root/include/linux/sched.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. add_wait_queue
  2. remove_wait_queue
  3. select_wait
  4. down
  5. up

   1 #ifndef _LINUX_SCHED_H
   2 #define _LINUX_SCHED_H
   3 
   4 /*
   5  * define DEBUG if you want the wait-queues to have some extra
   6  * debugging code. It's not normally used, but might catch some
   7  * wait-queue coding errors.
   8  *
   9  *  #define DEBUG
  10  */
  11 
  12 #include <asm/param.h>  /* for HZ */
  13 
  14 extern unsigned long intr_count;
  15 extern unsigned long event;
  16 
  17 #include <linux/binfmts.h>
  18 #include <linux/personality.h>
  19 #include <linux/tasks.h>
  20 #include <linux/kernel.h>
  21 #include <asm/system.h>
  22 #include <asm/page.h>
  23 
  24 #include <linux/smp.h>
  25 
  26 /*
  27  * cloning flags:
  28  */
  29 #define CSIGNAL         0x000000ff      /* signal mask to be sent at exit */
  30 #define CLONE_VM        0x00000100      /* set if VM shared between processes */
  31 #define CLONE_FS        0x00000200      /* set if fs info shared between processes */
  32 #define CLONE_FILES     0x00000400      /* set if open files shared between processes */
  33 #define CLONE_SIGHAND   0x00000800      /* set if signal handlers shared */
  34 #define CLONE_PID       0x00001000      /* set if pid shared */
  35 
  36 /*
  37  * These are the constant used to fake the fixed-point load-average
  38  * counting. Some notes:
  39  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
  40  *    a load-average precision of 10 bits integer + 11 bits fractional
  41  *  - if you want to count load-averages more often, you need more
  42  *    precision, or rounding will get you. With 2-second counting freq,
  43  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
  44  *    11 bit fractions.
  45  */
  46 extern unsigned long avenrun[];         /* Load averages */
  47 
  48 #define FSHIFT          11              /* nr of bits of precision */
  49 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
  50 #define LOAD_FREQ       (5*HZ)          /* 5 sec intervals */
  51 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
  52 #define EXP_5           2014            /* 1/exp(5sec/5min) */
  53 #define EXP_15          2037            /* 1/exp(5sec/15min) */
  54 
  55 #define CALC_LOAD(load,exp,n) \
  56         load *= exp; \
  57         load += n*(FIXED_1-exp); \
  58         load >>= FSHIFT;
  59 
  60 #define CT_TO_SECS(x)   ((x) / HZ)
  61 #define CT_TO_USECS(x)  (((x) % HZ) * 1000000/HZ)
  62 
  63 extern int nr_running, nr_tasks;
  64 
  65 #define FIRST_TASK task[0]
  66 #define LAST_TASK task[NR_TASKS-1]
  67 
  68 #include <linux/head.h>
  69 #include <linux/fs.h>
  70 #include <linux/signal.h>
  71 #include <linux/time.h>
  72 #include <linux/param.h>
  73 #include <linux/resource.h>
  74 #include <linux/vm86.h>
  75 #include <linux/math_emu.h>
  76 #include <linux/ptrace.h>
  77 #include <linux/timer.h>
  78 
  79 #include <asm/processor.h>
  80 
  81 #define TASK_RUNNING            0
  82 #define TASK_INTERRUPTIBLE      1
  83 #define TASK_UNINTERRUPTIBLE    2
  84 #define TASK_ZOMBIE             3
  85 #define TASK_STOPPED            4
  86 #define TASK_SWAPPING           5
  87 
  88 #ifndef NULL
  89 #define NULL ((void *) 0)
  90 #endif
  91 
  92 #ifdef __KERNEL__
  93 
  94 #define barrier() __asm__("": : :"memory")
  95 
  96 extern void sched_init(void);
  97 extern void show_state(void);
  98 extern void trap_init(void);
  99 
 100 asmlinkage void schedule(void);
 101 
 102 struct files_struct {
 103         int count;
 104         fd_set close_on_exec;
 105         struct file * fd[NR_OPEN];
 106 };
 107 
 108 #define INIT_FILES { \
 109         1, \
 110         { { 0, } }, \
 111         { NULL, } \
 112 }
 113 
 114 struct fs_struct {
 115         int count;
 116         unsigned short umask;
 117         struct inode * root, * pwd;
 118 };
 119 
 120 #define INIT_FS { \
 121         1, \
 122         0022, \
 123         NULL, NULL \
 124 }
 125 
 126 struct mm_struct {
 127         int count;
 128         pgd_t * pgd;
 129         unsigned long start_code, end_code, start_data, end_data;
 130         unsigned long start_brk, brk, start_stack, start_mmap;
 131         unsigned long arg_start, arg_end, env_start, env_end;
 132         unsigned long rss;
 133         struct vm_area_struct * mmap;
 134         struct vm_area_struct * mmap_avl;
 135 };
 136 
