1
2/*--------------------------------------------------------------------*/
3/*--- The scheduler.                          pub_core_scheduler.h ---*/
4/*--------------------------------------------------------------------*/
5
6/*
7   This file is part of Valgrind, a dynamic binary instrumentation
8   framework.
9
10   Copyright (C) 2000-2011 Julian Seward
11      jseward@acm.org
12
13   This program is free software; you can redistribute it and/or
14   modify it under the terms of the GNU General Public License as
15   published by the Free Software Foundation; either version 2 of the
16   License, or (at your option) any later version.
17
18   This program is distributed in the hope that it will be useful, but
19   WITHOUT ANY WARRANTY; without even the implied warranty of
20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21   General Public License for more details.
22
23   You should have received a copy of the GNU General Public License
24   along with this program; if not, write to the Free Software
25   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26   02111-1307, USA.
27
28   The GNU General Public License is contained in the file COPYING.
29*/
30
31#ifndef __PUB_CORE_SCHEDULER_H
32#define __PUB_CORE_SCHEDULER_H
33
34//--------------------------------------------------------------------
35// PURPOSE: This module is the scheduler, which is the main loop
36// controlling the running of all the program's threads.
37// It's at the centre of everything.
38//--------------------------------------------------------------------
39
40/* Allocate a new ThreadState */
41extern ThreadId VG_(alloc_ThreadState)(void);
42
43/* A thread exits.  tid must currently be running. */
44extern void VG_(exit_thread)(ThreadId tid);
45
46/* If 'tid' is blocked in a syscall, send it SIGVGKILL so as to get it
47   out of the syscall and onto doing the next thing, whatever that is.
48   If it isn't blocked in a syscall, has no effect on the thread. */
49extern void VG_(get_thread_out_of_syscall)(ThreadId tid);
50
51/* Nuke all threads except tid. */
52extern void VG_(nuke_all_threads_except) ( ThreadId me,
53                                           VgSchedReturnCode reason );
54
55/* Make a thread the running thread.  The thread must previously been
56   sleeping, and not holding the CPU lock.  This will set the
57   thread state to VgTs_Runnable, and the thread will attempt to take
58   the CPU lock.  By the time it returns, tid will be the running
59   thread. */
60extern void VG_(acquire_BigLock) ( ThreadId tid, HChar* who );
61
62/* Simple version, which simply acquires the lock, but does not mess
63   with the guest state in the same way as the non _LL version
64   does. */
65extern void VG_(acquire_BigLock_LL) ( HChar* who );
66
67/* Set a thread into a sleeping state.  Before the call, the thread
68   must be runnable, and holding the CPU lock.  When this call
69   returns, the thread will be set to the specified sleeping state,
70   and will not be holding the CPU lock.  Note that another
71   thread could be running by the time this call returns, so the
72   caller must be careful not to touch any shared state.  It is also
73   the caller's responsibility to actually block until the thread is
74   ready to run again. */
75extern void VG_(release_BigLock) ( ThreadId tid,
76                                   ThreadStatus state, HChar* who );
77
78/* Matching function to acquire_BigLock_LL. */
79extern void VG_(release_BigLock_LL) ( HChar* who );
80
81/* Yield the CPU for a while.  Drops/acquires the lock using the
82   normal (non _LL) functions. */
83extern void VG_(vg_yield)(void);
84
85// The scheduler.
86extern VgSchedReturnCode VG_(scheduler) ( ThreadId tid );
87
88// Initialise, phase 1.  Zero out VG_(threads), decide on the root
89// ThreadId and initialise the bigLock.
90extern ThreadId VG_(scheduler_init_phase1) ( void );
91
92// Initialise, phase 2.  Is passed the extent of the root thread's
93// client stack and the root ThreadId decided on by phase 1.
94extern void VG_(scheduler_init_phase2) ( ThreadId main_tid,
95                                         Addr     clstack_end,
96                                         SizeT    clstack_size );
97
98// Allows to disable the polling done to detect vgdb input
99// or to force a poll at next scheduler call.
100extern void VG_(disable_vgdb_poll) (void );
101extern void VG_(force_vgdb_poll) ( void );
102
103/* Stats ... */
104extern void VG_(print_scheduler_stats) ( void );
105
106/* If False, a fault is Valgrind-internal (ie, a bug) */
107extern Bool VG_(in_generated_code);
108
109/* Sanity checks which may be done at any time.  The scheduler decides when. */
110extern void VG_(sanity_check_general) ( Bool force_expensive );
111
112#endif   // __PUB_CORE_SCHEDULER_H
113
114/*--------------------------------------------------------------------*/
115/*--- end                                                          ---*/
116/*--------------------------------------------------------------------*/
117