nunc-stans.h File Reference

Nunc Stans public API. More...

#include "nspr.h"

Go to the source code of this file.

Data Structures
struct	ns_thrpool_config

Macros
#define	NS_JOB_NONE   0x0
#define	NS_JOB_ACCEPT   0x1
#define	NS_JOB_CONNECT   0x2
#define	NS_JOB_READ   0x4
#define	NS_JOB_WRITE   0x8
#define	NS_JOB_TIMER   0x10
#define	NS_JOB_SIGNAL   0x20
#define	NS_JOB_PERSIST   0x40
#define	NS_JOB_THREAD   0x80
#define	NS_JOB_PRESERVE_FD   0x100
#define	NS_JOB_DISABLE_ONLY   0x200
#define	NS_JOB_IS_ACCEPT(eee)   ((eee)&NS_JOB_ACCEPT)
#define	NS_JOB_IS_READ(eee)   ((eee)&NS_JOB_READ)
#define	NS_JOB_IS_CONNECT(eee)   ((eee)&NS_JOB_CONNECT)
#define	NS_JOB_IS_WRITE(eee)   ((eee)&NS_JOB_WRITE)
#define	NS_JOB_IS_TIMER(eee)   ((eee)&NS_JOB_TIMER)
#define	NS_JOB_IS_SIGNAL(eee)   ((eee)&NS_JOB_SIGNAL)
#define	NS_JOB_IS_PERSIST(eee)   ((eee)&NS_JOB_PERSIST)
#define	NS_JOB_IS_IO(eee)   (NS_JOB_IS_ACCEPT(eee)||NS_JOB_IS_READ(eee)||NS_JOB_IS_CONNECT(eee)||NS_JOB_IS_WRITE(eee))
#define	NS_JOB_IS_THREAD(eee)   ((eee)&NS_JOB_THREAD)
#define	NS_JOB_IS_PRESERVE_FD(eee)   ((eee)&NS_JOB_PRESERVE_FD)
#define	NS_JOB_IS_DISABLE_ONLY(eee)   ((eee)&NS_JOB_DISABLE_ONLY)
#define	NS_JOB_SET_READ(eee)   ((eee) |= NS_JOB_READ)
#define	NS_JOB_SET_WRITE(eee)   ((eee) |= NS_JOB_WRITE)
#define	NS_JOB_SET_THREAD(eee)   ((eee) |= NS_JOB_THREAD)
#define	NS_JOB_UNSET_READ(eee)   ((eee) &= ~NS_JOB_READ)
#define	NS_JOB_UNSET_WRITE(eee)   ((eee) &= ~NS_JOB_WRITE)
#define	NS_JOB_UNSET_THREAD(eee)   ((eee) &= ~NS_JOB_THREAD)
#define	NS_JOB_UNSET_DISABLE_ONLY(eee)   ((eee) &= ~NS_JOB_DISABLE_ONLY)

Typedefs
typedef struct ns_thrpool_t	ns_thrpool_t
typedef void(*	ns_job_func_t )(struct ns_job_t *)
typedef unsigned short	ns_job_type_t

Functions
void	ns_thrpool_config_init (struct ns_thrpool_config *tp_config)
void	ns_job_done (struct ns_job_t *job)
PRStatus	ns_add_io_job (struct ns_thrpool_t *tp, PRFileDesc *fd, ns_job_type_t job_type, ns_job_func_t func, void *data, struct ns_job_t **job)
PRStatus	ns_add_timeout_job (struct ns_thrpool_t *tp, struct timeval *tv, ns_job_type_t job_type, ns_job_func_t func, void *data, struct ns_job_t **job)
PRStatus	ns_add_io_timeout_job (struct ns_thrpool_t *tp, PRFileDesc *fd, struct timeval *tv, ns_job_type_t job_type, ns_job_func_t func, void *data, struct ns_job_t **job)
PRStatus	ns_add_signal_job (ns_thrpool_t *tp, PRInt32 signum, ns_job_type_t job_type, ns_job_func_t func, void *data, struct ns_job_t **job)
PRStatus	ns_add_job (ns_thrpool_t *tp, ns_job_type_t job_type, ns_job_func_t func, void *data, struct ns_job_t **job)
PRFileDesc *	ns_job_get_fd (struct ns_job_t *job)
void *	ns_job_get_data (struct ns_job_t *job)
ns_job_type_t	ns_job_get_type (struct ns_job_t *job)
ns_thrpool_t *	ns_job_get_tp (struct ns_job_t *job)
ns_job_type_t	ns_job_get_output_type (struct ns_job_t *job)
struct ns_thrpool_t *	ns_thrpool_new (struct ns_thrpool_config *config)
void	ns_thrpool_destroy (struct ns_thrpool_t *tp)
void	ns_thrpool_shutdown (struct ns_thrpool_t *tp)
PRInt32	ns_thrpool_is_shutdown (struct ns_thrpool_t *tp)
PRStatus	ns_thrpool_wait (struct ns_thrpool_t *tp)
void	ns_job_rearm (struct ns_job_t *job)
void	ns_job_modify (struct ns_job_t *job, ns_job_type_t job_type)

