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[doxygen][libc] Add some comments for posix pthread functions (#7467) 

Signed-off-by: Rain Park <1162678210@qq.com>
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Rain Park 2023-05-10 14:01:33 +08:00 committed by GitHub
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390
components/libc/posix/pthreads/pthread_attr.c
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2006-2021, RT-Thread Development Team
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
@ -29,6 +29,24 @@ const pthread_attr_t pthread_default_attr =
PTHREAD_CREATE_JOINABLE, /* detach state */
};
/**
* @brief This function will initialize thread attributes object.
*
* @note The pthread_attr_t type should be treated as opaque: any access to the object other
* than via pthreads functions is nonportable and produces undefined results.
* The resulting attribute object (possibly modified by setting individual attribute values),
* when used by pthread_create(), defines the attributes of the thread created. A single attributes
* object can be used in multiple simultaneous calls to pthread_create().
*
* @see pthread_create()
*
* @param attr is a thread attributes object.
*
* @return Upon successful completion, pthread_attr_init() return a value of 0.
* Otherwise, it means that the event detach failed.
*
* @warning This function will fail if attr is null.
*/
int pthread_attr_init(pthread_attr_t *attr)
{
RT_ASSERT(attr != RT_NULL);
@ -39,6 +57,24 @@ int pthread_attr_init(pthread_attr_t *attr)
}
RTM_EXPORT(pthread_attr_init);
/**
* @brief This function will destroy thread attributes object.
*
* @note When a thread attributes object is no longer required, it should be destroyed
* using the pthread_attr_destroy() function. Destroying a thread attributes object
* has no effect on threads that were created using that object.
* Once a thread attributes object has been destroyed, it can be reinitialized using pthread_attr_init().
* Any other use of a destroyed thread attributes object has undefined results.
*
* @see pthread_attr_init(), pthread_attr_getdetachstate(), pthread_create()
*
* @param attr is a thread attributes object.
*
* @return Upon successful completion, pthread_attr_destroy() and shall return a value of 0;
* Otherwise, an error number shall be returned to indicate the error.
*
* @warning This function will fail if attr is null.
*/
int pthread_attr_destroy(pthread_attr_t *attr)
{
RT_ASSERT(attr != RT_NULL);
@ -49,6 +85,33 @@ int pthread_attr_destroy(pthread_attr_t *attr)
}
RTM_EXPORT(pthread_attr_destroy);
/**
* @brief This function set detach state attribute in thread attributes object.
*
* @note This function sets the detach state attribute of the thread attributes object
* referred to by attr to the value specified in detachstate. The detach state
* attribute determines whether a thread created using the thread attributes
* object attr will be created in a joinable or a detached state.
*
* @see pthread_attr_init(), pthread_create(), pthread_detach(), pthread_join(), pthreads()
*
* @param attr is a thread attributes object.
*
* @param state is attribute in the attr object.
* attribute controls whether the thread is created in a detached state.
* The detachstate can be ONE of the following values:
*
* PTHREAD_CREATE_DETACHED It causes all threads created with attr to be in the detached state.
*
* PTHREAD_CREATE_JOINABLE Default value, it causes all threads created with attr to be in the joinable state.
*
* @return Upon successful completion, pthread_attr_setdetachstate() and return a value of 0.
* Otherwise, an error number is returned to indicate the error.
*
* @warning The pthread_attr_setdetachstate() function will fail if:
* [EINVAL]
* The value of detach state was not valid
*/
int pthread_attr_setdetachstate(pthread_attr_t *attr, int state)
{
RT_ASSERT(attr != RT_NULL);
@ -62,6 +125,31 @@ int pthread_attr_setdetachstate(pthread_attr_t *attr, int state)
}
RTM_EXPORT(pthread_attr_setdetachstate);
/**
* @brief This function get detach state attribute in thread attributes object.
*
* @note The detachstate attribute controls whether the thread is created in a detached state.
* If the thread is created detached, then use of the ID of the newly created thread by
* the pthread_detach() or pthread_join() function is an error.
