[lldb] Give more time to test/API/multiple-debuggers

This test occasionally fails on two of the busiest CI bots (asan and
matrix), and we can't reproduce it locally. This leads to the
hypothesis that the test is timing out (in the sense of the number of
"join attempts" performed by this test's driver).

This commit doubles the number of iterations performed and also does
an NFC refactor of the main test loop so that it can be more easily
understood.

(cherry picked from commit 869f551)

Author: adrian-prantl

lldb/test/API/api/multiple-debuggers/multi-process-driver.cpp

@@ -216,6 +216,22 @@ void *do_one_debugger (void *in)
     return (void*) 1;
 }
 
+int count_completed_threads(int num_threads) {
+  int num_completed_threads = 0;
+  for (int i = 0; i < num_threads; i++)
+    if (completed_threads_array[i])
+      num_completed_threads++;
+  return num_completed_threads;
+}
+
+int count_successful_threads(int num_threads) {
+  int num_successful_threads = 0;
+  for (int i = 0; i < num_threads; i++)
+    if (successful_threads_array[i])
+      num_successful_threads++;
+  return num_successful_threads;
+}
+
 int main (int argc, char **argv)
 {
 #if !defined(_MSC_VER)
@@ -241,26 +257,15 @@ int main (int argc, char **argv)
     }
 
 
-    int max_time_to_wait = 20;  // 20 iterations, or 60 seconds
-    int iter = 0;
-    while (1)
-    {
+    int max_time_to_wait = 40;  // 40 iterations, or 120 seconds
+    if (getenv("ASAN_OPTIONS"))
+      max_time_to_wait *= 4;
+    for (int iter = 0; iter < max_time_to_wait; iter++) {
         std::this_thread::sleep_for(std::chrono::seconds(3));
-        bool all_done = true;
-        int successful_threads = 0;
-        int total_completed_threads = 0;
-        for (uint64_t i = 0; i < NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS; i++)
-        {
-            if (successful_threads_array[i] == true)
-                successful_threads++;
-            if (completed_threads_array[i] == true)
-                total_completed_threads++;
-            if (completed_threads_array[i] == false)
-            {
-                all_done = false;
-            }
-        }
-        if (all_done)
+        int successful_threads = count_successful_threads(NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS);
+        int total_completed_threads = count_completed_threads(NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS);
+
+        if (total_completed_threads == NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS)
         {
 #if DEBUG == 1
             printf ("All threads completed.\n");
@@ -275,14 +280,14 @@ int main (int argc, char **argv)
             printf ("%d threads completed so far (%d successfully), out of %d\n", total_completed_threads, successful_threads, NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS);
 #endif
         }
-        if (iter++ == max_time_to_wait)
-        {
-            printf ("reached maximum timeout but only %d threads have completed so far (%d successfully), out of %d.  Exiting.\n", total_completed_threads, successful_threads, NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS);
-            break;
-        }
+        if (iter == max_time_to_wait)
+          printf("reached maximum timeout but only %d threads have completed "
+                 "so far "
+                 "(%d successfully), out of %d.  Exiting.\n",
+                 total_completed_threads, successful_threads,
+                 NUMBER_OF_SIMULTANEOUS_DEBUG_SESSIONS);
     }
 
-
     SBDebugger::Terminate();
     exit (1);
 }