Added debugging/profiling lab

.gitignore

+*.mem
+dividearrays
+fileutil
+workitems
+a.out
+copy.txt
+

debugging/Makefile

+all: workitems dividearrays fileutil
+
+workitems: workitems.c
+	$(CC) -g -O0 -o $@ $< -lpthread
+dividearrays: dividearrays.cpp
+	$(CXX) -g -O0 -o $@ $<
+fileutil: fileutil.cpp
+	$(CXX) -g -O0 -o $@ $<
+run: fileutil
+	./fileutil
+	diff -u bible.txt copy.txt

debugging/dividearrays.cpp

+#include <random>
+
+int main(int argc, char **argv)
+{
+  std::random_device generator;
+  std::uniform_int_distribution<int> intdist(0,50);
+  double res[1024];
+
+  for (int i=0; i<1024; i++) {
+    int nom = intdist(generator);
+    int denom = intdist(generator);
+    res[i] = nom / denom;
+  }
+  return 0;
+}

debugging/fileutil.cpp

+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+namespace std {
+
+static void getline(char *line, FILE *fin)
+{
+  int c = '\0', cur = 0;
+  while (c != '\n' && (c = fgetc(fin)) != EOF) {
+    line[cur++] = c;
+  }
+  line[cur] = '\0';
+}
+
+}
+
+using namespace std;
+
+int main(int argc, char **argv)
+{
+  int cur = 0;
+  char *lines[16536];
+  char line[80];
+  // Fix num lines, num columns, strdup-1
+  FILE *fin = fopen("bible.txt", "r");
+  while (!feof(fin)) {
+    getline(line, fin);
+    lines[cur] = (char*) malloc(strlen(line));
+    strcpy(lines[cur], line);
+    cur++;
+  }
+  fclose(fin);
+  FILE *fout = fopen("copy.txt", "w");
+  for (int i=0; i<cur; i++) {
+    fputs(lines[i], fout);
+  }
+  fclose(fout);
+  return 0;
+}

debugging/workitems.c

+#include <assert.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+typedef struct workitem {
+  void (*fn)(double *);
+  int current;
+  int len;
+  double *data;
+  int started;
+} workitem;
+
+static void* launchThread(void *in)
+{
+  int n;
+  workitem *data = (workitem*) in;
+  volatile int started = 0;
+  while (!(started = data->started));
+  while (1) {
+    n = data->current++;
+    if (n >= data->len) break;
+    data->fn(&data->data[n]);
+  }
+  return NULL;
+}
+
+void launchParallel(int numThreads, double *values, int len, void (*fn)(double *))
+{
+  workitem *data = calloc(1, sizeof(workitem));
+  pthread_t th[numThreads];
+
+  memset(th, 0, numThreads*sizeof(pthread_t));
+
+  data->fn = fn;
+  data->current = 0;
+  data->len = len;
+  data->data = values;
+  data->started = 0;
+
+  for (int i=0; i<numThreads; i++) {
+    assert(0 == pthread_create(&th[i], NULL, launchThread, data));
+  }
+  data->started = 1;
+  for (int i=0; i<numThreads; i++) {
+    assert(th[i] && 0==pthread_join(th[i], NULL));
+  }
+  assert(data->current >= len);
+  free(data);
+}
+
+void mul2(double *d)
+{
+  *d = *d * 2;
+}
+
+int main(int argc, char **argv)
+{
+  double vals[100];
+  for (int i=0; i<100; i++) {
+    vals[i] = i*1.5;
+  }
+  launchParallel(4 /* Increase this if no error occurs */, vals, 100, mul2);
+  for (int i=0; i<100; i++) {
+    if (vals[i] != 1.5*2*i) {
+      fprintf(stderr, "Expected vals[%d] to have value %.1f, got value %.1f\n", i, (double)1.5*2*i, (double)vals[i]);
+    }
+  }
+  return 0;
+}

julia/Makefile

@@ -5,6 +5,7 @@ run: julia-1.0.4/bin/julia
 
 julia-1.0.4/bin/julia: julia-1.0.4-linux-x86_64.tar.gz
 	tar xzf $<
+	$@ -e 'using Pkg; Pkg.add("BenchmarkTools"); Pkg.add("StatProfilerHTML")'
 	touch $@
 julia-1.0.4-linux-x86_64.tar.gz:
 	wget https://julialang-s3.julialang.org/bin/linux/x64/1.0/julia-1.0.4-linux-x86_64.tar.gz

profiling/Makefile

+.PHONY: run
+
+run: ../julia/julia-1.0.4/bin/julia
+	$< test.jl
+
+../julia/julia-1.0.4/bin/julia:
+	$(MAKE) -C ../julia julia-1.0.4/bin/julia

profiling/test.jl

+using BenchmarkTools
+using Random
+
+function f()
+  lst = rand(50000)
+  for i in lst
+    s = "List entry $(i)\r" # The \r makes it so the terminal isn't filled
+    if i > 0.99
+      print(s)
+    end
+  end
+end
+
+f()
+@time f()
+x = @benchmark f()
+println()
+println(x)