POSIX Thread

POSIX thread operations for the QuantumRT Real-Time Kernel.

Part of QuantumRT Real-Time Kernel.

Defines

PTHREAD_CREATE_JOINABLE

Joinable thread attribute.

PTHREAD_CREATE_DETACHED

Detached thread attribute.

PTHREAD_CANCEL_ENABLE

Cancel enable attribute.

PTHREAD_CANCEL_DISABLE

Cancel disable attribute.

PTHREAD_CANCEL_DEFERRED

Deferred cancel attribute.

PTHREAD_CANCEL_ASYNCHRONOUS

Asynchronous cancel attribute.

PTHREAD_PRIO_INHERIT

Priority inheritance protocol.

PTHREAD_PRIO_NONE

No priority protocol.

PTHREAD_PRIO_PROTECT

Priority protect protocol.

PTHREAD_MUTEX_DEFAULT

Default mutex type.

PTHREAD_MUTEX_ERRORCHECK

Error-checking mutex type.

PTHREAD_MUTEX_NORMAL

Normal mutex type.

PTHREAD_MUTEX_RECURSIVE

Recursive mutex type.

PTHREAD_MUTEX_ROBUST

Robust mutex type. Not supported.

PTHREAD_MUTEX_STALLED

Stalled mutex type. Not supported.

PTHREAD_PROCESS_SHARED

Process-shared mutex attribute. Not supported.

PTHREAD_PROCESS_PRIVATE

Process-private mutex attribute. Not supported.

PTHREAD_SCOPE_PROCESS

Process scope mutex attribute. Not supported.

PTHREAD_SCOPE_SYSTEM

System scope mutex attribute. Not supported.

PTHREAD_INHERIT_SCHED

Inherit scheduling attribute.

PTHREAD_EXPLICIT_SCHED

Explicit scheduling attribute.

PTHREAD_PRIVILEGED_NP

Privileged thread attribute.

PTHREAD_UNPRIVILEGED_NP

Unprivileged thread attribute.

PTHREAD_ONCE_INIT

Once initialization. Not supported.

PTHREAD_COND_INITIALIZER

Condition variable initialization. Not supported.

PTHREAD_MUTEX_INITIALIZER

Mutex initialization.

PTHREAD_RWLOCK_INITIALIZER

Read-write lock initialization. Not supported.

PTHREAD_NULL

Not equal to valid thread.

Functions

int pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime)

Lock a mutex with a timeout. If the mutex is already locked, the calling thread will block until the mutex becomes available or the specified absolute time is reached.

Error numbers:

• EDEADLK: The current thread already owns the mutex and the mutex type is PTHREAD_MUTEX_ERRORCHECK.

• EAGAIN: The maximum number of recursive locks for the mutex has been exceeded.

• EINVAL: The mutex object is not valid.

• EINVAL: The mutex was created with PTHREAD_PRIO_PROTECT and the current thread’s priority is higher than the current priority ceiling.

• EINVAL: The thread would have blocked but the abstime parameter specified nanoseconds outside the valid range of [0, 999’999’999].

Parameters:

• mutex – Pointer to the mutex to lock.

• abstime – Pointer to the absolute time to wait until.

Returns:

0 on success, or an error number on failure.

int pthread_mutex_destroy(pthread_mutex_t *mutex)

Destroy a mutex.

Error numbers:

• EBUSY: The mutex object is currently in use.

Parameters:

• mutex – Pointer to the mutex to destroy.

Returns:

0 on success, or an error number on failure.

int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)

Initialize a mutex with specified attributes.

Parameters:

• mutex – Pointer to the mutex to initialize.

• attr – Pointer to the mutex attributes. NULL for default attributes.

Returns:

0 on success, or -1 on failure.

int pthread_mutex_getprioceiling(const pthread_mutex_t *mutex, int *prioceiling)

Get the priority ceiling of a mutex.

Error numbers:

• EINVAL: The mutex object is not valid.

