forked from cloudius-systems/osv
-
Notifications
You must be signed in to change notification settings - Fork 0
/
pthread.cc
680 lines (591 loc) · 17.1 KB
/
pthread.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
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
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
/*
* Copyright (C) 2013 Cloudius Systems, Ltd.
*
* This work is open source software, licensed under the terms of the
* BSD license as described in the LICENSE file in the top-level directory.
*/
#include <osv/sched.hh>
#include "signal.hh"
#include <pthread.h>
#include <errno.h>
#include <mutex>
#include <vector>
#include <algorithm>
#include <string.h>
#include <list>
#ifndef AARCH64_PORT_STUB
#include <osv/mmu.hh>
#endif /* !AARCH64_PORT_STUB */
#include <osv/debug.hh>
#include <osv/prio.hh>
#include <osv/mutex.h>
#include <osv/condvar.h>
#include <osv/stubbing.hh>
#include <osv/lazy_indirect.hh>
#include <api/time.h>
namespace pthread_private {
const unsigned tsd_nkeys = 100;
__thread void* tsd[tsd_nkeys];
__thread pthread_t current_pthread;
__attribute__ ((init_priority ((int)init_prio::pthread))) mutex tsd_key_mutex;
__attribute__ ((init_priority ((int)init_prio::pthread))) std::vector<bool>
tsd_used_keys(tsd_nkeys);
__attribute__ ((init_priority ((int)init_prio::pthread)))
std::vector<void (*)(void*)> tsd_dtor(tsd_nkeys);
struct thread_attr;
class pthread {
public:
explicit pthread(void *(*start)(void *arg), void *arg, sigset_t sigset,
const thread_attr* attr);
static pthread* from_libc(pthread_t p);
pthread_t to_libc();
int join(void** retval);
void* _retval;
// must be initialized last
sched::thread _thread;
private:
sched::thread::stack_info allocate_stack(thread_attr attr);
static void free_stack(sched::thread::stack_info si);
sched::thread::attr attributes(thread_attr attr);
};
struct thread_attr {
void* stack_begin;
size_t stack_size;
size_t guard_size;
bool detached;
thread_attr() : stack_begin{}, stack_size{1<<20}, guard_size{4096}, detached{false} {}
};
pthread::pthread(void *(*start)(void *arg), void *arg, sigset_t sigset,
const thread_attr* attr)
: _thread([=] {
current_pthread = to_libc();
sigprocmask(SIG_SETMASK, &sigset, nullptr);
_retval = start(arg);
}, attributes(attr ? *attr : thread_attr()))
{
_thread.set_cleanup([=] { delete this; });
_thread.start();
}
sched::thread::attr pthread::attributes(thread_attr attr)
{
sched::thread::attr a;
a.stack(allocate_stack(attr));
a.detached(attr.detached);
return a;
}
sched::thread::stack_info pthread::allocate_stack(thread_attr attr)
{
if (attr.stack_begin) {
return {attr.stack_begin, attr.stack_size};
}
size_t size = attr.stack_size;
#ifdef AARCH64_PORT_STUB
size = (size + (0xfff)) & (~0xfffull);
void *addr = malloc(size);
#else /* !AARCH64_PORT_STUB */
void *addr = mmu::map_anon(nullptr, size, mmu::mmap_populate, mmu::perm_rw);
mmu::mprotect(addr, attr.guard_size, 0);
#endif /* !AARCH64_PORT_STUB */
sched::thread::stack_info si{addr, size};
si.deleter = free_stack;
return si;
}
void pthread::free_stack(sched::thread::stack_info si)
{
#ifdef AARCH64_PORT_STUB
free(si.begin);
#else /* !AARCH64_PORT_STUB */
mmu::munmap(si.begin, si.size);
#endif /* !AARCH64_PORT_STUB */
}
int pthread::join(void** retval)
{
_thread.join();
if (retval) {
*retval = _retval;
}
return 0;
}
pthread* pthread::from_libc(pthread_t p)
{
return reinterpret_cast<pthread*>(p);
}
static_assert(sizeof(thread_attr) <= sizeof(pthread_attr_t),
"thread_attr too big");
pthread_t pthread::to_libc()
{
return reinterpret_cast<pthread_t>(this);
}
thread_attr* from_libc(pthread_attr_t* a)
{
return reinterpret_cast<thread_attr*>(a);
}
const thread_attr* from_libc(const pthread_attr_t* a)
{
return reinterpret_cast<const thread_attr*>(a);
}
}
using namespace pthread_private;
int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine) (void *), void *arg)
