Examples

Simple, asynchronous thread creation.

#include <l4/thread/thread.h>

/* thread function */
void
thread_fn(void * data)
{
  /* do something */
  ...
}

/* parent */
int 
main (int argc, char * argv[])
{
  l4thread_t t;

  /* create thread */
  t = l4thread_create(thread_fn,             // thread function
                      NULL,                  // no thread data
                      L4THREAD_CREATE_ASYNC  // do not wait for thread
                      );
  if (t < 0)
    {
      /* thread creation failed */
      ...
    }

  /* do something */
  ...
}

Synchronous thread creation.

#include <l4/thread/thread.h>

/* thread function */
void
thread_fn(void * data)
{
  void * ret_val;

  /* thread initialization */
  ...

  /* we are up */
  if (l4thread_started(ret_val) < 0)
    {
      /* startup notification failed */
      ...
    }

  /* do something */
  ... 
}

/* parent */
int 
main (int argc, char * argv[])
{
  l4thread_t t;
  void * ret_val;

  /* create thread */
  t = l4thread_create(thread_fn,             // thread function
                      NULL,                  // no thread data
                      L4THREAD_CREATE_SYNC   // wait for new thread
                      );
  if (t < 0)
    {
      /* thread creation failed */
      ...
    }

  /* read startup return data */
  ret_val = l4thread_startup_return(t);

  /* do something */
  ...
}

Thread creation, long version

#include <l4/thread/thread.h>

/* thread function */
void
thread_fn(void * data)
{
  /* do something */
  ...
}

#define STACK_SIZE 1024
static unsigned char stack[STACK_SIZE];

/* parent */
int 
main (int argc, char * argv[])
{
  l4thread_t t;
  
  /* create thread */
  t = l4thread_create_long(5,                              // create thread 5
                           thread_fn,                      // thread function
                           (l4_addr_t)&stack[STACK_SIZE],  // initial stack pointer
                           STACK_SIZE,                     // stack size
                           L4THREAD_DEFAULT_PRIO,          // use default priority
                           NULL,                           // no thread data
                           L4THREAD_CREATE_ASYNC           // do not wait for thread
                           );
  if (t < 0)
    {
      /* thread creation failed */
      ...
    }

  /* do something */
  ...
}

Thread shutdown / exit functions

#include <l4/thread/thread.h>

/* exit handler */
void
on_exit(l4thread_t thread, void * data)
{
  /* do cleanup */
  ...
}

/* declare exit function descriptor */
L4THREAD_EXIT_FN(exit_fn,on_exit);

/* thread function */
void
thread_fn(void * data)
{
  void * ret_val;
  int ret;

  /* register exit function */
  ret = l4thread_on_exit(&exit_fn,           // exit function descriptor
                         NULL                // no data pointer
                         );
  if (ret < 0)
    {
      /* register error function failed */
      ...
    }

  /* we are up */
  if (l4thread_started(ret_val) < 0)
    {
      /* startup notification failed */
      ...
    }

  /* do something */
  ... 
}

/* parent */
int 
main (int argc, char * argv[])
{
  l4thread_t t;
  void * ret_val;

  /* create thread */
  t = l4thread_create(thread_fn,             // thread function
                      NULL,                  // no thread data
                      L4THREAD_CREATE_SYNC   // wait for new thread
                      );
  if (t < 0)
    {
      /* thread creation failed */
      ...
    }

  /* read startup return data */
  ret_val = l4thread_startup_return(t);

  /* do something */
  ...

  /* shutdown thread */
  if (l4thread_shutdown(t) < 0)
    {
      /* shutdown failed */
      ...
    }
}

Thread data

#include <l4/thread/thread.h>

/* data key */
int data_key;

/* thread function */
void
thread_fn(void * data)
{
  /* set thread local data */
  if (l4thread_data_set_current(data_key,...) < 0)
    {
      /* set data failed */
    }

  /* do something */
  ...
}

/* parent */
int 
main (int argc, char * argv[])
{
  l4thread_t t;

  /* allocate data key */
  data_key = l4thread_data_allocate_key();
  if (data_key < 0)
    {
      /* allocation failed */
      ...
    }

  /* create thread */
  t = l4thread_create(thread_fn,             // thread function
                      NULL,                  // no thread data
                      L4THREAD_CREATE_ASYNC  // do not wait for thread
                      );
  if (t < 0)
    {
      /* thread creation failed */
      ...
    }

  /* do something */
  ...
}

Library configuration

#include <l4/thread/thread.h>

/* overwrite l4thread configuration */
const int l4thread_max_threads = 127;
const l4_size_t l4thread_stack_size = 131072;

/* do something */
int 
main (int argc, char * argv[])
{
  ...
}