From: Sam Moore <sam@daedalus.(none)>
Date: Sun, 9 Sep 2012 10:53:14 +0000 (+0800)
Subject: Parallel Programming - Start OpenMP Version
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=f012817dee17e24eee2e8951d138dab40b808ad3;p=matches%2Fhonours.git

Parallel Programming - Start OpenMP Version

Almost finished
---

diff --git a/course/semester2/pprog/assignment1/mthread/nbody.c b/course/semester2/pprog/assignment1/mthread/nbody.c
index afd1d607..42b97cf4 100644
--- a/course/semester2/pprog/assignment1/mthread/nbody.c
+++ b/course/semester2/pprog/assignment1/mthread/nbody.c
@@ -7,6 +7,8 @@
 #include "nbody.h" // Declarations
 #include "../single-thread/nbody.c" // Include all functions from the single threaded version
 
+#include "graphics.h" // For declaration of Graphics_Run only
+
 // --- Variable declarations --- //
 
 pthread_t compute_thread; // The thread responsible for computations; it spawns worker threads
@@ -86,19 +88,16 @@ void * Compute_Thread(void * arg)
 	while (true)
 	{
 		
-		if (runstate != RUN) pthread_exit(NULL); //Check whether the main thread wants to exit
+		if (runstate != RUN) pthread_exit(NULL); //Check whether the thread needs to exit
 
 
 	
 		//Check whether the program should quit due to steps being computed, or a timeout
-		if (options.timeout > 0.0)
+		if (ExitCondition())
 		{
-			if ((unsigned)(time(NULL) - options.start_time.tv_sec) >= options.timeout)
-				QuitProgram(false);
-		}
-
-		if (options.num_steps > 0 && universe.steps > options.num_steps)
 			QuitProgram(false);
+			continue; // The check at the start of the next loop will stop the thread
+		}
 
 		if (options.draw_graphics == false && options.verbosity != 0 
 			&& universe.steps % options.verbosity == 1)
@@ -217,7 +216,8 @@ void * Position_Thread(void * s)
  */
 void QuitProgram(bool error)
 {
-	
+	if (runstate == QUIT || runstate == QUIT_ERROR)
+		return; //Don't do anything if already quitting
 	pthread_mutex_lock(&mutex_runstate); // aquire mutex
 	if (error) // set the runstate
 		runstate = QUIT_ERROR;
@@ -247,29 +247,24 @@ void Thread_Cleanup(void)
  * @function Simulation_Run
  * @purpose Initialise and start the simulation. Will be called in the main thread.
  * 	Replaces the single-threaded macro that does nothing, and sets up the compute thread
+ * @param argc - Number of arguments - Passed to Graphics_Run if needed
+ * @param argv - Argument strings - Passed to Graphics_Run if needed
  */
-void Simulation_Run()
+void Simulation_Run(int argc, char ** argv)
 {
 	atexit(Thread_Cleanup);
 
-	if (options.draw_graphics == false)
-	{
-		Compute_Thread((void*)(&universe));
-
-		// If there are no graphics, run the computation loop in the main thread
-		// The call to pthread_exit(NULL) in the computation loop ends the main thread
-
-		// This means the main function never calls the Graphics_Run function
-		// Without this condition here, Graphics_Display would essentially be running a busy loop in the main thread
-		
-		fprintf(stderr,"Should not see this\n");
-		exit(EXIT_FAILURE);
-	}
-	
-	// Create a thread to handle computation loop
-	if (pthread_create(&compute_thread, NULL, Compute_Thread, (void*)&universe) != 0)
+	if (options.draw_graphics)
 	{
-		perror("Error creating compute thread");
-		exit(EXIT_FAILURE);
+		// The graphics are enabled, so create a thread to do computations
+		// Graphics are done in the main loop
+		if (pthread_create(&compute_thread, NULL, Compute_Thread, (void*)&universe) != 0)
+		{
+			perror("Error creating compute thread");
+			exit(EXIT_FAILURE);
+		}
+		Graphics_Run(argc, argv);
 	}
+	else
+		Compute_Thread((void*)(&universe)); // Graphics are disabled, so do computations in the main thread
 }
diff --git a/course/semester2/pprog/assignment1/mthread/nbody.h b/course/semester2/pprog/assignment1/mthread/nbody.h
index 9b76bc75..0b3208a9 100644
--- a/course/semester2/pprog/assignment1/mthread/nbody.h
+++ b/course/semester2/pprog/assignment1/mthread/nbody.h
@@ -12,7 +12,7 @@
 
