CSC/ECE 506 Spring 2010/ch 3 yl - Revision history

Admin: /* DOPIPE */

2010-05-04T04:02:24Z

DOPIPE

← Older revision		Revision as of 04:02, 4 May 2010
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	26: }		26: }

	Ideally, We ~~paralleled~~ the original program in two steps.		Ideally, We parallelized the original program into two steps.

	*First step: We divide i loop among the other processors by inserting an OpenMP to construct “#programa omp for nowait” (line 16). Afterwards, each processor will take interations of the loop i. Now, there are two loop i existing and each loop i contains different statements. Also, we will keep other statements remained.		*First step: We divide i loop among the other processors by inserting an OpenMP to construct “#programa omp for nowait” (line 16). Afterwards, each processor will take interations of the loop i. Now, there are two loop i existing and each loop i contains different statements. Also, we will keep other statements remained.

Admin: /* Synchronization clauses */

2010-05-04T04:00:14Z

Synchronization clauses

← Older revision		Revision as of 04:00, 4 May 2010
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	''structured_block''		''structured_block''

	CRITICAL SECTION ~~behave~~ as follows:		CRITICAL SECTION behaves as follows:
	1.f a thread is currently executing inside a CRITICAL region and another thread reaches that CRITICAL region and attempts to execute it, it will block until the first thread exits that CRITICAL region.		1.f a thread is currently executing inside a CRITICAL region and another thread reaches that CRITICAL region and attempts to execute it, it will block until the first thread exits that CRITICAL region.
	2. It is illegal to branch into or out of a CRITICAL block.		2. It is illegal to branch into or out of a CRITICAL block.

Zliu8: /* References */

2010-03-04T22:01:35Z

References

← Older revision		Revision as of 22:01, 4 March 2010
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	==References==		==References==
	<ol>		<ol>
	~~<li>[http://en.wikipedia.org/wiki/Parallel_computing Wikipedia: Parallel Computing]</li>~~
	~~<li>[http://www.cesr.ncsu.edu/solihin/Main.html FUNDAMENTALS OF PARALLEL COMPUTER ARCHITECTURE, Yan Solihin, Aug 2009]</li>~~
	<li>[http://openmp.org/wp/about-openmp/ OpenMP.org]</li>		<li>[http://openmp.org/wp/about-openmp/ OpenMP.org]</li>
	<li>[https://docs.google.com/viewer?a=v&pid=gmail&attid=0.1&thid=126f8a391c11262c&mt=application%2Fpdf&url=https%3A%2F%2Fmail.google.com%2Fmail%2F%3Fui%3D2%26ik%3Dd38b56c94f%26view%3Datt%26th%3D126f8a391c11262c%26attid%3D0.1%26disp%3Dattd%26realattid%3Df_g602ojwk0%26zw&sig=AHIEtbTeQDhK98IswmnVSfrPBMfmPLH5Nw An Optimal Abtraction Model for Hardware Multithreading in Modern Processor Architectures]</li>		<li>[https://docs.google.com/viewer?a=v&pid=gmail&attid=0.1&thid=126f8a391c11262c&mt=application%2Fpdf&url=https%3A%2F%2Fmail.google.com%2Fmail%2F%3Fui%3D2%26ik%3Dd38b56c94f%26view%3Datt%26th%3D126f8a391c11262c%26attid%3D0.1%26disp%3Dattd%26realattid%3Df_g602ojwk0%26zw&sig=AHIEtbTeQDhK98IswmnVSfrPBMfmPLH5Nw An Optimal Abtraction Model for Hardware Multithreading in Modern Processor Architectures]</li>

Zliu8: /* DOACROSS */

2010-03-04T06:30:41Z

DOACROSS

← Older revision		Revision as of 06:30, 4 March 2010
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	pthread_exit(NULL);		pthread_exit(NULL);
	}		}

			This example demonstrates how to "wait" for thread completions by using the Pthread join routine. Since some implementations of Pthreads may not create threads in a joinable state, the threads in this example are explicitly created in a joinable state so that they can be joined later.

	====DOPIPE====		====DOPIPE====

Zliu8: /* DOACROSS */

2010-03-04T06:29:38Z

DOACROSS

← Older revision		Revision as of 06:29, 4 March 2010
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	pthread_exit((void*) t);		pthread_exit((void*) t);
	}		}

	int main (int argc, char *argv[])		int main (int argc, char *argv[])
	{		{
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	long t;		long t;
	void *status;		void *status;

	/* Initialize and set thread detached attribute */		/* Initialize and set thread detached attribute */
	pthread_attr_init(&attr);		pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);

	for(t=0; t<NUM_THREADS; t++) {		for(t=0; t<NUM_THREADS; t++) {
	printf("Main: creating thread %ld\n", t);		printf("Main: creating thread %ld\n", t);
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	}		}
	}		}

