libc/pthread: Implement pthread_rwlockattr API

https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_getpshared.html

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

Documentation/reference/user/08_pthread.rst

@@ -131,14 +131,6 @@ No support for the following pthread interfaces is provided by NuttX:
      attribute of the mutex attributes object.
   -  ``pthread_mutexattr_setprioceiling``. get and set the prioceiling
      attribute of the mutex attributes object.
-  -  ``pthread_rwlockattr_destroy``. destroy and initialize the read-write
-     lock attributes object.
-  -  ``pthread_rwlockattr_getpshared``. get and set the process-shared
-     attribute of the read-write lock attributes object.
-  -  ``pthread_rwlockattr_init``. destroy and initialize the read-write
-     lock attributes object.
-  -  ``pthread_rwlockattr_setpshared``. get and set the process-shared
-     attribute of the read-write lock attributes object.
   -  ``pthread_setconcurrency``. get and set the level of concurrency.
 
 .. c:function:: int pthread_attr_init(pthread_attr_t *attr);

include/pthread.h

@@ -369,6 +369,16 @@ typedef bool pthread_once_t;
 #  define __PTHREAD_ONCE_T_DEFINED 1
 #endif
 
+struct pthread_rwlockattr_s
+{
+  int pshared;
+};
+
+#ifndef __PTHREAD_RWLOCKATTR_T_DEFINED
+typedef struct pthread_rwlockattr_s pthread_rwlockattr_t;
+#  define __PTHREAD_RWLOCKATTR_T_DEFINED 1
+#endif
+
 struct pthread_rwlock_s
 {
   pthread_mutex_t lock;
@@ -378,9 +388,10 @@ struct pthread_rwlock_s
   bool write_in_progress;
 };
 
+#ifndef __PTHREAD_RWLOCK_T_DEFINED
 typedef struct pthread_rwlock_s pthread_rwlock_t;
-
-typedef int pthread_rwlockattr_t;
+#  define __PTHREAD_RWLOCK_T_DEFINED 1
+#endif
 
 #define PTHREAD_RWLOCK_INITIALIZER  {PTHREAD_MUTEX_INITIALIZER, \
                                      PTHREAD_COND_INITIALIZER, \
@@ -651,6 +662,15 @@ int pthread_barrier_wait(FAR pthread_barrier_t *barrier);
 int pthread_once(FAR pthread_once_t *once_control,
                  CODE void (*init_routine)(void));
 
+/* Pthread rwlock attributes */
+
+int pthread_rwlockattr_init(FAR pthread_rwlockattr_t *attr);
+int pthread_rwlockattr_destroy(FAR pthread_rwlockattr_t *attr);
+int pthread_rwlockattr_getpshared(FAR const pthread_rwlockattr_t *attr,
+                                  FAR int *pshared);
+int pthread_rwlockattr_setpshared(FAR pthread_rwlockattr_t *attr,
+                                  int pshared);
+
 /* Pthread rwlock */
 
 int pthread_rwlock_destroy(FAR pthread_rwlock_t *rw_lock);
@@ -772,6 +792,18 @@ typedef struct pthread_barrier_s pthread_barrier_t;
 #  define __PTHREAD_BARRIER_T_DEFINED 1
 #endif
 
+#ifndef __PTHREAD_RWLOCKATTR_T_DEFINED
+struct pthread_rwlockattr_s;
+typedef struct pthread_rwlockattr_s pthread_rwlockattr_t;
+#  define __PTHREAD_RWLOCKATTR_T_DEFINED 1
+#endif
+
+#ifndef __PTHREAD_RWLOCK_T_DEFINED
+struct pthread_rwlock_s;
+typedef struct pthread_rwlock_s pthread_rwlock_t;
+#  define __PTHREAD_RWLOCK_T_DEFINED 1
+#endif
+
 #ifdef CONFIG_PTHREAD_SPINLOCKS
 #  ifndef __PTHREAD_SPINLOCK_T_DEFINED
 struct pthread_spinlock_s;

