Process groups

Process groups. More...

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Detailed Description

Process groups.

Process groups allow related processes to be grouped together, enabling operations such as sending notes to all processes within a group.

As an example, if a user wishes to terminate a shell they most likely additionally want to terminate all child processes of that shell. By placing all such processes in the same group, a single "terminate" note can be sent to the entire group.

Data Structures
struct	group_member_t
	Group member structure. More...
struct	group_t
	Process group structure. More...

Functions
uint64_t	group_member_init (group_member_t *member, group_member_t *group)
	Initializes a group member.
void	group_member_deinit (group_member_t *member)
	Deinitializes a group member.
group_t *	group_get (group_member_t *member)
	Retrieve the group of a group member.
void	group_add (group_t *group, group_member_t *member)
	Joins a process to a specific group.
void	group_remove (group_member_t *member)
	Removes a process from its group.
uint64_t	group_send_note (group_member_t *member, const char *note)
	Sends a note to all processes in the group of the specified member.

Function Documentation

group_member_init()

uint64_t group_member_init	(	group_member_t *	member,
		group_member_t *	group
	)

Initializes a group member.

Parameters

member	The group member to initialize.
group	A member storing the group to add the new member to, or NULL to create a new group.

Returns

On success, 0. On failure, ERR and errno is set to:

Definition at line 42 of file group.c.

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group_member_deinit()

void group_member_deinit

(

group_member_t *

member

)

Deinitializes a group member.

Parameters

member

The group member to deinitialize.

Definition at line 74 of file group.c.

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group_get()

group_t * group_get

(

group_member_t *

member

)

Retrieve the group of a group member.

It is the responsibility of the caller to use UNREF() or UNREF_DEFER() on the returned group when it is no longer needed.

Parameters

member

The group member.

Returns

On success, a reference to the group. On failure, NULL and errno is set to:

• EINVAL: Invalid parameters.
• ESRCH: The member is not part of any group.

Definition at line 79 of file group.c.

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group_add()

void group_add	(	group_t *	group,
		group_member_t *	member
	)

Joins a process to a specific group.

If the member is already in a group it will be removed from that group first.

Parameters

group	The group to join.
member	The group member of the process to add to the group.

Definition at line 98 of file group.c.

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group_remove()

void group_remove

(

group_member_t *

member

)

Removes a process from its group.

If the group becomes empty after removing the process, it will be freed.

Parameters

member

The group member of the process to remove from its group, or NULL for no-op.

Definition at line 120 of file group.c.

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group_send_note()

uint64_t group_send_note	(	group_member_t *	member,
		const char *	note
	)

Sends a note to all processes in the group of the specified member.

Parameters

member	The member within the group to send the note to.
note	The note string to send.

Returns

On success, 0. On failure, ERR and errno is set to:

• EINVAL: Invalid parameters.
• Other values from thread_send_note().

Definition at line 142 of file group.c.

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