update new exercises and descriptions

.gitignore

@@ -2,5 +2,6 @@
 _site
 .jekyll-cache
 CodingTutorialC++/cmake-build-debug
+CodingTutorialC++/misc.xml
 ruby
 .bundle

CodingTutorialC++/CMakeLists.txt

@@ -16,4 +16,9 @@ add_executable(ACO_practice overflow.cpp
         different_arrays.cpp
         vector.cpp
         Sort_index.cpp
+        openmp-no-parallel.cpp
+        openmp-sections.cpp
+        openmp-nested-for-loop.cpp
+        openmp-parallel-output.cpp
+        problemtic_program_for_gdb.cpp
 )

CodingTutorialC++/Makefile

@@ -15,15 +15,17 @@ TARGET = ACO_practice
 # Source files: SRCS is a list of source files
 SRCS = overflow.cpp MainArgs.cpp openmp-example.cpp pi.cpp pointer-dam.cpp pointer-dam3D.cpp \
 		pointer-update-parameter.cpp IO.cpp class.cpp structure.cpp Sort_index.cpp vector.cpp \
-		different_arrays.cpp
+		different_arrays.cpp openmp-nested-for-loop.cpp openp-no-parallel.cpp openmp-parallle-output.cpp \
+		openmp-sections.cpp problemtic_program_for_gdb.cpp
 
 # Object files
 # The $(SRCS:.cpp=.o) is a substitution reference which replaces the .cpp extension with .o in SRCS
 OBJS = $(SRCS:.cpp=.o)
 
 # Executables
 EXECS = overflow MainArgs openmp-example pi pointer-dam pointer-dam3D IO pointer-update-parameter \
- 		class structure Sort_index vector different_arrays
+ 		class structure Sort_index vector different_arrays openmp-nested-for-loop openmp-no-parallel \
+ 		openmp-parallle-output openmp-sections problemtic_program_for_gdb
 
 # Number of threads for OpenMP
 # OMP_NUM_THREADS is an environment variable that specifies the number of threads to use for OpenMP
@@ -78,6 +80,21 @@ vector: vector.o
 different_arrays: different_arrays.o
 	$(CXX) $(CXXFLAGS) -o different_arrays different_arrays.o
 
+openmp-nested-for-loop: openmp-nested-for-loop.o
+	$(CXX) $(CXXFLAGS) -o openmp-nested-for-loop openmp-nested-for-loop.o
+
+openmp-no-parallel: openmp-no-parallel.o
+	$(CXX) $(CXXFLAGS) -o openmp-no-parallel openmp-no-parallel.o
+
+openmp-parallle-output: openmp-parallle-output.o
+	$(CXX) $(CXXFLAGS) -o openmp-parallle-output openmp-parallle-output.o
+
+openmp-sections: openmp-sections.o
+	$(CXX) $(CXXFLAGS) -o openmp-sections openmp-sections.o
+
+problemtic_program_for_gdb: problemtic_program_for_gdb.o
+	$(CXX) $(CXXFLAGS) -o problemtic_program_for_gdb problemtic_program_for_gdb.o
+
 
 # Rule for building object files from source files
 # The $(CXX) $(CXXFLAGS) -c $< -o $@ command compiles the source file into an object file

CodingTutorialC++/README.md

@@ -16,6 +16,27 @@ This file contains a program that prints the name of the program and all the arg
 
 This file contains a program that uses OpenMP to calculate the sum of numbers from 1 to 1e5. It sets the number of threads to the number of processors available, and each thread calculates a portion of the sum.
 