*
* @see pthread_attr_destroy(), pthread_attr_getstackaddr(), pthread_attr_getstacksize(), pthread_create()
*
* @param attr is a thread attributes object.
*
* @param state is attribute in the attr object.
* attribute controls whether the thread is created in a detached state.
* The detachstate can be ONE of the following values:
*
* PTHREAD_CREATE_DETACHED It causes all threads created with attr to be in the detached state.
*
* PTHREAD_CREATE_JOINABLE Default value, it causes all threads created with attr to be in the joinable state.
*
* @return Upon successful completion, pthread_attr_getdetachstate() and shall return a value of 0;
* otherwise, an error number shall be returned to indicate the error.
*
* The pthread_attr_getdetachstate() function stores the value of the detachstate
* attribute in detachstate if successful.
*/
int pthread_attr_getdetachstate(pthread_attr_t const *attr, int *state)
{
RT_ASSERT(attr != RT_NULL);
@ -72,6 +160,27 @@ int pthread_attr_getdetachstate(pthread_attr_t const *attr, int *state)
}
RTM_EXPORT(pthread_attr_getdetachstate);
/**
* @brief This function sets schedpolicy attribute.
*
* @note The function function sets the scheduling policy attribute of the thread
* attributes object referred to by attr to the value specified in policy.
*
* @see pthread_attr_init(), pthread_attr_setscope(), pthread_attr_setinheritsched(), pthread_attr_setschedparam(), pthread_create()
*
* @param attr is a thread attributes object.
*
* @param policy is attribute in the attr object.
* The policy can be ONE of the following values:
*
* SCHED_FIFO First in-first out scheduling.
*
* SCHED_RR Round-robin scheduling.
*
* SCHED_OTHER Default Linux time-sharing scheduling.
*
* @return On success, these functions return 0.
*/
int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
{
RT_ASSERT(attr != RT_NULL);
@ -82,6 +191,26 @@ int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
}
RTM_EXPORT(pthread_attr_setschedpolicy);
/**
* @brief This function gets schedpolicy attribute.
*
* @note The function gets the schedpolicy attribute in the attr argument.
*
* @see pthread_attr_destroy(), pthread_attr_getscope(), pthread_attr_getinheritsched(), pthread_attr_getschedparam(), pthread_create()
*
* @param attr is a thread attributes object.
*
* @param policy is attribute in the attr object.
* The policy can be ONE of the following values:
*
* SCHED_FIFO First in-first out scheduling.
*
* SCHED_RR Round-robin scheduling.
*
* SCHED_OTHER Default Linux time-sharing scheduling.
*
* @return On success, these functions return 0.
*/
int pthread_attr_getschedpolicy(pthread_attr_t const *attr, int *policy)
{
RT_ASSERT(attr != RT_NULL);
@ -92,6 +221,19 @@ int pthread_attr_getschedpolicy(pthread_attr_t const *attr, int *policy)
}
RTM_EXPORT(pthread_attr_getschedpolicy);
/**
* @brief This function set the scheduling parameter attributes in the attr argument.
* @see pthread_attr_init(), pthread_attr_setscope(), pthread_attr_setinheritsched(), pthread_attr_setschedpolicy()
*
* @param attr is a thread attributes object.
*
* @param param is scheduling parameter attributes in the attr argument.
* The contents of the param structure are defined in <pthread.h>.
* For the SCHED_FIFO and SCHED_RR policies, the only required member of param is sched_priority.
*
* @return On success, these functions return 0.
*/
int pthread_attr_setschedparam(pthread_attr_t *attr,
struct sched_param const *param)
{
@ -104,6 +246,19 @@ int pthread_attr_setschedparam(pthread_attr_t *attr,
}
RTM_EXPORT(pthread_attr_setschedparam);
/**
* @brief This function get the scheduling parameter attributes in the attr argument.
* @see pthread_attr_init(), pthread_attr_setscope(), pthread_attr_setinheritsched(), pthread_attr_setschedpolicy()
*
* @param attr is a thread attributes object.
*
* @param param is scheduling parameter attributes in the attr argument.