 137 #define INIT_MM { \
 138                 1, \
 139                 swapper_pg_dir, \
 140                 0, 0, 0, 0, \
 141                 0, 0, 0, 0, \
 142                 0, 0, 0, 0, \
 143                 0, \
 144                 &init_mmap, &init_mmap }
 145 
 146 struct signal_struct {
 147         int count;
 148         struct sigaction action[32];
 149 };
 150 
 151 #define INIT_SIGNALS { \
 152                 1, \
 153                 { {0,}, } }
 154 
 155 struct task_struct {
 156 /* these are hardcoded - don't touch */
 157         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
 158         long counter;
 159         long priority;
 160         unsigned long signal;
 161         unsigned long blocked;  /* bitmap of masked signals */
 162         unsigned long flags;    /* per process flags, defined below */
 163         int errno;
 164         long debugreg[8];  /* Hardware debugging registers */
 165         struct exec_domain *exec_domain;
 166 /* various fields */
 167         struct linux_binfmt *binfmt;
 168         struct task_struct *next_task, *prev_task;
 169         struct task_struct *next_run,  *prev_run;
 170         unsigned long saved_kernel_stack;
 171         unsigned long kernel_stack_page;
 172         int exit_code, exit_signal;
 173         unsigned long personality;
 174         int dumpable:1;
 175         int did_exec:1;
 176         int pid,pgrp,tty_old_pgrp,session,leader;
 177         int     groups[NGROUPS];
 178         /* 
 179          * pointers to (original) parent process, youngest child, younger sibling,
 180          * older sibling, respectively.  (p->father can be replaced with 
 181          * p->p_pptr->pid)
 182          */
 183         struct task_struct *p_opptr, *p_pptr, *p_cptr, *p_ysptr, *p_osptr;
 184         struct wait_queue *wait_chldexit;       /* for wait4() */
 185         unsigned short uid,euid,suid,fsuid;
 186         unsigned short gid,egid,sgid,fsgid;
 187         unsigned long timeout;
 188         unsigned long it_real_value, it_prof_value, it_virt_value;
 189         unsigned long it_real_incr, it_prof_incr, it_virt_incr;
 190         struct timer_list real_timer;
 191         long utime, stime, cutime, cstime, start_time;
 192 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 193         unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
 194         int swappable:1;
 195         unsigned long swap_address;
 196         unsigned long old_maj_flt;      /* old value of maj_flt */
 197         unsigned long dec_flt;          /* page fault count of the last time */
 198         unsigned long swap_cnt;         /* number of pages to swap on next pass */
 199 /* limits */
 200         struct rlimit rlim[RLIM_NLIMITS];
 201         unsigned short used_math;
 202         char comm[16];
 203 /* file system info */
 204         int link_count;
 205         struct tty_struct *tty; /* NULL if no tty */
 206 /* ipc stuff */
 207         struct sem_undo *semundo;
 208         struct sem_queue *semsleeping;
 209 /* ldt for this task - used by Wine.  If NULL, default_ldt is used */
 210         struct desc_struct *ldt;
 211 /* tss for this task */
 212         struct thread_struct tss;
 213 /* filesystem information */
 214         struct fs_struct *fs;
 215 /* open file information */
 216         struct files_struct *files;
 217 /* memory management info */
 218         struct mm_struct *mm;
 219 /* signal handlers */
 220         struct signal_struct *sig;
 221 #ifdef __SMP__
 222         int processor;
 223         int last_processor;
 224         int lock_depth;         /* Lock depth. We can context switch in and out of holding a syscall kernel lock... */  
 225 #endif  
 226 };
 227 
 228 /*
 229  * Per process flags
 230  */
 231 #define PF_ALIGNWARN    0x00000001      /* Print alignment warning msgs */
 232                                         /* Not implemented yet, only for 486*/
 233 #define PF_PTRACED      0x00000010      /* set if ptrace (0) has been called. */
 234 #define PF_TRACESYS     0x00000020      /* tracing system calls */
 235 
 236 #define PF_STARTING     0x00000100      /* being created */
 237 #define PF_EXITING      0x00000200      /* getting shut down */
 238 
 239 #define PF_USEDFPU      0x00100000      /* Process used the FPU this quantum (SMP only) */
 240 
 241 /*
 242  * Limit the stack by to some sane default: root can always
 243  * increase this limit if needed..  8MB seems reasonable.