+### [`openmp-nested-for-loop.cpp`](./openmp-nested-for-loop.cpp)
+
+This file contains a program that demonstrates the use of nested for loops in OpenMP. It shows how to parallelize both outer and inner loops for efficient computation.
+
+### [`openmp-no-parallel.cpp`](./openmp-no-parallel.cpp)
+
+This file contains a program that demonstrates the cases that OpenMP parallelization can not be used. It shows how a program behaves when run on a single thread.
+
+### [`openmp-parallel-output.cpp`](./openmp-parallel-output.cpp)
+
+This file contains a program that demonstrates the use of OpenMP for parallel output. It shows how to write to different files in parallel using OpenMP.
+
+### [`openmp-sections.cpp`](./openmp-sections.cpp)
+
+This file contains a program that demonstrates the use of sections in OpenMP. It shows how to divide a program into sections that can be executed in parallel.
+
+### [`problemtic_program_for_gdb.cpp`](./problemtic_program_for_gdb.cpp)
+
+This file contains a program that is designed to be debugged using GDB. It includes intentional errors that can be investigated using the debugger.
+
+
 ### [`pi.cpp`](./pi.cpp)
 
 This file contains a program that calculates the value of pi using the Leibniz formula for π. The program uses OpenMP for parallel computation, allowing it to calculate pi to a high degree of precision in a shorter amount of time. The number of threads used for the computation can be specified as a command-line argument when running the program.
@@ -92,6 +113,14 @@ make pointer-update-parameter
 make IO
 make class
 make structure
+make different_arrays
+make vector
+make Sort_index
+make openmp-nested-for-loop
+make openmp-no-parallel
+make openmp-parallel-output
+make openmp-sections
+make problemtic_program_for_gdb
 ```
 
 To clean up the built files, use the make clean command:

CodingTutorialC++/different_arrays.cpp

@@ -27,6 +27,7 @@ int main() {
     // test array out of scope
     test_array_out_of_scope();
     int* arr2 = new int[100000000];
+    int arr3[100000];
     test_array_out_of_scope(); // run twice to see if the memory location is the same
     delete[] arr2;
 

CodingTutorialC++/openmp-nested-for-loop.cpp

@@ -0,0 +1,22 @@
+//
+// Created by weiguang on 9/05/24.
+//
+#include <omp.h>
+#include <iostream>
+
+int main() {
+    int N = 1000;
+    int M = 10;
+    int matrix[N][M];
+
+//    #pragma omp parallel for collapse(2)
+    #pragma omp parallel for
+    for(int i = 0; i < N; i++) {
+//        #pragma omp parallel for
+        for(int j = 0; j < M; j++) {
+            matrix[i][j] = i * j;
+        }
+    }
+
+    return 0;
+}

CodingTutorialC++/openmp-no-parallel.cpp

@@ -0,0 +1,84 @@
+//
+// Created by weiguang on 9/05/24.
+//
+#include <omp.h>
+#include <iostream>
+#include <vector>
+
+// Sequential tasks
+void sequentialTasks() {
+    int arr[10];
+    arr[0] = 1;
+    int brr[10];
+    brr[0] = 1;
+
+//#pragma omp parallel sections
+    for(int i = 1; i < 10; i++) {
+//#pragma omp parallel sections  // any difference?
+//        #pragma omp section
+        arr[i] = arr[i-1] * 2; // Each iteration depends on the previous one
+//        #pragma omp section
+        brr[i] = brr[i-1] * 3;
+    }
+
+    for(int i = 0; i < 10; i++) {
+        std::cout << arr[i] << " ";
+    }
+    std::cout << std::endl;
+}
+
+// Shared resource access
+void sharedResourceAccess() {
+    std::vector<int> sharedVector;
+
+//    #pragma omp parallel for
+    for(int i = 0; i < 100; i++) {
+        sharedVector.push_back(i); // Race condition here
+    }
+
+    std::cout << "Vector size: " << sharedVector.size() << std::endl;
+}
+
+// Recursion
+int fibonacci(int n) {
+    if(n <= 1) {
+        return n;
+    } else {
+        return fibonacci(n-1) + fibonacci(n-2); // Recursive calls
+    }
+}
+
+void testFibonacci() {
+    std::cout << "Fibonacci(10): " << fibonacci(10) << std::endl;
+}
+
