A process in Contiki consists of a single protothread. More...

Macros
#define	NULL 0

#define	OC_PROCESS_BROADCAST NULL

#define	OC_PROCESS_EVENT_COM 0x89

#define	OC_PROCESS_EVENT_CONTINUE 0x85

#define	OC_PROCESS_EVENT_EXIT 0x83

#define	OC_PROCESS_EVENT_EXITED 0x87

#define	OC_PROCESS_EVENT_INIT 0x81

#define	OC_PROCESS_EVENT_MAX 0x8a

#define	OC_PROCESS_EVENT_MSG 0x86

#define	OC_PROCESS_EVENT_NONE 0x80

#define	OC_PROCESS_EVENT_POLL 0x82

#define	OC_PROCESS_EVENT_SERVICE_REMOVED 0x84

#define	OC_PROCESS_EVENT_TIMER 0x88

#define	OC_PROCESS_LIST() oc_process_list

#define	OC_PROCESS_NONE NULL

#define	OC_PROCESS_ZOMBIE ((struct oc_process *)0x1)

Typedefs
typedef void *	oc_process_data_t

typedef unsigned char	oc_process_event_t

typedef unsigned long	oc_process_num_events_t

Variables
struct oc_process *	oc_process_list

Functions called from application programs
typedef bool(*	oc_process_drop_event_t) (oc_process_event_t ev, oc_process_data_t data, const void *user_data)
	This function is responsible for determining whether an event should be removed from the event queue of a given process. More...

struct oc_process *	oc_process_current

void	oc_process_start (struct oc_process *p, oc_process_data_t data)
	Start a process. More...

int	oc_process_post (struct oc_process *p, oc_process_event_t ev, oc_process_data_t data)
	Post an asynchronous event. More...

int	oc_process_drop (const struct oc_process p, oc_process_drop_event_t drop_event, const void user_data)
	Drop events from a process' event queue. More...

void	oc_process_post_synch (struct oc_process *p, oc_process_event_t ev, oc_process_data_t data)
	Post a synchronous event to a process. More...

void	oc_process_exit (struct oc_process *p)
	Cause a process to exit. More...

oc_process_event_t	oc_process_alloc_event (void)
	Allocate a global event number. More...

#define	OC_PROCESS_CURRENT()
	Get a pointer to the currently running process. More...

#define	OC_PROCESS_CONTEXT_BEGIN(p)
	Switch context to another process. More...

#define	OC_PROCESS_CONTEXT_END(p)
	End a context switch. More...

Functions called from device drivers
void	oc_process_poll (struct oc_process *p)
	Request a process to be polled. More...

Functions called by the system and boot-up code
int	oc_process_run (void)
	Run the system once - call poll handlers and process one event. More...

int	oc_process_is_running (const struct oc_process *p)
	Check if a process is running. More...

int	oc_process_nevents (void)
	Number of events waiting to be processed. More...

bool	oc_process_needs_poll (void)
	Check if processes need to be polled. More...

bool	oc_process_is_closing_all_tls_sessions (void)
	Check if closing of all tls sessions is currently scheduled by the process. More...

Return values
#define	OC_PROCESS_ERR_OK 0
	Return value indicating that an operation was successful. More...

#define	OC_PROCESS_ERR_FULL 1
	Return value indicating that the event queue was full. More...

Process protothread functions
#define	OC_PROCESS_BEGIN()
	Define the beginning of a process. More...

#define	OC_PROCESS_END()
	Define the end of a process. More...

#define	OC_PROCESS_WAIT_EVENT()
	Wait for an event to be posted to the process. More...

#define	OC_PROCESS_WAIT_EVENT_UNTIL(c)
	Wait for an event to be posted to the process, with an extra condition. More...

#define	OC_PROCESS_YIELD()
	Yield the currently running process. More...

#define	OC_PROCESS_YIELD_UNTIL(c)
	Yield the currently running process until a condition occurs. More...

#define	OC_PROCESS_WAIT_UNTIL(c)
	Wait for a condition to occur. More...

#define	OC_PROCESS_WAIT_WHILE(c) PT_WAIT_WHILE(process_pt, c)

#define	OC_PROCESS_EXIT()
	Exit the currently running process. More...

