1 //===-- sanitizer_thread_registry.cc --------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is shared between sanitizer tools.
11 //
12 // General thread bookkeeping functionality.
13 //===----------------------------------------------------------------------===//
14
15 #include "sanitizer_thread_registry.h"
16
17 namespace __sanitizer {
18
ThreadContextBase(u32 tid)19 ThreadContextBase::ThreadContextBase(u32 tid)
20 : tid(tid), unique_id(0), reuse_count(), os_id(0), user_id(0),
21 status(ThreadStatusInvalid),
22 detached(false), parent_tid(0), next(0) {
23 name[0] = '\0';
24 }
25
~ThreadContextBase()26 ThreadContextBase::~ThreadContextBase() {
27 // ThreadContextBase should never be deleted.
28 CHECK(0);
29 }
30
SetName(const char * new_name)31 void ThreadContextBase::SetName(const char *new_name) {
32 name[0] = '\0';
33 if (new_name) {
34 internal_strncpy(name, new_name, sizeof(name));
35 name[sizeof(name) - 1] = '\0';
36 }
37 }
38
SetDead()39 void ThreadContextBase::SetDead() {
40 CHECK(status == ThreadStatusRunning ||
41 status == ThreadStatusFinished);
42 status = ThreadStatusDead;
43 user_id = 0;
44 OnDead();
45 }
46
SetJoined(void * arg)47 void ThreadContextBase::SetJoined(void *arg) {
48 // FIXME(dvyukov): print message and continue (it's user error).
49 CHECK_EQ(false, detached);
50 CHECK_EQ(ThreadStatusFinished, status);
51 status = ThreadStatusDead;
52 user_id = 0;
53 OnJoined(arg);
54 }
55
SetFinished()56 void ThreadContextBase::SetFinished() {
57 if (!detached)
58 status = ThreadStatusFinished;
59 OnFinished();
60 }
61
SetStarted(uptr _os_id,void * arg)62 void ThreadContextBase::SetStarted(uptr _os_id, void *arg) {
63 status = ThreadStatusRunning;
64 os_id = _os_id;
65 OnStarted(arg);
66 }
67
SetCreated(uptr _user_id,u64 _unique_id,bool _detached,u32 _parent_tid,void * arg)68 void ThreadContextBase::SetCreated(uptr _user_id, u64 _unique_id,
69 bool _detached, u32 _parent_tid, void *arg) {
70 status = ThreadStatusCreated;
71 user_id = _user_id;
72 unique_id = _unique_id;
73 detached = _detached;
74 // Parent tid makes no sense for the main thread.
75 if (tid != 0)
76 parent_tid = _parent_tid;
77 OnCreated(arg);
78 }
79
Reset()80 void ThreadContextBase::Reset() {
81 status = ThreadStatusInvalid;
82 SetName(0);
83 OnReset();
84 }
85
86 // ThreadRegistry implementation.
87
88 const u32 ThreadRegistry::kUnknownTid = ~0U;
89
ThreadRegistry(ThreadContextFactory factory,u32 max_threads,u32 thread_quarantine_size,u32 max_reuse)90 ThreadRegistry::ThreadRegistry(ThreadContextFactory factory, u32 max_threads,
91 u32 thread_quarantine_size, u32 max_reuse)
92 : context_factory_(factory),
93 max_threads_(max_threads),
94 thread_quarantine_size_(thread_quarantine_size),
95 max_reuse_(max_reuse),
96 mtx_(),
97 n_contexts_(0),
98 total_threads_(0),
99 alive_threads_(0),
100 max_alive_threads_(0),
101 running_threads_(0) {
102 threads_ = (ThreadContextBase **)MmapOrDie(max_threads_ * sizeof(threads_[0]),
103 "ThreadRegistry");
104 dead_threads_.clear();
105 invalid_threads_.clear();
106 }
107
GetNumberOfThreads(uptr * total,uptr * running,uptr * alive)108 void ThreadRegistry::GetNumberOfThreads(uptr *total, uptr *running,
109 uptr *alive) {
110 BlockingMutexLock l(&mtx_);
111 if (total) *total = n_contexts_;
112 if (running) *running = running_threads_;
113 if (alive) *alive = alive_threads_;
114 }
115
GetMaxAliveThreads()116 uptr ThreadRegistry::GetMaxAliveThreads() {
117 BlockingMutexLock l(&mtx_);
118 return max_alive_threads_;
119 }
120
CreateThread(uptr user_id,bool detached,u32 parent_tid,void * arg)121 u32 ThreadRegistry::CreateThread(uptr user_id, bool detached, u32 parent_tid,
122 void *arg) {
123 BlockingMutexLock l(&mtx_);
124 u32 tid = kUnknownTid;
125 ThreadContextBase *tctx = QuarantinePop();
126 if (tctx) {
127 tid = tctx->tid;
128 } else if (n_contexts_ < max_threads_) {
129 // Allocate new thread context and tid.