 244  */
 245 #define _STK_LIM        (8*1024*1024)
 246 
 247 #define DEF_PRIORITY    (15*HZ/100)     /* 150 ms time slices */
 248 
 249 /*
 250  *  INIT_TASK is used to set up the first task table, touch at
 251  * your own risk!. Base=0, limit=0x1fffff (=2MB)
 252  */
 253 #define INIT_TASK \
 254 /* state etc */ { 0,DEF_PRIORITY,DEF_PRIORITY,0,0,0,0, \
 255 /* debugregs */ { 0, },            \
 256 /* exec domain */&default_exec_domain, \
 257 /* binfmt */    NULL, \
 258 /* schedlink */ &init_task,&init_task, &init_task, &init_task, \
 259 /* stack */     0,(unsigned long) &init_kernel_stack, \
 260 /* ec,brk... */ 0,0,0,0,0, \
 261 /* pid etc.. */ 0,0,0,0,0, \
 262 /* suppl grps*/ {NOGROUP,}, \
 263 /* proc links*/ &init_task,&init_task,NULL,NULL,NULL,NULL, \
 264 /* uid etc */   0,0,0,0,0,0,0,0, \
 265 /* timeout */   0,0,0,0,0,0,0, \
 266 /* timer */     { NULL, NULL, 0, 0, it_real_fn }, \
 267 /* utime */     0,0,0,0,0, \
 268 /* flt */       0,0,0,0,0,0, \
 269 /* swp */       0,0,0,0,0, \
 270 /* rlimits */   INIT_RLIMITS, \
 271 /* math */      0, \
 272 /* comm */      "swapper", \
 273 /* fs info */   0,NULL, \
 274 /* ipc */       NULL, NULL, \
 275 /* ldt */       NULL, \
 276 /* tss */       INIT_TSS, \
 277 /* fs */        &init_fs, \
 278 /* files */     &init_files, \
 279 /* mm */        &init_mm, \
 280 /* signals */   &init_signals, \
 281 }
 282 
 283 extern struct   mm_struct init_mm;
 284 extern struct task_struct init_task;
 285 extern struct task_struct *task[NR_TASKS];
 286 extern struct task_struct *last_task_used_math;
 287 extern struct task_struct *current_set[NR_CPUS];
 288 /*
 289  *      On a single processor system this comes out as current_set[0] when cpp
 290  *      has finished with it, which gcc will optimise away.
 291  */
 292 #define current (0+current_set[smp_processor_id()])     /* Current on this processor */
 293 extern unsigned long volatile jiffies;
 294 extern unsigned long itimer_ticks;
 295 extern unsigned long itimer_next;
 296 extern struct timeval xtime;
 297 extern int need_resched;
 298 extern void do_timer(struct pt_regs *);
 299 
 300 extern unsigned long * prof_buffer;
 301 extern unsigned long prof_len;
 302 extern unsigned long prof_shift;
 303 
 304 #define CURRENT_TIME (xtime.tv_sec)
 305 
 306 extern void sleep_on(struct wait_queue ** p);
 307 extern void interruptible_sleep_on(struct wait_queue ** p);
 308 extern void wake_up(struct wait_queue ** p);
 309 extern void wake_up_interruptible(struct wait_queue ** p);
 310 extern void wake_up_process(struct task_struct * tsk);
 311 
 312 extern void notify_parent(struct task_struct * tsk);
 313 extern int send_sig(unsigned long sig,struct task_struct * p,int priv);
 314 extern int in_group_p(gid_t grp);
 315 
 316 extern int request_irq(unsigned int irq,void (*handler)(int, struct pt_regs *),
 317         unsigned long flags, const char *device);
 318 extern void free_irq(unsigned int irq);
 319 
 320 extern void copy_thread(int, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
 321 extern void flush_thread(void);
 322 extern void exit_thread(void);
 323 
 324 extern void exit_fs(struct task_struct *);
 325 extern void exit_files(struct task_struct *);
 326 extern void exit_sighand(struct task_struct *);
 327 extern void release_thread(struct task_struct *);
 328 
 329 extern int do_execve(char *, char **, char **, struct pt_regs *);
 330 extern int do_fork(unsigned long, unsigned long, struct pt_regs *);
 331 
 332 /*
 333  * The wait-queues are circular lists, and you have to be *very* sure
 334  * to keep them correct. Use only these two functions to add/remove
 335  * entries in the queues.
