cpython/Python/thread_nt.h at 8374981fb4d781d5ddbca313656bd3f32b49cef4 · python/cpython · GitHub

History

369 lines (316 loc) · 8.14 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

/* This code implemented by Dag.Gruneau@elsa.preseco.comm.se */

/* Fast NonRecursiveMutex support by Yakov Markovitch, markovitch@iso.ru */

/* Eliminated some memory leaks, gsw@agere.com */

#include <windows.h>

#include <limits.h>

#ifdef HAVE_PROCESS_H

#include <process.h>

#endif

typedef struct NRMUTEX {

LONG owned ;

DWORD thread_id ;

HANDLE hevent ;

} NRMUTEX, *PNRMUTEX ;

BOOL

InitializeNonRecursiveMutex(PNRMUTEX mutex)

{

mutex->owned = -1 ; /* No threads have entered NonRecursiveMutex */

mutex->thread_id = 0 ;

mutex->hevent = CreateEvent(NULL, FALSE, FALSE, NULL) ;

return mutex->hevent != NULL ; /* TRUE if the mutex is created */

}

VOID

DeleteNonRecursiveMutex(PNRMUTEX mutex)

{

/* No in-use check */

CloseHandle(mutex->hevent) ;

mutex->hevent = NULL ; /* Just in case */

}

DWORD

EnterNonRecursiveMutex(PNRMUTEX mutex, BOOL wait)

{

/* Assume that the thread waits successfully */

DWORD ret ;

/* InterlockedIncrement(&mutex->owned) == 0 means that no thread currently owns the mutex */

if (!wait)

{

if (InterlockedCompareExchange(&mutex->owned, 0, -1) != -1)

return WAIT_TIMEOUT ;

ret = WAIT_OBJECT_0 ;

}

else

ret = InterlockedIncrement(&mutex->owned) ?

/* Some thread owns the mutex, let's wait... */

WaitForSingleObject(mutex->hevent, INFINITE) : WAIT_OBJECT_0 ;

mutex->thread_id = GetCurrentThreadId() ; /* We own it */

return ret ;

}

BOOL

LeaveNonRecursiveMutex(PNRMUTEX mutex)

{

/* We don't own the mutex */

mutex->thread_id = 0 ;

return

InterlockedDecrement(&mutex->owned) < 0 ||

SetEvent(mutex->hevent) ; /* Other threads are waiting, wake one on them up */

}

PNRMUTEX

AllocNonRecursiveMutex(void)

{

PNRMUTEX mutex = (PNRMUTEX)malloc(sizeof(NRMUTEX)) ;

if (mutex && !InitializeNonRecursiveMutex(mutex))

{

free(mutex) ;

mutex = NULL ;

}

return mutex ;

}

void

FreeNonRecursiveMutex(PNRMUTEX mutex)

{

if (mutex)

{

DeleteNonRecursiveMutex(mutex) ;

free(mutex) ;

}

long PyThread_get_thread_ident(void);

* Initialization of the C package, should not be needed.

static void

PyThread__init_thread(void)

{

}

* Thread support.

typedef struct {

void (*func)(void*);

void *arg;

} callobj;

/* thunker to call adapt between the function type used by the system's

thread start function and the internally used one. */

#if defined(MS_WINCE)

static DWORD WINAPI

#else

static unsigned __stdcall

#endif

bootstrap(void *call)

{

callobj *obj = (callobj*)call;

void (*func)(void*) = obj->func;

void *arg = obj->arg;

HeapFree(GetProcessHeap(), 0, obj);

func(arg);

return 0;

}

long

PyThread_start_new_thread(void (*func)(void *), void *arg)

{

HANDLE hThread;

unsigned threadID;

callobj *obj;

dprintf(("%ld: PyThread_start_new_thread called\n",

PyThread_get_thread_ident()));

if (!initialized)

PyThread_init_thread();

obj = (callobj*)HeapAlloc(GetProcessHeap(), 0, sizeof(*obj));

if (!obj)

return -1;

obj->func = func;

obj->arg = arg;

#if defined(MS_WINCE)

hThread = CreateThread(NULL,

Py_SAFE_DOWNCAST(_pythread_stacksize, Py_ssize_t, SIZE_T),

bootstrap, obj, 0, &threadID);

#else

hThread = (HANDLE)_beginthreadex(0,

Py_SAFE_DOWNCAST(_pythread_stacksize,

Py_ssize_t, unsigned int),

bootstrap, obj,

0, &threadID);

#endif

if (hThread == 0) {

#if defined(MS_WINCE)

/* Save error in variable, to prevent PyThread_get_thread_ident

from clobbering it. */

unsigned e = GetLastError();

dprintf(("%ld: PyThread_start_new_thread failed, win32 error code %u\n",

PyThread_get_thread_ident(), e));

#else

/* I've seen errno == EAGAIN here, which means "there are

* too many threads".

int e = errno;

dprintf(("%ld: PyThread_start_new_thread failed, errno %d\n",

PyThread_get_thread_ident(), e));

#endif

threadID = (unsigned)-1;

HeapFree(GetProcessHeap(), 0, obj);

}

else {

dprintf(("%ld: PyThread_start_new_thread succeeded: %p\n",

PyThread_get_thread_ident(), (void*)hThread));