Detailed Description

Nunc Stans public API.

This is the public API for Nunc Stans

Macro Definition Documentation

#define NS_JOB_ACCEPT   0x1

Flag for accept() jobs - new connection listeners

Use this flag when creating jobs that listen for and accept new connections. This is typically used in conjunction with the NS_JOB_PERSIST flag so that the job does not have to be rearmed every time it is called.

struct ns_job_t *listenerjob;
PRFileDesc *listenfd = PR_OpenTCPSocket(...);
PR_Bind(listenfd, ...);
PR_Listen(listenfd, ...);
listenerctx = new_listenerctx(...); // the application context object
ns_add_io_job(threadpool, NS_JOB_ACCEPT|NS_JOB_PERSIST,
              accept_new_connection, listenerctx, &listenerjob);

You will probably want to keep track of listenerjob and use it with ns_job_done() at application shutdown time to avoid leaking resources.

See Also

ns_add_io_job, ns_add_io_timeout_job, NS_JOB_IS_ACCEPT, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_CONNECT   0x2

Flag for jobs that will use connect()

When creating an I/O job, set this flag in the job_type to be notified when the file descriptor is available for outgoing connections. In the job callback, use ns_job_get_output_type() and NS_JOB_IS_CONNECT to see if the callback was called due to connect available if the callback is used with more than one of the job flags.

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_CONNECT

#define NS_JOB_DISABLE_ONLY   0x200

Flag to use when a modifying a job to be disabled

Use this flag when using ns_job_modify() if you only want to add/remove flags and do not want to immediately execute the job callback. For example, if you want to remove a persistent listener job from being called for some period of time:

ns_job_modify(listener_job, NS_JOB_DISABLE_ONLY);

This will simply remove the listener job, and not cause the job callback to be executed. To re-enable this job and start listening again, use ns_job_modify() with the original flags you used with the listener_job:

ns_job_modify(listener_job, NS_JOB_ACCEPT|NS_JOB_PERSIST);

See Also

ns_job_modify, NS_JOB_IS_DISABLE_ONLY, NS_JOB_ACCEPT, NS_JOB_PERSIST

#define NS_JOB_IS_ACCEPT

(

eee

)

((eee)&NS_JOB_ACCEPT)

Used to test an ns_job_type_t value for NS_JOB_ACCEPT

See Also

NS_JOB_ACCEPT, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_CONNECT

(

eee

)

((eee)&NS_JOB_CONNECT)

Used to test an ns_job_type_t value for NS_JOB_CONNECT

See Also

NS_JOB_CONNECT, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_DISABLE_ONLY

(

eee

)

((eee)&NS_JOB_DISABLE_ONLY)

Used to test an ns_job_type_t value for NS_JOB_DISABLE_ONLY

See Also

NS_JOB_DISABLE_ONLY, ns_job_modify, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_IO

(

eee

)

(NS_JOB_IS_ACCEPT(eee)||NS_JOB_IS_READ(eee)||NS_JOB_IS_CONNECT(eee)||NS_JOB_IS_WRITE(eee))

Used to test an ns_job_type_t value to see if it is any sort of I/O job

See Also

NS_JOB_IS_ACCEPT, NS_JOB_IS_READ, NS_JOB_IS_CONNECT, NS_JOB_IS_WRITE, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_PERSIST

(

eee

)

((eee)&NS_JOB_PERSIST)

Used to test an ns_job_type_t value for NS_JOB_PERSIST

See Also

NS_JOB_PERSIST, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_PRESERVE_FD

(

eee

)

((eee)&NS_JOB_PRESERVE_FD)

