add MPI broadcast example

exercises/MPI_examples/round_trip/Makefile → exercises/MPI_examples/broadcast/Makefile

-PROG = round_trip
-OBJECTS = round_trip.o
+PROG = broadcast
+OBJECTS = broadcast.o
 CC = mpicc
 CFLAGS = -Wall -std=c11
 CFLAGS += -I. # add the current directory to the include path

exercises/MPI_examples/ordering_2/ordering_2.c → exercises/MPI_examples/broadcast/broadcast.c

@@ -6,8 +6,7 @@
 
 int main(int argc, char **argv) {
 
-  char token;
-  MPI_Status status;
+  int arg;
   MPI_Init(&argc, &argv);
 
   // Get the number of processes
@@ -23,17 +22,23 @@ int main(int argc, char **argv) {
   int name_len;
   MPI_Get_processor_name(processor_name, &name_len);
 
-  // all processes send to rank 0
-  if (rank != 0) {
-    token = 'A' + rank;
-    MPI_Send(&token, 1, MPI_CHAR, 0, 0, MPI_COMM_WORLD);
-  } else {
-    for (int i = 1; i < num_processes; i++) {
-      MPI_Recv(&token, 1, MPI_CHAR, MPI_ANY_SOURCE, 0, MPI_COMM_WORLD, &status);
-      printf("Process 0 received token %c from process %d\n", token, status.MPI_SOURCE);
+  if (rank == 0) {
+
+    if (argc == 1 || // the program is called without parameters
+        (argc > 1 && !strcmp(argv[1], "-h")) // user asked for help )
+    ) {
+      printf("\nUsage: init [0-9]+\n");
+      MPI_Abort(MPI_COMM_WORLD, 1);
     }
+
+    arg = atoi(argv[1]);
   }
 
+  MPI_Bcast(&arg, 1, MPI_INT, 0, MPI_COMM_WORLD);
+
+  printf("Process %d of %d on %s: arg = %d\n", rank, num_processes,
+         processor_name, arg);
+
   // Finalize the MPI environment. No more MPI calls can be made after this
   MPI_Finalize();
 }

exercises/MPI_examples/deadlock/Makefile

-PROG = deadlock
-OBJECTS = deadlock.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun -np 2 ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/deadlock/deadlock.c

-#include <mpi.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-int main(int argc, char **argv) {
-
-  char message[32];
-  int err;
-  MPI_Status status;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // forcing the program to run with exactly two processes
-  if (num_processes != 2) {
-    fprintf(stderr, "Must use exactly two processes for this program\n");
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  } else {
-    if (rank == 0) {
-      err = MPI_Recv(message, 32, MPI_CHAR, 1, 0, MPI_COMM_WORLD, &status);
-      if (err == MPI_SUCCESS)
-          printf("[%s] Message received: %s\n", processor_name, message);
-      strncpy(message, "Message from process #0", 32);
-      err = MPI_Send(message, 32, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
-      if (err == MPI_SUCCESS)
-          printf("[%s] Message sent: %s\n", processor_name, message);
-    } else {
-      err = MPI_Recv(message, 32, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
-      if (err == MPI_SUCCESS)
-        printf("[%s] Message received: %s\n", processor_name, message);
-      strncpy(message, "Message from process #1", 32);
-      err = MPI_Send(message, 32, MPI_CHAR, 0, 0, MPI_COMM_WORLD);
-      if (err == MPI_SUCCESS)
-          printf("[%s] Message sent: %s\n", processor_name, message);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/deadlock_2/Makefile

-PROG = deadlock_2
-OBJECTS = deadlock_2.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun -np 2 ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/deadlock_2/deadlock_2.c

-#include <mpi.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-int main(int argc, char **argv) {
-
-  char *sendbuf, *recvbuf;
-  MPI_Status status;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // forcing the program to run with exactly two processes
-  if (num_processes != 2) {
-    fprintf(stderr, "Must use exactly two processes for this program\n");
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  } else {
-    int other = 1 - rank;
-    // testing different message sizes that will cause deadlock
-    for (int size = 1; size < 2000000000; size *= 10) {
-      sendbuf = malloc(size * sizeof(char));
-      recvbuf = malloc(size * sizeof(char));
-      if (!sendbuf || !recvbuf) {
-        fprintf(stderr, "Failed to allocate memory\n");
-        MPI_Abort(MPI_COMM_WORLD, 1);
-      }
-      MPI_Send(sendbuf, size, MPI_CHAR, other, 0, MPI_COMM_WORLD);
-      MPI_Recv(recvbuf, size, MPI_CHAR, other, 0, MPI_COMM_WORLD, &status);
-
-      if (rank == 0) {
-          printf("Send did not block for %d bytes\n",size);
-      }
-      free(sendbuf);
-      free(recvbuf);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/hello_world/Makefile