#define	OC_PROCESS_PT_SPAWN(pt, thread)
	Spawn a protothread from the process. More...

#define	OC_PROCESS_PAUSE()
	Yield the process for a short while. More...

Poll and exit handlers
#define	OC_PROCESS_POLLHANDLER(handler)
	Specify an action when a process is polled. More...

#define	OC_PROCESS_EXITHANDLER(handler)
	Specify an action when a process exits. More...

Process declaration and definition
#define	OC_PROCESS_THREAD(name, ev, data)
	Define the body of a process. More...

#define	OC_PROCESS_NAME(name)
	Declare the name of a process. More...

#define	OC_PROCESS(name, strname)
	Declare a process. More...

Detailed Description

A process in Contiki consists of a single protothread.

Macro Definition Documentation

◆ OC_PROCESS

#define OC_PROCESS	(	name,
		strname
	)

Declare a process.

This macro declares a process. The process has two names: the variable of the process structure, which is used by the C program, and a human readable string name, which is used when debugging. A configuration option allows removal of the readable name to save RAM.

Parameters

name	The variable name of the process structure.
strname	The string representation of the process' name.

◆ OC_PROCESS_BEGIN

#define OC_PROCESS_BEGIN ( )

Define the beginning of a process.

This macro defines the beginning of a process, and must always appear in a OC_PROCESS_THREAD() definition. The OC_PROCESS_END() macro must come at the end of the process.

◆ OC_PROCESS_CONTEXT_BEGIN

#define OC_PROCESS_CONTEXT_BEGIN ( p )

Value:

  {                                                                            \
    struct oc_process *tmp_current = OC_PROCESS_CURRENT();                     \
    oc_process_current = p;

Switch context to another process.

This function switch context to the specified process and executes the code as if run by that process. Typical use of this function is to switch context in services, called by other processes. Each OC_PROCESS_CONTEXT_BEGIN() must be followed by the OC_PROCESS_CONTEXT_END() macro to end the context switch.

Example:

OC_PROCESS_CONTEXT_BEGIN(&test_process);
etimer_set(&timer, CLOCK_SECOND);
OC_PROCESS_CONTEXT_END(&test_process);

Parameters

p	The process to use as context

See also: OC_PROCESS_CONTEXT_END(); OC_PROCESS_CURRENT()

◆ OC_PROCESS_CONTEXT_END

#define OC_PROCESS_CONTEXT_END ( p )

Value:

oc_process_current = tmp_current; \

}

End a context switch.

This function ends a context switch and changes back to the previous process.

Parameters

p	The process used in the context switch

See also: OC_PROCESS_CONTEXT_START()

◆ OC_PROCESS_CURRENT

#define OC_PROCESS_CURRENT ( )

Get a pointer to the currently running process.

This macro get a pointer to the currently running process. Typically, this macro is used to post an event to the current process with process_post().

◆ OC_PROCESS_END

#define OC_PROCESS_END ( )

Define the end of a process.

This macro defines the end of a process. It must appear in a OC_PROCESS_THREAD() definition and must always be included. The process exits when the OC_PROCESS_END() macro is reached.

◆ OC_PROCESS_ERR_FULL

#define OC_PROCESS_ERR_FULL 1

Return value indicating that the event queue was full.

        This value is returned from process_post() to indicate
        that the event queue was full and that an event could
        not be posted.

◆ OC_PROCESS_ERR_OK

#define OC_PROCESS_ERR_OK 0

Return value indicating that an operation was successful.

        This value is returned to indicate that an operation
        was successful.

◆ OC_PROCESS_EXIT

#define OC_PROCESS_EXIT ( )

Exit the currently running process.

◆ OC_PROCESS_EXITHANDLER

#define OC_PROCESS_EXITHANDLER ( handler )

Specify an action when a process exits.

Note: This declaration must come immediately before the OC_PROCESS_BEGIN() macro.

Parameters

handler The action to be performed.

◆ OC_PROCESS_NAME

#define OC_PROCESS_NAME ( name )

Declare the name of a process.

This macro is typically used in header files to declare the name of a process that is implemented in the C file.

◆ OC_PROCESS_PAUSE

#define OC_PROCESS_PAUSE ( )

Yield the process for a short while.

This macro yields the currently running process for a short while, thus letting other processes run before the process continues.

