194 lines
8.1 KiB
Scheme
194 lines
8.1 KiB
Scheme
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; This is adapted from a benchmark written by John Ellis and Pete Kovac
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; of Post Communications.
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; It was modified by Hans Boehm of Silicon Graphics.
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; It was translated into Scheme by William D Clinger of Northeastern Univ;
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; the Scheme version uses (RUN-BENCHMARK <string> <thunk>)
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; Last modified 30 May 1997.
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;
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; This is no substitute for real applications. No actual application
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; is likely to behave in exactly this way. However, this benchmark was
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; designed to be more representative of real applications than other
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; Java GC benchmarks of which we are aware.
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; It attempts to model those properties of allocation requests that
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; are important to current GC techniques.
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; It is designed to be used either to obtain a single overall performance
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; number, or to give a more detailed estimate of how collector
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; performance varies with object lifetimes. It prints the time
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; required to allocate and collect balanced binary trees of various
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; sizes. Smaller trees result in shorter object lifetimes. Each cycle
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; allocates roughly the same amount of memory.
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; Two data structures are kept around during the entire process, so
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; that the measured performance is representative of applications
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; that maintain some live in-memory data. One of these is a tree
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; containing many pointers. The other is a large array containing
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; double precision floating point numbers. Both should be of comparable
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; size.
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;
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; The results are only really meaningful together with a specification
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; of how much memory was used. It is possible to trade memory for
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; better time performance. This benchmark should be run in a 32 MB
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; heap, though we don't currently know how to enforce that uniformly.
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; In the Java version, this routine prints the heap size and the amount
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; of free memory. There is no portable way to do this in Scheme; each
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; implementation needs its own version.
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(library (r6rs-benchmarks gcbench)
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(export main)
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(import (r6rs) (r6rs arithmetic flonums) (r6rs-benchmarks))
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(define (run-benchmark2 name thunk)
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(display name)
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(newline)
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(thunk))
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(define (PrintDiagnostics)
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(display " Total memory available= ???????? bytes")
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(display " Free memory= ???????? bytes")
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(newline))
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(define (gcbench kStretchTreeDepth)
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; Nodes used by a tree of a given size
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(define (TreeSize i)
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(- (expt 2 (+ i 1)) 1))
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; Number of iterations to use for a given tree depth
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(define (NumIters i)
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(quotient (* 2 (TreeSize kStretchTreeDepth))
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(TreeSize i)))
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; Parameters are determined by kStretchTreeDepth.
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; In Boehm's version the parameters were fixed as follows:
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; public static final int kStretchTreeDepth = 18; // about 16Mb
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; public static final int kLongLivedTreeDepth = 16; // about 4Mb
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; public static final int kArraySize = 500000; // about 4Mb
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; public static final int kMinTreeDepth = 4;
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; public static final int kMaxTreeDepth = 16;
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; In Larceny the storage numbers above would be 12 Mby, 3 Mby, 6 Mby.
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(let* ((kLongLivedTreeDepth (- kStretchTreeDepth 2))
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(kArraySize (* 4 (TreeSize kLongLivedTreeDepth)))
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(kMinTreeDepth 4)
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(kMaxTreeDepth kLongLivedTreeDepth))
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; Elements 3 and 4 of the allocated vectors are useless.
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(let* ((make-empty-node (lambda () (make-vector 4 0)))
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(make-node
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(lambda (l r)
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(let ((v (make-empty-node)))
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(vector-set! v 0 l)
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(vector-set! v 1 r)
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v)))
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(node.left (lambda (node) (vector-ref node 0)))
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(node.right (lambda (node) (vector-ref node 1)))
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(node.left-set! (lambda (node x) (vector-set! node 0 x)))
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(node.right-set! (lambda (node x) (vector-set! node 1 x))))
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; Build tree top down, assigning to older objects.
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(define (Populate iDepth thisNode)
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(if (<= iDepth 0)
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#f
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(let ((iDepth (- iDepth 1)))
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(node.left-set! thisNode (make-empty-node))
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(node.right-set! thisNode (make-empty-node))
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(Populate iDepth (node.left thisNode))
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(Populate iDepth (node.right thisNode)))))
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; Build tree bottom-up
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(define (MakeTree iDepth)
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(if (<= iDepth 0)
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(make-empty-node)
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(make-node (MakeTree (- iDepth 1))
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(MakeTree (- iDepth 1)))))
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(define (TimeConstruction depth)
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(let ((iNumIters (NumIters depth)))
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(display (string-append "Creating "
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(number->string iNumIters)
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" trees of depth "
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(number->string depth)))
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(newline)
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(run-benchmark2
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"GCBench: Top down construction"
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(lambda ()
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(do ((i 0 (+ i 1)))
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((>= i iNumIters))
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(Populate depth (make-empty-node)))))
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(run-benchmark2
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"GCBench: Bottom up construction"
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(lambda ()
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(do ((i 0 (+ i 1)))
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((>= i iNumIters))
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(MakeTree depth))))))
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(define (main)
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(display "Garbage Collector Test")
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(newline)
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(display (string-append
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" Stretching memory with a binary tree of depth "
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(number->string kStretchTreeDepth)))
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(newline)
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(PrintDiagnostics)
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(run-benchmark2
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"GCBench: Main"
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(lambda ()
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; Stretch the memory space quickly
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(MakeTree kStretchTreeDepth)
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; Create a long lived object
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(display (string-append
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" Creating a long-lived binary tree of depth "
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(number->string kLongLivedTreeDepth)))
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(newline)
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(let ((longLivedTree (make-empty-node)))
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(Populate kLongLivedTreeDepth longLivedTree)
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; Create long-lived array, filling half of it
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(display (string-append
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" Creating a long-lived array of "
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(number->string kArraySize)
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" inexact reals"))
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(newline)
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(let ((array (make-vector kArraySize 0.0)))
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(do ((i 0 (+ i 1)))
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((>= i (quotient kArraySize 2)))
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(vector-set! array i (/ 1.0 (exact->inexact (+ i 1)))))
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(PrintDiagnostics)
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(do ((d kMinTreeDepth (+ d 2)))
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((> d kMaxTreeDepth))
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(TimeConstruction d))
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(if (or (eq? longLivedTree '())
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(let ((n (min 1000
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(- (quotient (vector-length array)
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2)
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1))))
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(not (fl=? (vector-ref array n)
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(/ 1.0 (exact->inexact (+ n 1)))))))
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(begin (display "Failed") (newline)))
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; fake reference to LongLivedTree
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; and array
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; to keep them from being optimized away
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))))
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(PrintDiagnostics))
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(main))))
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(define (main . rest)
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(let ((k (if (null? rest) 18 (car rest))))
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(display "The garbage collector should touch about ")
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(display (expt 2 (- k 13)))
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(display " megabytes of heap storage.")
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(newline)
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(display "The use of more or less memory will skew the results.")
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(newline)
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(run-benchmark
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(string-append "GCBench" (number->string k))
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gcbench-iters
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(lambda (result) #t)
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(lambda (k) (lambda () (gcbench k)))
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k))))
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