SimGrid  3.15
Versatile Simulation of Distributed Systems
Process Management Functions

Detailed Description

This section describes the process structure of MSG (msg_process_t) and the functions for managing it.

Processes (msg_process_t) are independent agents that can do stuff on their own.

They are in charge of executing your code interacting with the simulated world. A process may be defined as a code with some private data. Processes must be located on hosts (msg_host_t), and they exchange data by sending tasks (msg_task_t) that are similar to envelops containing data.

Typedefs

typedef s4u_Actormsg_process_t
 Process datatype. More...
 

Functions

msg_process_t MSG_process_create (const char *name, xbt_main_func_t code, void *data, msg_host_t host)
 Creates and runs a new msg_process_t. More...
 
msg_process_t MSG_process_create_with_arguments (const char *name, xbt_main_func_t code, void *data, msg_host_t host, int argc, char **argv)
 Creates and runs a new msg_process_t. More...
 
msg_process_t MSG_process_create_with_environment (const char *name, xbt_main_func_t code, void *data, msg_host_t host, int argc, char **argv, xbt_dict_t properties)
 Creates and runs a new msg_process_t. More...
 
void MSG_process_kill (msg_process_t process)
 
msg_error_t MSG_process_migrate (msg_process_t process, msg_host_t host)
 Migrates a process to another location. More...
 
voidMSG_process_get_data (msg_process_t process)
 Returns the user data of a process. More...
 
msg_error_t MSG_process_set_data (msg_process_t process, void *data)
 Sets the user data of a process. More...
 
void MSG_process_set_data_cleanup (void_f_pvoid_t data_cleanup)
 Sets a cleanup function to be called to free the userdata of a process when a process is destroyed. More...
 
msg_host_t MSG_process_get_host (msg_process_t process)
 Return the location on which a process is running. More...
 
msg_process_t MSG_process_from_PID (int PID)
 Return a msg_process_t given its PID. More...
 
msg_error_t MSG_process_set_kill_time (msg_process_t process, double kill_time)
 Set the kill time of a process. More...
 
int MSG_process_get_PID (msg_process_t process)
 Returns the process ID of process. More...
 
int MSG_process_get_PPID (msg_process_t process)
 Returns the process ID of the parent of process. More...
 
const char * MSG_process_get_name (msg_process_t process)
 Return the name of a process. More...
 
const char * MSG_process_get_property_value (msg_process_t process, const char *name)
 Returns the value of a given process property. More...
 
xbt_dict_t MSG_process_get_properties (msg_process_t process)
 Return the list of properties. More...
 
int MSG_process_self_PID ()
 Return the PID of the current process. More...
 
int MSG_process_self_PPID ()
 Return the PPID of the current process. More...
 
msg_process_t MSG_process_self ()
 Return the current process. More...
 
msg_error_t MSG_process_suspend (msg_process_t process)
 Suspend the process. More...
 
msg_error_t MSG_process_resume (msg_process_t process)
 Resume a suspended process. More...
 
int MSG_process_is_suspended (msg_process_t process)
 Returns true if the process is suspended . More...
 
void MSG_process_on_exit (int_f_pvoid_pvoid_t fun, void *data)
 Add a function to the list of "on_exit" functions for the current process. More...
 
void MSG_process_auto_restart_set (msg_process_t process, int auto_restart)
 Sets the "auto-restart" flag of the process. More...
 
msg_process_t MSG_process_restart (msg_process_t process)
 Restarts a process from the beginning. More...
 
void MSG_process_daemonize (msg_process_t process)
 This process will be terminated automatically when the last non-daemon process finishes. More...
 
void MSG_process_ref (msg_process_t process)
 Take an extra reference on that process to prevent it to be garbage-collected. More...
 
void MSG_process_unref (msg_process_t process)
 Release a reference on that process so that it can get be garbage-collected. More...
 

Typedef Documentation

◆ msg_process_t

Process datatype.

A process may be defined as a code, with some private data, executing in a location.