◆ OC_PROCESS_POLLHANDLER

#define OC_PROCESS_POLLHANDLER ( handler )

Specify an action when a process is polled.

Note: This declaration must come immediately before the OC_PROCESS_BEGIN() macro.

Parameters

handler The action to be performed.

◆ OC_PROCESS_PT_SPAWN

#define OC_PROCESS_PT_SPAWN	(	pt,
		thread
	)

Spawn a protothread from the process.

Parameters

pt	The protothread state (struct pt) for the new protothread
thread	The call to the protothread function.

See also: PT_SPAWN()

◆ OC_PROCESS_THREAD

#define OC_PROCESS_THREAD	(	name,
		ev,
		data
	)

Define the body of a process.

This macro is used to define the body (protothread) of a process. The process is called whenever an event occurs in the system, A process always start with the OC_PROCESS_BEGIN() macro and end with the OC_PROCESS_END() macro.

◆ OC_PROCESS_WAIT_EVENT

#define OC_PROCESS_WAIT_EVENT ( )

Wait for an event to be posted to the process.

This macro blocks the currently running process until the process receives an event.

◆ OC_PROCESS_WAIT_EVENT_UNTIL

#define OC_PROCESS_WAIT_EVENT_UNTIL ( c )

Wait for an event to be posted to the process, with an extra condition.

This macro is similar to OC_PROCESS_WAIT_EVENT() in that it blocks the currently running process until the process receives an event. But OC_PROCESS_WAIT_EVENT_UNTIL() takes an extra condition which must be true for the process to continue.

Parameters

c	The condition that must be true for the process to continue.

See also: PT_WAIT_UNTIL()

◆ OC_PROCESS_WAIT_UNTIL

#define OC_PROCESS_WAIT_UNTIL ( c )

Wait for a condition to occur.

This macro does not guarantee that the process yields, and should therefore be used with care. In most cases, OC_PROCESS_WAIT_EVENT(), OC_PROCESS_WAIT_EVENT_UNTIL(), OC_PROCESS_YIELD() or OC_PROCESS_YIELD_UNTIL() should be used instead.

Parameters

c	The condition to wait for.

◆ OC_PROCESS_YIELD

#define OC_PROCESS_YIELD ( )

Yield the currently running process.

◆ OC_PROCESS_YIELD_UNTIL

#define OC_PROCESS_YIELD_UNTIL ( c )

Yield the currently running process until a condition occurs.

This macro is different from OC_PROCESS_WAIT_UNTIL() in that OC_PROCESS_YIELD_UNTIL() is guaranteed to always yield at least once. This ensures that the process does not end up in an infinite loop and monopolizing the CPU.

Parameters

c	The condition to wait for.

Typedef Documentation

◆ oc_process_drop_event_t

typedef bool(* oc_process_drop_event_t) (oc_process_event_t ev, oc_process_data_t data, const void *user_data)

This function is responsible for determining whether an event should be removed from the event queue of a given process.

Parameters

ev	The event to be dropped.
data	The auxiliary data to be sent with the event
user_data	Data to be passed to the drop_event function.

Returns: true Drop the event.

Function Documentation

◆ oc_process_alloc_event()

oc_process_event_t oc_process_alloc_event ( void )

Allocate a global event number.

Returns

The allocated event number

        In Contiki, event numbers above 128 are global and may
        be posted from one process to another. This function
        allocates one such event number.

Note: There currently is no way to deallocate an allocated event number.

◆ oc_process_drop()

int oc_process_drop	(	const struct oc_process *	p,
		oc_process_drop_event_t	drop_event,
		const void *	user_data
	)

Drop events from a process' event queue.

Parameters

p	A pointer to the process' process structure.
drop_event	function to determine if an event should be dropped.
user_data	Data to be passed to the drop_event function.

Returns: int Number of events dropped.

◆ oc_process_exit()

void oc_process_exit ( struct oc_process * p )

Cause a process to exit.

Parameters

p	The process that is to be exited This function causes a process to exit. The process can either be the currently executing process, or another process that is currently running.

See also: OC_PROCESS_CURRENT()

◆ oc_process_is_closing_all_tls_sessions()

bool oc_process_is_closing_all_tls_sessions ( void )

Check if closing of all tls sessions is currently scheduled by the process.

