pthread: add pthread_{get|set}concurrency support

Add support for pthread_{get|set}concurrency support.

NuttX uses 1:1 threading model (every pthread is a kernel-managed thread),
so this function has no real effect on the scheduling behavior.

Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>

libs/libc/pthread/CMakeLists.txt

@@ -106,7 +106,8 @@ if(NOT CONFIG_DISABLE_PTHREAD)
     pthread_testcancel.c
     pthread_getcpuclockid.c
     pthread_self.c
-    pthread_gettid_np.c)
+    pthread_gettid_np.c
+    pthread_concurrency.c)
 
   if(CONFIG_SMP)
     list(APPEND SRCS pthread_attr_getaffinity.c pthread_attr_setaffinity.c)

libs/libc/pthread/Make.defs

@@ -64,6 +64,7 @@ CSRCS += pthread_rwlock.c pthread_rwlock_rdlock.c pthread_rwlock_wrlock.c
 CSRCS += pthread_setcancelstate.c pthread_setcanceltype.c
 CSRCS += pthread_testcancel.c pthread_getcpuclockid.c
 CSRCS += pthread_self.c pthread_gettid_np.c
+CSRCS += pthread_concurrency.c
 
 ifeq ($(CONFIG_SMP),y)
 CSRCS += pthread_attr_getaffinity.c pthread_attr_setaffinity.c

libs/libc/pthread/pthread_concurrency.c

@@ -0,0 +1,87 @@
+/****************************************************************************
+ * libs/libc/pthread/pthread_concurrency.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <pthread.h>
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+static int g_pthread_concurrency_level = 0;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: pthread_setconcurrency
+ *
+ * Description:
+ *   The pthread_setconcurrency() function informs the implementation of
+ *   the application's desired concurrency level.
+ *
+ *   NuttX uses 1:1 threading model, so this function has no real effect
+ *   on the scheduling behavior.
+ *
+ * Input Parameters:
+ *  new_level - desired concurrency level
+ *
+ * Returned Value:
+ *  Returns 0 on success, on error it returns a nonzero error number
+ *
+ ****************************************************************************/
+
+int pthread_setconcurrency(int new_level)
+{
+  if (new_level < 0)
+    {
+      return EINVAL;
+    }
+
+  g_pthread_concurrency_level = new_level;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: pthread_getconcurrency
+ *
+ * Description:
+ *   The pthread_getconcurrency() returns the value previously set by
+ *   pthread_setconcurrency().
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Returns the current value of concurrency level.
+ *
+ ****************************************************************************/
+
+int pthread_getconcurrency(void)
+{
+  return g_pthread_concurrency_level;
+}