* The contents of the param structure are defined in <pthread.h>.
* For the SCHED_FIFO and SCHED_RR policies, the only required member of param is sched_priority.
*
* @return On success, these functions return 0.
*/
int pthread_attr_getschedparam(pthread_attr_t const *attr,
struct sched_param *param)
{
@ -116,6 +271,17 @@ int pthread_attr_getschedparam(pthread_attr_t const *attr,
}
RTM_EXPORT(pthread_attr_getschedparam);
/**
* @brief This function set the thread creation stacksize attribute in the attr object.
*
* @see pthread_attr_init(), pthread_attr_setstackaddr(), pthread_attr_setdetachstate()
*
* @param attr is a thread attributes object.
*
* @param stack_size is the minimum stack size (in bytes) allocated for the created threads stack.
*
* @return Upon successful completion, This function return a value of 0.
*/
int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stack_size)
{
RT_ASSERT(attr != RT_NULL);
@ -126,6 +292,17 @@ int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stack_size)
}
RTM_EXPORT(pthread_attr_setstacksize);
/**
* @brief This function get the thread creation stacksize attribute in the attr object.
*
* @see pthread_attr_init(), pthread_attr_getstackaddr(), pthread_attr_getdetachstate()
*
* @param attr is a thread attributes object.
*
* @param stack_size is the minimum stack size (in bytes) allocated for the created threads stack.
*
* @return Upon successful completion, This function return a value of 0.
*/
int pthread_attr_getstacksize(pthread_attr_t const *attr, size_t *stack_size)
{
RT_ASSERT(attr != RT_NULL);
@ -136,6 +313,18 @@ int pthread_attr_getstacksize(pthread_attr_t const *attr, size_t *stack_size)
}
RTM_EXPORT(pthread_attr_getstacksize);
/**
* @brief This function sets the thread creation stackaddr attribute in the attr object.
*
* @see pthread_attr_init(), pthread_attr_setdetachstate(), pthread_attr_setstacksize()
*
* @param attr is a thread attributes object.
*
* @param The stack_addr attribute specifies the location of storage to be used for the created
* thread's stack.
*
* @return Upon successful completion, This function return a value of 0.
*/
int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stack_addr)
{
RT_ASSERT(attr != RT_NULL);
@ -144,6 +333,18 @@ int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stack_addr)
}
RTM_EXPORT(pthread_attr_setstackaddr);
/**
* @brief This function gets the thread creation stackaddr attribute in the attr object.
*
* @see pthread_attr_init(), pthread_attr_setdetachstate(), pthread_attr_setstacksize()
*
* @param attr is a thread attributes object.
*
* @param The stack_addr attribute specifies the location of storage to be used for the created
* thread's stack.
*
* @return Upon successful completion, This function return a value of 0.
*/
int pthread_attr_getstackaddr(pthread_attr_t const *attr, void **stack_addr)
{
RT_ASSERT(attr != RT_NULL);
@ -152,6 +353,29 @@ int pthread_attr_getstackaddr(pthread_attr_t const *attr, void **stack_addr)
}
RTM_EXPORT(pthread_attr_getstackaddr);
/**
* @brief This function set the thread creation stack attributes stackaddr and stacksize in the attr object.
*
* @note The stack attributes specify the area of storage to be used for the created thread's stack.
* The base (lowest addressable byte) of the storage shall be stack_base, and the size of the storage
* shall be stack_size bytes.
* All pages within the stack described by stackaddr and stacksize shall be both readable
* and writable by the thread.
*
* @see pthread_attr_destroy, pthread_attr_getdetachstate, pthread_attr_getstacksize, pthread_create
*
* @param attr is a thread attributes object.
*
* @param stack_base is the base (lowest addressable byte) of the storage.
*
* @param stack_size is the size of the storage.
*
* @return Upon successful completion, these functions shall return a value of 0;
* otherwise, an error number shall be returned to indicate the error.
*
* @warning The behavior is undefined if the value specified by the attr argument to or pthread_attr_setstack()
* does not refer to an initialized thread attributes object.