 336  */
 337 extern inline void add_wait_queue(struct wait_queue ** p, struct wait_queue * wait)
     /* [previous][next][first][last][top][bottom][index][help] */
 338 {
 339         unsigned long flags;
 340 
 341 #ifdef DEBUG
 342         if (wait->next) {
 343                 __label__ here;
 344                 unsigned long pc;
 345                 pc = (unsigned long) &&here;
 346               here:
 347                 printk("add_wait_queue (%08lx): wait->next = %08lx\n",pc,(unsigned long) wait->next);
 348         }
 349 #endif
 350         save_flags(flags);
 351         cli();
 352         if (!*p) {
 353                 wait->next = wait;
 354                 *p = wait;
 355         } else {
 356                 wait->next = (*p)->next;
 357                 (*p)->next = wait;
 358         }
 359         restore_flags(flags);
 360 }
 361 
 362 extern inline void remove_wait_queue(struct wait_queue ** p, struct wait_queue * wait)
     /* [previous][next][first][last][top][bottom][index][help] */
 363 {
 364         unsigned long flags;
 365         struct wait_queue * tmp;
 366 #ifdef DEBUG
 367         unsigned long ok = 0;
 368 #endif
 369 
 370         save_flags(flags);
 371         cli();
 372         if ((*p == wait) &&
 373 #ifdef DEBUG
 374             (ok = 1) &&
 375 #endif
 376             ((*p = wait->next) == wait)) {
 377                 *p = NULL;
 378         } else {
 379                 tmp = wait;
 380                 while (tmp->next != wait) {
 381                         tmp = tmp->next;
 382 #ifdef DEBUG
 383                         if (tmp == *p)
 384                                 ok = 1;
 385 #endif
 386                 }
 387                 tmp->next = wait->next;
 388         }
 389         wait->next = NULL;
 390         restore_flags(flags);
 391 #ifdef DEBUG
 392         if (!ok) {
 393                 __label__ here;
 394                 ok = (unsigned long) &&here;
 395                 printk("removed wait_queue not on list.\n");
 396                 printk("list = %08lx, queue = %08lx\n",(unsigned long) p, (unsigned long) wait);
 397               here:
 398                 printk("eip = %08lx\n",ok);
 399         }
 400 #endif
 401 }
 402 
 403 extern inline void select_wait(struct wait_queue ** wait_address, select_table * p)
     /* [previous][next][first][last][top][bottom][index][help] */
 404 {
 405         struct select_table_entry * entry;
 406 
 407         if (!p || !wait_address)
 408                 return;
 409         if (p->nr >= __MAX_SELECT_TABLE_ENTRIES)
 410                 return;
 411         entry = p->entry + p->nr;
 412         entry->wait_address = wait_address;
 413         entry->wait.task = current;
 414         entry->wait.next = NULL;
 415         add_wait_queue(wait_address,&entry->wait);
 416         p->nr++;
 417 }
 418 
 419 extern void __down(struct semaphore * sem);
 420 
 421 /*
 422  * These are not yet interrupt-safe
 423  */
 424 extern inline void down(struct semaphore * sem)
     /* [previous][next][first][last][top][bottom][index][help] */
 425 {
 426         if (sem->count <= 0)
 427                 __down(sem);
 428         sem->count--;
 429 }
 430 
 431 extern inline void up(struct semaphore * sem)
     /* [previous][next][first][last][top][bottom][index][help] */
 432 {
 433         sem->count++;
 434         wake_up(&sem->wait);
 435 }       
 436 
 437 #define REMOVE_LINKS(p) do { unsigned long flags; \
 438         save_flags(flags) ; cli(); \
 439         (p)->next_task->prev_task = (p)->prev_task; \
 440         (p)->prev_task->next_task = (p)->next_task; \
 441         restore_flags(flags); \
 442         if ((p)->p_osptr) \
 443                 (p)->p_osptr->p_ysptr = (p)->p_ysptr; \
 444         if ((p)->p_ysptr) \
 445                 (p)->p_ysptr->p_osptr = (p)->p_osptr; \
 446         else \
 447                 (p)->p_pptr->p_cptr = (p)->p_osptr; \
 448         } while (0)
 449 
 450 #define SET_LINKS(p) do { unsigned long flags; \
 451         save_flags(flags); cli(); \
 452         (p)->next_task = &init_task; \
 453         (p)->prev_task = init_task.prev_task; \
 454         init_task.prev_task->next_task = (p); \
 455         init_task.prev_task = (p); \
 456         restore_flags(flags); \
 457         (p)->p_ysptr = NULL; \
 458         if (((p)->p_osptr = (p)->p_pptr->p_cptr) != NULL) \
 459                 (p)->p_osptr->p_ysptr = p; \
 460         (p)->p_pptr->p_cptr = p; \
 461         } while (0)
 462 
 463 #define for_each_task(p) \
 464         for (p = &init_task ; (p = p->next_task) != &init_task ; )
 465 
 466 #endif /* __KERNEL__ */
 467 
 468 #endif

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