{
sigset_t sigset;
sigprocmask(SIG_SETMASK, nullptr, &sigset);
auto t = new pthread(start_routine, arg, sigset, from_libc(attr));
*thread = t->to_libc();
return 0;
}
int pthread_join(pthread_t thread, void** retval)
{
int ret = pthread::from_libc(thread)->join(retval);
delete(pthread::from_libc(thread));
return ret;
}
int pthread_key_create(pthread_key_t* key, void (*dtor)(void*))
{
std::lock_guard<mutex> guard(tsd_key_mutex);
auto p = std::find(tsd_used_keys.begin(), tsd_used_keys.end(), false);
if (p == tsd_used_keys.end()) {
return ENOMEM;
}
*p = true;
*key = p - tsd_used_keys.begin();
tsd_dtor[*key] = dtor;
return 0;
}
int pthread_atfork(void (*prepare)(void), void (*parent)(void),
void (*child)(void))
{
return 0;
}
extern "C" int register_atfork(void (*prepare)(void), void (*parent)(void),
void (*child)(void), void *__dso_handle)
{
return 0;
}
extern "C" {
int __register_atfork(void (*prepare)(void), void (*parent)(void),
void (*child)(void), void *__dso_handle) __attribute__((alias("register_atfork")));
int __pthread_key_create(pthread_key_t* key, void (*dtor)(void*))
__attribute__((alias("pthread_key_create")));
}
int pthread_key_delete(pthread_key_t key)
{
WARN_STUBBED();
return EINVAL;
}
void* pthread_getspecific(pthread_key_t key)
{
return tsd[key];
}
int pthread_setspecific(pthread_key_t key, const void* value)
{
tsd[key] = const_cast<void*>(value);
return 0;
}
pthread_t pthread_self()
{
return current_pthread;
}
int pthread_getcpuclockid(pthread_t thread, clockid_t *clock_id)
{
if (clock_id) {
pthread *p = pthread::from_libc(thread);
auto id = p->_thread.id();
*clock_id = id + _OSV_CLOCK_SLOTS;
}
return 0;
}
#ifdef LOCKFREE_MUTEX
typedef lazy_indirect<mutex> indirect_mutex;
static_assert(sizeof(indirect_mutex) <= sizeof(pthread_mutex_t), "mutex overflow");
static_assert(sizeof(indirect_mutex) <= 16, "pthread_mutex_t not zeroed at byte 16");
int pthread_mutex_init(pthread_mutex_t* __restrict m,
const pthread_mutexattr_t* __restrict attr)
{
// FIXME: respect attr
new (m) indirect_mutex;
return 0;
}
int pthread_mutex_destroy(pthread_mutex_t *m)
{
reinterpret_cast<indirect_mutex*>(m)->~indirect_mutex();
return 0;
}
mutex* from_libc(pthread_mutex_t* m)
{
return reinterpret_cast<indirect_mutex*>(m)->get();
}
#else
static_assert(sizeof(mutex) <= sizeof(pthread_mutex_t), "mutex overflow");
mutex* from_libc(pthread_mutex_t* m)
{
return reinterpret_cast<mutex*>(m);
}
int pthread_mutex_init(pthread_mutex_t* __restrict m,
const pthread_mutexattr_t* __restrict attr)
{
// FIXME: respect attr
new (m) mutex;
return 0;
}
int pthread_mutex_destroy(pthread_mutex_t *m)
{
from_libc(m)->~mutex();
return 0;
}
#endif
int pthread_mutex_lock(pthread_mutex_t *m)
{
from_libc(m)->lock();
return 0;
}
int pthread_mutex_trylock(pthread_mutex_t *m)
{
if (!from_libc(m)->try_lock()) {
return -EBUSY;
}
return 0;
}
int pthread_mutex_timedlock(pthread_mutex_t *m,
const struct timespec *abs_timeout)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_mutex_unlock(pthread_mutex_t *m)
{
from_libc(m)->unlock();
return 0;
}
int pthread_sigmask(int how, const sigset_t* set, sigset_t* oldset)
{
return sigprocmask(how, set, oldset);
}
#ifdef LOCKFREE_MUTEX
struct pthread_condvar {
condvar cond;
clockid_t clock {CLOCK_REALTIME};
};
typedef lazy_indirect<pthread_condvar> indirect_condvar;
static_assert(sizeof(indirect_condvar) < sizeof(pthread_cond_t), "condvar overflow");
int pthread_cond_init(pthread_cond_t* __restrict c,
const pthread_condattr_t* __restrict attr)
{
new (c) indirect_condvar;
// There's not much that attr can say. OSv doesn't have processes so the
// pshared attribute is irrelevant. All that remains is the clock, and
// since this can only specify CLOCK_REALTIME or CLOCK_MONOTONIC, a
// single byte in pthread_condattr_t is enough for us.
