1 /* Freezer declarations */
3 #include <linux/sched.h>
7 * Check if a process has been frozen
9 static inline int frozen(struct task_struct *p)
11 return p->flags & PF_FROZEN;
15 * Check if there is a request to freeze a process
17 static inline int freezing(struct task_struct *p)
19 return test_tsk_thread_flag(p, TIF_FREEZE);
23 * Request that a process be frozen
25 static inline void freeze(struct task_struct *p)
27 set_tsk_thread_flag(p, TIF_FREEZE);
31 * Sometimes we may need to cancel the previous 'freeze' request
33 static inline void do_not_freeze(struct task_struct *p)
35 clear_tsk_thread_flag(p, TIF_FREEZE);
39 * Wake up a frozen process
41 * task_lock() is taken to prevent the race with refrigerator() which may
42 * occur if the freezing of tasks fails. Namely, without the lock, if the
43 * freezing of tasks failed, thaw_tasks() might have run before a task in
44 * refrigerator() could call frozen_process(), in which case the task would be
45 * frozen and no one would thaw it.
47 static inline int thaw_process(struct task_struct *p)
51 p->flags &= ~PF_FROZEN;
56 clear_tsk_thread_flag(p, TIF_FREEZE);
62 * freezing is complete, mark process as frozen
64 static inline void frozen_process(struct task_struct *p)
66 p->flags |= PF_FROZEN;
68 clear_tsk_thread_flag(p, TIF_FREEZE);
71 extern void refrigerator(void);
72 extern int freeze_processes(void);
73 extern void thaw_processes(void);
75 static inline int try_to_freeze(void)
77 if (freezing(current)) {
84 extern void thaw_some_processes(int all);
87 static inline int frozen(struct task_struct *p) { return 0; }
88 static inline int freezing(struct task_struct *p) { return 0; }
89 static inline void freeze(struct task_struct *p) { BUG(); }
90 static inline int thaw_process(struct task_struct *p) { return 1; }
91 static inline void frozen_process(struct task_struct *p) { BUG(); }
93 static inline void refrigerator(void) {}
94 static inline int freeze_processes(void) { BUG(); return 0; }
95 static inline void thaw_processes(void) {}
97 static inline int try_to_freeze(void) { return 0; }