Threads

Thread of execution. More...

Collaboration diagram for Threads:

Detailed Description

Thread of execution.

Data Structures
struct	thread_t
	Thread of execution structure. More...

Typedefs
typedef void(*	thread_kernel_entry_t) (void *arg)
	Kernel thread entry point function type.

Enumerations
enum	thread_state_t {   THREAD_PARKED = 0 , THREAD_ACTIVE , THREAD_PRE_BLOCK , THREAD_BLOCKED ,   THREAD_UNBLOCKING , THREAD_DYING }
	Thread state enum. More...

Functions
thread_t *	thread_new (process_t *process)
	Creates a new thread structure.
tid_t	thread_kernel_create (thread_kernel_entry_t entry, void *arg)
	Creates a new thread that runs in kernel mode and submits it to the scheduler.
void	thread_free (thread_t *thread)
	Frees a thread structure.
void	thread_save (thread_t *thread, const interrupt_frame_t *frame)
	Save state to a thread.
void	thread_load (thread_t *thread, interrupt_frame_t *frame)
	Load state from a thread.
bool	thread_is_note_pending (thread_t *thread)
	Check if a thread has a note pending.
uint64_t	thread_send_note (thread_t *thread, const void *buffer, uint64_t count)
	Send a note to a thread.
uint64_t	thread_copy_from_user (thread_t *thread, void *dest, const void *userSrc, uint64_t length)
	Safely copy data from user space.
uint64_t	thread_copy_to_user (thread_t *thread, void *dest, const void *userSrc, uint64_t length)
	Safely copy data to user space.
uint64_t	thread_copy_from_user_terminated (thread_t *thread, const void *userArray, const void *terminator, uint8_t objectSize, uint64_t maxCount, void **outArray, uint64_t *outCount)
	Safely copy a null-terminated array of objects from user space.
uint64_t	thread_copy_from_user_pathname (thread_t *thread, pathname_t *pathname, const char *userPath)
	Safely copy a string from user space and use it to initialize a pathname.
uint64_t	thread_copy_from_user_string_array (thread_t *thread, const char **user, char ***out, uint64_t *outAmount)
	Safely copy a null-terminated array of strings and their contents from user space into a string vector.
uint64_t	thread_load_atomic_from_user (thread_t *thread, atomic_uint64_t *userObj, uint64_t *outValue)
	Atomically load a 64-bit value from a user-space atomic variable.
_NORETURN void	thread_jump (thread_t *thread)
	Jump to a thread by calling thread_load() and then loading its interrupt frame.

Typedef Documentation

thread_kernel_entry_t

typedef void(* thread_kernel_entry_t) (void *arg)

Kernel thread entry point function type.

Definition at line 103 of file thread.h.

Enumeration Type Documentation

thread_state_t

enum thread_state_t

Thread state enum.

Enumerator
THREAD_PARKED	Is doing nothing, not in a queue, not blocking, think of it as "other".
THREAD_ACTIVE	Is either running or ready to run.
THREAD_PRE_BLOCK	Has started the process of blocking but has not yet been given to a owner cpu.
THREAD_BLOCKED	Is blocking and waiting in one or multiple wait queues.
THREAD_UNBLOCKING	Has started unblocking, used to prevent the same thread being unblocked multiple times.
THREAD_DYING	The thread is currently dying, it will be freed by the scheduler once its invoked. Warning This state is more fragile than the others. Since a thread could technically be killed at any time and we have several systems relying on the thread state as a form of synchronization, this state should only be set when the thread is running in an interrupt context.

Definition at line 29 of file thread.h.

Function Documentation

thread_new()

thread_t * thread_new

(

process_t *

process

)

Creates a new thread structure.

Does not push the created thread to the scheduler or similar, merely handling allocation and initialization.

Parameters

process

The parent process that the thread will execute within.

Returns

On success, returns the newly created thread. On failure, returns NULL and errno is set.

Definition at line 70 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_kernel_create()

tid_t thread_kernel_create	(	thread_kernel_entry_t	entry,
		void *	arg
	)

Creates a new thread that runs in kernel mode and submits it to the scheduler.

Parameters

entry	The entry point function for the thread.
arg	An argument to pass to the entry point function.

Returns

On success, returns the newly created thread ID. On failure, returns ERR and errno is set.

Definition at line 97 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_free()

void thread_free

(

thread_t *

thread

)

Frees a thread structure.

Parameters

thread

The thread to be freed.

Definition at line 124 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_save()

void thread_save	(	thread_t *	thread,
		const interrupt_frame_t *	frame
	)

Save state to a thread.