+// Complex dependencies
+void complexDependencies() {
+    std::vector<int> numbers = {1, 2, 3, 4, 5};
+    std::vector<int> results(numbers.size());
+
+    for(int i = 1; i < numbers.size() - 1; i++) {
+        results[i] = numbers[i-1] * numbers[i+1]; // Each operation depends on the previous and next number
+    }
+
+    for(int i = 0; i < results.size(); i++) {
+        std::cout << results[i] << " ";
+    }
+    std::cout << std::endl;
+}
+
+int main() {
+    std::cout << "Sequential tasks example:\n";
+    sequentialTasks();
+
+    std::cout << "\nShared resource access example:\n";
+    sharedResourceAccess();
+
+    std::cout << "\nRecursion example:\n";
+    testFibonacci();
+
+    std::cout << "\nComplex dependencies example:\n";
+    complexDependencies();
+
+    return 0;
+}

CodingTutorialC++/openmp-parallel-output.cpp

@@ -0,0 +1,49 @@
+//
+// Created by weiguang on 9/05/24.
+//
+#include <omp.h>
+#include <fstream>
+#include <sstream>
+
+int main() {
+    int N = omp_get_max_threads();
+    int data[1000];  // Assuming you have 1000 data points
+
+    // Initialize the data array
+    for(int i = 0; i < 1000; i++) {
+        data[i] = i * i;  // Just an example, replace with your actual data
+    }
+
+    int chunk_size = 1000 / N;  // Size of each chunk of data
+
+    // Write data to files in parallel
+    #pragma omp parallel num_threads(N)
+    {
+        int thread_id = omp_get_thread_num();
+
+        // Create a unique filename for each thread
+        std::stringstream ss;
+        ss << "output" << thread_id << ".txt";
+
+        // Open the file and write to it
+        std::ofstream file(ss.str());
+
+        // Calculate the start and end indices for this thread's chunk of data
+        int start = thread_id * chunk_size;
+        int end = start + chunk_size;
+
+        // If this is the last thread, make sure it processes all remaining data
+        if(thread_id == N - 1) {
+            end = 1000;
+        }
+
+        for(int i = start; i < end; i++) {
+            file << "Data: " << data[i] << std::endl;
+        }
+
+        // Close the file
+        file.close();
+    }
+
+    return 0;
+}

CodingTutorialC++/openmp-sections.cpp

@@ -0,0 +1,48 @@
+//
+// Created by weiguang on 9/05/24.
+//
+#include <omp.h>
+#include <iostream>
+
+void task1() {
+    std::cout << "Task 1 executed by thread " << omp_get_thread_num() << std::endl;
+}
+
+void task2() {
+    std::cout << "Task 2 executed by thread " << omp_get_thread_num() << std::endl;
+}
+
+void task3() {
+    std::cout << "Task 3 executed by thread " << omp_get_thread_num() << std::endl;
+}
+
+void task4() {
+    std::cout << "Task 4 executed by thread " << omp_get_thread_num() << std::endl;
+}
+
+int main() {
+    #pragma omp parallel sections
+    {
+        #pragma omp section
+        {
+            task1();
+        }
+
+        #pragma omp section
+        {
+            task2();
+        }
+
+        #pragma omp section
+        {
+            task3();
+        }
+
+        #pragma omp section
+        {
+            task4();
+        }
+    }
+
+    return 0;
+}

CodingTutorialC++/problemtic_program_for_gdb.cpp

@@ -0,0 +1,16 @@
+//
+// Created by weiguang on 10/05/24.
+//
+#include <iostream>
+
+int main() {
+    int arr[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+    // Attempt to access the array out of its bounds
+    for (int i = 0; i <= 10; i++) {
+        arr[i] += i;
+        std::cout << arr[i] << std::endl;  // This will cause a segmentation fault when i == 10
+    }
+
+    return 0;
+}

Exercises/Mandelbrot/Makefile

@@ -5,7 +5,7 @@ CXX = g++
 CXXFLAGS = -DHIGH_TIME_PRECISION
 
 # Compiler flags
-CXXFLAGS += -Wall -Wextra -O2 -fopenmp
+CXXFLAGS += -pg -ftest-coverage -lgcov -Wall -Wextra -O2 -fopenmp
 
 
 
@@ -30,4 +30,4 @@ $(EXEC): $(OBJS)
 	$(CXX) $(CXXFLAGS) -c $< -o $@
 
 clean:
-	rm -f $(OBJS) $(EXEC)
+	rm -f $(OBJS) $(EXEC)