Used to test an ns_job_type_t value for NS_JOB_PRESERVE_FD

See Also

NS_JOB_PRESERVE_FD, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_READ

(

eee

)

((eee)&NS_JOB_READ)

Used to test an ns_job_type_t value for NS_JOB_READ

See Also

NS_JOB_READ, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_SIGNAL

(

eee

)

((eee)&NS_JOB_SIGNAL)

Used to test an ns_job_type_t value for NS_JOB_SIGNAL

See Also

NS_JOB_SIGNAL, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_THREAD

(

eee

)

((eee)&NS_JOB_THREAD)

Used to test an ns_job_type_t value for NS_JOB_THREAD

See Also

NS_JOB_THREAD, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_TIMER

(

eee

)

((eee)&NS_JOB_TIMER)

Used to test an ns_job_type_t value for NS_JOB_TIMER

See Also

NS_JOB_TIMER, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_IS_WRITE

(

eee

)

((eee)&NS_JOB_WRITE)

Used to test an ns_job_type_t value for NS_JOB_WRITE

See Also

NS_JOB_WRITE, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_NONE   0x0

Flag for jobs that are not associated with an event.

Use this flag when creating a job that you want to be run but not associated with an event. Usually used in conjunction with ns_add_job() and NS_JOB_THREAD to execute a function using the thread pool.

See Also

ns_add_job, NS_JOB_THREAD

#define NS_JOB_PERSIST   0x40

Flag to make jobs persistent

By default, when an event (I/O, timer, signal) is triggered and the job callback is called, the event is removed from the event framework, and the application will no longer receive callbacks for events. The application is then responsible for calling ns_job_rearm to "re-arm" the job to respond to the event again. Adding the job with the NS_JOB_PERSIST flag added to the job_type means the job will not have to be rearmed. This is usually used in conjunction with NS_JOB_ACCEPT for accept jobs. Use ns_job_get_type() or ns_job_get_output_type() with NS_JOB_IS_PERSIST to test if the job is persistent.

Note

Be very careful when using this flag in conjunction with NS_JOB_THREAD. For example, for a NS_JOB_ACCEPT job, once you call accept(), the socket may be immediately available for another accept, and your callback could be called again immediately in another thread. Same for the other types of I/O jobs. In that case, your job callback function must be thread safe - global resources must be protected with a mutex, the function must be reentrant, etc.

See Also

NS_JOB_ACCEPT, NS_JOB_THREAD, NS_JOB_IS_PERSIST, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_PRESERVE_FD   0x100

Flag to tell ns_job_done() not to close the job fd

I/O jobs will have a file descriptor (fd). If the job->fd lifecycle is managed by the application, this flag tells ns_job_done() not to close the fd.

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_PRESERVE_FD

#define NS_JOB_READ   0x4

Flag for I/O read jobs

When creating an I/O job, set this flag in the job_type to be notified when the file descriptor is available for reading. In the job callback, use ns_job_get_output_type() and NS_JOB_IS_READ to see if the callback was called due to read available if the callback is used with more than one of the job flags.

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_READ

#define NS_JOB_SET_READ

(

eee

)

((eee) |= NS_JOB_READ)

Used to set an ns_job_type_t value to have NS_JOB_READ

#define NS_JOB_SET_THREAD

(

eee

)

((eee) |= NS_JOB_THREAD)

Used to set an ns_job_type_t value to have NS_JOB_THREAD

#define NS_JOB_SET_WRITE

(

eee

)

((eee) |= NS_JOB_WRITE)

Used to set an ns_job_type_t value to have NS_JOB_WRITE

#define NS_JOB_SIGNAL   0x20

Flag for signal jobs

When creating a signal job, set this flag in the job_type to be notified when the process receives the given signal. In the job callback, use ns_job_get_output_type() and NS_JOB_IS_SIGNAL to see if the callback was called due to receiving the signal if the callback is used with more than one of the job flags.

See Also

ns_add_signal_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_SIGNAL

#define NS_JOB_THREAD   0x80

Flag to make jobs run in a thread pool thread

This flag allows you to specify if you want a job to run threaded or not. If the job is threaded, the job callback is executed by a thread in the thread pool, and the job callback function must be thread safe and reentrant. If the job is not threaded, the job runs in the same thread as the event loop thread.

