Operating Systems 2017F: Tutorial 4 - Revision history

Soma: /* 3000random.c */

2017-10-27T18:55:36Z

3000random.c

← Older revision		Revision as of 18:55, 27 October 2017
Line 422:		Line 422:

	if (count > sizeof(unsigned long)) {		if (count > sizeof(unsigned long)) {
	r->current = count / sizeof(unsigned long); /* was %, that was wrong! */		r->current = (count / sizeof(unsigned long)) - 1;
			/* was %, that was wrong! */
			/* left out -1, that was wrong! */
	} else {		} else {
	fprintf(stderr, "Couldn't fill random buffer.\n");		fprintf(stderr, "Couldn't fill random buffer.\n");

Soma: /* 3000random.c */

2017-10-23T18:34:32Z

3000random.c

← Older revision		Revision as of 18:34, 23 October 2017
Line 422:		Line 422:

	if (count > sizeof(unsigned long)) {		if (count > sizeof(unsigned long)) {
	r->current = count % sizeof(unsigned long);		r->current = count / sizeof(unsigned long); /* was %, that was wrong! */
	} else {		} else {
	fprintf(stderr, "Couldn't fill random buffer.\n");		fprintf(stderr, "Couldn't fill random buffer.\n");

Soma at 15:18, 16 October 2017

2017-10-16T15:18:02Z

← Older revision		Revision as of 15:18, 16 October 2017
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	~~'''This tutorial is not yet finalized.'''~~

	In this tutorial you will be experimenting with and extending [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000pc.c 3000pc.c] and [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000random.c 3000random.c] (both listed below).		In this tutorial you will be experimenting with and extending [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000pc.c 3000pc.c] and [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000random.c 3000random.c] (both listed below).

Jean: /* 3000random.c */

2017-10-15T22:02:09Z

3000random.c

← Older revision		Revision as of 22:02, 15 October 2017
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	==Code==		==Code==

	===~~3000random~~.c===		===3000pc.c===
	<source lang="c" line>		<source lang="c" line>
	/* 3000pc.c */		/* 3000pc.c */

Soma at 21:28, 15 October 2017

2017-10-15T21:28:42Z

← Older revision		Revision as of 21:28, 15 October 2017
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	# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?		# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?
	# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?		# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?
	# '(~~advanced~~)' Modify 3000pc.c so it takes in an additional command line argument that is the filename of a word list. This file should have one word per line. The program should then use this read-in word list rather than the hard coded word list. Pay attention to:		# '''(Bonus)''' Modify 3000pc.c so it takes in an additional command line argument that is the filename of a word list. This file should have one word per line. The program should then use this read-in word list rather than the hard coded word list. Pay attention to:
	#* where you read the file (in the producer, consumer, or before the fork)		#* where you read the file (in the producer, consumer, or before the fork)
	#* where and how you store the words in memory (the word list should be arbitrarily long, but the maximum length of a word can be fixed)		#* where and how you store the words in memory (the word list should be arbitrarily long, but the maximum length of a word can be fixed)
	# '(~~advanced~~)' Modify 3000pc.c so that it has multiple producers and consumers running concurrently, with the number of each specified on the command line.		# '''(Bonus)''' Modify 3000pc.c so that it has multiple producers and consumers running concurrently, with the number of each specified on the command line.

	==Code==		==Code==

Soma at 21:27, 15 October 2017

2017-10-15T21:27:44Z

← Older revision		Revision as of 21:27, 15 October 2017
Line 16:		Line 16:
	# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?		# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?
	# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?		# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?
	# (advanced) Modify 3000pc.c so it takes in an additional command line argument that is the filename of a word list. This file should have one word per line. The program should then use this read-in word list rather than the hard coded word list. Pay attention to:		# '(advanced)' Modify 3000pc.c so it takes in an additional command line argument that is the filename of a word list. This file should have one word per line. The program should then use this read-in word list rather than the hard coded word list. Pay attention to:
	#* where you read the file (in the producer, consumer, or before the fork)		#* where you read the file (in the producer, consumer, or before the fork)
	#* where and how you store the words in memory (the word list should be arbitrarily long, but the maximum length of a word can be fixed)		#* where and how you store the words in memory (the word list should be arbitrarily long, but the maximum length of a word can be fixed)
	# (advanced) Modify 3000pc.c so that it has multiple producers and consumers running concurrently, with the number of each specified on the command line.		# '(advanced)' Modify 3000pc.c so that it has multiple producers and consumers running concurrently, with the number of each specified on the command line.