-PROG = hello_world
-OBJECTS = hello_world.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/hello_world/hello_world.c

-#include <mpi.h>
-#include <stdio.h>
-
-int main(int argc, char **argv) {
-  // Initialize the MPI environment.
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // Print off a hello world message
-  printf("Hello world, processor: %s, rank: %d, total num of processors: %d\n",
-         processor_name, rank, num_processes);
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/nb_point_2_point/Makefile

-PROG = nb_point_2_point
-OBJECTS = nb_point_2_point.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun -np 2 ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/nb_point_2_point/nb_point_2_point.c

-#include <mpi.h>
-#include <stdio.h>
-#include <string.h>
-
-static void busy(void) {
-  int i;
-  for (i = 0; i < 10000000; i++) {
-      if (i % 5000000 == 0) {
-          printf("Busy...\n");
-          fflush(stdout);
-      }
-  }
-    printf("Busy...\n");
-}
-
-int main(int argc, char **argv) {
-
-  char message[32];
-  MPI_Status status;
-  MPI_Request request;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // forcing the program to run with exactly two processes
-  if (num_processes != 2) {
-    fprintf(stderr, "Must use exactly two processes for this program\n");
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  } else {
-    if (rank == 0) {
-      strncpy(message, "This is not a message!", 32);
-      MPI_Isend(message, 32, MPI_CHAR, 1, 0, MPI_COMM_WORLD, &request);
-      busy();
-      MPI_Wait(&request, &status);
-      printf("[%s] Message sent: %s\n", processor_name, message);
-    } else {
-      MPI_Irecv(message, 32, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &request);
-      busy();
-      MPI_Wait(&request, &status);
-      printf("[%s] Message received: %s\n", processor_name, message);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/nb_waitall/Makefile

-PROG = nb_waitall
-OBJECTS = nb_waitall.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun ./$(PROG);
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/nb_waitall/nb_waitall.c

-#include <mpi.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-int main(int argc, char **argv) {
-
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  MPI_Request *requests =
-      (MPI_Request *) malloc(num_processes * sizeof(MPI_Request));
-  MPI_Status *statuses =
-      (MPI_Status *) malloc(num_processes * sizeof(MPI_Status));
-
-  char *recv_buffers = (char *)malloc(num_processes * sizeof(char));
-  char send_buffers = 'A';
-
-  send_buffers += rank;
-
-  MPI_Isend(&send_buffers, 1, MPI_CHAR, 0, 0,
-            MPI_COMM_WORLD, &requests[rank]);
-
-  // all processes send to rank 0
-  if (rank == 0) {
-    for (int i = 0; i < num_processes; i++)
-        MPI_Irecv(&recv_buffers[i], 1, MPI_CHAR, i, 0,
-                  MPI_COMM_WORLD, &requests[i]);
-    MPI_Waitall(num_processes, requests, statuses);
-    for (int i = 0; i < num_processes; i++) {
-      printf("Process 0 received token %c from process %d\n", recv_buffers[i],
-             statuses[i].MPI_SOURCE);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/ordering/Makefile

-PROG = ordering
-OBJECTS = ordering.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun -np 2 ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/ordering/ordering.c

-#include <mpi.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-int main(int argc, char **argv) {
-
-  char token;
-  MPI_Status status;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // forcing the program to run with exactly two processes
-  if (num_processes != 2) {
-    fprintf(stderr, "Must use exactly two processes for this program\n");
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  } else {
-    if (rank == 0) {
-      token = 'A';
-      MPI_Send(&token, 1, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
-      token = 'B';
-      MPI_Send(&token, 1, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
-      token = 'C';
-      MPI_Send(&token, 1, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
-    } else {
-      sleep(1);
-      MPI_Recv(&token, 1, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
-      printf("Process 1 received token %c from process 0\n", token);
-      MPI_Recv(&token, 1, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
-      printf("Process 1 received token %c from process 0\n", token);
-      MPI_Recv(&token, 1, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
-      printf("Process 1 received token %c from process 0\n", token);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/ordering_2/Makefile

