Header file with agent related operations. More...

#include <host.h>
#include <job.h>
#include <scheduler.h>
#include <sys/types.h>
#include <gio/gio.h>
#include <glib.h>

Include dependency graph for agent.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	meta_agent_t

struct	agent_t

Macros
#define	MAX_CMD 1023
	the size of the agent's command buffer (arbitrary)

#define	MAX_NAME 255
	the size of the agent's name buffer (arbitrary)

#define	MAX_ARGS 32
	the size of the argument buffer (arbitrary)

#define	DEFAULT_RET -1
	default return code (arbitrary)

#define	LOCAL_HOST "localhost"

#define	SAG_NOKILL (1 << 0)
	This agent should not be killed when updating the agent.

#define	SAG_EXCLUSIVE (1 << 1)
	This agent must not run at the same time as any other agent.

#define	SAG_NOEMAIL (1 << 2)
	This agent should not send notification emails.

#define	SAG_LOCAL (1 << 3)
	This agent should only run on localhost.

#define	AGENT_STATUS_TYPES(apply)

#define	SELECT_ENUM(passed) AG_##passed,

Typedefs
typedef int	agent_pk

Enumerations
enum	agent_status { AGENT_STATUS_TYPES =(SELECT_ENUM) }

Functions
meta_agent_t *	meta_agent_init (char name, char cmd, int max, int spc)
	Creates a new meta agent. More...

void	meta_agent_destroy (meta_agent_t *meta_agent)

agent_t *	agent_init (scheduler_t scheduler, host_t host, job_t *owner)
	Allocate and spawn a new agent. More...

void	agent_destroy (agent_t *agent)
	Frees the memory associated with an agent. More...

void	agent_death_event (scheduler_t scheduler, pid_t pids)

void	agent_create_event (scheduler_t scheduler, agent_t agent)
	Event created when a new agent has been created. More...

void	agent_ready_event (scheduler_t scheduler, agent_t agent)
	Event created when an agent is ready for more data. More...

void	agent_update_event (scheduler_t scheduler, void unused)

void	agent_fail_event (scheduler_t scheduler, agent_t agent)
	Fails an agent. More...

void	list_agents_event (scheduler_t scheduler, GOutputStream ostr)
	Receive agent on interface. More...

void	agent_transition (agent_t *agent, agent_status new_status)

void	agent_pause (agent_t *agent)

void	agent_unpause (agent_t *agent)

void	agent_print_status (agent_t agent, GOutputStream ostr)
	Prints the status of the agent to the output stream provided. More...

void	agent_kill (agent_t *agent)
	Unclean kill of an agent. More...

int	aprintf (agent_t agent, const char fmt,...)

ssize_t	agent_write (agent_t agent, const void buf, int count)

void	test_agents (scheduler_t *scheduler)
	Calls the agent test function for every type of agent. More...

int	add_meta_agent (GTree meta_agents, char name, char *cmd, int max, int spc)

void	kill_agents (scheduler_t *scheduler)
	Call the agent_kill function for every agent within the system. More...

int	is_meta_special (meta_agent_t *ma, int special_type)
	tests if a particular meta agent has a specific special flag set More...

int	is_agent_special (agent_t *agent, int special_type)
	tests if a particular agent has a specific special flag set More...

void	meta_agent_increase_count (meta_agent_t *)

void	meta_agent_decrease_count (meta_agent_t *)

Variables
const char *	agent_status_strings []

Detailed Description

Header file with agent related operations.

Definition in file agent.h.

Macro Definition Documentation

◆ AGENT_STATUS_TYPES

#define AGENT_STATUS_TYPES ( apply )

Value:

                          \
  apply(FAILED)                                                     \                 \
  apply(CREATED)                                                    \       \
  apply(SPAWNED)                                                    \                               \
  apply(RUNNING)                                                    \ \
  apply(PAUSED)                                                     \   \
  apply(CLOSED)                                                     \

Implementation of x macros used for the creation of the agent status enum. This is used so that if a new agent status is needed, it can be added here and all relevant declarations can be changed.

If you are unfamiliar with X macros, this is a very simply implementation of them and I suggest you look them up online.

Definition at line 50 of file agent.h.

◆ SELECT_ENUM

#define SELECT_ENUM ( passed ) AG_##passed,

Enum to keep track of the state of an agent

Definition at line 65 of file agent.h.

Typedef Documentation

◆ agent_pk

typedef int agent_pk

Todo:

Definition at line 74 of file agent.h.

Function Documentation

◆ add_meta_agent()

int add_meta_agent	(	GTree *	meta_agents,
		char *	name,
		char *	cmd,
		int	max,
		int	spc
	)

Creates a new meta agent and adds it to the list of meta agents. This will parse the shell command that will start the agent process.