Note

When NS_JOB_THREAD is not used, the job callback will be run in the event loop thread, and will block all events from being processed. Care must be taken to ensure that the job callback does not block.

Use ns_job_get_type() or ns_job_get_output_type() with NS_JOB_IS_THREAD to test if the job is threaded.

See Also

NS_JOB_IS_THREAD, ns_job_get_type, ns_job_get_output_type

#define NS_JOB_TIMER   0x10

Flag for timer jobs

When creating a timeout or I/O timeout job, set this flag in the job_type to be notified when the time given by the timeval argument has elapsed. In the job callback, use ns_job_get_output_type() and NS_JOB_IS_TIMER to see if the callback was called due to elapsed time if the callback is used with more than one of the job flags.

See Also

ns_add_timeout_job, ns_add_io_timeout_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_TIMER

#define NS_JOB_UNSET_DISABLE_ONLY

(

eee

)

((eee) &= ~NS_JOB_DISABLE_ONLY)

Remove NS_JOB_DISABLE_ONLY from an ns_job_type_t value

#define NS_JOB_UNSET_READ

(

eee

)

((eee) &= ~NS_JOB_READ)

Remove NS_JOB_READ from an ns_job_type_t value

#define NS_JOB_UNSET_THREAD

(

eee

)

((eee) &= ~NS_JOB_THREAD)

Remove NS_JOB_THREAD from an ns_job_type_t value

#define NS_JOB_UNSET_WRITE

(

eee

)

((eee) &= ~NS_JOB_WRITE)

Remove NS_JOB_WRITE from an ns_job_type_t value

#define NS_JOB_WRITE   0x8

Flag for I/O write jobs

When creating an I/O job, set this flag in the job_type to be notified when the file descriptor is available for writing. In the job callback, use ns_job_get_output_type() and NS_JOB_IS_WRITE to see if the callback was called due to write available if the callback is used with more than one of the job flags.

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_job_get_type, ns_job_get_output_type, NS_JOB_IS_WRITE

Typedef Documentation

typedef void(* ns_job_func_t)(struct ns_job_t *)

The job callback function type

Job callback functions must have a function signature of ns_job_func_t.

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_add_timeout_job, ns_add_signal_job, ns_add_job

typedef unsigned short ns_job_type_t

Bitflag type for job types

This is the job_type bitfield argument used when adding jobs, and the return value of the functions ns_job_get_type() and ns_job_get_output_type(). The value is one or more of the NS_JOB_* macros OR'd together.

ns_job_type_t job_type = NS_JOB_READ|NS_JOB_SIGNAL;

When used with ns_job_get_type() or ns_job_get_output_type() to see what type of job it is, use the return value with one of the NS_JOB_IS_* macros:

if (NS_JOB_IS_TIMER(ns_job_get_output_type(job))) {
  // handle timeout
}

See Also

ns_add_io_job, ns_add_io_timeout_job, ns_add_job, ns_add_signal_job, ns_add_timeout_job, ns_job_get_type, ns_job_get_output_type, ns_job_modify

typedef struct ns_thrpool_t ns_thrpool_t

This is the thread pool typedef

The actual thread pool is opaque to applications.

See Also

ns_thrpool_new, ns_thrpool_wait, ns_thrpool_destroy, ns_job_get_tp

Function Documentation

PRStatus ns_add_io_job	(	struct ns_thrpool_t *	tp,
		PRFileDesc *	fd,
		ns_job_type_t	job_type,
		ns_job_func_t	func,
		void *	data,
		struct ns_job_t **	job
	)

Adds an I/O job to the thread pool

Specify the type of I/O job using the job_type bitfield. You can specify more than one type of I/O job. Use ns_job_get_output_type(job) to determine which event triggered the I/O.

ns_add_io_job(tp, fd, NS_JOB_READ|NS_JOB_WRITE, my_io_callback, ...);
...
void my_io_callback(struct ns_job_t *job)
{
    if (NS_JOB_IS_READ(ns_job_get_output_type(job))) {
        // handle reading from fd
    } else {
        // handle writing to fd
    }
}

The callback will need to rearm the job or add another job if it wants to be notified of more events, or use NS_JOB_PERSIST. If you want an I/O job that will timeout if I/O is not detected within a certain period of time, use ns_add_io_timeout_job().