CloseHandle(hThread);

}

return (long) threadID;

}

* Return the thread Id instead of an handle. The Id is said to uniquely identify the

* thread in the system

long

PyThread_get_thread_ident(void)

{

if (!initialized)

PyThread_init_thread();

return GetCurrentThreadId();

}

void

PyThread_exit_thread(void)

{

dprintf(("%ld: PyThread_exit_thread called\n", PyThread_get_thread_ident()));

if (!initialized)

exit(0);

#if defined(MS_WINCE)

ExitThread(0);

#else

_endthreadex(0);

#endif

}

#ifndef NO_EXIT_PROG

void

PyThread_exit_prog(int status)

{

dprintf(("PyThread_exit_prog(%d) called\n", status));

if (!initialized)

exit(status);

}

#endif /* NO_EXIT_PROG */

* Lock support. It has too be implemented as semaphores.

* I [Dag] tried to implement it with mutex but I could find a way to

* tell whether a thread already own the lock or not.

PyThread_type_lock

PyThread_allocate_lock(void)

{

PNRMUTEX aLock;

dprintf(("PyThread_allocate_lock called\n"));

if (!initialized)

PyThread_init_thread();

aLock = AllocNonRecursiveMutex() ;

dprintf(("%ld: PyThread_allocate_lock() -> %p\n", PyThread_get_thread_ident(), aLock));

return (PyThread_type_lock) aLock;

}

void

PyThread_free_lock(PyThread_type_lock aLock)

{

dprintf(("%ld: PyThread_free_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

FreeNonRecursiveMutex(aLock) ;

}

* Return 1 on success if the lock was acquired

* and 0 if the lock was not acquired. This means a 0 is returned

* if the lock has already been acquired by this thread!

int

PyThread_acquire_lock(PyThread_type_lock aLock, int waitflag)

{

int success ;

dprintf(("%ld: PyThread_acquire_lock(%p, %d) called\n", PyThread_get_thread_ident(),aLock, waitflag));

success = aLock && EnterNonRecursiveMutex((PNRMUTEX) aLock, (waitflag ? INFINITE : 0)) == WAIT_OBJECT_0 ;

dprintf(("%ld: PyThread_acquire_lock(%p, %d) -> %d\n", PyThread_get_thread_ident(),aLock, waitflag, success));

return success;

}

void

PyThread_release_lock(PyThread_type_lock aLock)

{

dprintf(("%ld: PyThread_release_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock)))

dprintf(("%ld: Could not PyThread_release_lock(%p) error: %ld\n", PyThread_get_thread_ident(), aLock, GetLastError()));

}

/* minimum/maximum thread stack sizes supported */

#define THREAD_MIN_STACKSIZE 0x8000 /* 32kB */

#define THREAD_MAX_STACKSIZE 0x10000000 /* 256MB */

/* set the thread stack size.

* Return 0 if size is valid, -1 otherwise.

static int

_pythread_nt_set_stacksize(size_t size)

{

/* set to default */

if (size == 0) {

_pythread_stacksize = 0;

return 0;

}

/* valid range? */

if (size >= THREAD_MIN_STACKSIZE && size < THREAD_MAX_STACKSIZE) {

_pythread_stacksize = size;

return 0;

}

return -1;

}

#define THREAD_SET_STACKSIZE(x) _pythread_nt_set_stacksize(x)

/* use native Windows TLS functions */

#define Py_HAVE_NATIVE_TLS

#ifdef Py_HAVE_NATIVE_TLS

int

PyThread_create_key(void)

{

return (int) TlsAlloc();

}

void

PyThread_delete_key(int key)

{

TlsFree(key);

}

/* We must be careful to emulate the strange semantics implemented in thread.c,

* where the value is only set if it hasn't been set before.

int

PyThread_set_key_value(int key, void *value)

{

BOOL ok;

void *oldvalue;

assert(value != NULL);

oldvalue = TlsGetValue(key);

if (oldvalue != NULL)

/* ignore value if already set */

return 0;

ok = TlsSetValue(key, value);

if (!ok)

return -1;

return 0;

}

void *

PyThread_get_key_value(int key)

{

/* because TLS is used in the Py_END_ALLOW_THREAD macro,

* it is necessary to preserve the windows error state, because

* it is assumed to be preserved across the call to the macro.

* Ideally, the macro should be fixed, but it is simpler to

* do it here.

DWORD error = GetLastError();

void *result = TlsGetValue(key);

SetLastError(error);

return result;

}

void

PyThread_delete_key_value(int key)

{

/* NULL is used as "key missing", and it is also the default

* given by TlsGetValue() if nothing has been set yet.

TlsSetValue(key, NULL);

}

/* reinitialization of TLS is not necessary after fork when using

* the native TLS functions. And forking isn't supported on Windows either.

void

PyThread_ReInitTLS(void)

{}

#endif

cpython/Python/thread_nt.h at 8374981fb4d781d5ddbca313656bd3f32b49cef4 · python/cpython · GitHub

Uh oh!

Expand file tree

Breadcrumbs

thread_nt.h

Latest commit

History

Breadcrumbs

thread_nt.h

File metadata and controls