• EINVAL: The mutex protocol attribute is set to PTHREAD_PRIO_NONE.

Parameters:

• mutex – Pointer to the mutex.

• prioceiling – Pointer to store the priority ceiling value.

Returns:

0 on success, or an error number on failure.

int pthread_mutex_setprioceiling(pthread_mutex_t *mutex, int prioceiling, int *old_ceiling)

Set the priority ceiling of a mutex.

Error numbers:

• EINVAL: The mutex object is not valid.

• EINVAL: The mutex protocol attribute is set to PTHREAD_PRIO_NONE.

• EINVAL: The mutex was created with PTHREAD_PRIO_PROTECT and the current thread’s priority is higher than the current priority ceiling.

• EAGAIN: The system lacked the necessary resources to change the priority ceiling.

• EDEADLK: A deadlock condition was detected.

Parameters:

• mutex – Pointer to the mutex.

• prioceiling – New priority ceiling value.

• old_ceiling – Pointer to store the old priority ceiling value.

Returns:

0 on success, or an error number on failure.

int pthread_mutex_lock(pthread_mutex_t *mutex)

Lock a mutex. If the mutex is already locked, the calling thread will block until the mutex becomes available.

Error numbers:

• EDEADLK: The current thread already owns the mutex and the mutex type is PTHREAD_MUTEX_ERRORCHECK.

• EAGAIN: The maximum number of recursive locks for the mutex has been exceeded.

• EINVAL: The mutex object is not valid.

• EINVAL: The mutex was created with PTHREAD_PRIO_PROTECT and the current thread’s priority is higher than the current priority ceiling.

Parameters:

• mutex – Pointer to the mutex to lock.

Returns:

0 on success, or an error number on failure.

#include "pthread.h"
#include "tensorflow/lite/c/c_api.h"

// Shared model and interpreter
pthread_mutex_t      model_lock  = PTHREAD_MUTEX_INITIALIZER;
TfLiteModel         *model       = NULL;
TfLiteInterpreter   *interpreter = NULL;

int main(void)
{
    TfLiteInterpreterOptions *options;
    pthread_t t_cam;
    pthread_t t_mic;

    model = TfLiteModelCreateFromFile("/flash/model.tflite");

    options = TfLiteInterpreterOptionsCreate();
    TfLiteInterpreterOptionsSetNumThreads(options, 1);

    interpreter = TfLiteInterpreterCreate(model, options);
    TfLiteInterpreterAllocateTensors(interpreter);

    pthread_create(&t_cam, NULL, inference_thread, camera_input);
    pthread_create(&t_mic, NULL, inference_thread, mic_input);
}

void *inference_thread(void *arg)
{
    TfLiteTensor *input;
    TfLiteTensor *output;
    const float  *input_data = (const float*)arg;

    for (;;)
    {
        // Multiple inference threads share the same model and interpreter
        // Protect the interpreter and tensor buffer during inference
        pthread_mutex_lock(&model_lock);

        input = TfLiteInterpreterGetInputTensor(interpreter, 0);
        memcpy(input->data.f, input_data, input->bytes);

        TfLiteInterpreterInvoke(interpreter);

        output = TfLiteInterpreterGetOutputTensor(interpreter, 0);
        handle_results(output);

        // Unlock the model and interpreter for other threads
        pthread_mutex_unlock(&model_lock);
    }
    return NULL;
}

int pthread_mutex_trylock(pthread_mutex_t *mutex)

Try to lock a mutex. If the mutex is already locked, the function will return immediately.

Error numbers:

• EBUSY: The mutex is already locked by another thread.

• EDEADLK: The current thread already owns the mutex and the mutex type is PTHREAD_MUTEX_ERRORCHECK.

• EINVAL: The mutex object is not valid.

• EAGAIN: The maximum number of recursive locks for the mutex has been exceeded.

• EINVAL: The mutex was created with PTHREAD_PRIO_PROTECT and the current thread’s priority is higher than the current priority ceiling.

