thread.h

https://github.com/wookayin/pintos/blob/master/src/threads/thread.h

#ifndef THREADS_THREAD_H
	#define THREADS_THREAD_H
	#include <debug.h>
	#include <list.h>
	#include <stdint.h>
	#ifdef VM
	#include "vm/page.h"
	#endif
	/* States in a thread's life cycle. */
	enum thread_status
	{
	THREAD_RUNNING, /* Running thread. */
	THREAD_READY, /* Not running but ready to run. */
	THREAD_BLOCKED, /* Waiting for an event to trigger. */
	THREAD_DYING /* About to be destroyed. */
	};
	/* Thread identifier type.
	You can redefine this to whatever type you like. */
	typedef int tid_t;
	#define TID_ERROR ((tid_t) -1) /* Error value for tid_t. */
	/* Thread priorities. */
	#define PRI_MIN 0 /* Lowest priority. */
	#define PRI_DEFAULT 31 /* Default priority. */
	#define PRI_MAX 63 /* Highest priority. */
	/* A kernel thread or user process.
	Each thread structure is stored in its own 4 kB page. The
	thread structure itself sits at the very bottom of the page
	(at offset 0). The rest of the page is reserved for the
	thread's kernel stack, which grows downward from the top of
	the page (at offset 4 kB). Here's an illustration:
	4 kB +---------------------------------+
	| kernel stack |
	| | |
	| | |
	| V |
	| grows downward |
	| |
	| |
	| |
	| |
	| |
	| |
	| |
	| |
	+---------------------------------+
	| magic |
	| : |
	| : |
	| name |
	| status |
	0 kB +---------------------------------+
	The upshot of this is twofold:
	1. First, `struct thread' must not be allowed to grow too
	big. If it does, then there will not be enough room for
	the kernel stack. Our base `struct thread' is only a
	few bytes in size. It probably should stay well under 1
	kB.
	2. Second, kernel stacks must not be allowed to grow too
	large. If a stack overflows, it will corrupt the thread
	state. Thus, kernel functions should not allocate large
	structures or arrays as non-static local variables. Use
	dynamic allocation with malloc() or palloc_get_page()
	instead.
	The first symptom of either of these problems will probably be
	an assertion failure in thread_current(), which checks that
	the `magic' member of the running thread's `struct thread' is
	set to THREAD_MAGIC. Stack overflow will normally change this
	value, triggering the assertion. */
	/* The `elem' member has a dual purpose. It can be an element in
	the run queue (thread.c), or it can be an element in a
	semaphore wait list (synch.c). It can be used these two ways
	only because they are mutually exclusive: only a thread in the
	ready state is on the run queue, whereas only a thread in the
	blocked state is on a semaphore wait list. */
	struct thread
	{
	/* Owned by thread.c. */
	tid_t tid; /* Thread identifier. */
	enum thread_status status; /* Thread state. */
	char name[16]; /* Name (for debugging purposes). */
	uint8_t *stack; /* Saved stack pointer. */
	int priority; /* Priority. */
	int original_priority; /* Priority, before donation */
	struct list_elem allelem; /* List element for all threads list. */
	struct list_elem waitelem; /* List element, stored in the wait_list queue */
	int64_t sleep_endtick; /* The tick after which the thread should awake (if the thread is in sleep) */
	/* Shared between thread.c and synch.c. */
	struct list_elem elem; /* List element, stored in the ready_list queue */
	// needed for priority donations
	struct lock *waiting_lock; /* The lock object on which this thread is waiting (or NULL if not locked) */
	struct list locks; /* List of locks the thread holds (for multiple donations) */
	#ifdef USERPROG
	/* Owned by userprog/process.c. */
	uint32_t *pagedir; /* Page directory. */
	// Project 2: file descriptors and process table
	/* Owned by userprog/process.c and userprog/syscall.c */
	struct process_control_block *pcb; /* Process Control Block */
	struct list child_list; /* List of children processes of this thread,
	each elem is defined by pcb#elem */
	struct list file_descriptors; /* List of file_descriptors the thread contains */
	struct file *executing_file; /* The executable file of associated process. */
	uint8_t *current_esp; /* The current value of the user program’s stack pointer.
	A page fault might occur in the kernel, so we might
	need to store esp on transition to kernel mode. (4.3.3) */
	#endif
	#ifdef VM
	// Project 3: Supplemental page table.
	struct supplemental_page_table *supt; /* Supplemental Page Table. */
	// Project 3: Memory Mapped Files.
	struct list mmap_list; /* List of struct mmap_desc. */
	#endif
	// Project 4: CWD.
	struct dir *cwd;
	/* Owned by thread.c. */
	unsigned magic; /* Detects stack overflow. */
	};
	/* If false (default), use round-robin scheduler.
	If true, use multi-level feedback queue scheduler.
	Controlled by kernel command-line option "-o mlfqs". */
	extern bool thread_mlfqs;
	void thread_init (void);
	void thread_start (void);
	void thread_tick (int64_t tick);
	void thread_print_stats (void);
	typedef void thread_func (void *aux);
	tid_t thread_create (const char *name, int priority, thread_func *, void *);
	void thread_block (void);
	void thread_unblock (struct thread *);
	void thread_sleep_until (int64_t wake_tick);
	struct thread *thread_current (void);
	tid_t thread_tid (void);
	const char *thread_name (void);
	void thread_exit (void) NO_RETURN;
	void thread_yield (void);
	/* Performs some operation on thread t, given auxiliary data AUX. */
	typedef void thread_action_func (struct thread *t, void *aux);
	void thread_foreach (thread_action_func *, void *);
	int thread_get_priority (void);
	void thread_set_priority (int);
	void thread_priority_donate(struct thread *, int priority);
	int thread_get_nice (void);
	void thread_set_nice (int);
	int thread_get_recent_cpu (void);
	int thread_get_load_avg (void);
	#endif /* threads/thread.h */