Parameters

meta_agents	GTree of meta agents available for the scheduler
name	the name of the meta agent (e.g. "nomos", "copyright", etc...)
cmd	the shell command used to the run the agent
max	the max number of this type of agent that can run concurrently
spc	anything special about the agent type

Definition at line 1316 of file agent.c.

◆ agent_create_event()

void agent_create_event	(	scheduler_t *	scheduler,
		agent_t *	agent
	)

Event created when a new agent has been created.

This means that the agent has been allocated internally and the fork() call has successfully executed. The agent has not yet communicated with the scheduler when this event is created.

Parameters

scheduler	the scheduler reference to which agent has to attach
agent	the agent that has been created.

Definition at line 1021 of file agent.c.

◆ agent_death_event()

void agent_death_event	(	scheduler_t *	scheduler,
		pid_t *	pid
	)

Event created when a SIGCHLD is received for an agent. If one SIGCHILD is received for several process deaths, there will be seperate events for each pid.

Parameters

scheduler	the scheduler reference to which process was attached to
pid	the pid of the process that died

Definition at line 952 of file agent.c.

◆ agent_destroy()

void agent_destroy ( agent_t * agent )

Frees the memory associated with an agent.

This include:

All of the files that are open in the agent
All of the pipes still open for the agent
Inform the os that the process can die using a waitpid()
Free the internal data structure of the agent

Parameters

agent the agent to destroy

Definition at line 924 of file agent.c.

◆ agent_fail_event()

void agent_fail_event	(	scheduler_t *	scheduler,
		agent_t *	agent
	)

Fails an agent.

This will move the agent status to AG_FAILED and send a SIGKILL to the relevant agent. It will also update the agents status within the job that owns it and close the associated communication thread.

Parameters

scheduler	the scheduler to which agent is attached
agent	the agent that is failing.

Definition at line 1102 of file agent.c.

◆ agent_init()

agent_t* agent_init	(	scheduler_t *	scheduler,
		host_t *	host,
		job_t *	job
	)

Allocate and spawn a new agent.

The agent that is spawned will be of the same type as the meta_agent that is passed to this function and the agent will run on the host that is passed.

Parameters

scheduler	the scheduler this agent is being created under
host	the machine to start the agent on
job	the job that this agent belongs to

Definition at line 802 of file agent.c.

◆ agent_kill()

void agent_kill ( agent_t * agent )

Unclean kill of an agent.

This simply sends a SIGKILL to the agent and lets everything else get cleaned up normally.

Parameters

agent the agent to kill

Definition at line 1223 of file agent.c.

◆ agent_pause()

void agent_pause ( agent_t * agent )

Pauses an agent, this will pause the agent by sending a SIGSTOP to the process and then decrease the load on the host machine.

Parameters

agent the agent to pause

Definition at line 1164 of file agent.c.

◆ agent_print_status()

void agent_print_status	(	agent_t *	agent,
		GOutputStream *	ostr
	)

Prints the status of the agent to the output stream provided.

The formating for this is as such:

`agent:<pid> host:<host> type:<type> status:<status> time:<time>`

Parameters

agent	Agent to get info from
ostr	Stream to write info to

Definition at line 1193 of file agent.c.

◆ agent_ready_event()

void agent_ready_event	(	scheduler_t *	scheduler,
		agent_t *	agent
	)

Event created when an agent is ready for more data.

This will event will be created when an agent first communicates with the scheduler, so this will handle changing its status to AG_RUNNING. This will also be created every time an agent finishes a block of data.

Parameters

scheduler	the scheduler reference to which agent is attached
agent	the agent that is ready

Definition at line 1042 of file agent.c.

◆ agent_transition()

void agent_transition	(	agent_t *	agent,
		agent_status	new_status
	)

Changes the status of the agent internal to the scheduler. This function is used to transition between agent states instead of a raw set of the status so that correct printing of the verbose message is guaranteed

Parameters

agent	the agent to change the status for
new_status	the new status of the agentchar* sysconfdir = NULL; // system configuration directory (SYSCONFDIR)

Definition at line 1136 of file agent.c.

◆ agent_unpause()

void agent_unpause ( agent_t * agent )

Unpause the agent, this will send a SIGCONT to the process regardless of if a SIGCONT was sent. If the process wasn't SIGSTOP'd this will do nothing. Also increases the load on the host.

Parameters

agent the agent to unpause

Definition at line 1177 of file agent.c.

◆ agent_update_event()

void agent_update_event	(	scheduler_t *	scheduler,
		void *	unused
	)

Event created when the scheduler receives a SIGALRM. This will loop over every agent and call the update function on it. This will kill any agents that are hung without heart beat or any agents that have stopped updating the number of item processed.

