100.0-(FLET#:无中断-BODY-74:在SAVE-LISP-AND-DIE中)
37 0 0.0 195 100.0 195 100.0-(标签SB-IMPL::RESTART-LISP:IN SAVE-LISP-AND-DIE)
38 0 0.0 69 35.4 195 100.0 1500 FACT-OPTI-ITER
39 0 0.0 65 33.3 195 100.0 1125750事实记录
40 0.0 61 31.3 195 100.0 1500 FACT-ITER
------------------------------------------------------------------------
0.0其他地方
没有提到事实调用,即使它确实被调用过。此外,还有一个条目用于事实记录
。如果事实调用
的调用在堆栈中较深,并且记录了事实记录
,是否也应该记录
谢谢您确定对
事实调用
的调用保持在堆栈上吗?你查过了吗
SBCL编译器可以执行TCO(尾部调用优化)。函数fact call
在尾部位置调用fact rec
。此函数调用可以替换为跳转,重用当前堆栈帧
TCO
让我们修改fact rec
,以便它调用break
,我们可以查看堆栈:
(defun fact-rec (n)
(if (zerop n)
(progn (break) 1)
(* n (fact-rec (1- n)))))
(defun fact-call (n)
(fact-rec n)) ; tail call to FACT-REC
让我们从test
调用它:
(defun test ()
(fact-call 4))
回溯看起来像这样-no事实调用
Backtrace:
0: (FACT-REC 0)
1: (FACT-REC 1)
2: (FACT-REC 2)
3: (FACT-REC 3)
4: (FACT-REC 4)
无TCO
现在我们告诉SBCL编译器不要在事实调用中使用TCO:
(defun fact-call (n)
(declare (optimize (debug 3))) ; debug level 3 does no TCO
(fact-rec n))
现在这是调用堆栈:
Backtrace:
0: (FACT-REC 0)
1: (FACT-REC 1)
2: (FACT-REC 2)
3: (FACT-REC 3)
4: (FACT-REC 4)
5: (FACT-CALL 4)
如您所见,对FACT-call
的调用保持在堆栈上