Parameters

	tp	The thread pool you want to add an I/O job to.
	fd	The file descriptor to use for I/O.
	job_type	A set of flags that indicates the job type.
	func	The callback function to call when processing the job.
	data	Arbitrary data that will be available to the job callback function.
[out]	job	The address of a job pointer that will be filled in once the job is allocated. NULL can be passed if a pointer to the job is not needed.

Return values

PR_SUCCESS	Job was successfully added.
PR_FAILURE	Failed to add job.

Warning

The thread pool will not allow a job to be added when it has been signaled to shutdown. It will return PR_FAILURE in that case.

See Also

ns_job_t, ns_job_get_data, NS_JOB_READ, NS_JOB_WRITE, NS_JOB_ACCEPT, NS_JOB_CONNECT, NS_JOB_IS_IO, ns_job_done

PRStatus ns_add_io_timeout_job	(	struct ns_thrpool_t *	tp,
		PRFileDesc *	fd,
		struct timeval *	tv,
		ns_job_type_t	job_type,
		ns_job_func_t	func,
		void *	data,
		struct ns_job_t **	job
	)

Adds an I/O job to the thread pool's work queue with a timeout.

The callback func function should test the type of event that triggered the callback using ns_job_get_output_type(job) to get the ns_job_type_t, then use NS_JOB_IS_TIMER(output_type) to see if this callback was triggered by a timer event. This is useful if you want to perform some sort of I/O, but you require that I/O must happen in a certain amount of time.

ns_add_io_timeout_job(tp, fd, &tv, NS_JOB_READ|NS_JOB_TIMER, my_iot_callback, ...);
...
void my_iot_callback(struct ns_job_t *job)
{
    if (NS_JOB_IS_TIMER(ns_job_get_output_type(job))) {
        // handle timeout condition
    } else {
        // handle read from fd
    }
}

Note

This is like adding an I/O job, with an optional timeout. This is not like adding a timeout job with an additional I/O event component. This depends on the underlying event framework having the ability to have a timed I/O job. For example, libevent I/O events can have a timeout.

Parameters

	tp	The thread pool whose work queue you want to add an I/O job to.
	fd	The file descriptor to use for I/O.
	tv	The timer that needs to expire before triggering the callback function.
	job_type	A set of flags that indicates the job type.
	func	The callback function for a worker thread to call when processing the job.
	data	Arbitrary data that will be available to the job callback function.
[out]	job	The address of a job pointer that will be filled in once the job is allocated. NULL can be passed if a pointer to the job is not needed.

Return values

PR_SUCCESS	Job was successfully added.
PR_FAILURE	Failed to add job.

Warning

The thread pool will not allow a job to be added when it has been signaled to shutdown. It will return PR_FAILURE in that case.

See Also

ns_job_t, ns_job_get_data, NS_JOB_READ, NS_JOB_WRITE, NS_JOB_ACCEPT, NS_JOB_CONNECT, NS_JOB_IS_IO, ns_job_done, NS_JOB_TIMER, NS_JOB_IS_TIMER

PRStatus ns_add_job	(	ns_thrpool_t *	tp,
		ns_job_type_t	job_type,
		ns_job_func_t	func,
		void *	data,
		struct ns_job_t **	job
	)

Add a non-event related job to the thread pool

A non-event related job is a job that is executed immediately that is not contingent on an event or signal. This is typically used when the application wants to do some processing in parallel using a thread from the thread pool.

ns_add_job(tp, NS_JOB_NONE|NS_JOB_THREAD, my_callback, ...);
...
void my_callback(struct ns_job_t *job)
{
   // now in a separate thread
}

Parameters

	tp	The thread pool you want to add the job to.
	job_type	A set of flags that indicates the job type (usually just NS_JOB_NONE|NS_JOB_THREAD)
	func	The callback function to call when processing the job.
	data	Arbitrary data that will be available to the job callback function.
[out]	job	The address of a job pointer that will be filled in once the job is allocated. NULL can be passed if a pointer to the job is not needed.

Return values

PR_SUCCESS	Job was successfully added.
PR_FAILURE	Failed to add job.

Warning

The thread pool will not allow a job to be added when it has been signaled to shutdown. It will return PR_FAILURE in that case.

See Also

ns_job_t, ns_job_get_data, NS_JOB_NONE, NS_JOB_THREAD

PRStatus ns_add_signal_job	(	ns_thrpool_t *	tp,
		PRInt32	signum,
		ns_job_type_t	job_type,
		ns_job_func_t	func,
		void *	data,
		struct ns_job_t **	job
	)

Adds a signal job to the thread pool

The func function will be called when the signal is received by the process.

