1 2 /*--------------------------------------------------------------------*/ 3 /*--- Definitions for Locks and Threads. ---*/ 4 /*--- hg_lock_n_thread.h ---*/ 5 /*--------------------------------------------------------------------*/ 6 7 /* 8 This file is part of Helgrind, a Valgrind tool for detecting errors 9 in threaded programs. 10 11 Copyright (C) 2007-2015 OpenWorks Ltd 12 info@open-works.co.uk 13 14 This program is free software; you can redistribute it and/or 15 modify it under the terms of the GNU General Public License as 16 published by the Free Software Foundation; either version 2 of the 17 License, or (at your option) any later version. 18 19 This program is distributed in the hope that it will be useful, but 20 WITHOUT ANY WARRANTY; without even the implied warranty of 21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 General Public License for more details. 23 24 You should have received a copy of the GNU General Public License 25 along with this program; if not, write to the Free Software 26 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 27 02111-1307, USA. 28 29 The GNU General Public License is contained in the file COPYING. 30 */ 31 32 #ifndef __HG_LOCK_N_THREAD_H 33 #define __HG_LOCK_N_THREAD_H 34 35 36 /*----------------------------------------------------------------*/ 37 /*--- Primary data definitions ---*/ 38 /*----------------------------------------------------------------*/ 39 40 /* Magic numbers, for doing assertions that structures really are of 41 the right type. Useful as some of the code can get a bit 42 complex. */ 43 #define Thread_MAGIC 0x504fc5e5 44 #define LockN_MAGIC 0x6545b557 /* normal nonpersistent locks */ 45 #define LockP_MAGIC 0x755b5456 /* persistent (copied) locks */ 46 47 48 /* These are handles for Word sets. CONSTRAINTS: must be small ints 49 numbered from zero, since 32-bit versions of them are used to 50 encode lock-sets in libhb's history records (Thr_n_RCEC). */ 51 typedef WordSet WordSetID; 52 53 54 /* Synchronisation Objects, exported abstractly by libhb. */ 55 typedef struct _SO SO; 56 57 /* Thr, libhb's private thread record, exported abstractly. Thr's are 58 allocated and never deallocated (simply leaked). Also ThrID, which 59 is a small integer which uniquely identifies a Thr and which is 60 used in ScalarTS because it is smaller than a Thr*. There is a 1-1 61 mapping between Thr's and ThrIDs. */ 62 typedef struct _Thr Thr; 63 typedef UInt ThrID; 64 65 66 /* Stores information about a thread. Addresses of these also serve 67 as unique thread identifiers and so are never freed, so they should 68 be as small as possible. Freeing Thread structures makes the 69 storage management just too complex, and most programs don't create 70 many threads, so tolerating this leak seems like a not-bad 71 tradeoff. 72 73 Since these are never freed, the .coretid field only indicates the 74 core's ThreadId associated with this Thread whilst it is alive. 75 Once the thread finishes, the ThreadId is set to 76 VG_INVALID_THREADID. 77 78 The core may later re-use the same ThreadId for what is a logically 79 completely different thread, which of course must have a different 80 Thread structure. */ 81 typedef 82 struct _Thread { 83 /* ADMIN */ 84 struct _Thread* admin; 85 UInt magic; 86 Thr* hbthr; /* which in turn points back here .. */ 87 ThreadId coretid; /* .. via its hgthread field */ 88 /* USEFUL */ 89 WordSetID locksetA; /* WordSet of Lock* currently held by thread */ 90 WordSetID locksetW; /* subset of locksetA held in w-mode */ 91 /* EXPOSITION */ 92 /* Place where parent was when this thread was created. */ 93 ExeContext* created_at; 94 Bool announced; 95 /* Index for generating references in error messages. */ 96 Int errmsg_index; 97 98 /* Nesting level of pthread_create(). New memory allocated is untracked 99 when this value is > 0: race reporting is suppressed there. DRD does 100 the same thing implicitly. This is necessary because for example 101 Solaris libc caches many objects and reuses them for different threads 102 and that confuses Helgrind. With libvki it would be possible to 103 explictly use VG_USERREQ__HG_CLEAN_MEMORY on such objects. 