This section describes the task structure of MSG (msg_task_t) and the functions for managing it. See Task Actions to see how to put the tasks in action. More...

Macros
#define	MSG_TASK_UNINITIALIZED NULL
	Default value for an uninitialized msg_task_t.

Typedefs
typedef struct msg_task *	msg_task_t
	Task datatype.A task may then be defined by a computing amount, a message size and some private data.
typedef struct msg_gpu_task *	msg_gpu_task_t
	GPU task datatype.A task may then be defined by a computing amount, a dispatch latency and a collect latency.

Functions
msg_task_t	MSG_task_create (const char name, double compute_duration, double message_size, void data)
	Creates a new msg_task_t.
msg_task_t	MSG_parallel_task_create (const char name, int host_nb, const msg_host_t host_list, double computation_amount, double communication_amount, void *data)
	Creates a new msg_task_t (a parallel one....).
msg_gpu_task_t	MSG_gpu_task_create (const char *name, double compute_duration, double dispatch_latency, double collect_latency)
	Creates a new msg_gpu_task_t.
void *	MSG_task_get_data (msg_task_t task)
	Return the user data of a msg_task_t.
void	MSG_task_set_data (msg_task_t task, void *data)
	Sets the user data of a msg_task_t.
void	MSG_task_set_copy_callback (void(*callback)(msg_task_t task, msg_process_t sender, msg_process_t receiver))
	Sets a function to be called when a task has just been copied.
msg_process_t	MSG_task_get_sender (msg_task_t task)
	Return the sender of a msg_task_t.
msg_host_t	MSG_task_get_source (msg_task_t task)
	Return the source of a msg_task_t.
const char *	MSG_task_get_name (msg_task_t task)
	Return the name of a msg_task_t.
void	MSG_task_set_name (msg_task_t task, const char *name)
	Sets the name of a msg_task_t.
msg_error_t	MSG_task_destroy (msg_task_t task)
	Destroy a msg_task_t.
double	MSG_task_get_compute_duration (msg_task_t task)
	Returns the computation amount needed to process a task msg_task_t.
void	MSG_task_set_compute_duration (msg_task_t task, double computation_amount)
	set the computation amount needed to process a task msg_task_t.
double	MSG_task_get_remaining_computation (msg_task_t task)
	Returns the remaining computation amount of a task msg_task_t.
double	MSG_task_get_remaining_communication (msg_task_t task)
	Returns the total amount received by a task msg_task_t. If the communication does not exist it will return 0. So, if the communication has FINISHED or FAILED it returns zero.
double	MSG_task_get_data_size (msg_task_t task)
	Returns the size of the data attached to a task msg_task_t.
void	MSG_task_set_priority (msg_task_t task, double priority)
	Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2 will make a task receive two times more cpu power than the other ones.

Detailed Description

This section describes the task structure of MSG (msg_task_t) and the functions for managing it. See Task Actions to see how to put the tasks in action.

Since most scheduling algorithms rely on a concept of task that can be either computed locally or transferred on another processor, it seems to be the right level of abstraction for our purposes. A task may then be defined by a computing amount, a message size and some private data.

Typedef Documentation

typedef struct msg_gpu_task* msg_gpu_task_t

GPU task datatype.A task may then be defined by a computing amount, a dispatch latency and a collect latency.

See Also: Task Management Functions

Function Documentation

msg_task_t MSG_task_create	(	const char *	name,
		double	compute_duration,
		double	message_size,
		void *	data
	)

Creates a new msg_task_t.

A constructor for msg_task_t taking four arguments and returning the corresponding object.

Parameters

name	a name for the object. It is for user-level information and can be NULL.
compute_duration	a value of the processing amount (in flop) needed to process this new task. If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
message_size	a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
data	a pointer to any data may want to attach to the new object. It is for user-level information and can be NULL. It can be retrieved with the function MSG_task_get_data.