You should not access directly to the fields of the pointed structure, but always use the provided API to interact with processes.

Function Documentation

◆ MSG_process_create()

msg_process_t MSG_process_create ( const char *  name,
xbt_main_func_t  code,
void data,
msg_host_t  host 
)

Creates and runs a new msg_process_t.

Does exactly the same as MSG_process_create_with_arguments but without providing standard arguments (argc, argv, start_time, kill_time).

See also
MSG_process_create_with_arguments

◆ MSG_process_create_with_arguments()

msg_process_t MSG_process_create_with_arguments ( const char *  name,
xbt_main_func_t  code,
void data,
msg_host_t  host,
int  argc,
char **  argv 
)

Creates and runs a new msg_process_t.

A constructor for msg_process_t taking four arguments and returning the corresponding object. The structure (and the corresponding thread) is created, and put in the list of ready process.

Parameters
namea name for the object. It is for user-level information and can be nullptr.
codeis a function describing the behavior of the process. It should then only use functions described in Process Management Functions (to create a new msg_process_t for example), in Host Management Functions (only the read-only functions i.e. whose name contains the word get), in Task Management Functions (to create or destroy some msg_task_t for example) and in Task Actions (to handle file transfers and task processing).
dataa pointer to any data one may want to attach to the new object. It is for user-level information and can be nullptr. It can be retrieved with the function MSG_process_get_data.
hostthe location where the new process is executed.
argcfirst argument passed to code
argvsecond argument passed to code
See also
msg_process_t
Returns
The new corresponding object.

◆ MSG_process_create_with_environment()

msg_process_t MSG_process_create_with_environment ( const char *  name,
xbt_main_func_t  code,
void data,
msg_host_t  host,
int  argc,
char **  argv,
xbt_dict_t  properties 
)

Creates and runs a new msg_process_t.

A constructor for msg_process_t taking four arguments and returning the corresponding object. The structure (and the corresponding thread) is created, and put in the list of ready process.

Parameters
namea name for the object. It is for user-level information and can be nullptr.
codeis a function describing the behavior of the process. It should then only use functions described in Process Management Functions (to create a new msg_process_t for example), in Host Management Functions (only the read-only functions i.e. whose name contains the word get), in Task Management Functions (to create or destroy some msg_task_t for example) and in Task Actions (to handle file transfers and task processing).
dataa pointer to any data one may want to attach to the new object. It is for user-level information and can be nullptr. It can be retrieved with the function MSG_process_get_data.
hostthe location where the new process is executed.
argcfirst argument passed to code
argvsecond argument passed to code. WARNING, these strings are freed by the SimGrid kernel when the process exits, so they cannot be static nor shared between several processes.
propertieslist a properties defined for this process
See also
msg_process_t
Returns
The new corresponding object.

◆ MSG_process_kill()

void MSG_process_kill ( msg_process_t  process)
Parameters
processpoor victim

This function simply kills a process... scary isn't it ? :)

◆ MSG_process_migrate()

msg_error_t MSG_process_migrate ( msg_process_t  process,
msg_host_t  host 
)

Migrates a process to another location.

This function checks whether process and host are valid pointers and change the value of the msg_host_t on which process is running.

◆ MSG_process_get_data()

void* MSG_process_get_data ( msg_process_t  process)

Returns the user data of a process.

This function checks whether process is a valid pointer and returns the user data associated to this process.

◆ MSG_process_set_data()

msg_error_t MSG_process_set_data ( msg_process_t  process,
void data 
)

Sets the user data of a process.

This function checks whether process is a valid pointer and sets the user data associated to this process.

◆ MSG_process_set_data_cleanup()

void MSG_process_set_data_cleanup ( void_f_pvoid_t  data_cleanup)

Sets a cleanup function to be called to free the userdata of a process when a process is destroyed.

Parameters
data_cleanupa cleanup function for the userdata of a process, or nullptr to call no function

◆ MSG_process_get_host()

msg_host_t MSG_process_get_host ( msg_process_t  process)

Return the location on which a process is running.