Parameters

	tp	The thread pool you want to add a signal job to.
	signum	The signal number that you want to trigger the callback function.
	job_type	A set of flags that indicates the job type.
	func	The callback function to call when processing the job.
	data	Arbitrary data that will be available to the job callback function.
[out]	job	The address of a job pointer that will be filled in once the job is allocated. NULL can be passed if a pointer to the job is not needed.

Return values

PR_SUCCESS	Job was successfully added.
PR_FAILURE	Failed to add job.

Warning

The thread pool will not allow a job to be added when it has been signaled to shutdown. It will return PR_FAILURE in that case.

See Also

ns_job_t, ns_job_get_data, NS_JOB_SIGNAL, NS_JOB_IS_SIGNAL

PRStatus ns_add_timeout_job	(	struct ns_thrpool_t *	tp,
		struct timeval *	tv,
		ns_job_type_t	job_type,
		ns_job_func_t	func,
		void *	data,
		struct ns_job_t **	job
	)

Adds a timeout job to the thread pool

The func function will be called when the timer expires.

Parameters

	tp	The thread pool you want to add a timeout job to.
	tv	The timer that needs to expire before triggering the callback function.
	job_type	A set of flags that indicates the job type - NS_JOB_TIMER + other flags
	func	The callback function to call when processing the job.
	data	Arbitrary data that will be available to the job callback function.
[out]	job	The address of a job pointer that will be filled in once the job is allocated. NULL can be passed if a pointer to the job is not needed.

Return values

PR_SUCCESS	Job was successfully added.
PR_FAILURE	Failed to add job.

Warning

The thread pool will not allow a job to be added when it has been signaled to shutdown. It will return PR_FAILURE in that case.

See Also

ns_job_t, ns_job_get_data, NS_JOB_TIMER, NS_JOB_IS_TIMER, ns_job_done

void ns_job_done

(

struct ns_job_t *

job

)

The application is finished with this job

The application uses this function to tell nunc-stans that it is finished using this job. Once the application calls this function, it may no longer refer to job - it should be considered as an allocated pointer that the free() function has been called with. An application will typically call ns_job_done() at the end of a job callback function for non-persistent jobs (not using NS_JOB_PERSIST), or at application shutdown time for persistent jobs (using NS_JOB_PERSIST). For an I/O job, ns_job_done will close() the file descriptor associated with the job unless the NS_JOB_PRESERVE_FD is specified when the job is added.

void read_callback(struct ns_job_t *job)
{
    appctx_t *appctx = (appctx_t *)ns_job_get_data(job);
    ...
    ns_job_done(job);
    // ok to use appctx here, but not job
    // app must free or ensure appctx is not leaked
    return;
}

Parameters

job	the job to clean up

See Also

ns_job_t, ns_job_get_data, NS_JOB_PERSIST, NS_JOB_PRESERVE_FD

void* ns_job_get_data

(

struct ns_job_t *

job

)

Allows the callback to access the private data field in the job.

This is the data field passed in when the job is added. This data is private to the application - nunc-stans does not touch it in any way. The application is responsible for managing the lifecycle of this data.

void my_job_callback(struct ns_job_t *job)
{
    myappctx_t *myappctx = (myappctx_t *)ns_job_get_data(job);
    ...
}

Parameters

job	The job to get the data for.

Returns

The private data associated with the job.

See Also

ns_job_t

PRFileDesc* ns_job_get_fd

(

struct ns_job_t *

job

)

Allows the callback to access the file descriptor for an I/O job

void my_io_job_callback(struct ns_job_t *job)
{
    PRFileDesc *fd = ns_job_get_fd(job);
    rc = PR_Read(fd, ...);
    ...
}

If the job is not an I/O job, the function will return NULL.

Parameters

job	The job to get the fd for.

Return values

fd	The file descriptor associated with the I/O job.
NULL	The job is not an I/O job

See Also

ns_job_t, ns_add_io_job, ns_add_io_timeout_job

ns_job_type_t ns_job_get_output_type

(

struct ns_job_t *

job

)

Allows the callback to know which event triggered the callback.