Parameters:

• mutex – Pointer to the mutex to lock.

Returns:

0 on success, or an error number on failure.

int pthread_mutex_unlock(pthread_mutex_t *mutex)

Unlock a mutex.

Error numbers:

• EPERM: The current thread does not own the mutex.

• EINVAL: The mutex object is not valid.

Parameters:

• mutex – Pointer to the mutex to unlock.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_destroy(pthread_mutexattr_t *attr)

Destroy a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

Parameters:

• attr – Pointer to the mutex attributes to destroy.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_init(pthread_mutexattr_t *attr)

Initialize a mutex attributes object with default values.

The default protocol is PTHREAD_PRIO_NONE. Error numbers:

• EINVAL: The mutex attributes object is not valid.

Parameters:

• attr – Pointer to the mutex attributes to initialize.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *attr, int *prioceiling)

Get the priority ceiling attribute from a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• prioceiling – Pointer to store the priority ceiling value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling)

Set the priority ceiling attribute in a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• prioceiling – New priority ceiling value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr, int *protocol)

Get the protocol attribute from a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

• EINVAL: The protocol value is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• protocol – Pointer to store the protocol value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol)

Set the protocol attribute in a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

• EINVAL: The protocol value is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• protocol – New protocol value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *type)

Get the type attribute from a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

• EINVAL: The type value is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• type – Pointer to store the type value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)

Set the type attribute in a mutex attributes object.

Error numbers:

• EINVAL: The mutex attributes object is not valid.

• EINVAL: The type value is not valid.

Parameters:

• attr – Pointer to the mutex attributes object.

• type – New type value.

Returns:

0 on success, or an error number on failure.

int pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared)

Not supported.

Returns:

ENOSYS.

int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared)

Not supported.

Returns:

ENOSYS.

int pthread_mutexattr_getrobust(const pthread_mutexattr_t *attr, int *robust)

Not supported.

Returns:

ENOSYS.

int pthread_mutexattr_setrobust(pthread_mutexattr_t *attr, int robust)

Not supported.

Returns:

ENOSYS.

int pthread_mutex_consistent(pthread_mutex_t *mutex)

Not supported.

Returns:

ENOSYS.

int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void*), void *arg)

Create a new thread.

Parameters:

• thread – Pointer to the thread handle. NULL if not needed.

• attr – Pointer to the thread attributes. NULL for default attributes.

• start_routine – Pointer to the function to be executed by the thread.

• arg – Argument to be passed to the thread function.

Returns:

0 on success, or an error number on failure.

#include "pthread.h"
#include "stdio.h"

void *thread_a(void *arg)
{
    void            *ret;
    pthread_t        thread;

    if (pthread_create(&thread, NULL, thread_b, "thread_b entered") == -1)
    {
        exit(2);
    }

    if (pthread_join(thread, ret) == -1)
    {
        exit(3);
    }

    printf("thread_b() exited with return value %s\r\n", (char *)ret);

    return NULL;
}

void *thread_b(void *arg)
{
    char *ret = "thread_b exited\r\n";

    printf("thread_b() entered with argument %s\r\n", (char *)arg);

    // Perform thread operations...

    return ret;
}

void pthread_cleanup_push(void (*routine)(void*), void *arg)

Push a cleanup handler onto the thread’s cleanup stack.

Parameters:

• routine – Pointer to the cleanup handler function.

• arg – Argument to be passed to the cleanup handler.

  #include "pthread.h"
  
  pthread_mutex_t lock;
  
  void lock_cleanup(void *arg)
  {
      pthread_mutex_unlock((pthread_mutex_t *)arg);
  }
  
  void *thread(void *arg)
  {
      // Even if the thread is cancelled while in the critical,
      // section the lock will be unlocked.
  
      pthread_mutex_t *lock = (pthread_mutex_t *)arg;
  
      pthread_cleanup_push(lock_cleanup, (void *)lock);
  
      do_critical_section_work();
  
      pthread_cleanup_pop(1); // Execute cleanup handler
  
      return NULL;
  }
  

void pthread_cleanup_pop(int execute)

Pop a cleanup handler from the thread’s cleanup stack.