104 Also mutex activity is ignored so that they do not impose false 105 ordering between creator and created thread. */ 106 Int pthread_create_nesting_level; 107 108 /* Nesting level of synchronization functions called by the client. 109 Loads and stores are ignored when its value > 0. 110 Currently this is used solely for suppressing races of primitive 111 synchronization objects themselves - mutexes, condition variables, 112 read-write locks and their associated sleep queues. 113 See also documentation for command line option 114 --ignore-thread-creation. */ 115 Int synchr_nesting; 116 117 #if defined(VGO_solaris) 118 Int bind_guard_flag; /* Bind flag from the runtime linker. */ 119 #endif /* VGO_solaris */ 120 } 121 Thread; 122 123 /* Get hg's admin_threads value, so libhb can visit all of them. */ 124 Thread* get_admin_threads ( void ); 125 126 /* Stores information about a lock's current state. These are 127 allocated and later freed (when the containing memory becomes 128 NoAccess). This gives a problem for the XError type, which 129 contains Lock*s. Solution is to copy any Lock which is to be 130 incorporated into an XErrors, so as to make it independent from the 131 'normal' collection of Locks, which can come and go. When the lock 132 is copied, its .magic is changed from LockN_Magic to 133 LockP_Magic. */ 134 135 /* Lock kinds. */ 136 typedef 137 enum { 138 LK_mbRec=1001, /* normal mutex, possibly recursive */ 139 LK_nonRec, /* normal mutex, definitely non recursive */ 140 LK_rdwr /* reader-writer lock */ 141 } 142 LockKind; 143 144 typedef 145 struct _Lock { 146 /* ADMIN */ 147 struct _Lock* admin_next; /* fields for a double linked */ 148 struct _Lock* admin_prev; /* list of these locks */ 149 ULong unique; /* used for persistence-hashing */ 150 UInt magic; /* LockN_MAGIC or LockP_MAGIC */ 151 /* EXPOSITION */ 152 /* Place where lock first came to the attention of Helgrind. */ 153 ExeContext* appeared_at; 154 /* If the lock is held, place where the lock most recently made 155 an unlocked->locked transition. Must be sync'd with .heldBy: 156 either both NULL or both non-NULL. */ 157 ExeContext* acquired_at; 158 /* USEFUL-STATIC */ 159 SO* hbso; /* associated SO */ 160 Addr guestaddr; /* Guest address of lock */ 161 LockKind kind; /* what kind of lock this is */ 162 /* USEFUL-DYNAMIC */ 163 Bool heldW; 164 WordBag* heldBy; /* bag of threads that hold this lock */ 165 /* .heldBy is NULL: lock is unheld, and .heldW is meaningless 166 but arbitrarily set to False 167 .heldBy is non-NULL: 168 .heldW is True: lock is w-held by threads in heldBy 169 .heldW is False: lock is r-held by threads in heldBy 170 Either way, heldBy may not validly be an empty Bag. 171 172 for LK_nonRec, r-holdings are not allowed, and w-holdings may 173 only have sizeTotal(heldBy) == 1 174 175 for LK_mbRec, r-holdings are not allowed, and w-holdings may 176 only have sizeUnique(heldBy) == 1 177 178 for LK_rdwr, w-holdings may only have sizeTotal(heldBy) == 1 */ 179 } 180 Lock; 181 182 #define Lock_INVALID ((Lock*)1UL) 183 184 /*----------------------------------------------------------------*/ 185 /*--- Sanity checking ---*/ 186 /*----------------------------------------------------------------*/ 187 188 Bool HG_(is_sane_Thread) ( Thread* thr ); 189 Bool HG_(is_sane_LockP) ( Lock* lock ); 190 Bool HG_(is_sane_LockN) ( Lock* lock ); 191 Bool HG_(is_sane_LockNorP) ( Lock* lock ); 192 193 194 #endif /* ! __HG_LOCK_N_THREAD_H */ 195 196 /*--------------------------------------------------------------------*/ 197 /*--- end hg_lock_n_thread.h ---*/ 198 /*--------------------------------------------------------------------*/ 199