seems nice

main.cpp

@@ -5,6 +5,9 @@
 #include <unistd.h>
 #include <sys/time.h>
 #include <cstdlib>
+#include <ctime>
+#include <iomanip>
+#include <sstream>
 
 using namespace std;
 
@@ -15,36 +18,35 @@ struct SharedData {
     int arr[MAX];
 };
 
-// ================= TIME =================
-double now() {
-    timeval t;
-    gettimeofday(&t, NULL);
-    return t.tv_sec + t.tv_usec / 1e6;
+string now() {
+    timeval tv;
+    gettimeofday(&tv, NULL);
+
+    ostringstream oss;
+    oss << tv.tv_sec << "."
+        << setfill('0') << setw(6) << tv.tv_usec;
+
+    return oss.str();
 }
 
-// ================= MERGE =================
 void merge(int *arr, int l, int m, int r) {
     int *temp = new int[r - l + 1];
 
     int i = l, j = m + 1, k = 0;
 
     while (i <= m && j <= r) {
-        if (arr[i] < arr[j])
-            temp[k++] = arr[i++];
-        else
-            temp[k++] = arr[j++];
+        if (arr[i] < arr[j]) temp[k++] = arr[i++];
+        else temp[k++] = arr[j++];
     }
 
     while (i <= m) temp[k++] = arr[i++];
     while (j <= r) temp[k++] = arr[j++];
 
-    for (int x = 0; x < k; x++)
-        arr[l + x] = temp[x];
+    for (int x = 0; x < k; x++) arr[l + x] = temp[x];
 
     delete[] temp;
 }
 
-// ================= LOCAL SORT =================
 void local_sort(int *arr, int l, int r) {
     if (l >= r) return;
     int m = (l + r) / 2;
@@ -53,45 +55,53 @@ void local_sort(int *arr, int l, int r) {
     merge(arr, l, m, r);
 }
 
-// ================= PARALLEL SORT =================
-void parallel_sort(int *arr, int l, int r, int depth) {
-    if (l >= r) return;
+void parallel_sort(int l, int r, int depth, int shmid) {
+    SharedData *data = (SharedData*) shmat(shmid, NULL, 0);
+    int *arr = data->arr;
 
-    double start = now();
+    string start_time = now();
 
-    pid_t pid = getpid();
-    pid_t ppid = getppid();
-
-    cout << "[START] t=" << start
-         << " PID=" << pid
-         << " PPID=" << ppid
+    cout << "START PID=" << getpid()
+         << " PPID=" << getppid()
          << " depth=" << depth
-         << " range=[" << l << "," << r << "]\n";
+         << " range=[" << l << "," << r << "]"
+         << " time=" << start_time << "\n";
+
+    if (l >= r) {
+        string end_time = now();
+        cout << "END   PID=" << getpid()
+             << " range=[" << l << "," << r << "]"
+             << " time=" << end_time << "\n";
+        shmdt(data);
+        return;
+    }
 
     int m = (l + r) / 2;
 
     if (depth >= MAX_DEPTH) {
         local_sort(arr, l, r);
 
-        double end = now();
-        cout << "[END]   t=" << end
-             << " PID=" << pid
-             << " duration=" << (end - start)
-             << " sec\n";
+        string end_time = now();
+        cout << "END   PID=" << getpid()
+             << " depth=" << depth
+             << " range=[" << l << "," << r << "]"
+             << " time=" << end_time << "\n";
+
+        shmdt(data);
         return;
     }
 
     pid_t left = fork();
 
     if (left == 0) {
-        parallel_sort(arr, l, m, depth + 1);
+        parallel_sort(l, m, depth + 1, shmid);
         _exit(0);
     }
 
     pid_t right = fork();
 
     if (right == 0) {
-        parallel_sort(arr, m + 1, r, depth + 1);
+        parallel_sort(m + 1, r, depth + 1, shmid);
         _exit(0);
     }
 
@@ -100,20 +110,21 @@ void parallel_sort(int *arr, int l, int r, int depth) {
 
     merge(arr, l, m, r);
 
-    double end = now();
+    string end_time = now();
 
-    cout << "[END]   t=" << end
-         << " PID=" << pid
-         << " duration=" << (end - start)
-         << " sec\n";
+    cout << "END   PID=" << getpid()
+         << " depth=" << depth
+         << " range=[" << l << "," << r << "]"
+         << " time=" << end_time << "\n";
+
+    shmdt(data);
 }
 
-// ================= MAIN =================
 int main() {
     key_t key = ftok("shmfile", 65);
     int shmid = shmget(key, sizeof(SharedData), 0666 | IPC_CREAT);
 
-    SharedData *data = (SharedData*) shmat(shmid, (void*)0, 0);
+    SharedData *data = (SharedData*) shmat(shmid, NULL, 0);
 
     int n = 20000;
 
@@ -122,27 +133,17 @@ int main() {
     for (int i = 0; i < n; i++)
         data->arr[i] = rand() % 100000;
 
-    double global_start = now();
+    cout << "Before:\n";
+    for (int i = 0; i < 20; i++)
+        cout << data->arr[i] << " ";
+    cout << "\n\n";
 
-    cout << "Main PID=" << getpid() << "\n\n";
+    parallel_sort(0, n - 1, 0, shmid);
 
-    parallel_sort(data->arr, 0, n - 1, 0);
-
-    double global_end = now();
-
-    cout << "\nExecution time: "
-         << (global_end - global_start)
-         << " sec\n";
-
-    // Проверка
-    for (int i = 1; i < n; i++) {
-        if (data->arr[i - 1] > data->arr[i]) {
-            cout << "ERROR: not sorted!\n";
-            break;
-        }
-    }
-
-    cout << "Sorted correctly\n";
+    cout << "\nAfter:\n";
+    for (int i = 0; i < 20; i++)
+        cout << data->arr[i] << " ";
+    cout << "\n";
 
     shmdt(data);
     shmctl(shmid, IPC_RMID, NULL);