See also

pthread_cleanup_push() for example.

Parameters:

• execute – If non-zero, the cleanup handler is executed.

int pthread_getschedparam(pthread_t thread, int *policy, struct sched_param *param)

Get the scheduling parameters of the specified thread.

Parameters:

• thread – The thread to query.

• policy – Pointer to a location where the scheduling policy will be stored.

• param – Pointer to a location where the scheduling parameters will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_setschedparam(pthread_t thread, int policy, const struct sched_param *param)

Set the scheduling policy and parameters of the specified thread. May trigger a context switch if the new priority is higher than the current priority.

Parameters:

• thread – The thread to set the scheduling policy and parameters for.

• policy – The new scheduling policy. One of:

  • SCHED_FIFO

  • SCHED_RR

• param – Pointer to a structure containing the new scheduling parameters.

Returns:

0 on success, or an error number on failure.

int pthread_setschedprio(pthread_t thread, int prio)

Set thread scheduling priority. May trigger a context switch if the new priority is higher than the current priority.

Parameters:

• thread – The thread to set the priority for.

• prio – The new priority value.

Returns:

0 on success, or an error number on failure.

void pthread_exit(void *value_ptr)

Terminate the calling thread. Same as returning from the thread function.

void *thread(void *arg)
{
    // Perform thread operations...

    pthread_exit((void *)0);
}

Parameters:

• value_ptr – Pointer to the return value of the thread.

int pthread_equal(pthread_t t1, pthread_t t2)

Compare two thread identifiers.

Parameters:

• t1 – First thread identifier.

• t2 – Second thread identifier.

Returns:

0 if equal, non-zero otherwise.

pthread_t pthread_self(void)

Get the calling thread’s identifier.

Returns:

The calling thread’s ID.

int pthread_cancel(pthread_t thread)

Request cancellation of the specified thread.

Parameters:

• thread – The thread to cancel.

Returns:

0 on success, or an error number on failure.

void *worker_thread(void *arg)
{ 
    pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);

    // Simulate work

    // Create a cancellation point
    pthread_testcancel();

    return NULL;
}

void *thread(void *arg)
{
    struct timespec ts = {0, 100000000};

    // Let the worker thread run for a while
    nanosleep(&ts, NULL);

    pthread_cancel(worker);

    pthread_join(worker, NULL);

    return NULL;
}

int pthread_setcancelstate(int state, int *oldstate)

Set the cancelability state of the calling thread.

Parameters:

• state – One of the cancelability states:

  • PTHREAD_CANCEL_ENABLE

  • PTHREAD_CANCEL_DISABLE

• oldstate – Pointer to a location where the old state will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_setcanceltype(int type, int *oldtype)

Set the cancelability type of the calling thread.

See also

pthread_cancel() for example.

Parameters:

• type – One of the cancelability types:

  • PTHREAD_CANCEL_DEFERRED

  • PTHREAD_CANCEL_ASYNCHRONOUS

• oldtype – Pointer to a location where the old type will be stored.

Returns:

0 on success, or an error number on failure.

void pthread_testcancel(void)

Create a cancellation point in the calling thread. A cancellation point is location where the control flow is returned back to the scheduler.

See also

pthread_cancel() for example.

int pthread_join(pthread_t thread, void **value_ptr)

Wait for the specified thread to terminate.

See also

pthread_create() for example.

Parameters:

• thread – The thread to wait for.

• value_ptr – Pointer to a location where the return value of the thread will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_detach(pthread_t thread)

Detach the specified thread. A detached thread’s resources are automatically released upon termination.

Parameters:

• thread – The thread to detach.

