New threadpool

- removed some whitespace noise.
 - cleaned up CMakeLists.txt
 - reintegrated task_manager.c into thread-pool.c
 - cleaned up some unnecessary code

Co-authored-by: Cedric Roux <cedric.roux@eurecom.fr>
Co-authored-by: Mikel Irazabal <mikel.irazabal@openairinterface.com>

common/utils/threadPool/task_ans.c

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include "task_ans.h"
+#include "assertions.h"
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <time.h>
+
+void completed_task_ans(task_ans_t* task)
+{
+  DevAssert(task != NULL);
+
+  if (atomic_load_explicit(&task->status, memory_order_acquire) != 0)
+    AssertFatal(0, "Task already finished?");
+
+  atomic_store_explicit(&task->status, 1, memory_order_release);
+}
+
+void join_task_ans(task_ans_t* arr, size_t len)
+{
+  DevAssert(len < INT_MAX);
+  DevAssert(arr != NULL);
+
+  // Spin lock inspired by:
+  // The Art of Writing Efficient Programs:
+  // An advanced programmer's guide to efficient hardware utilization
+  // and compiler optimizations using C++ examples
+  const struct timespec ns = {0, 1};
+  uint64_t i = 0;
+  int j = len - 1;
+  for (; j != -1; i++) {
+    for (; j != -1; --j) {
+      int const task_completed = 1;
+      if (atomic_load_explicit(&arr[j].status, memory_order_acquire) != task_completed)
+        break;
+    }
+    if (i % 8 == 0) {
+      nanosleep(&ns, NULL);
+    }
+  }
+}