*/
int pthread_attr_setstack(pthread_attr_t *attr,
void *stack_base,
size_t stack_size)
@ -165,6 +389,27 @@ int pthread_attr_setstack(pthread_attr_t *attr,
}
RTM_EXPORT(pthread_attr_setstack);
/**
* @brief This function shall get the thread creation stack attributes stackaddr and stacksize in the attr object.
*
* @note The stack attributes specify the area of storage to be used for the created thread's stack.
* The base (lowest addressable byte) of the storage shall be stack_base, and the size of the storage
* shall be stack_size bytes.
* All pages within the stack described by stack_base and stack_size shall be both readable
* and writable by the thread.
*
* @see pthread_attr_destroy, pthread_attr_getdetachstate, pthread_attr_getstacksize, pthread_create
*
* @param attr is a thread attributes object.
*
* @param stack_base is the base (lowest addressable byte) of the storage.
*
* @param stack_size is the size of the storage.
*
* @return Upon successful completion, these functions shall return a value of 0;
* otherwise, an error number shall be returned to indicate the error.
* This function shall store the stack attribute values in stack_base and stack_size if successful.
*/
int pthread_attr_getstack(pthread_attr_t const *attr,
void **stack_base,
size_t *stack_size)
@ -178,17 +423,103 @@ int pthread_attr_getstack(pthread_attr_t const *attr,
}
RTM_EXPORT(pthread_attr_getstack);
/**
* @brief This function shall set the guardsize attribute in the attr object.
*
* @note The guardsize attribute controls the size of the guard area for the created thread's stack.
* The guardsize attribute provides protection against overflow of the stack pointer.
* If a thread's stack is created with guard protection, the implementation allocates extra
* memory at the overflow end of the stack as a buffer against stack overflow of the stack pointer.
* If an application overflows into this buffer an error shall result (possibly in a SIGSEGV signal
* being delivered to the thread).
*
* @see <pthread.h>, <sys/mman.h>
*
* @param attr is a thread attributes object.
*
* @param guard_size is the size of the guard area for the created thread's stack.
*
* @return Upon successful completion, these functions shall return a value of 0;
*
* @warning The guardsize attribute is provided to the application for two reasons:
*
* 1. Overflow protection can potentially result in wasted system resources.
* An application that creates a large number of threads, and which knows its threads
* never overflow their stack, can save system resources by turning off guard areas.
*
* 2. When threads allocate large data structures on the stack, large guard areas may be
* needed to detect stack overflow.
*
* The default size of the guard area is left implementation-defined since on systems
* supporting very large page sizes, the overhead might be substantial if at least one guard
* page is required by default.
*/
int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guard_size)
{
return EOPNOTSUPP;
}
/**
* @brief This function get the guardsize attribute in the attr object.
* This attribute shall be returned in the guard_size parameter.
*
* @note The guardsize attribute controls the size of the guard area for the created thread's stack.
* The guardsize attribute provides protection against overflow of the stack pointer.
* If a thread's stack is created with guard protection, the implementation allocates extra
* memory at the overflow end of the stack as a buffer against stack overflow of the stack pointer.
*
* @see <pthread.h>, <sys/mman.h>
*
* @param attr is a thread attributes object.
*
* @param guard_size is the size of the guard area for the created thread's stack.
*
* @return Upon successful completion, these functions shall return a value of 0;
*
* @warning The guardsize attribute is provided to the application for two reasons:
*
* 1. Overflow protection can potentially result in wasted system resources.
* An application that creates a large number of threads, and which knows its threads
* never overflow their stack, can save system resources by turning off guard areas.
*
* 2. When threads allocate large data structures on the stack, large guard areas may be
* needed to detect stack overflow.
*
* The default size of the guard area is left implementation-defined since on systems
* supporting very large page sizes, the overhead might be substantial if at least one guard
* page is required by default.
*/
int pthread_attr_getguardsize(pthread_attr_t const *attr, size_t *guard_size)
{
return EOPNOTSUPP;
}
RTM_EXPORT(pthread_attr_getguardsize);
/**
* @brief This function sets inherit-scheduler attribute in thread attributes object.