Parameters

scheduler	the scheduler reference to inform
unused	needed since this an event, but should be NULL

Definition at line 1087 of file agent.c.

◆ agent_write()

ssize_t agent_write	(	agent_t *	agent,
		const void *	buf,
		int	count
	)

Write information to the communication thread for the agent. This is used when the scheduler needs to wake up or kill the thread used to talk to the agent. When using this function, one should always print "@@@..." where ... is the message that is actually getting sent.

Parameters

agent	the agent to send the information to
buf	the actual data
count	the number of bytes to write to the agent

Returns: returns if the write was successful

Definition at line 1274 of file agent.c.

◆ aprintf()

int aprintf	(	agent_t *	agent,
		const char *	fmt,
			...
	)

Acts as a standard printf, but prints the agents instead of stdout. This is the main function used by the scheduler when communicating with the agents.

Parameters

agent	the agent to send the formated data to
fmt	the formating string for the data

Returns: if the print was successful

Definition at line 1238 of file agent.c.

◆ is_agent_special()

int is_agent_special	(	agent_t *	agent,
		int	special_type
	)

tests if a particular agent has a specific special flag set

Parameters

a	the agent that should be tested
special_type	in what way is the agent special

Returns: true or false

Definition at line 1353 of file agent.c.

◆ is_meta_special()

int is_meta_special	(	meta_agent_t *	ma,
		int	special_type
	)

tests if a particular meta agent has a specific special flag set

Parameters

ma	the meta agent that should be checked
special_type	in what way is the agent special

Returns: true or false

Definition at line 1341 of file agent.c.

◆ kill_agents()

void kill_agents ( scheduler_t * scheduler )

Call the agent_kill function for every agent within the system.

This will send a SIGKILL to every child process of the scheduler. Used when shutting down the scheduler.

Definition at line 1301 of file agent.c.

◆ list_agents_event()

void list_agents_event	(	scheduler_t *	scheduler,
		GOutputStream *	ostr
	)

Receive agent on interface.

Calls agent_list() and print evert agent attached to the scheduler.

Parameters

scheduler	the scheduler to which agent is attached
ostr	Stream to write info to

Definition at line 1118 of file agent.c.

◆ meta_agent_decrease_count()

void meta_agent_decrease_count ( meta_agent_t * ma )

Decrease the running agent count.

Parameters

ma	Agent's meta

Definition at line 1372 of file agent.c.

◆ meta_agent_destroy()

void meta_agent_destroy ( meta_agent_t * ma )

Free the memory associated with a meta_agent. This is a destructor, and as a result the meta_agent should not be used again after a call to this method

Parameters

ma	the meta_agent to clear

Definition at line 784 of file agent.c.

◆ meta_agent_increase_count()

void meta_agent_increase_count ( meta_agent_t * ma )

Increase the running agent count.

Parameters

ma	Agent's meta

Definition at line 1362 of file agent.c.

◆ meta_agent_init()

meta_agent_t* meta_agent_init	(	char *	name,
		char *	cmd,
		int	max,
		int	spc
	)

Creates a new meta agent.

This will take and parse the information necessary for the creation of a new agent instance. The name of the agent, the cmd for starting the agent, the number of these agents that can run simutaniously, and any special conditions for this agent. This function is where the cmd will get parsed to be passed as command line args to the new agent.

Parameters

name	the name of the agent (i.e. nomos, buckets, etc...)
cmd	the command for starting the agent in a shell
max	the number of these that can concurrently, -1 for no limit
spc	any special conditions associated with the agent

Returns: meta_agent_t Meta agent

Definition at line 744 of file agent.c.

◆ test_agents()

void test_agents ( scheduler_t * scheduler )

Calls the agent test function for every type of agent.

This is used when either the -t or -T option are used upon scheduler creation.

Parameters

scheduler scheduler reference to test attached agents

Definition at line 1290 of file agent.c.

Classes

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ AGENT_STATUS_TYPES

◆ SELECT_ENUM

Typedef Documentation

◆ agent_pk

Function Documentation

◆ add_meta_agent()

◆ agent_create_event()

◆ agent_death_event()

◆ agent_destroy()

◆ agent_fail_event()

◆ agent_init()

◆ agent_kill()

◆ agent_pause()

◆ agent_print_status()

◆ agent_ready_event()

◆ agent_transition()

◆ agent_unpause()

◆ agent_update_event()

◆ agent_write()

◆ aprintf()

◆ is_agent_special()

◆ is_meta_special()

◆ kill_agents()

◆ list_agents_event()

◆ meta_agent_decrease_count()

◆ meta_agent_destroy()

◆ meta_agent_increase_count()

◆ meta_agent_init()

◆ test_agents()