Returns: true closing of all tls is sessions is scheduled by the process; false otherwise

◆ oc_process_is_running()

int oc_process_is_running ( const struct oc_process * p )

Check if a process is running.

This function checks if a specific process is running.

Parameters

p	The process.

Return values

Non-zero	if the process is running.
Zero	if the process is not running.

◆ oc_process_needs_poll()

bool oc_process_needs_poll ( void )

Check if processes need to be polled.

Returns: True if there are processes that need to be polled.

◆ oc_process_nevents()

int oc_process_nevents ( void )

Number of events waiting to be processed.

Returns: The number of events that are currently waiting to be processed.

◆ oc_process_poll()

void oc_process_poll ( struct oc_process * p )

Request a process to be polled.

This function typically is called from an interrupt handler to cause a process to be polled.

Parameters

p	A pointer to the process' process structure.

◆ oc_process_post()

int oc_process_post	(	struct oc_process *	p,
		oc_process_event_t	ev,
		oc_process_data_t	data
	)

Post an asynchronous event.

This function posts an asynchronous event to one or more processes. The handing of the event is deferred until the target process is scheduled by the kernel. An event can be broadcast to all processes, in which case all processes in the system will be scheduled to handle the event.

Parameters

ev	The event to be posted.
data	The auxiliary data to be sent with the event
p	The process to which the event should be posted, or OC_PROCESS_BROADCAST if the event should be posted to all processes.

Return values

OC_PROCESS_ERR_OK	The event could be posted.
OC_PROCESS_ERR_FULL	The event queue was full and the event could not be posted.

◆ oc_process_post_synch()

void oc_process_post_synch	(	struct oc_process *	p,
		oc_process_event_t	ev,
		oc_process_data_t	data
	)

Post a synchronous event to a process.

Parameters

p	A pointer to the process' process structure.
ev	The event to be posted.
data	A pointer to additional data that is posted together with the event.

◆ oc_process_run()

int oc_process_run ( void )

Run the system once - call poll handlers and process one event.

This function should be called repeatedly from the main() program to actually run the Contiki system. It calls the necessary poll handlers, and processes one event. The function returns the number of events that are waiting in the event queue so that the caller may choose to put the CPU to sleep when there are no pending events.

Returns: The number of events that are currently waiting in the event queue.

◆ oc_process_start()

void oc_process_start	(	struct oc_process *	p,
		oc_process_data_t	data
	)

Start a process.

Parameters

p	A pointer to a process structure.
data	An argument pointer that can be passed to the new process

Macros

Typedefs

Variables

Functions called from application programs

Functions called from device drivers

Functions called by the system and boot-up code

Return values

Process protothread functions

Poll and exit handlers

Process declaration and definition

Detailed Description

Macro Definition Documentation

◆ OC_PROCESS

◆ OC_PROCESS_BEGIN

◆ OC_PROCESS_CONTEXT_BEGIN

◆ OC_PROCESS_CONTEXT_END

◆ OC_PROCESS_CURRENT

◆ OC_PROCESS_END

◆ OC_PROCESS_ERR_FULL

◆ OC_PROCESS_ERR_OK

◆ OC_PROCESS_EXIT

◆ OC_PROCESS_EXITHANDLER

◆ OC_PROCESS_NAME

◆ OC_PROCESS_PAUSE

◆ OC_PROCESS_POLLHANDLER

◆ OC_PROCESS_PT_SPAWN

◆ OC_PROCESS_THREAD

◆ OC_PROCESS_WAIT_EVENT

◆ OC_PROCESS_WAIT_EVENT_UNTIL

◆ OC_PROCESS_WAIT_UNTIL

◆ OC_PROCESS_YIELD

◆ OC_PROCESS_YIELD_UNTIL

Typedef Documentation

◆ oc_process_drop_event_t

Function Documentation

◆ oc_process_alloc_event()

◆ oc_process_drop()

◆ oc_process_exit()

◆ oc_process_is_closing_all_tls_sessions()

◆ oc_process_is_running()

◆ oc_process_needs_poll()

◆ oc_process_nevents()

◆ oc_process_poll()

◆ oc_process_post()

◆ oc_process_post_synch()

◆ oc_process_run()

◆ oc_process_start()