Returns:

0 on success, or an error number on failure.

int pthread_attr_init(pthread_attr_t *attr)

Initialize a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

  #include "pthread.h"
  
  void *thread(void *arg)
  {
      pthread_attr_t attr;
      pthread_attr_init(&attr);
  
      pthread_create(NULL, &attr, new_thread, NULL);
  
      return NULL;
  }
  

Parameters:

• attr – Pointer to the thread attributes object to initialize.

Returns:

0 on success, or an error number on failure.

int pthread_attr_destroy(pthread_attr_t *attr)

Destroy a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object to destroy.

Returns:

0 on success, or an error number on failure.

int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inheritsched)

Get the inherit scheduling attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• inheritsched – Pointer to a location where the inherit scheduling attribute will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched)

Set the inherit scheduling attribute in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

• ENOTSUP: Attempt to set an unsupported inherit scheduling attribute.

Parameters:

• attr – Pointer to the thread attributes object.

• inheritsched – The inherit scheduling attribute to set. One of:

  • PTHREAD_INHERIT_SCHED

  • PTHREAD_EXPLICIT_SCHED

Returns:

0 on success, or an error number on failure.

int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate)

Get the detach state attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• detachstate – Pointer to a location where the detach state attribute will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate)

Set the detach state attribute in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• detachstate – The detach state attribute to set. One of:

  • PTHREAD_CREATE_JOINABLE

  • PTHREAD_CREATE_DETACHED

Returns:

0 on success, or an error number on failure.

#include "pthread.h"

void *thread(void *arg)
{
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

    pthread_create(NULL, &attr, new_thread, NULL);

    return NULL;
}

int pthread_attr_getstack(const pthread_attr_t *attr, void **stackaddr, size_t *stacksize)

Get the stack address and size attributes from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• stackaddr – Pointer to the stack base address.

• stacksize – Pointer to a size_t variable where the stack size will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr, size_t stacksize)

Set the stack address and size attributes in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• stackaddr – Pointer to the stack base address.

• stacksize – Stack size.

Returns:

0 on success, or an error number on failure.

unsigned char myStack[1024u];

void *thread_a(void *arg)
{
    pthread_attr_t attr;
    pthread_attr_init(&attr);

    pthread_attr_setstack(&attr, myStack, sizeof(myStack));
    pthread_create(NULL, &attr, thread_b, NULL);

    return NULL;
}

void *thread_b(void *arg)
{
    // Thread implementation
    return NULL;
}

int pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize)

Get the stack size attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• stacksize – Pointer to a size_t variable where the stack size will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)

Set the stack size attribute in a thread attributes object. pthread_create() will allocate a stack with at least this size for the new thread. The allocated stack size is rounded up to the nearest power of two.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• stacksize – Stack size.

Returns:

0 on success, or an error number on failure.

void *thread_a(void *arg)
{
    pthread_attr_t attr;
    pthread_attr_init(&attr);

    // Set thread attributes as needed
    pthread_attr_setstacksize(&attr, sizeof(myStack));

    // No need to provide stack address,
    // it will be allocated by pthread_create()
    pthread_create(NULL, &attr, thread_b, NULL);

    return NULL;
}

void *thread_b(void *arg)
{
    // Thread implementation
    return NULL;
}

int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy)

Get the scheduling policy attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• policy – Pointer to a location where the scheduling policy attribute will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)

Set the scheduling policy attribute in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

• ENOTSUP: Invalid scheduling policy value.

Parameters:

• attr – Pointer to the thread attributes object.

• policy – The scheduling policy attribute to set. One of:

  • SCHED_FIFO

  • SCHED_RR

Returns:

0 on success, or an error number on failure.

#include "pthread.h"

void *thread(void *arg)
{
    pthread_attr_t attr;
    pthread_attr_init(&attr);

    // Default policy is SCHED_FIFO
    pthread_attr_setschedpolicy(&attr, SCHED_RR);

    pthread_create(NULL, &attr, new_thread, NULL);

    return NULL;
}

int pthread_attr_getschedparam(const pthread_attr_t *attr, struct sched_param *param)

Get the scheduling parameters attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

• EINVAL: The scheduling parameters pointer is NULL.