 //Undefine default macros, replace with functions
 #undef Simulation_Run
-void Simulation_Run(void);
+void Simulation_Run(int argc, char ** argv);
 #undef QuitProgram
 void QuitProgram(bool error);
 
diff --git a/course/semester2/pprog/assignment1/openmp/Makefile b/course/semester2/pprog/assignment1/openmp/Makefile
new file mode 120000
index 00000000..b0d614da
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/Makefile
@@ -0,0 +1 @@
+../single-thread/Makefile
\ No newline at end of file
diff --git a/course/semester2/pprog/assignment1/openmp/graphics.c b/course/semester2/pprog/assignment1/openmp/graphics.c
new file mode 120000
index 00000000..6fc2284c
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/graphics.c
@@ -0,0 +1 @@
+../single-thread/graphics.c
\ No newline at end of file
diff --git a/course/semester2/pprog/assignment1/openmp/graphics.h b/course/semester2/pprog/assignment1/openmp/graphics.h
new file mode 120000
index 00000000..aebee138
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/graphics.h
@@ -0,0 +1 @@
+../single-thread/graphics.h
\ No newline at end of file
diff --git a/course/semester2/pprog/assignment1/openmp/main.c b/course/semester2/pprog/assignment1/openmp/main.c
new file mode 120000
index 00000000..37e59853
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/main.c
@@ -0,0 +1 @@
+../single-thread/main.c
\ No newline at end of file
diff --git a/course/semester2/pprog/assignment1/openmp/nbody.c b/course/semester2/pprog/assignment1/openmp/nbody.c
new file mode 100644
index 00000000..69988922
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/nbody.c
@@ -0,0 +1,107 @@
+/**
+ * @file nbody.c
+ * @purpose OpenMP version of N-Body simulator, implementation
+ * @author Sam Moore (20503628) - 2012
+ */
+
+#include "nbody.h"
+#include "../single-thread/nbody.c" // Include original code
+#include "graphics.h" // For Graphics_Run function only
+
+/**
+ * @function Simulation_Run
+ * @purpose Start the simulation
+ * @param argc, argv - Passed to Graphics_Run if needed, otherwise unused
+ */
+void Simulation_Run(int argc, char ** argv)
+{	
+	omp_set_nested(1);
+	if (omp_get_nested() != 1)
+	{
+		fprintf(stderr, "Couldn't set nested parallelism, I kind of need that\n");
+		exit(EXIT_FAILURE);
+	}	
+		
+
+	if (options.num_threads == 0)
+		options.num_threads = omp_get_max_threads();
+
+	if (options.draw_graphics)
+		omp_set_num_threads(2);
+	else
+		omp_set_num_threads(1);
+
+
+		
+
+	#pragma omp parallel sections
+	{
+		
+		#pragma omp section
+		{
+			omp_set_num_threads(options.num_threads);
+			while (true)
+			{
+				
+				if (runstate != RUN) break; //Check whether the main thread wants to exit
+				
+				if (ExitCondition())
+				{
+					break;
+				}				
+
+
+				if (options.draw_graphics == false && options.verbosity != 0 
+					&& universe.steps % options.verbosity == 1)
+				{
+					DisplayStatistics();
+				}
+				
+						
+				Compute();
+			}
+		}
+
+		#pragma omp section
+		{
+			if (options.draw_graphics)
+				Graphics_Run(argc, argv);
+			printf("Got to bit after Graphics_Run()\n");
+		}
+
+	}
+}
+
+/**
+ * @function Compute
+ * @purpose Compute a single step, multithreaded using OpenMP
+ */
+void Compute(void)
+{
+	//printf("There are %d threads working and %d available\n", omp_get_num_threads(), omp_get_max_threads());
+	//return;
+	unsigned n_per_thread = (universe.N) / options.num_threads;
+	unsigned remainder = (universe.N) % options.num_threads;
+	#pragma omp parallel for
+	for (unsigned i = 0; i < options.num_threads; ++i)
+	{
+		//printf("Thread %d executes iteration %u\n", omp_get_thread_num(), i);
+		System s;
+		s.body = universe.body + (i * n_per_thread);
+		s.N = (i == options.num_threads - 1) ? n_per_thread : n_per_thread + remainder;
+		System_Forces(&s, &universe);
+	}
+
+	#pragma omp parallel for
+	for (unsigned i = 0; i < options.num_threads; ++i)
+	{
+		//printf("Thread %d executes iteration %u\n", omp_get_thread_num(), i);
+		System s;
+		s.body = universe.body + (i * n_per_thread);
+		s.N = (i == options.num_threads - 1) ? n_per_thread : n_per_thread + remainder;
+		System_Positions(&s);
+	}
+
+	universe.steps += 1;
+
+}
diff --git a/course/semester2/pprog/assignment1/openmp/nbody.h b/course/semester2/pprog/assignment1/openmp/nbody.h
new file mode 100644
index 00000000..b7d0b417
--- /dev/null
+++ b/course/semester2/pprog/assignment1/openmp/nbody.h
@@ -0,0 +1,27 @@
+#ifndef _NBODY_OPENMP_H
+#define _NBODY_OPENMP_H
+
+/**
+ * @file nbody.h
+ * @purpose OpenMP version of N-Body simulator, declarations
+ * @author Sam Moore (20503628) - 2012
+ */
+
+#include "../single-thread/nbody.h" //Include original code
+#include <omp.h>
+
+
+#undef SINGLE_THREADED
+#define OMP_THREADED
+
+// Replace default macros with thread-safe functions
+#undef Simulation_Run
+void Simulation_Run(int argc, char ** argv);
+//#undef QuitProgram
+//void QuitProgram(bool error); 
+
+void Compute(); //Compute a single step
+
+#endif //_NBODY_OPENMP_H
+
+//EOF
diff --git a/course/semester2/pprog/assignment1/single-thread/Makefile b/course/semester2/pprog/assignment1/single-thread/Makefile
index f34eab2a..b1640378 100644
--- a/course/semester2/pprog/assignment1/single-thread/Makefile
+++ b/course/semester2/pprog/assignment1/single-thread/Makefile
@@ -11,7 +11,7 @@ LINK_OBJ = main.o nbody.o graphics.o
 BIN = nbody
 