See Also: msg_task_t

Returns: The new corresponding object.

msg_task_t MSG_parallel_task_create	(	const char *	name,
		int	host_nb,
		const msg_host_t *	host_list,
		double *	computation_amount,
		double *	communication_amount,
		void *	data
	)

Creates a new msg_task_t (a parallel one....).

A constructor for msg_task_t taking six arguments and returning the corresponding object.

Parameters

name	a name for the object. It is for user-level information and can be NULL.
host_nb	the number of hosts implied in the parallel task.
host_list	an array of `host_nb` msg_host_t.
computation_amount	an array of `host_nb` doubles. computation_amount[i] is the total number of operations that have to be performed on host_list[i].
communication_amount	an array of `host_nb*` `host_nb` doubles.
data	a pointer to any data may want to attach to the new object. It is for user-level information and can be NULL. It can be retrieved with the function MSG_task_get_data.

See Also: msg_task_t

Returns: The new corresponding object.

msg_gpu_task_t MSG_gpu_task_create	(	const char *	name,
		double	compute_duration,
		double	dispatch_latency,
		double	collect_latency
	)

Creates a new msg_gpu_task_t.

A constructor for msg_gpu_task_t taking four arguments and returning a pointer to the new created GPU task.

Parameters

name	a name for the object. It is for user-level information and can be NULL.
compute_duration	a value of the processing amount (in flop) needed to process this new task. If 0, then it cannot be executed with MSG_gpu_task_execute(). This value has to be >=0.
dispatch_latency	time in seconds to load this task on the GPU
collect_latency	time in seconds to transfer result from the GPU back to the CPU (host) when done

See Also: msg_gpu_task_t

Returns: The new corresponding object.

void* MSG_task_get_data ( msg_task_t task )

Return the user data of a msg_task_t.

This function checks whether task is a valid pointer or not and return the user data associated to task if it is possible.

void MSG_task_set_data	(	msg_task_t	task,
		void *	data
	)

Sets the user data of a msg_task_t.

This function allows to associate a new pointer to the user data associated of task.

void MSG_task_set_copy_callback ( void(*)(msg_task_t task, msg_process_t sender, msg_process_t receiver) callback )

Sets a function to be called when a task has just been copied.

Parameters

callback a callback function

msg_process_t MSG_task_get_sender ( msg_task_t task )

Return the sender of a msg_task_t.

This functions returns the msg_process_t which sent this task

msg_host_t MSG_task_get_source ( msg_task_t task )

Return the source of a msg_task_t.

This functions returns the msg_host_t from which this task was sent

const char* MSG_task_get_name ( msg_task_t task )

Return the name of a msg_task_t.

This functions returns the name of a msg_task_t as specified on creation

void MSG_task_set_name	(	msg_task_t	task,
		const char *	name
	)

Sets the name of a msg_task_t.

This functions allows to associate a name to a task

msg_error_t MSG_task_destroy ( msg_task_t task )

Destroy a msg_task_t.

Destructor for msg_task_t. Note that you should free user data, if any, before calling this function.

Only the process that owns the task can destroy it. The owner changes after a successful send. If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not use it anymore. If the task failed to be sent, the sender remains the owner of the task.

double MSG_task_get_compute_duration ( msg_task_t task )

Returns the computation amount needed to process a task msg_task_t.

Once a task has been processed, this amount is set to 0. If you want, you can reset this value with MSG_task_set_compute_duration before restarting the task.

void MSG_task_set_compute_duration	(	msg_task_t	task,
		double	computation_amount
	)

set the computation amount needed to process a task msg_task_t.

Warning: If the computation is ongoing (already started and not finished), it is not modified by this call. And the termination of the ongoing task with set the computation_amount to zero, overriding any value set during the execution.

double MSG_task_get_remaining_computation ( msg_task_t task )

Returns the remaining computation amount of a task msg_task_t.

If the task is ongoing, this call retrieves the remaining amount of work. If it is not ongoing, it returns the total amount of work that will be executed when the task starts.

Macros

Typedefs

Functions

Detailed Description

Typedef Documentation

Function Documentation