sched.h

unix/linux 编程实践一书的所有源代码

#ifndef _LINUX_SCHED_H
#define _LINUX_SCHED_H

#include <asm/param.h>	/* for HZ */

extern unsigned long global_event;

#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/tasks.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/times.h>
#include <linux/timex.h>

#include <asm/system.h>
#include <asm/semaphore.h>
#include <asm/page.h>

#include <linux/smp.h>
#include <linux/tty.h>
#include <linux/sem.h>
#include <linux/signal.h>
#include <linux/securebits.h>

/*
 * cloning flags:
 */
#define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
#define CLONE_VM	0x00000100	/* set if VM shared between processes */
#define CLONE_FS	0x00000200	/* set if fs info shared between processes */
#define CLONE_FILES	0x00000400	/* set if open files shared between processes */
#define CLONE_SIGHAND	0x00000800	/* set if signal handlers shared */
#define CLONE_PID	0x00001000	/* set if pid shared */
#define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
#define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */

/*
 * These are the constant used to fake the fixed-point load-average
 * counting. Some notes:
 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 *    a load-average precision of 10 bits integer + 11 bits fractional
 *  - if you want to count load-averages more often, you need more
 *    precision, or rounding will get you. With 2-second counting freq,
 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 *    11 bit fractions.
 */
extern unsigned long avenrun[];		/* Load averages */

#define FSHIFT		11		/* nr of bits of precision */
#define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
#define LOAD_FREQ	(5*HZ)		/* 5 sec intervals */
#define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
#define EXP_5		2014		/* 1/exp(5sec/5min) */
#define EXP_15		2037		/* 1/exp(5sec/15min) */

#define CALC_LOAD(load,exp,n) \
	load *= exp; \
	load += n*(FIXED_1-exp); \
	load >>= FSHIFT;

#define CT_TO_SECS(x)	((x) / HZ)
#define CT_TO_USECS(x)	(((x) % HZ) * 1000000/HZ)

extern int nr_running, nr_tasks;
extern int last_pid;

#include <linux/fs.h>
#include <linux/time.h>
#include <linux/param.h>
#include <linux/resource.h>
#include <linux/timer.h>

#include <asm/processor.h>

#define TASK_RUNNING		0
#define TASK_INTERRUPTIBLE	1
#define TASK_UNINTERRUPTIBLE	2
#define TASK_ZOMBIE		4
#define TASK_STOPPED		8
#define TASK_SWAPPING		16

/*
 * Scheduling policies
 */
#define SCHED_OTHER		0
#define SCHED_FIFO		1
#define SCHED_RR		2

/*
 * This is an additional bit set when we want to
 * yield the CPU for one re-schedule..
 */
#define SCHED_YIELD		0x10

struct sched_param {
	int sched_priority;
};

#ifdef __KERNEL__

#include <asm/spinlock.h>

/*
 * This serializes "schedule()" and also protects
 * the run-queue from deletions/modifications (but
 * _adding_ to the beginning of the run-queue has
 * a separate lock).
 */
extern rwlock_t tasklist_lock;
extern spinlock_t runqueue_lock;

extern void sched_init(void);
extern void init_idle(void);
extern void show_state(void);
extern void trap_init(void);

#define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
extern signed long FASTCALL(schedule_timeout(signed long timeout));
asmlinkage void schedule(void);

/*
 * The default fd array needs to be at least BITS_PER_LONG,
 * as this is the granularity returned by copy_fdset().
 */
#define NR_OPEN_DEFAULT BITS_PER_LONG

/*
 * Open file table structure
 */
struct files_struct {
	atomic_t count;
	int max_fds;
	int max_fdset;
	int next_fd;
	struct file ** fd;	/* current fd array */
	fd_set *close_on_exec;
	fd_set *open_fds;
	fd_set close_on_exec_init;
	fd_set open_fds_init;
	struct file * fd_array[NR_OPEN_DEFAULT];
};

#define INIT_FILES { \
	ATOMIC_INIT(1), \
	NR_OPEN_DEFAULT, \
	__FD_SETSIZE, \
	0, \
	&init_files.fd_array[0], \
	&init_files.close_on_exec_init, \
	&init_files.open_fds_init, \
	{ { 0, } }, \
	{ { 0, } }, \
	{ NULL, } \
}

struct fs_struct {
	atomic_t count;
	int umask;
	struct dentry * root, * pwd;
};

