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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) 2000-2017 Julian Seward
     11       jseward (at) 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 /*--------------------------------------------------------------------*/
    126