-PROG = ordering_2
-OBJECTS = ordering_2.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	for i in `seq 3`; do \
-		echo "Run $$i:"; \
-		mpirun ./$(PROG); \
-	done
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/point_2_point/Makefile

-PROG = point_2_point
-OBJECTS = point_2_point.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-
-$(PROG): $(OBJECTS) # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-.Phone: run
-run: $(PROG) # build and run the program
-	mpirun -np 2 ./$(PROG)
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(PROG)
-

exercises/MPI_examples/point_2_point/point_2_point.c

-#include <mpi.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-int main(int argc, char **argv) {
-
-  char message[32];
-  int err;
-  MPI_Status status;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int num_processes;
-  MPI_Comm_size(MPI_COMM_WORLD, &num_processes);
-
-  // Get the rank of the process
-  int rank;
-  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-
-  // Get the name of the processor
-  char processor_name[MPI_MAX_PROCESSOR_NAME];
-  int name_len;
-  MPI_Get_processor_name(processor_name, &name_len);
-
-  // forcing the program to run with exactly two processes
-  if (num_processes != 2) {
-    fprintf(stderr, "Must use exactly two processes for this program\n");
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  } else {
-    if (rank == 0) {
-      strncpy(message, "This is not a message!", 32);
-      err = MPI_Send(message, 32, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
-      if (err == MPI_SUCCESS)
-          printf("[%s] Message sent: %s\n", processor_name, message);
-    } else {
-      err = MPI_Recv(message, 32, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
-      if (err == MPI_SUCCESS)
-        printf("[%s] Message received: %s\n", processor_name, message);
-    }
-  }
-
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}

exercises/MPI_examples/questions/Makefile

-OBJECTS = q1.o q2.o q3.o q4.o q5.o
-CC = mpicc
-CFLAGS = -Wall -std=c11
-CFLAGS += -I. # add the current directory to the include path
-PHONY_RUNS = run1 run2 run3 run4 run5
-PHONY_CLEANS = clean1 clean2 clean3 clean4 clean5
-
-.PHONY: all
-all: $(patsubst %.o,%,$(OBJECTS)) # build all binaries
-
-.PHONY: $(PHONY_RUNS)
-$(PHONY_RUNS): run%: q% # run a binary
-	time mpirun $<
-
-$(patsubst %.o,%,$(OBJECTS)): %: %.o # link the object files into a binary
-	$(CC) $(CFLAGS) $^ -o $@
-
-$(OBJECTS): %.o: %.c  # compile the source files into object files
-	$(CC) $(CFLAGS) -c $<
-
-.PHONY: clean
-clean: # remove the object files and the binary
-	rm -f $(OBJECTS) $(patsubst %.o,%,$(OBJECTS))
-
-.PHONY: $(PHONY_RUNS)
-$(PHONY_CLEANS): clean%: q% # run a binary
-	rm -f $<.o $<
-

exercises/MPI_examples/questions/README.md

-# Code from the questions
-
-This folder contains all the programs that are presented in the question PDF.
-
-## Build
-
-```c
-# build all programs
-make 
-
-# run specific program
-make run1
-make run2
-...
-make run5
-
-# clean specific build
-make clean1
-make clean2
-...
-make clean5
-
-# clean all builds
-make clean
-```

exercises/MPI_examples/questions/q1.c

-#include <mpi.h>
-#include <stdio.h>
-
-int main(int argc, char **argv) {
-
-  int sbuffer = 1;
-  int rbuffer = 2;
-  const int buflen = 1;
-  MPI_Init(&argc, &argv);
-
-  // Get the number of processes
-  int nprocs;
-  MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
-
-  // Get the rank of the process
-  int procid;
-  MPI_Comm_rank(MPI_COMM_WORLD, &procid);
-
-  for (int p = 0; p < nprocs; p++) {
-    if (p != procid)
-      MPI_Send(&sbuffer, buflen, MPI_INT, p, 0, MPI_COMM_WORLD);
-    printf("Process %d blocking sent message to process %d\n", procid, p);
-  }
-
-  for (int p = 0; p < nprocs; p++) {
-    if (p != procid)
-      MPI_Recv(&rbuffer, buflen, MPI_INT, p, 0, MPI_COMM_WORLD,
-               MPI_STATUS_IGNORE);
-    printf("Process %d blocking received message from process %d\n", procid, p);
-  }
-  // Finalize the MPI environment. No more MPI calls can be made after this
-  MPI_Finalize();
-}