*
* @note The function sets the inherit-scheduler attribute of the thread attributes object
* referred to by attr to the value specified in inheritsched.
* The inherit-scheduler attribute determines whether a thread created using the thread
* attributes object attr will inherit its scheduling attributes from the calling thread
* or whether it will take them from attr.
*
* @see pthread_attr_init(), pthread_attr_setschedpolicy(), pthread_attr_setschedparam()
*
* @param attr is a thread attributes object.
*
* @param inheritsched the inheritsched attribute determines how the other scheduling attributes of the created thread are to be set:
* The policy can be ONE of the following values:
*
* PTHREAD_INHERIT_SCHED Specifies that the scheduling policy and associated attributes are
* to be inherited from the creating thread, and the scheduling attributes
* in this attr argument are to be ignored.
*
* PTHREAD_EXPLICIT_SCHED Specifies that the scheduling policy and associated attributes are to be
* set to the corresponding values from this attribute object.
*
* @return Upon successful completion, these functions shall return a value of 0;
*/
int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched)
{
RT_ASSERT(attr != RT_NULL);
@ -199,6 +530,31 @@ int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched)
}
RTM_EXPORT(pthread_attr_setinheritsched);
/**
* @brief This function get and set the inheritsched attribute in the attr argument.
*
* @note The function sets the inherit-scheduler attribute of the thread attributes object
* referred to by attr to the value specified in inheritsched.
* The inherit-scheduler attribute determines whether a thread created using the thread
* attributes object attr will inherit its scheduling attributes from the calling thread
* or whether it will take them from attr.
*
* @see pthread_attr_init(), pthread_attr_getschedpolicy(), pthread_attr_getschedparam()
*
* @param attr is a thread attributes object.
*
* @param inheritsched the inheritsched attribute determines how the other scheduling attributes of the created thread are to be set:
* The inheritsched can be ONE of the following values:
*
* PTHREAD_INHERIT_SCHED Specifies that the scheduling policy and associated attributes are
* to be inherited from the creating thread, and the scheduling attributes
* in this attr argument are to be ignored.
*
* PTHREAD_EXPLICIT_SCHED Specifies that the scheduling policy and associated attributes are to be
* set to the corresponding values from this attribute object.
*
* @return Upon successful completion, these functions shall return a value of 0;
*/
int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inheritsched)
{
RT_ASSERT(attr != RT_NULL);
@ -209,6 +565,22 @@ int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inheritsched)
}
RTM_EXPORT(pthread_attr_getinheritsched);
/**
* @brief This function set contentionscope attribute.
*
* @note The function are used to set the contentionscope attribute in the attr object.
*
* @param attr is a thread attributes object.
*
* @param scope is the value of contentionscope attribute.
* The scope can be ONE of the following values:
*
* PTHREAD_SCOPE_SYSTEM signifying system scheduling contention scope.
*
* PTHREAD_SCOPE_PROCESS signifying process scheduling contention scope.
*
* @return Upon successful completion, these functions shall return a value of 0;
*/
int pthread_attr_setscope(pthread_attr_t *attr, int scope)
{
if (scope == PTHREAD_SCOPE_SYSTEM)
@ -220,6 +592,22 @@ int pthread_attr_setscope(pthread_attr_t *attr, int scope)
}
RTM_EXPORT(pthread_attr_setscope);
/**
* @brief This function get contentionscope attribute.
*
* @note The function are used to get the contentionscope attribute in the attr object.
*
* @param attr is a thread attributes object.
*
* @param scope is the value of contentionscope attribute.
* The scope can be ONE of the following values:
*
* PTHREAD_SCOPE_SYSTEM signifying system scheduling contention scope.
*
* PTHREAD_SCOPE_PROCESS signifying process scheduling contention scope.
*
* @return Upon successful completion, these functions shall return a value of 0;
*/
int pthread_attr_getscope(pthread_attr_t const *attr, int *scope)
{
return PTHREAD_SCOPE_SYSTEM;