coregrind/pub_core_scheduler.h

   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) 2000-2017 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 /* This causes all threads except tid to forceably exit.  They aren't actually
  55    dead by the time this returns; you need to call
  56    VG_(reap_threads)() to wait for them. */
  57 extern void VG_(nuke_all_threads_except) ( ThreadId me,
  58                                            VgSchedReturnCode reason );
  59
  60 /* Make a thread the running thread.  The thread must previously been
  61    sleeping, and not holding the CPU lock.  This will set the
  62    thread state to VgTs_Runnable, and the thread will attempt to take
  63    the CPU lock.  By the time it returns, tid will be the running
  64    thread. */
  65 extern void VG_(acquire_BigLock) ( ThreadId tid, const HChar* who );
  66
  67 /* Simple version, which simply acquires the lock, but does not mess
  68    with the guest state in the same way as the non _LL version
  69    does. */
  70 extern void VG_(acquire_BigLock_LL) ( const HChar* who );
  71
  72 /* Set a thread into a sleeping state.  Before the call, the thread
  73    must be runnable, and holding the CPU lock.  When this call
  74    returns, the thread will be set to the specified sleeping state,
  75    and will not be holding the CPU lock.  Note that another
  76    thread could be running by the time this call returns, so the
  77    caller must be careful not to touch any shared state.  It is also
  78    the caller's responsibility to actually block until the thread is
  79    ready to run again. */
  80 extern void VG_(release_BigLock) ( ThreadId tid,
  81                                    ThreadStatus state, const HChar* who );
  82
  83 /* Matching function to acquire_BigLock_LL. */
  84 extern void VG_(release_BigLock_LL) ( const HChar* who );
  85
  86 /* Whether the specified thread owns the big lock. */
  87 extern Bool VG_(owns_BigLock_LL) ( ThreadId tid );
  88
  89 /* Yield the CPU for a while.  Drops/acquires the lock using the
  90    normal (non _LL) functions. */
  91 extern void VG_(vg_yield)(void);
  92
  93 // The scheduler.
  94 extern VgSchedReturnCode VG_(scheduler) ( ThreadId tid );
  95
  96 // Initialise, phase 1.  Zero out VG_(threads), decide on the root
  97 // ThreadId and initialise the bigLock.
  98 extern ThreadId VG_(scheduler_init_phase1) ( void );
  99
 100 // Initialise, phase 2.  Is passed the extent of the root thread's
 101 // client stack end (highest addressable byte) and the root ThreadId
 102 // decided on by phase 1.
 103 extern void VG_(scheduler_init_phase2) ( ThreadId main_tid,
 104                                          Addr     clstack_end,
 105                                          SizeT    clstack_size );
 106
 107 // Allows to disable the polling done to detect vgdb input
 108 // or to force a poll at next scheduler call.
 109 extern void VG_(disable_vgdb_poll) (void );
 110 extern void VG_(force_vgdb_poll) ( void );
 111
 112 /* Stats ... */
 113 extern void VG_(print_scheduler_stats) ( void );
 114
 115 /* If False, a fault is Valgrind-internal (ie, a bug) */
 116 extern Bool VG_(in_generated_code);
 117
 118 /* Sanity checks which may be done at any time.  The scheduler decides when. */
 119 extern void VG_(sanity_check_general) ( Bool force_expensive );
 120
 121 #endif   // __PUB_CORE_SCHEDULER_H
 122
 123 /*--------------------------------------------------------------------*/
 124 /*--- end                                                          ---*/
 125 /*--------------------------------------------------------------------*/