130 tid = n_contexts_++;
131 tctx = context_factory_(tid);
132 threads_[tid] = tctx;
133 } else {
134 #ifndef SANITIZER_GO
135 Report("%s: Thread limit (%u threads) exceeded. Dying.\n",
136 SanitizerToolName, max_threads_);
137 #else
138 Printf("race: limit on %u simultaneously alive goroutines is exceeded,"
139 " dying\n", max_threads_);
140 #endif
141 Die();
142 }
143 CHECK_NE(tctx, 0);
144 CHECK_NE(tid, kUnknownTid);
145 CHECK_LT(tid, max_threads_);
146 CHECK_EQ(tctx->status, ThreadStatusInvalid);
147 alive_threads_++;
148 if (max_alive_threads_ < alive_threads_) {
149 max_alive_threads_++;
150 CHECK_EQ(alive_threads_, max_alive_threads_);
151 }
152 tctx->SetCreated(user_id, total_threads_++, detached,
153 parent_tid, arg);
154 return tid;
155 }
156
RunCallbackForEachThreadLocked(ThreadCallback cb,void * arg)157 void ThreadRegistry::RunCallbackForEachThreadLocked(ThreadCallback cb,
158 void *arg) {
159 CheckLocked();
160 for (u32 tid = 0; tid < n_contexts_; tid++) {
161 ThreadContextBase *tctx = threads_[tid];
162 if (tctx == 0)
163 continue;
164 cb(tctx, arg);
165 }
166 }
167
FindThread(FindThreadCallback cb,void * arg)168 u32 ThreadRegistry::FindThread(FindThreadCallback cb, void *arg) {
169 BlockingMutexLock l(&mtx_);
170 for (u32 tid = 0; tid < n_contexts_; tid++) {
171 ThreadContextBase *tctx = threads_[tid];
172 if (tctx != 0 && cb(tctx, arg))
173 return tctx->tid;
174 }
175 return kUnknownTid;
176 }
177
178 ThreadContextBase *
FindThreadContextLocked(FindThreadCallback cb,void * arg)179 ThreadRegistry::FindThreadContextLocked(FindThreadCallback cb, void *arg) {
180 CheckLocked();
181 for (u32 tid = 0; tid < n_contexts_; tid++) {
182 ThreadContextBase *tctx = threads_[tid];
183 if (tctx != 0 && cb(tctx, arg))
184 return tctx;
185 }
186 return 0;
187 }
188
FindThreadContextByOsIdCallback(ThreadContextBase * tctx,void * arg)189 static bool FindThreadContextByOsIdCallback(ThreadContextBase *tctx,
190 void *arg) {
191 return (tctx->os_id == (uptr)arg && tctx->status != ThreadStatusInvalid &&
192 tctx->status != ThreadStatusDead);
193 }
194
FindThreadContextByOsIDLocked(uptr os_id)195 ThreadContextBase *ThreadRegistry::FindThreadContextByOsIDLocked(uptr os_id) {
196 return FindThreadContextLocked(FindThreadContextByOsIdCallback,
197 (void *)os_id);
198 }
199
SetThreadName(u32 tid,const char * name)200 void ThreadRegistry::SetThreadName(u32 tid, const char *name) {
201 BlockingMutexLock l(&mtx_);
202 CHECK_LT(tid, n_contexts_);
203 ThreadContextBase *tctx = threads_[tid];
204 CHECK_NE(tctx, 0);
205 CHECK_EQ(ThreadStatusRunning, tctx->status);
206 tctx->SetName(name);
207 }
208
SetThreadNameByUserId(uptr user_id,const char * name)209 void ThreadRegistry::SetThreadNameByUserId(uptr user_id, const char *name) {
210 BlockingMutexLock l(&mtx_);
211 for (u32 tid = 0; tid < n_contexts_; tid++) {