	/* Free attribute and wait for the other threads */		/* Free attribute and wait for the other threads */
	pthread_attr_destroy(&attr);		pthread_attr_destroy(&attr);

Zliu8: /* DOACROSS */

2010-03-04T06:29:08Z

DOACROSS

← Older revision		Revision as of 06:29, 4 March 2010
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	When it comes to using Pthreads to implement DOACROSS, it could express functional parallelism easily, but make the parallelism unnecessarily complicated. See an example below: from '''POSIX Threads Programming''' by Blaise Barney		When it comes to using Pthreads to implement DOACROSS, it could express functional parallelism easily, but make the parallelism unnecessarily complicated. See an example below: from '''POSIX Threads Programming''' by Blaise Barney

	#include <pthread.h>		#include <pthread.h>
	#include <stdio.h>		#include <stdio.h>
	#include <stdlib.h>		#include <stdlib.h>
	#define NUM_THREADS 4		#define NUM_THREADS

	void BusyWork(void t)		void BusyWork(void t)
	{		{
	int i;		int i;
	long tid;		long tid;
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	printf("Thread %ld done. Result = %e\n",tid, result);		printf("Thread %ld done. Result = %e\n",tid, result);
	pthread_exit((void*) t);		pthread_exit((void*) t);
	}		}

	int main (int argc, char *argv[])		int main (int argc, char *argv[])
	{		{
	pthread_t thread[NUM_THREADS];		pthread_t thread[NUM_THREADS];
	pthread_attr_t attr;		pthread_attr_t attr;
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	}		}

	printf("Main: program completed. Exiting.\n");		printf("Main: program completed. Exiting.\n");
	pthread_exit(NULL);		pthread_exit(NULL);
	}		}

	====DOPIPE====		====DOPIPE====

Zliu8: /* DOPIPE */

2010-03-04T06:28:28Z

DOPIPE

← Older revision		Revision as of 06:28, 4 March 2010
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	====DOPIPE====		====DOPIPE====
	~~Here~~ is ~~an example by~~ using Posix Threads to implement DOPIPE parallelism. Due to the long length, we won't provide it here. If the reader is interested, it could be found in <li>[http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>		There is examples of using Posix Threads to implement DOPIPE parallelism, but unnecessarily complex. Due to the long length, we won't provide it here. If the reader is interested, it could be found in <li>[http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>

	===Comparison among the three===		===Comparison among the three===

Zliu8: /* DOPIPE */

2010-03-04T06:27:10Z

DOPIPE

← Older revision		Revision as of 06:27, 4 March 2010
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	====DOPIPE====		====DOPIPE====
	Here is an example by using Posix Threads to implement DOPIPE parallelism. ~~However,~~ the length ~~of source is too long~~. ~~We attach~~ the ~~link as below.~~ <li>[http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>		Here is an example by using Posix Threads to implement DOPIPE parallelism. Due to the long length, we won't provide it here. If the reader is interested, it could be found in <li>[http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>

	===Comparison among the three===		===Comparison among the three===

Cyang8: /* References */

2010-03-04T06:26:04Z

References

← Older revision		Revision as of 06:26, 4 March 2010
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	<li>[http://software.intel.com/en-us/articles/intel-threading-building-blocks-openmp-or-native-threads/ Intel® Threading Building Blocks, OpenMP, or native threads?]</li>		<li>[http://software.intel.com/en-us/articles/intel-threading-building-blocks-openmp-or-native-threads/ Intel® Threading Building Blocks, OpenMP, or native threads?]</li>
	<li>[https://computing.llnl.gov/tutorials/pthreads/#Joining POSIX Threads Programming by Blaise Barney, Lawrence Livermore National Laboratory]</li>		<li>[https://computing.llnl.gov/tutorials/pthreads/#Joining POSIX Threads Programming by Blaise Barney, Lawrence Livermore National Laboratory]</li>
	<li>http://homepage.mac.com/dbutenhof/Threads/source.html Programing with POSIX Threads source code</li>		<li>[http://homepage.mac.com/dbutenhof/Threads/source.html Programing with POSIX Threads source code]</li>
	</ol>		</ol>

Zliu8: /* DOPIPE */

2010-03-04T06:25:55Z

DOPIPE

← Older revision		Revision as of 06:25, 4 March 2010
Line 655:		Line 655:

	====DOPIPE====		====DOPIPE====
	Here is an example by using Posix Threads to implement DOPIPE parallelism. However, the length of source is too long. We attach the link as below. <li>[~~http://homepage.mac.com/dbutenhof/Threads/code/pipe.c~~ http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>		Here is an example by using Posix Threads to implement DOPIPE parallelism. However, the length of source is too long. We attach the link as below. <li>[http://homepage.mac.com/dbutenhof/Threads/code/pipe.c Pthreads DOPIPE example]</li>

	===Comparison among the three===		===Comparison among the three===