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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) 2000-2013 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 #include "pub_core_basics.h"        // VG_ macro
35 #include "pub_core_threadstate.h"   // VgSchedReturnCode
36 
37 //--------------------------------------------------------------------
38 // PURPOSE: This module is the scheduler, which is the main loop
39 // controlling the running of all the program's threads.
40 // It's at the centre of everything.
41 //--------------------------------------------------------------------
42 
43 /* Allocate a new ThreadState */
44 extern ThreadId VG_(alloc_ThreadState)(void);
45 
46 /* A thread exits.  tid must currently be running. */
47 extern void VG_(exit_thread)(ThreadId tid);
48 
49 /* If 'tid' is blocked in a syscall, send it SIGVGKILL so as to get it
50    out of the syscall and onto doing the next thing, whatever that is.
51    If it isn't blocked in a syscall, has no effect on the thread. */
52 extern void VG_(get_thread_out_of_syscall)(ThreadId tid);
53 
54 /* Nuke all threads except tid. */
55 extern void VG_(nuke_all_threads_except) ( ThreadId me,
56                                            VgSchedReturnCode reason );
57 
58 /* Make a thread the running thread.  The thread must previously been
59    sleeping, and not holding the CPU lock.  This will set the
60    thread state to VgTs_Runnable, and the thread will attempt to take
61    the CPU lock.  By the time it returns, tid will be the running
62    thread. */
63 extern void VG_(acquire_BigLock) ( ThreadId tid, const HChar* who );
64 
65 /* Simple version, which simply acquires the lock, but does not mess
66    with the guest state in the same way as the non _LL version
67    does. */
68 extern void VG_(acquire_BigLock_LL) ( const HChar* who );
69 
70 /* Set a thread into a sleeping state.  Before the call, the thread
71    must be runnable, and holding the CPU lock.  When this call
72    returns, the thread will be set to the specified sleeping state,
73    and will not be holding the CPU lock.  Note that another
74    thread could be running by the time this call returns, so the
75    caller must be careful not to touch any shared state.  It is also
76    the caller's responsibility to actually block until the thread is
77    ready to run again. */
78 extern void VG_(release_BigLock) ( ThreadId tid,
79                                    ThreadStatus state, const HChar* who );
80 
81 /* Matching function to acquire_BigLock_LL. */
82 extern void VG_(release_BigLock_LL) ( const HChar* who );
83 
84 /* Whether the specified thread owns the big lock. */
85 extern Bool VG_(owns_BigLock_LL) ( ThreadId tid );
86 
87 /* Yield the CPU for a while.  Drops/acquires the lock using the
88    normal (non _LL) functions. */
89 extern void VG_(vg_yield)(void);
90 
91 // The scheduler.
92 extern VgSchedReturnCode VG_(scheduler) ( ThreadId tid );
93 
94 // Initialise, phase 1.  Zero out VG_(threads), decide on the root
95 // ThreadId and initialise the bigLock.
96 extern ThreadId VG_(scheduler_init_phase1) ( void );
97 
98 // Initialise, phase 2.  Is passed the extent of the root thread's
99 // client stack and the root ThreadId decided on by phase 1.
100 extern void VG_(scheduler_init_phase2) ( ThreadId main_tid,
101                                          Addr     clstack_end,
102                                          SizeT    clstack_size );
103 
104 // Allows to disable the polling done to detect vgdb input
105 // or to force a poll at next scheduler call.
106 extern void VG_(disable_vgdb_poll) (void );
107 extern void VG_(force_vgdb_poll) ( void );
108 
109 /* Stats ... */
110 extern void VG_(print_scheduler_stats) ( void );
111 
112 /* If False, a fault is Valgrind-internal (ie, a bug) */
113 extern Bool VG_(in_generated_code);
114 
115 /* Sanity checks which may be done at any time.  The scheduler decides when. */
116 extern void VG_(sanity_check_general) ( Bool force_expensive );
117 
118 #endif   // __PUB_CORE_SCHEDULER_H
119 
120 /*--------------------------------------------------------------------*/
121 /*--- end                                                          ---*/
122 /*--------------------------------------------------------------------*/
123