The callback func may need to know which event triggered the callback. This function will allow access to the type of event that triggered the callback. For example, when using ns_add_io_timeout_job(), the callback can be called either because of an I/O event or a timer event. Use NS_JOB_IS_TIMER to tell if the event is a timer event, like this:

if (NS_JOB_IS_TIMER(ns_job_get_output_type(job))) {
   ... handle timeout ...
} else {
   ... handle I/O ...
}

Parameters

job	The job to get the output type for.

Returns

The ns_job_type_t corresponding to the event that triggered the callback

See Also

ns_job_t, NS_JOB_IS_TIMER, NS_JOB_IS_READ, NS_JOB_IS_WRITE, NS_JOB_IS_IO, ns_add_io_timeout_job

ns_thrpool_t* ns_job_get_tp

(

struct ns_job_t *

job

)

Allows the callback to access the thread pool that the job is associated with.

Useful for adding jobs from within job callbacks.

void my_job_callback(struct ns_job_t *job)
{
   // do some work
   // need to listen for some events
   ns_add_io_job(ns_job_get_tp(job), fd, ...);
   // finished with job
   ns_job_done(job);
   return;
}

Parameters

job	The job to get the thread pool for.

Returns

The thread pool associated with the job.

See Also

ns_job_t, ns_add_io_job

ns_job_type_t ns_job_get_type

(

struct ns_job_t *

job

)

Allows the callback to access the job type flags.

Usually used in conjunction with one of the NS_JOB_IS_* macros.

void my_job_callback(struct ns_job_t *job)
{
    if (NS_JOB_IS_READ(ns_job_get_type(job)) {
    ...
    }
}

Parameters

job	The job to get the type for.

Returns

The ns_job_type_t flags for the job

See Also

ns_job_t, NS_JOB_IS_READ, NS_JOB_IS_WRITE, NS_JOB_IS_IO, NS_JOB_IS_TIMER

void ns_job_modify	(	struct ns_job_t *	job,
		ns_job_type_t	job_type
	)

Modify the type of events a job will listen for

This allows you to reuse a job, but just change the type of events the job is listening for, rather than having to call ns_job_done() and ns_job_add*. If you just want the job to be called again with the same flags, use ns_job_rearm(). For example, if you have an I/O read job, and the reading is done, and now you need to write, you can use ns_job_modify() to change the job to a write job:

void app_job_read_and_write_callback(struct ns_job_t *job)
{
  // read from fd
  if (need_write) {
    ns_job_type_t flags = ns_job_get_type(job);
    NS_JOB_UNSET_READ(flags);
    NS_JOB_SET_WRITE(flags);
    ns_job_modify(job, flags);
    // now app_job_read_and_write_callback will be called back for write, not read
  }
}

ns_job_modify() is also useful when you need to temporarily disable a job. Use the NS_JOB_DISABLE_ONLY so that the job callback will not be executed.

ns_job_modify(listener_job, NS_JOB_DISABLE_ONLY);

You can even use this to turn a job from an event job to a non-event job. For example, you are done with I/O for the moment and want to execute some other part of the job as a threaded task, which will then modify the job back into an I/O job:

ns_job_modify(listener_job, NS_JOB_NONE|NS_JOB_THREAD);

Note

Do not call ns_job_done() with the job in this case

Parameters

job	The job to modify
job_type	The new job type flags

See Also

ns_job_t, ns_job_done, ns_get_job_type, NS_JOB_UNSET_READ, NS_JOB_SET_WRITE, NS_JOB_DISABLE_ONLY, NS_JOB_NONE, NS_JOB_THREAD

void ns_job_rearm

(

struct ns_job_t *

job

)

Convenience function to re-arm the same job

This is used for non-persistent (not using NS_JOB_PERSIST) jobs. For example, if you have an I/O reading job, and the job needs to read more data, the job callback can just call ns_job_rearm(), and the job callback will be called again when read is ready on the job fd. Once this function is called, the job callback may be called immediately if the job uses NS_JOB_THREAD. Do not refer to job after calling ns_job_rearm(). If you need to call the job callback again, but want to change the type of event the job listens for, either use ns_job_modify() to change the job flags, or call ns_job_done() to finish this job and call ns_job_add_* to add a new job.