Parameters
processa process (nullptr means the current one)
Returns
the msg_host_t corresponding to the location on which process is running.

◆ MSG_process_from_PID()

msg_process_t MSG_process_from_PID ( int  PID)

Return a msg_process_t given its PID.

This function search in the list of all the created msg_process_t for a msg_process_t whose PID is equal to PID. If no host is found, nullptr is returned. Note that the PID are uniq in the whole simulation, not only on a given host.

◆ MSG_process_set_kill_time()

msg_error_t MSG_process_set_kill_time ( msg_process_t  process,
double  kill_time 
)

Set the kill time of a process.

Parameters
processa process
kill_timethe time when the process is killed.

◆ MSG_process_get_PID()

int MSG_process_get_PID ( msg_process_t  process)

Returns the process ID of process.

This function checks whether process is a valid pointer and return its PID (or 0 in case of problem).

◆ MSG_process_get_PPID()

int MSG_process_get_PPID ( msg_process_t  process)

Returns the process ID of the parent of process.

This function checks whether process is a valid pointer and return its PID. Returns -1 if the process has not been created by any other process.

◆ MSG_process_get_name()

const char* MSG_process_get_name ( msg_process_t  process)

Return the name of a process.

This function checks whether process is a valid pointer and return its name.

◆ MSG_process_get_property_value()

const char* MSG_process_get_property_value ( msg_process_t  process,
const char *  name 
)

Returns the value of a given process property.

Parameters
processa process
namea property name
Returns
value of a property (or nullptr if the property is not set)

◆ MSG_process_get_properties()

xbt_dict_t MSG_process_get_properties ( msg_process_t  process)

Return the list of properties.

This function returns all the parameters associated with a process

◆ MSG_process_self_PID()

int MSG_process_self_PID ( )

Return the PID of the current process.

This function returns the PID of the currently running msg_process_t.

◆ MSG_process_self_PPID()

int MSG_process_self_PPID ( )

Return the PPID of the current process.

This function returns the PID of the parent of the currently running msg_process_t.

◆ MSG_process_self()

msg_process_t MSG_process_self ( )

Return the current process.

This function returns the currently running msg_process_t.

◆ MSG_process_suspend()

msg_error_t MSG_process_suspend ( msg_process_t  process)

Suspend the process.

This function suspends the process by suspending the task on which it was waiting for the completion.

◆ MSG_process_resume()

msg_error_t MSG_process_resume ( msg_process_t  process)

Resume a suspended process.

This function resumes a suspended process by resuming the task on which it was waiting for the completion.

◆ MSG_process_is_suspended()

int MSG_process_is_suspended ( msg_process_t  process)

Returns true if the process is suspended .

This checks whether a process is suspended or not by inspecting the task on which it was waiting for the completion.

◆ MSG_process_on_exit()

void MSG_process_on_exit ( int_f_pvoid_pvoid_t  fun,
void data 
)

Add a function to the list of "on_exit" functions for the current process.

The on_exit functions are the functions executed when your process is killed. You should use them to free the data used by your process.

◆ MSG_process_auto_restart_set()

void MSG_process_auto_restart_set ( msg_process_t  process,
int  auto_restart 
)

Sets the "auto-restart" flag of the process.

If the flag is set to 1, the process will be automatically restarted when its host comes back up.

◆ MSG_process_restart()

msg_process_t MSG_process_restart ( msg_process_t  process)

Restarts a process from the beginning.

◆ MSG_process_daemonize()

void MSG_process_daemonize ( msg_process_t  process)

This process will be terminated automatically when the last non-daemon process finishes.

◆ MSG_process_ref()

void MSG_process_ref ( msg_process_t  process)

Take an extra reference on that process to prevent it to be garbage-collected.

◆ MSG_process_unref()

void MSG_process_unref ( msg_process_t  process)

Release a reference on that process so that it can get be garbage-collected.