LXR linux/include/linux/sched/task.h

   1#ifndef _LINUX_SCHED_TASK_H
   2#define _LINUX_SCHED_TASK_H
   3
   4/*
   5 * Interface between the scheduler and various task lifetime (fork()/exit())
   6 * functionality:
   7 */
   8
   9#include <linux/sched.h>
  10
  11struct task_struct;
  12struct rusage;
  13union thread_union;
  14
  15/*
  16 * This serializes "schedule()" and also protects
  17 * the run-queue from deletions/modifications (but
  18 * _adding_ to the beginning of the run-queue has
  19 * a separate lock).
  20 */
  21extern rwlock_t tasklist_lock;
  22extern spinlock_t mmlist_lock;
  23
  24extern union thread_union init_thread_union;
  25extern struct task_struct init_task;
  26
  27#ifdef CONFIG_PROVE_RCU
  28extern int lockdep_tasklist_lock_is_held(void);
  29#endif /* #ifdef CONFIG_PROVE_RCU */
  30
  31extern asmlinkage void schedule_tail(struct task_struct *prev);
  32extern void init_idle(struct task_struct *idle, int cpu);
  33extern void init_idle_bootup_task(struct task_struct *idle);
  34
  35extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
  36extern void sched_dead(struct task_struct *p);
  37
  38void __noreturn do_task_dead(void);
  39
  40extern void proc_caches_init(void);
  41
  42extern void release_task(struct task_struct * p);
  43
  44#ifdef CONFIG_HAVE_COPY_THREAD_TLS
  45extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
  46                        struct task_struct *, unsigned long);
  47#else
  48extern int copy_thread(unsigned long, unsigned long, unsigned long,
  49                        struct task_struct *);
  50
  51/* Architectures that haven't opted into copy_thread_tls get the tls argument
  52 * via pt_regs, so ignore the tls argument passed via C. */
  53static inline int copy_thread_tls(
  54                unsigned long clone_flags, unsigned long sp, unsigned long arg,
  55                struct task_struct *p, unsigned long tls)
  56{
  57        return copy_thread(clone_flags, sp, arg, p);
  58}
  59#endif
  60extern void flush_thread(void);
  61
  62#ifdef CONFIG_HAVE_EXIT_THREAD
  63extern void exit_thread(struct task_struct *tsk);
  64#else
  65static inline void exit_thread(struct task_struct *tsk)
  66{
  67}
  68#endif
  69extern void do_group_exit(int);
  70
  71extern void exit_files(struct task_struct *);
  72extern void exit_itimers(struct signal_struct *);
  73
  74extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
  75extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
  76struct task_struct *fork_idle(int);
  77extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
  78extern long kernel_wait4(pid_t, int *, int, struct rusage *);
  79
  80extern void free_task(struct task_struct *tsk);
  81
  82/* sched_exec is called by processes performing an exec */
  83#ifdef CONFIG_SMP
  84extern void sched_exec(void);
  85#else
  86#define sched_exec()   {}
  87#endif
  88
  89#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
  90
  91extern void __put_task_struct(struct task_struct *t);
  92
  93static inline void put_task_struct(struct task_struct *t)
  94{
  95        if (atomic_dec_and_test(&t->usage))
  96                __put_task_struct(t);
  97}
  98
  99struct task_struct *task_rcu_dereference(struct task_struct **ptask);
 100
 101#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
 102extern int arch_task_struct_size __read_mostly;
 103#else
 104# define arch_task_struct_size (sizeof(struct task_struct))
 105#endif
 106
 107#ifdef CONFIG_VMAP_STACK
 108static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
 109{
 110        return t->stack_vm_area;
 111}
 112#else
 113static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
 114{
 115        return NULL;
 116}
 117#endif
 118
 119/*
 120 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
 121 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
 122 * pins the final release of task.io_context.  Also protects ->cpuset and
 123 * ->cgroup.subsys[]. And ->vfork_done.
 124 *
 125 * Nests both inside and outside of read_lock(&tasklist_lock).
 126 * It must not be nested with write_lock_irq(&tasklist_lock),
 127 * neither inside nor outside.
 128 */
 129static inline void task_lock(struct task_struct *p)
 130{
 131        spin_lock(&p->alloc_lock);
 132}
 133
 134static inline void task_unlock(struct task_struct *p)
 135{
 136        spin_unlock(&p->alloc_lock);
 137}
 138
 139#endif /* _LINUX_SCHED_TASK_H */
 140