212 ThreadContextBase *tctx = threads_[tid];
213 if (tctx != 0 && tctx->user_id == user_id &&
214 tctx->status != ThreadStatusInvalid) {
215 tctx->SetName(name);
216 return;
217 }
218 }
219 }
220
DetachThread(u32 tid,void * arg)221 void ThreadRegistry::DetachThread(u32 tid, void *arg) {
222 BlockingMutexLock l(&mtx_);
223 CHECK_LT(tid, n_contexts_);
224 ThreadContextBase *tctx = threads_[tid];
225 CHECK_NE(tctx, 0);
226 if (tctx->status == ThreadStatusInvalid) {
227 Report("%s: Detach of non-existent thread\n", SanitizerToolName);
228 return;
229 }
230 tctx->OnDetached(arg);
231 if (tctx->status == ThreadStatusFinished) {
232 tctx->SetDead();
233 QuarantinePush(tctx);
234 } else {
235 tctx->detached = true;
236 }
237 }
238
JoinThread(u32 tid,void * arg)239 void ThreadRegistry::JoinThread(u32 tid, void *arg) {
240 BlockingMutexLock l(&mtx_);
241 CHECK_LT(tid, n_contexts_);
242 ThreadContextBase *tctx = threads_[tid];
243 CHECK_NE(tctx, 0);
244 if (tctx->status == ThreadStatusInvalid) {
245 Report("%s: Join of non-existent thread\n", SanitizerToolName);
246 return;
247 }
248 tctx->SetJoined(arg);
249 QuarantinePush(tctx);
250 }
251
FinishThread(u32 tid)252 void ThreadRegistry::FinishThread(u32 tid) {
253 BlockingMutexLock l(&mtx_);
254 CHECK_GT(alive_threads_, 0);
255 alive_threads_--;
256 CHECK_GT(running_threads_, 0);
257 running_threads_--;
258 CHECK_LT(tid, n_contexts_);
259 ThreadContextBase *tctx = threads_[tid];
260 CHECK_NE(tctx, 0);
261 CHECK_EQ(ThreadStatusRunning, tctx->status);
262 tctx->SetFinished();
263 if (tctx->detached) {
264 tctx->SetDead();
265 QuarantinePush(tctx);
266 }
267 }
268
StartThread(u32 tid,uptr os_id,void * arg)269 void ThreadRegistry::StartThread(u32 tid, uptr os_id, void *arg) {
270 BlockingMutexLock l(&mtx_);
271 running_threads_++;
272 CHECK_LT(tid, n_contexts_);
273 ThreadContextBase *tctx = threads_[tid];
274 CHECK_NE(tctx, 0);
275 CHECK_EQ(ThreadStatusCreated, tctx->status);
276 tctx->SetStarted(os_id, arg);
277 }
278
QuarantinePush(ThreadContextBase * tctx)279 void ThreadRegistry::QuarantinePush(ThreadContextBase *tctx) {
280 if (tctx->tid == 0)
281 return; // Don't reuse the main thread. It's a special snowflake.
282 dead_threads_.push_back(tctx);
283 if (dead_threads_.size() <= thread_quarantine_size_)
284 return;
285 tctx = dead_threads_.front();
286 dead_threads_.pop_front();
287 CHECK_EQ(tctx->status, ThreadStatusDead);
288 tctx->Reset();
289 tctx->reuse_count++;
290 if (max_reuse_ > 0 && tctx->reuse_count >= max_reuse_)
291 return;
292 invalid_threads_.push_back(tctx);
293 }
294
QuarantinePop()295 ThreadContextBase *ThreadRegistry::QuarantinePop() {
296 if (invalid_threads_.size() == 0)
297 return 0;
298 ThreadContextBase *tctx = invalid_threads_.front();
299 invalid_threads_.pop_front();
300 return tctx;
301 }
302
303 } // namespace __sanitizer
304