libc/pthread: Implement pthread_condattr_[set|get]pshared

https://pubs.opengroup.org/onlinepubs/009696799/functions/pthread_condattr_getpshared.html

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

Documentation/reference/user/08_pthread.rst

@@ -115,10 +115,6 @@ No support for the following pthread interfaces is provided by NuttX:
   -  ``pthread_attr_setguardsize``. get and set the thread guardsize
      attribute.
   -  ``pthread_attr_setscope``. get and set the contentionscope attribute.
-  -  ``pthread_condattr_getpshared``. get the process-shared condition
-     variable attribute.
-  -  ``pthread_condattr_setpshared``. set the process-shared condition
-     variable attribute.
   -  ``pthread_getconcurrency``. get and set the level of concurrency.
   -  ``pthread_getcpuclockid``. access a thread CPU-time clock.
   -  ``pthread_mutex_getprioceiling``. get and set the priority ceiling of

include/pthread.h

@@ -248,6 +248,7 @@ typedef pid_t pthread_t;
 
 struct pthread_condattr_s
 {
+  int pshared;
   clockid_t clockid;
 };
 
@@ -615,6 +616,9 @@ int pthread_mutex_consistent(FAR pthread_mutex_t *mutex);
 
 int pthread_condattr_init(FAR pthread_condattr_t *attr);
 int pthread_condattr_destroy(FAR pthread_condattr_t *attr);
+int pthread_condattr_getpshared(FAR const pthread_condattr_t *attr,
+                                FAR int *pshared);
+int pthread_condattr_setpshared(FAR pthread_condattr_t *attr, int pshared);
 int pthread_condattr_getclock(FAR const pthread_condattr_t *attr,
                               clockid_t *clock_id);
 int pthread_condattr_setclock(FAR pthread_condattr_t *attr,

libs/libc/pthread/Make.defs

@@ -39,6 +39,7 @@ CSRCS += pthread_barrierattr_init.c pthread_barrierattr_destroy.c
 CSRCS += pthread_barrierattr_getpshared.c pthread_barrierattr_setpshared.c
 CSRCS += pthread_barrierinit.c pthread_barrierdestroy.c pthread_barrierwait.c
 CSRCS += pthread_condattr_init.c pthread_condattr_destroy.c
+CSRCS += pthread_condattr_getpshared.c pthread_condattr_setpshared.c
 CSRCS += pthread_condattr_setclock.c pthread_condattr_getclock.c
 CSRCS += pthread_condinit.c pthread_conddestroy.c pthread_condtimedwait.c
 CSRCS += pthread_create.c pthread_exit.c

libs/libc/pthread/pthread_condattr_getpshared.c

@@ -0,0 +1,68 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_condattr_getpshared.c
+ *
+ * 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 <nuttx/config.h>
+
+#include <pthread.h>
+#include <errno.h>
+#include <debug.h>
+
+/********************************************************************************
+ * Public Functions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Name: pthread_condattr_getpshared
+ *
+ * Description:
+ *   The pthread_condattr_getpshared() function will obtain the value of the
+ *   process-shared attribute from the attributes object referenced by attr.
+ *
+ * Input Parameters:
+ *   attr - cond attributes to be queried.
+ *   pshared - the location to stored the current value of the pshared attribute.
+ *
+ * Returned Value:
+ *   0 (OK) on success or EINVAL if either attr or pshared is invalid.
+ *
+ * Assumptions:
+ *
+ ********************************************************************************/
+
+int pthread_condattr_getpshared(FAR const pthread_condattr_t *attr,
+                                FAR int *pshared)
+{
+  int ret = OK;
+
+  if (!attr || !pshared)
+    {
+      ret = EINVAL;
+    }
+  else
+    {
+      *pshared = attr->pshared;
+    }
+
+  return ret;
+}

libs/libc/pthread/pthread_condattr_setpshared.c

@@ -0,0 +1,99 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_condattr_setpshared.c
+ *
+ * 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 <nuttx/config.h>
+
+#include <pthread.h>
+#include <errno.h>
+#include <debug.h>
+
+/********************************************************************************
+ * Pre-processor Definitions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Private Type Declarations
+ ********************************************************************************/
+
+/********************************************************************************
+ * Public Data
+ ********************************************************************************/
+
+/********************************************************************************
+ * Private Data
+ ********************************************************************************/
+
+/********************************************************************************
+ * Private Function Prototypes
+ ********************************************************************************/
+
+/********************************************************************************
+ * Public Functions
+ ********************************************************************************/
+
+/********************************************************************************
+ * Name: pthread_condattr_setpshared
+ *
+ * Description:
+ *   The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit
+ *   a cond to be operated upon by any thread that has access to the
+ *   memory where the cond is allocated. If the process-shared attribute
+ *   is PTHREAD_PROCESS_PRIVATE, the cond can only be operated upon by
+ *   threads created within the same process as the thread that initialized
+ *   the cond.
+ *   If threads of different processes attempt to operate on such a cond,
+ *   the behavior is undefined. The default value of the attribute is
+ *   PTHREAD_PROCESS_PRIVATE.
+ *
+ *   Both constants PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE are
+ *   defined in pthread.h.
+ *
+ * Input Parameters:
+ *   attr - cond attributes to be modified.
+ *   pshared - the new value of the pshared attribute.
+ *
+ * Returned Value:
+ *   0 (OK) on success or EINVAL if either attr is invalid or pshared is not
+ *   one of PTHREAD_PROCESS_SHARED or PTHREAD_PROCESS_PRIVATE.
+ *
+ * Assumptions:
+ *
+ ********************************************************************************/
+
+int pthread_condattr_setpshared(FAR pthread_condattr_t *attr, int pshared)
+{
+  int ret = OK;
+
+  if (!attr || (pshared != PTHREAD_PROCESS_SHARED &&
+       pshared != PTHREAD_PROCESS_PRIVATE))
+    {
+      ret = EINVAL;
+    }
+  else
+    {
+      attr->pshared = pshared;
+    }
+
+  return ret;
+}