Parameters

thread	The destination thread where the state will be saved.
frame	The source frame..

Definition at line 140 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_load()

void thread_load	(	thread_t *	thread,
		interrupt_frame_t *	frame
	)

Load state from a thread.

Will retrieve the interrupt frame and setup the CPU with the threads contexts/data.

Parameters

thread	The source thread to load state from.
frame	The destination interrupt frame.

Definition at line 147 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_is_note_pending()

bool thread_is_note_pending

(

thread_t *

thread

)

Check if a thread has a note pending.

Parameters

thread

The thread to query.

Returns

True if there is a note pending, false otherwise.

Definition at line 156 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_send_note()

uint64_t thread_send_note	(	thread_t *	thread,
		const void *	buffer,
		uint64_t	count
	)

Send a note to a thread.

This function should always be used over the note_queue_push() function, as it performs additional checks, like unblocking the thread to notify it of the received note.

Parameters

thread	The destination thread.
buffer	The buffer to write.
count	The number of bytes to write.

Returns

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

Definition at line 161 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_copy_from_user()

uint64_t thread_copy_from_user	(	thread_t *	thread,
		void *	dest,
		const void *	userSrc,
		uint64_t	length
	)

Safely copy data from user space.

Will pin the user pages in memory while performing the copy and expand the user stack if necessary.

Parameters

thread	The thread performing the operation.
dest	The destination buffer in kernel space.
userSrc	The source buffer in user space.
length	The number of bytes to copy.

Returns

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

Definition at line 188 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_copy_to_user()

uint64_t thread_copy_to_user	(	thread_t *	thread,
		void *	dest,
		const void *	userSrc,
		uint64_t	length
	)

Safely copy data to user space.

Will pin the user pages in memory while performing the copy and expand the user stack if necessary.

Parameters

thread	The thread performing the operation.
dest	The destination buffer in user space.
userSrc	The source buffer in kernel space.
length	The number of bytes to copy.

Returns

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

Definition at line 206 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_copy_from_user_terminated()

uint64_t thread_copy_from_user_terminated	(	thread_t *	thread,
		const void *	userArray,
		const void *	terminator,
		uint8_t	objectSize,
		uint64_t	maxCount,
		void **	outArray,
		uint64_t *	outCount
	)

Safely copy a null-terminated array of objects from user space.

Parameters

thread	The thread performing the operation.
userArray	The source array in user space.
terminator	A pointer to the terminator object.
objectSize	The size of each object in the array.
maxCount	The maximum number of objects to copy.
outArray	Output pointer to store the allocated array in kernel space, must be freed by the caller.
outCount	Output pointer to store the number of objects copied, can be NULL.

Returns

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

Definition at line 224 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_copy_from_user_pathname()

uint64_t thread_copy_from_user_pathname	(	thread_t *	thread,
		pathname_t *	pathname,
		const char *	userPath
	)

Safely copy a string from user space and use it to initialize a pathname.

Parameters

thread	The thread performing the operation.
pathname	A pointer to the pathname to initialize.
userPath	The string in user space.

Returns

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

Definition at line 265 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_copy_from_user_string_array()

uint64_t thread_copy_from_user_string_array	(	thread_t *	thread,
		const char **	user,
		char ***	out,
		uint64_t *	outAmount
	)

Safely copy a null-terminated array of strings and their contents from user space into a string vector.

Parameters

thread	The thread performing the operation.
user	The source array of strings in user space.
out	Output pointer to store the allocated array of strings in kernel space, must be freed by the caller.
outAmount	Output pointer to store the number of strings copied, can be NULL.

Returns

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

Definition at line 294 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_load_atomic_from_user()

uint64_t thread_load_atomic_from_user	(	thread_t *	thread,
		atomic_uint64_t *	userObj,
		uint64_t *	outValue
	)

Atomically load a 64-bit value from a user-space atomic variable.

Will pin the user pages in memory while performing the load and expand the user stack if necessary.

Parameters

thread	The thread performing the operation.
userObj	The user-space atomic variable to load from.
outValue	Output pointer to store the loaded value.

Returns

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

Definition at line 333 of file thread.c.

Here is the call graph for this function:

Here is the caller graph for this function:

thread_jump()

_NORETURN void thread_jump ( thread_t *  thread )

extern

Jump to a thread by calling thread_load() and then loading its interrupt frame.

Must be done in assembly as it requires directly modifying registers.

Will never return instead it ends up at thread->frame.rip.

Parameters

thread

The thread to jump to.

Here is the caller graph for this function: