117 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
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<html>
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<head>
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<title>malloctest</title>
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<link rel="stylesheet" type="text/css" media="all" href="../man.css">
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</head>
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<body bgcolor=#ffffff>
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<h2 align=center>malloctest</h2>
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<h4 align=center>OS/161 Reference Manual</h4>
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<h3>Name</h3>
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<p>
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malloctest - some simple tests for userlevel malloc
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</p>
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<h3>Synopsis</h3>
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<p>
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<tt>/testbin/malloctest</tt> [<em>test</em>...]
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</p>
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<h3>Description</h3>
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<p>
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<tt>malloctest</tt> contains 7 tests, 1-7. These may be run
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interactively or from the command line.
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</p>
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<p>
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Test 1 checks if all the bytes we ask for actually get allocated.
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</p>
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<p>
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Test 2 checks if <tt>malloc</tt> gracefully handles failing requests.
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This test assumes that <tt>malloc</tt> will eventually fail if one
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keeps allocating enough memory, instead of promising memory it can't
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deliver and then (perhaps) killing processes when it runs out. More
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detail regarding this condition can be found in comments in the source
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code.
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</p>
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<p>
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Test 3 also checks if <tt>malloc</tt> gracefully handles failing
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requests, and thus has the same restrictions as test 2.
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</p>
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<p>
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Test 4 attempts to check if <tt>malloc</tt> coalesces the free list
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properly.  This test is only meant for first-fit, next-fit, or
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best-fit allocators; anything else will most likely confuse it.
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Running test 4 after other tests may confuse it as well.
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</p>
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<p>
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Tests 5-7 are a randomized stress test. Test 5 uses pseudorandom seed
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0. Test 6 seeds the random generator from the
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<A HREF=../dev/random.html>random:</A> device. Test 7 prompts you for a
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specific seed.
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</p>
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<h3>Requirements</h3>
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<p>
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<tt>malloctest</tt> uses the following system calls:
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<ul>
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<li> <A HREF=../syscall/open.html>open</A>
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<li> <A HREF=../syscall/read.html>read</A>
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<li> <A HREF=../syscall/write.html>write</A>
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<li> <A HREF=../syscall/close.html>close</A>
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<li> <A HREF=../syscall/_exit.html>_exit</A>
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</ul>
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</p>
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<p>
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Your system should pass all the <tt>malloctest</tt> tests, subject to
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the conditions described above, once you have implemented
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<A HREF=../syscalls/sbrk.html>sbrk</A>.
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</p>
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<h3>Bugs</h3>
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<p>
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Because OS/161 ships with a userlevel <tt>malloc</tt> implementation
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now, rather than making you write one, this test is not very useful.
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</p>
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<p>
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Because the userlevel <tt>malloc</tt> OS/161 ships with is quite dumb,
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test 3 can be amazingly slow.
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</p>
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</body>
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</html>
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