#define INIT_FS { \
	ATOMIC_INIT(1), \
	0022, \
	NULL, NULL \
}

/* Maximum number of active map areas.. This is a random (large) number */
#define MAX_MAP_COUNT	(65536)

/* Number of map areas at which the AVL tree is activated. This is arbitrary. */
#define AVL_MIN_MAP_COUNT	32

struct mm_struct {
	struct vm_area_struct *mmap;		/* list of VMAs */
	struct vm_area_struct *mmap_avl;	/* tree of VMAs */
	struct vm_area_struct *mmap_cache;	/* last find_vma result */
	pgd_t * pgd;
	atomic_t count;
	int map_count;				/* number of VMAs */
	struct semaphore mmap_sem;
	unsigned long context;
	unsigned long start_code, end_code, start_data, end_data;
	unsigned long start_brk, brk, start_stack;
	unsigned long arg_start, arg_end, env_start, env_end;
	unsigned long rss, total_vm, locked_vm;
	unsigned long def_flags;
	unsigned long cpu_vm_mask;
	unsigned long swap_cnt;	/* number of pages to swap on next pass */
	unsigned long swap_address;
	/*
	 * This is an architecture-specific pointer: the portable
	 * part of Linux does not know about any segments.
	 */
	void * segments;
};

#define INIT_MM {					\
		&init_mmap, NULL, NULL,			\
		swapper_pg_dir, 			\
		ATOMIC_INIT(1), 1,			\
		MUTEX,					\
		0,					\
		0, 0, 0, 0,				\
		0, 0, 0, 				\
		0, 0, 0, 0,				\
		0, 0, 0,				\
		0, 0, 0, 0, NULL }

struct signal_struct {
	atomic_t		count;
	struct k_sigaction	action[_NSIG];
	spinlock_t		siglock;
};


#define INIT_SIGNALS { \
		ATOMIC_INIT(1), \
		{ {{0,}}, }, \
		SPIN_LOCK_UNLOCKED }

/*
 * Some day this will be a full-fledged user tracking system..
 * Right now it is only used to track how many processes a
 * user has, but it has the potential to track memory usage etc.
 */
struct user_struct;

struct task_struct {
/* these are hardcoded - don't touch */
	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
	unsigned long flags;	/* per process flags, defined below */
	int sigpending;
	mm_segment_t addr_limit;	/* thread address space:
					 	0-0xBFFFFFFF for user-thead
						0-0xFFFFFFFF for kernel-thread
					 */
	struct exec_domain *exec_domain;
	long need_resched;

/* various fields */
	long counter;
	long priority;
	cycles_t avg_slice;
/* SMP and runqueue state */
	int has_cpu;
	int processor;
	int last_processor;
	int lock_depth;		/* Lock depth. We can context switch in and out of holding a syscall kernel lock... */	
	struct task_struct *next_task, *prev_task;
	struct task_struct *next_run,  *prev_run;

/* task state */
	struct linux_binfmt *binfmt;
	int exit_code, exit_signal;
	int pdeath_signal;  /*  The signal sent when the parent dies  */
	/* ??? */
	unsigned long personality;
	int dumpable:1;
	int did_exec:1;
	pid_t pid;
	pid_t pgrp;
	pid_t tty_old_pgrp;
	pid_t session;
	/* boolean value for session group leader */
	int leader;
	/* 
	 * pointers to (original) parent process, youngest child, younger sibling,
	 * older sibling, respectively.  (p->father can be replaced with 
	 * p->p_pptr->pid)
	 */
	struct task_struct *p_opptr, *p_pptr, *p_cptr, *p_ysptr, *p_osptr;

	/* PID hash table linkage. */
	struct task_struct *pidhash_next;
	struct task_struct **pidhash_pprev;