 $(BIN) : $(LINK_OBJ) 
-	$(CXX) -o $(BIN) $(LINK_OBJ) $(LIBRARIES)
+	$(CXX) -o $(BIN) $(LINK_OBJ) $(PREPROCESSOR_FLAGS) $(LIBRARIES)
 
 nbody : 
 
diff --git a/course/semester2/pprog/assignment1/single-thread/graphics.c b/course/semester2/pprog/assignment1/single-thread/graphics.c
index e3722e9c..1b4fcb31 100644
--- a/course/semester2/pprog/assignment1/single-thread/graphics.c
+++ b/course/semester2/pprog/assignment1/single-thread/graphics.c
@@ -14,6 +14,7 @@
 
 #include "graphics.h" //Function declarations
 #include "nbody.h" //The simulation
+#include <GL/freeglut.h>
 
 // --- Variable definitions --- //
 double previousTime, eyeTheta, eyePhi, eyeRho;
@@ -106,37 +107,34 @@ void Graphics_Run(int argc, char ** argv)
  */
 void Graphics_Display() 
 {
+	//Check whether the program should quit due to steps being computed, or a timeout
+	if (ExitCondition())
+	{
+		glutLeaveMainLoop();
+		return;
+	}
 
 
-	if (options.verbosity != 0 && universe.steps % options.verbosity == 1)
-		DisplayStatistics();
-
 	#ifdef SINGLE_THREADED
+		if (options.verbosity != 0 && universe.steps % options.verbosity == 1)
+			DisplayStatistics();
 		System_Compute(&universe);
-
-		//Check whether the program should quit due to steps being computed, or a timeout
-		if (options.timeout > 0.0)
-		{
-			if ((unsigned)(time(NULL) - options.start_time.tv_sec) >= options.timeout)
-				exit(EXIT_SUCCESS);
-		}
-		if (options.num_steps > 0 && universe.steps > options.num_steps)
-			exit(EXIT_SUCCESS);
-
-
 	#endif
 
 
+
 	//Check whether the runstate has been set to quit the program
 	switch (runstate)
 	{
 		case RUN:
 			break;
 		case QUIT:
-			exit(EXIT_SUCCESS);
+			glutLeaveMainLoop();
+			return;
 			break;
 		case QUIT_ERROR:
-			exit(EXIT_FAILURE);
+			glutLeaveMainLoop();
+			return;
 			break;
 	}
 