	==Code==		==Code==

Soma at 21:27, 15 October 2017

2017-10-15T21:27:23Z

← Older revision		Revision as of 21:27, 15 October 2017
Line 16:		Line 16:
	# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?		# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?
	# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?		# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?
			# (advanced) Modify 3000pc.c so it takes in an additional command line argument that is the filename of a word list. This file should have one word per line. The program should then use this read-in word list rather than the hard coded word list. Pay attention to:
			#* where you read the file (in the producer, consumer, or before the fork)
			#* where and how you store the words in memory (the word list should be arbitrarily long, but the maximum length of a word can be fixed)
			# (advanced) Modify 3000pc.c so that it has multiple producers and consumers running concurrently, with the number of each specified on the command line.

	==Code==		==Code==

Soma: /* Tasks/Questions */

2017-10-15T21:21:52Z

Tasks/Questions

← Older revision		Revision as of 21:21, 15 October 2017
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	# Modify the consumer so that it never unlocks each entry (but does lock it). What happens?		# Modify the consumer so that it never unlocks each entry (but does lock it). What happens?
	# What happens if you remove all entry locking/unlocking? How does the behavior change?		# What happens if you remove all entry locking/unlocking? How does the behavior change?
	~~# Change the producer and consumer so they only sleep for 1000 nanoseconds (1 millisecond) rather than 1 second during each delay interval. How does the behavior of the program change?~~
	# Remove the SIGUSR1 signal handler from the producer (so it uses the C library default signal handler). How does the program behave?		# Remove the SIGUSR1 signal handler from the producer (so it uses the C library default signal handler). How does the program behave?
	# Remove the SIGUSR1 signal handler from the consumer (so it uses the C library default signal handler). How does the program behave?		# Remove the SIGUSR1 signal handler from the consumer (so it uses the C library default signal handler). How does the program behave?
			# Change the producer and consumer so they only sleep for 1000 nanoseconds (1 millisecond) rather than 1 second during each delay interval. How does the behavior of the program change?
	# Compile and run 3000random.c. Note that it takes two arguments. Where does this program get its random numbers from?		# Compile and run 3000random.c. Note that it takes two arguments. Where does this program get its random numbers from?
			# Change 3000random.c to use /dev/random rather than /dev/urandom. How does its performance change, especially when generating a large number of random numbers?
	# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?		# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?

Soma: /* Tasks/Questions */

2017-10-15T21:20:41Z

Tasks/Questions

← Older revision		Revision as of 21:20, 15 October 2017
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	==Tasks/Questions==		==Tasks/Questions==

			# Compile and run 3000pc.c. Note that you'll need to add a "-pthread" option to your compile command. First run it with a -1 for both delay intervals, then try other values. When does the producer signal the consumer? When does the consumer signal the producer?
			# How can you output the random words to a file so that you only see the signal messages on the console?
			# Modify the producer so that it never unlocks each entry (but does lock it). What happens?
			# Modify the consumer so that it never unlocks each entry (but does lock it). What happens?
			# What happens if you remove all entry locking/unlocking? How does the behavior change?
			# Change the producer and consumer so they only sleep for 1000 nanoseconds (1 millisecond) rather than 1 second during each delay interval. How does the behavior of the program change?
			# Remove the SIGUSR1 signal handler from the producer (so it uses the C library default signal handler). How does the program behave?
			# Remove the SIGUSR1 signal handler from the consumer (so it uses the C library default signal handler). How does the program behave?
			# Compile and run 3000random.c. Note that it takes two arguments. Where does this program get its random numbers from?
			# Change 3000pc.c to use random numbers from /dev/urandom rather than using the standard library function random(). How does this change affect the relative speed of the producer and consumer processes?

	==Code==		==Code==

Soma at 20:55, 15 October 2017

2017-10-15T20:55:04Z

← Older revision		Revision as of 20:55, 15 October 2017
Line 1:		Line 1:
			'''This tutorial is not yet finalized.'''

	In this tutorial you will be experimenting with and extending [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000pc.c 3000pc.c] and [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000random.c 3000random.c] (both listed below).		In this tutorial you will be experimenting with and extending [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000pc.c 3000pc.c] and [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/tut4/3000random.c 3000random.c] (both listed below).