	/* Pointer to task[] array linkage. */
	struct task_struct **tarray_ptr;

	struct wait_queue *wait_chldexit;	/* for wait4() */
	struct semaphore *vfork_sem;		/* for vfork() */
	unsigned long policy, rt_priority;
	unsigned long it_real_value, it_prof_value, it_virt_value;
	unsigned long it_real_incr, it_prof_incr, it_virt_incr;
	struct timer_list real_timer;
	struct tms times;
	unsigned long start_time;
	long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS];
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
	unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
	int swappable:1;
/* process credentials */
	uid_t uid,euid,suid,fsuid;
	gid_t gid,egid,sgid,fsgid;
	int ngroups;
	gid_t	groups[NGROUPS];
        kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
	struct user_struct *user;
/* limits */
	struct rlimit rlim[RLIM_NLIMITS];
	unsigned short used_math;
	char comm[16];
/* file system info */
	int link_count;
	struct tty_struct *tty; /* NULL if no tty */
/* ipc stuff */
	struct sem_undo *semundo;
	struct sem_queue *semsleeping;
/* tss for this task */
	struct thread_struct tss;
/* filesystem information */
	struct fs_struct *fs;
/* open file information */
	struct files_struct *files;
/* memory management info */
	struct mm_struct *mm;

/* signal handlers */
	spinlock_t sigmask_lock;	/* Protects signal and blocked */
	struct signal_struct *sig;
	sigset_t signal, blocked;
	struct signal_queue *sigqueue, **sigqueue_tail;
	unsigned long sas_ss_sp;
	size_t sas_ss_size;
	
/* Thread group tracking */
   	u32 parent_exec_id;
   	u32 self_exec_id;
};

/*
 * Per process flags
 */
#define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
					/* Not implemented yet, only for 486*/
#define PF_STARTING	0x00000002	/* being created */
#define PF_EXITING	0x00000004	/* getting shut down */
#define PF_PTRACED	0x00000010	/* set if ptrace (0) has been called */
#define PF_TRACESYS	0x00000020	/* tracing system calls */
#define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
#define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
#define PF_DUMPCORE	0x00000200	/* dumped core */
#define PF_SIGNALED	0x00000400	/* killed by a signal */
#define PF_MEMALLOC	0x00000800	/* Allocating memory */
#define PF_VFORK	0x00001000	/* Wake up parent in mm_release */

#define PF_USEDFPU	0x00100000	/* task used FPU this quantum (SMP) */
#define PF_DTRACE	0x00200000	/* delayed trace (used on m68k, i386) */

/*
 * Limit the stack by to some sane default: root can always
 * increase this limit if needed..  8MB seems reasonable.
 */
#define _STK_LIM	(8*1024*1024)

#define DEF_PRIORITY	(20*HZ/100)	/* 210 ms time slices */

/*
 *  INIT_TASK is used to set up the first task table, touch at
 * your own risk!. Base=0, limit=0x1fffff (=2MB)
 */
#define INIT_TASK \
/* state etc */	{ 0,0,0,KERNEL_DS,&default_exec_domain,0, \
/* counter */	DEF_PRIORITY,DEF_PRIORITY,0, \
/* SMP */	0,0,0,-1, \
/* schedlink */	&init_task,&init_task, &init_task, &init_task, \
/* binfmt */	NULL, \
/* ec,brk... */	0,0,0,0,0,0, \
/* pid etc.. */	0,0,0,0,0, \
/* proc links*/ &init_task,&init_task,NULL,NULL,NULL, \
/* pidhash */	NULL, NULL, \
/* tarray */	&task[0], \
/* chld wait */	NULL, NULL, \
/* timeout */	SCHED_OTHER,0,0,0,0,0,0,0, \
/* timer */	{ NULL, NULL, 0, 0, it_real_fn }, \
/* utime */	{0,0,0,0},0, \
/* per CPU times */ {0, }, {0, }, \
/* flt */	0,0,0,0,0,0, \
/* swp */	0, \
/* process credentials */					\
/* uid etc */	0,0,0,0,0,0,0,0,				\
/* suppl grps*/ 0, {0,},					\
/* caps */      CAP_INIT_EFF_SET,CAP_INIT_INH_SET,CAP_FULL_SET, \
/* user */	NULL,						\
/* rlimits */   INIT_RLIMITS, \
/* math */	0, \
/* comm */	"swapper", \
/* fs info */	0,NULL, \
/* ipc */	NULL, NULL, \
/* tss */	INIT_TSS, \
/* fs */	&init_fs, \
/* files */	&init_files, \
/* mm */	&init_mm, \
/* signals */	SPIN_LOCK_UNLOCKED, &init_signals, {{0}}, {{0}}, NULL, &init_task.sigqueue, 0, 0, \
/* exec cts */	0,0, \
}

union task_union {
	struct task_struct task;
	unsigned long stack[2048];
};

extern union task_union init_task_union;

extern struct   mm_struct init_mm;