Parameters:

• attr – Pointer to the thread attributes object.

• param – Pointer to a location where the scheduling parameters will be stored.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setschedparam(pthread_attr_t *attr, const struct sched_param *param)

Set the scheduling parameters attribute in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

• EINVAL: The scheduling parameters pointer is NULL.

• ENOTSUP: Invalid scheduling priority value.

Parameters:

• attr – Pointer to the thread attributes object.

• param – Pointer to the scheduling parameters to set.

Returns:

0 on success, or an error number on failure.

#include "pthread.h"

void *thread(void *arg)
{
    struct sched_param param;
    pthread_attr_t attr;
    pthread_attr_init(&attr);

    param.sched_priority = 10;
    pthread_attr_setschedparam(&attr, &param);

    pthread_create(NULL, &attr, new_thread, NULL);

    return NULL;
}

int pthread_attr_getscope(const pthread_attr_t *attr, int *contentionscope)

Not supported.

Returns:

ENOSYS.

int pthread_attr_setscope(pthread_attr_t *attr, int contentionscope)

Not supported.

Returns:

ENOSYS.

int pthread_attr_getguardsize(const pthread_attr_t *attr, size_t *guardsize)

Not supported.

Returns:

ENOSYS.

int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize)

Not supported.

Returns:

ENOSYS.

int pthread_attr_getname_np(const pthread_attr_t *attr, char *name, size_t len)

Get the name attribute from a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• name – Pointer to a buffer to store the thread name.

• len – Length of the buffer.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setname_np(pthread_attr_t *attr, const char *name)

Set the name attribute in a thread attributes object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attributes object.

• name – The name to set for the thread.

Returns:

0 on success, or an error number on failure.

int pthread_setname_np(pthread_t thread, const char *name)

Set the name of the specified thread.

Error numbers:

• EINVAL: The thread object is not valid.

Parameters:

• thread – The thread to set the name of.

• name – The new name for the thread.

Returns:

0 on success, or an error number on failure.

int pthread_getname_np(pthread_t thread, char *name, size_t len)

Get the name of the specified thread.

Error numbers:

• EINVAL: The thread object is not valid.

Parameters:

• thread – The thread to get the name of.

• name – Pointer to a buffer to store the thread name.

• len – Length of the buffer.

Returns:

0 on success, or an error number on failure.

int pthread_getconcurrency(void)

Not supported.

Returns:

ENOSYS.

int pthread_setconcurrency(int new_level)

Not supported.

Returns:

ENOSYS.

int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))

Not supported.

Returns:

ENOSYS.

void *pthread_getspecific(pthread_key_t key)

Not supported.

Returns:

ENOSYS.

int pthread_setspecific(pthread_key_t key, const void *value)

Not supported.

Returns:

ENOSYS.

int pthread_key_create(pthread_key_t *key, void (*destructor)(void*))

Not supported.

Returns:

ENOSYS.

int pthread_key_delete(pthread_key_t key)

Not supported.

Returns:

ENOSYS.

int pthread_kill(pthread_t thread, int sig)

Not supported.

Returns:

ENOSYS.

int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))

Not supported.

Returns:

ENOSYS.

int pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)

Not supported.

Returns:

ENOSYS.

int pthread_getcpuclockid(pthread_t thread_id, clockid_t *clock_id)

Not supported.

Returns:

ENOSYS.

int pthread_spin_destroy(pthread_spinlock_t *lock)

Not supported.

Returns:

ENOSYS.

int pthread_spin_init(pthread_spinlock_t *lock, int pshared)

Not supported.

Returns:

ENOSYS.

int pthread_spin_lock(pthread_spinlock_t *lock)

Not supported.

Returns:

ENOSYS.

int pthread_spin_trylock(pthread_spinlock_t *lock)

Not supported.

Returns:

ENOSYS.

int pthread_spin_unlock(pthread_spinlock_t *lock)

Not supported.