@@ -172,7 +170,8 @@ void Graphics_Keyboard(unsigned char theKey, int mouseX, int mouseY)
 {
 	if (theKey == 'x' || theKey == 'X') 
 	{
-		exit(EXIT_SUCCESS);
+		glutLeaveMainLoop();
+		return;
 	}
 
 		if (theKey == 'i' || theKey == 'I') {
diff --git a/course/semester2/pprog/assignment1/single-thread/graphics.h b/course/semester2/pprog/assignment1/single-thread/graphics.h
index 2fbc0a6a..c2b99f38 100644
--- a/course/semester2/pprog/assignment1/single-thread/graphics.h
+++ b/course/semester2/pprog/assignment1/single-thread/graphics.h
@@ -28,7 +28,7 @@
 #define WORLD_FAR 1000000
 #define BALL_SIZE 0.5
 #define REFRESH_RATE 0.001
-#define LINE_SIZE 1000
+
 
 void Graphics_Run(int argc, char ** argv);
 void Graphics_Display(void);
diff --git a/course/semester2/pprog/assignment1/single-thread/main.c b/course/semester2/pprog/assignment1/single-thread/main.c
index f9f3b529..4b0c48ac 100644
--- a/course/semester2/pprog/assignment1/single-thread/main.c
+++ b/course/semester2/pprog/assignment1/single-thread/main.c
@@ -80,9 +80,9 @@ int main(int argc, char** argv)
 	}
 	
 	options.start_clock = clock(); //Get CPU cycles executed before simulation starts
-	Simulation_Run(); // Start the simulation
-	Graphics_Run(argc, argv); //Start the graphics loop
-
+	Simulation_Run(argc, argv); // Start the simulation
+	
+	printf("Got here!\n");
 	exit(EXIT_FAILURE); //Should never get to this line
 }
 
diff --git a/course/semester2/pprog/assignment1/single-thread/nbody.c b/course/semester2/pprog/assignment1/single-thread/nbody.c
index 47820d17..67c36d3b 100644
--- a/course/semester2/pprog/assignment1/single-thread/nbody.c
+++ b/course/semester2/pprog/assignment1/single-thread/nbody.c
@@ -136,7 +136,6 @@ void System_Positions(System * s)
  * @param s - The System
  * @param fileName - The input file
  */
-#define LINE_SIZE BUFSIZ
 void System_Init(System * s, const char *fileName) 
 {
 	char line[LINE_SIZE];
@@ -226,3 +225,15 @@ void DisplayStatistics()
 	printf("%u\t%f\t%u\t%f\n", universe.steps, runtime, (unsigned)(end - options.start_clock), clock_time);
 }
 
+
+/**
+ * @function ExitCondition
+ * @purpose Helper to check whether the program is supposed to exit
+ * 	Does not check for user triggered quit
+ *	Checks for either a timeout, or computation of the required number of steps
+ */
+bool ExitCondition(void)
+{
+	return ((options.timeout > 0.00 && ((unsigned)(time(NULL) - options.start_time.tv_sec) >= options.timeout))
+		|| (options.num_steps > 0 && universe.steps > options.num_steps));
+}
diff --git a/course/semester2/pprog/assignment1/single-thread/nbody.h b/course/semester2/pprog/assignment1/single-thread/nbody.h
index b8c98135..fc19d059 100644
--- a/course/semester2/pprog/assignment1/single-thread/nbody.h
+++ b/course/semester2/pprog/assignment1/single-thread/nbody.h
@@ -18,13 +18,14 @@
 #define SINGLE_THREADED
 
 //These macros will be undefined by the multithreaded versions
-#define Simulation_Run() //Sets up the simulation; in multithreaded versions, will spawn threads
+#define Simulation_Run(argc, argv) (Graphics_Run(argc, argv)) //Sets up the simulation; in multithreaded versions, will spawn threads
 #define QuitProgram(error) (runstate = (error == true) ? QUIT : QUIT_ERROR) //Prepares to exit program, is thread safe in multithreaded versions
 
 #define M_PI        3.14159265358979323846264338327950288   /* pi */
 #define G 6.67428E-11
 #define DELTA_T 0.05
 #define DIMENSIONS 3
+#define LINE_SIZE 1000
 #define square(x) ((x)*(x))
 
 
@@ -95,6 +96,8 @@ void Universe_Cleanup(); //Cleanup universe and write bodies to file
 void DisplayStatistics(); // Print information about steps computed, total (real) runtime, and CPU cycles
 
 
+bool ExitCondition(void); //Checks whether the program is supposed to exit automatically yet (ie: other than the user pressing "quit")
+
 
 typedef enum {RUN, QUIT, QUIT_ERROR} RUNSTATE;
 extern RUNSTATE runstate; // Set runstate to QUIT or QUIT_ERROR and the simulation will stop on the next step.