libs/libc/pthread/Make.defs

@@ -50,6 +50,8 @@ CSRCS += pthread_mutexattr_settype.c pthread_mutexattr_gettype.c
 CSRCS += pthread_mutexattr_setrobust.c pthread_mutexattr_getrobust.c
 CSRCS += pthread_mutex_lock.c
 CSRCS += pthread_once.c pthread_yield.c pthread_atfork.c
+CSRCS += pthread_rwlockattr_init.c pthread_rwlockattr_destroy.c
+CSRCS += pthread_rwlockattr_getpshared.c pthread_rwlockattr_setpshared.c
 CSRCS += pthread_rwlock.c pthread_rwlock_rdlock.c pthread_rwlock_wrlock.c
 CSRCS += pthread_setcancelstate.c pthread_setcanceltype.c
 CSRCS += pthread_testcancel.c

libs/libc/pthread/pthread_rwlockattr_destroy.c

@@ -0,0 +1,64 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_rwlockattr_destroy.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_rwlockattr_destroy
+ *
+ * Description:
+ *   The pthread_rwlockattr_destroy() function will destroy a rwlock attributes
+ *   object.  A destroyed attr attributes object can be reinitialized using
+ *   pthread_rwlockattr_init(); the results of otherwise referencing the object
+ *   after it has been destroyed are undefined.
+ *
+ * Input Parameters:
+ *   attr - rwlock attributes to be destroyed.
+ *
+ * Returned Value:
+ *   0 (OK) on success or EINVAL if attr is invalid.
+ *
+ * Assumptions:
+ *
+ ********************************************************************************/
+
+int pthread_rwlockattr_destroy(FAR pthread_rwlockattr_t *attr)
+{
+  int ret = OK;
+
+  if (!attr)
+    {
+      ret = EINVAL;
+    }
+
+  return ret;
+}

libs/libc/pthread/pthread_rwlockattr_getpshared.c

@@ -0,0 +1,68 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_rwlockattr_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_rwlockattr_getpshared
+ *
+ * Description:
+ *   The pthread_rwlockattr_getpshared() function will obtain the value of the
+ *   process-shared attribute from the attributes object referenced by attr.
+ *
+ * Input Parameters:
+ *   attr - rwlock 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_rwlockattr_getpshared(FAR const pthread_rwlockattr_t *attr,
+                                  FAR int *pshared)
+{
+  int ret = OK;
+
+  if (!attr || !pshared)
+    {
+      ret = EINVAL;
+    }
+  else
+    {
+      *pshared = attr->pshared;
+    }
+
+  return ret;
+}

libs/libc/pthread/pthread_rwlockattr_init.c

@@ -0,0 +1,67 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_rwlockattr_init.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_rwlockattr_init
+ *
+ * Description:
+ *   The pthread_rwlockattr_init() function will initialize a rwlock attribute
+ *   object attr with the default value for all of the attributes defined by the
+ *   implementation.
+ *
+ * Input Parameters:
+ *   attr - rwlock attributes to be initialized.
+ *
+ * Returned Value:
+ *   0 (OK) on success or EINVAL if attr is invalid.
+ *
+ * Assumptions:
+ *
+ ********************************************************************************/
+
+int pthread_rwlockattr_init(FAR pthread_rwlockattr_t *attr)
+{
+  int ret = OK;
+
+  if (!attr)
+    {
+      ret = EINVAL;
+    }
+  else
+    {
+      attr->pshared = PTHREAD_PROCESS_PRIVATE;
+    }
+
+  return ret;
+}

libs/libc/pthread/pthread_rwlockattr_setpshared.c

@@ -0,0 +1,99 @@
+/********************************************************************************
+ * libs/libc/pthread/pthread_rwlockattr_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_rwlockattr_setpshared
+ *
+ * Description:
+ *   The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit
+ *   a rwlock to be operated upon by any thread that has access to the
+ *   memory where the rwlock is allocated. If the process-shared attribute
+ *   is PTHREAD_PROCESS_PRIVATE, the rwlock can only be operated upon by
+ *   threads created within the same process as the thread that initialized
+ *   the rwlock.
+ *   If threads of different processes attempt to operate on such a rwlock,
+ *   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 - rwlock 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_rwlockattr_setpshared(FAR pthread_rwlockattr_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;
+}