Returns:

ENOSYS.

int pthread_barrier_destroy(pthread_barrier_t *barrier)

Not supported.

Returns:

ENOSYS.

int pthread_barrier_init(pthread_barrier_t *barrier, const pthread_barrierattr_t *attr, unsigned count)

Not supported.

Returns:

ENOSYS.

int pthread_barrier_wait(pthread_barrier_t *barrier)

Not supported.

Returns:

ENOSYS.

int pthread_barrierattr_destroy(pthread_barrierattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_barrierattr_init(pthread_barrierattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_barrierattr_getpshared(const pthread_barrierattr_t *attr, int *pshared)

Not supported.

Returns:

ENOSYS.

int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_clockrdlock(pthread_rwlock_t *rwlock, clockid_t clock_id, const struct timespec *abstime)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock, const struct timespec *abstime)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_clockwrlock(pthread_rwlock_t *rwlock, clockid_t clock_id, const struct timespec *abstime)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_timedwrlock(pthread_rwlock_t *rwlock, const struct timespec *abstime)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_destroy(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlock_unlock(pthread_rwlock_t *rwlock)

Not supported.

Returns:

ENOSYS.

int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *attr, int *pshared)

Not supported.

Returns:

ENOSYS.

int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared)

Not supported.

Returns:

ENOSYS.

int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_cond_destroy(pthread_cond_t *cond)

Not supported.

Returns:

ENOSYS.

int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)

Not supported.

Returns:

ENOSYS.

int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)

Not supported.

Returns:

ENOSYS.

int pthread_cond_signal(pthread_cond_t *cond)

Not supported.

Returns:

ENOSYS.

int pthread_cond_broadcast(pthread_cond_t *cond)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_init(pthread_condattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_destroy(pthread_condattr_t *attr)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_getclock(const pthread_condattr_t *attr, clockid_t *clock_id)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clock_id)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_getpshared(const pthread_condattr_t *attr, int *pshared)

Not supported.

Returns:

ENOSYS.

int pthread_condattr_setpshared(pthread_condattr_t *attr, int pshared)

Not supported.

Returns:

ENOSYS.

int pthread_attr_settimeslice_np(pthread_attr_t *attr, const struct timespec *timeSlice)

Set the time slice for a thread attribute object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• timeSlice – Pointer to a timespec structure that specifies the time slice duration.

Returns:

0 on success, or an error number on failure.

int pthread_attr_setprivilege_np(pthread_attr_t *attr, int privilege)

Set the privilege level from a thread attribute object.

Error numbers:

• EINVAL: The thread attributes object is not valid.

Parameters:

• attr – Pointer to the thread attribute object.

• privilege – One of the following values:

  • PTHREAD_PRIVILEGED_NP

  • PTHREAD_UNPRIVILEGED_NP

Returns:

0 on success, or an error number on failure.

#include "pthread.h"

void *thread(void *arg)
{
    pthread_attr_t attr;
    pthread_attr_init(&attr);

    // We want to create a privileged thread in this case,
    // but the default value is unprivileged.
    pthread_attr_setprivilege_np(&attr, PTHREAD_PRIVILEGED_NP);

    pthread_create(NULL, &attr, new_thread, NULL);

    return NULL;
}

int pthread_dropprivilege_np(void)

Drop the privilege level of the calling thread to unprivileged.

Returns:

0 on success, or an error number on failure.

#include "pthread.h"

int main(void)
{
    ...

    qrt_mpu_init(&__ROM_BASE,        (u32)&__ROM_SIZE,
                 &__RAM_BASE,        (u32)&__RAM_SIZE,
                 &__ROM_PRIV_BASE,   (u32)&__ROM_PRIV_SIZE,
                 &__RAM_PRIV_BASE,   (u32)&__RAM_PRIV_SIZE);

    qrt_kernelstart();

    // Main thread is created as privileged,
    // drop privilege if not needed.
    pthread_dropprivilege_np();

    ...
}