Note

Do not call ns_job_done() with a job if using ns_job_rearm() with the job

Parameters

job	The job to re-arm

See Also

ns_job_t, ns_job_done, ns_job_modify, NS_JOB_PERSIST, NS_JOB_THREAD

void ns_thrpool_config_init

(

struct ns_thrpool_config *

tp_config

)

Initialize a thrpool config struct

The config struct must be allocated/freed by the caller. A stack variable is typically used.

struct ns_thrpool_config nsconfig;
ns_thrpool_config_init(&nsconfig);
nsconfig.initial_threads = 16;
nsconfig.malloc_fct = mymalloc;
...
rc = ns_thrpool_new(&nsconfig);

See Also

ns_thrpool_config, ns_thrpool_new

Parameters

tp_config

- thread pool config struct

void ns_thrpool_destroy

(

struct ns_thrpool_t *

tp

)

Frees a thread pool from memory

This will free a thread pool and it's internal resources from memory. You should be sure that the thread pool has been shutdown before destroying it by calling ns_thrpool_wait(), then call ns_job_done() to finish any long-lived jobs. After calling ns_thrpool_destroy(), do not use tp.

Parameters

tp	The thread pool to destroy.

See Also

ns_thrpool_config, ns_thrpool_config_init, ns_thrpool_new, ns_thrpool_wait, ns_thrpool_shutdown

PRInt32 ns_thrpool_is_shutdown

(

struct ns_thrpool_t *

tp

)

Checks if a thread pool is shutting down

This can be called by worker threads so they know when the thread pool has been requested to shut down.

Return values

0	if the thread pool is not shutting down.
1	if the thread pool is shutting down.

See Also

ns_thrpool_shutdown

struct ns_thrpool_t* ns_thrpool_new

(

struct ns_thrpool_config *

config

)

Creates a new thread pool

Must be called with a struct ns_thrpool_config that has been initialized by ns_thrpool_config_init(). Typically, once the thread pool has been created, one or more listener jobs or other long lived jobs will be added, and the application will just call ns_thrpool_wait(). The application should add at least one job that will listen for shutdown events, signals, etc. which will call ns_thrpool_shutdown(). After ns_thrpool_wait() returns, the application should use ns_job_done() to finish any long-lived jobs, then call ns_thrpool_destroy().

Parameters

config

A pointer to a struct ns_thrpool_config

Returns

A pointer to the newly created thread pool.

See Also

ns_thrpool_config, ns_thrpool_config_init, ns_thrpool_wait, ns_thrpool_shutdown, ns_thrpool_destroy

void ns_thrpool_shutdown

(

struct ns_thrpool_t *

tp

)

Tells a thread pool to shutdown its threads

The application will usually call ns_thrpool_shutdown() from an event callback that is listening for shutdown events e.g. a signal job that is listening for SIGINT or SIGTERM events.

tp = ns_thrpool_new(...);
ns_add_signal_job(tp, SIGTERM, handle_shutdown_signal, NS_JOB_SIGNAL|NS_JOB_THREAD, ...);

void handle_shutdown_signal(job)
{
  ns_thrpool_shutdown(ns_job_get_tp(job));
  // set application shutdown flag
  return;
}

Use NS_JOB_SIGNAL|NS_JOB_THREAD so that the job will run in a worker thread, not in the event loop thread.

Note

The application must call ns_thrpool_shutdown() or ns_thrpool_wait() will never return.

Parameters

tp	The thread pool to shutdown.

Warning

This must only be called from a job that runs in a worker thread. Calling this function from the event thread can cause a deadlock.

See Also

ns_thrpool_config, ns_thrpool_config_init, ns_thrpool_new, ns_thrpool_wait, ns_thrpool_destroy, ns_add_signal_job, NS_JOB_THREAD

PRStatus ns_thrpool_wait

(

struct ns_thrpool_t *

tp

)

Waits for all threads in the pool to exit

This call will block the caller until all threads in the thread pool have exited. A program will typically create the thread pool by calling ns_thrpool_new(), then it will call ns_thrpool_wait() to wait until the thread pool is shutdown (which is likely initiated by a signal handler). Once this function successfully returns, the thread pool can be safely destroyed by calling ns_thrpool_destroy().

Note

The application must call ns_thrpool_shutdown() or ns_thrpool_wait() will never return.

Parameters

tp	The thread pool to wait for.

Return values

PR_SUCCESS	The thread pool threads completed successfully
PR_FAILURE	Failure waiting for the thread pool threads to terminate

See Also

ns_thrpool_config, ns_thrpool_config_init, ns_thrpool_new, ns_thrpool_destroy, ns_thrpool_shutdown