if (attr && *reinterpret_cast<const char*>(attr)) {
reinterpret_cast<indirect_condvar*>(c)->get()->clock = CLOCK_MONOTONIC;
}
return 0;
}
int pthread_cond_destroy(pthread_cond_t *c)
{
reinterpret_cast<indirect_condvar*>(c)->~indirect_condvar();
return 0;
}
condvar* from_libc(pthread_cond_t* c)
{
return &(reinterpret_cast<indirect_condvar*>(c)->get()->cond);
}
#else
condvar* from_libc(pthread_cond_t* cond)
{
return reinterpret_cast<condvar*>(cond);
}
int pthread_cond_init(pthread_cond_t *__restrict cond,
const pthread_condattr_t *__restrict attr)
{
static_assert(sizeof(condvar) <= sizeof(*cond), "cond_var overflow");
memset(cond, 0, sizeof(*cond));
return 0;
}
int pthread_cond_destroy(pthread_cond_t* cond)
{
return 0;
}
#endif
int pthread_cond_broadcast(pthread_cond_t *cond)
{
from_libc(cond)->wake_all();
return 0;
}
int pthread_cond_signal(pthread_cond_t *cond)
{
from_libc(cond)->wake_one();
return 0;
}
int pthread_cond_wait(pthread_cond_t *__restrict cond,
pthread_mutex_t *__restrict mutex)
{
return from_libc(cond)->wait(from_libc(mutex));
}
int pthread_cond_timedwait(pthread_cond_t *__restrict cond,
pthread_mutex_t *__restrict mutex,
const struct timespec* __restrict ts)
{
sched::timer tmr(*sched::thread::current());
switch(reinterpret_cast<indirect_condvar*>(cond)->get()->clock) {
case CLOCK_REALTIME:
tmr.set(osv::clock::wall::time_point(
std::chrono::seconds(ts->tv_sec) +
std::chrono::nanoseconds(ts->tv_nsec)));
break;
case CLOCK_MONOTONIC:
tmr.set(osv::clock::uptime::time_point(
std::chrono::seconds(ts->tv_sec) +
std::chrono::nanoseconds(ts->tv_nsec)));
break;
default:
assert(0); // pthread_cond_init() will never allow this case
}
return from_libc(cond)->wait(from_libc(mutex), &tmr);
}
int pthread_attr_init(pthread_attr_t *attr)
{
new (attr) thread_attr;
return 0;
}
int pthread_attr_destroy(pthread_attr_t *attr)
{
return 0;
}
int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr)
{
auto t = pthread::from_libc(thread);
auto a = from_libc(attr);
a->stack_begin = t->_thread.get_stack_info().begin;
a->stack_size = t->_thread.get_stack_info().size;
return 0;
}
int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate)
{
auto a = from_libc(attr);
a->detached = (detachstate == PTHREAD_CREATE_DETACHED);
return 0;
}
int pthread_attr_getstacksize(const pthread_attr_t *__restrict attr,
size_t * stacksize)
{
auto a = from_libc(attr);
*stacksize = a->stack_size;
return 0;
}
int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
{
from_libc(attr)->stack_size = stacksize;
return 0;
}
int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize)
{
from_libc(attr)->guard_size = guardsize;
return 0;
}
int pthread_attr_getstack(const pthread_attr_t * __restrict attr,
void **stackaddr, size_t *stacksize)
{
auto a = from_libc(attr);
*stackaddr = a->stack_begin;
*stacksize = a->stack_size;
return 0;
}
int pthread_setcancelstate(int state, int *oldstate)
{
WARN_STUBBED();
return 0;
}
int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
{
// In Linux (the target ABI we're trying to emulate, PTHREAD_ONCE_INIT
// is 0. Our implementation sets it to 1 when intialization is in progress
// (so other threads calling the same pthread_once know to block), and
// to 2 when initialization has alread completed.
// The performance pthread_once isn't critical, so let's go with a simple
// implementation of one shared mutex and wait queue for all once_control
// (don't worry, the mutual exclusion is just on access to the waiter
// list, not on running init_routine()).
static mutex m;
static struct waiter {
sched::thread *thread;
pthread_once_t *once_control;
struct waiter *next;
} *waiterlist = nullptr;
m.lock();
if (*once_control == 2) {
// initialization has already completed - return immediately.
m.unlock();
return 0;
} else if (*once_control == 1) {
// initialization of this once_control is in progress in another
// thread, so wait until it completes.
struct waiter *w = (struct waiter *) malloc(sizeof(struct waiter));
w->thread = sched::thread::current();
w->once_control = once_control;
w->next = waiterlist;
waiterlist = w;
sched::thread::wait_until(m, [=] { return *once_control != 1; });
if (*once_control == 2) {
m.unlock();
return 0;
}
// If we're still here, it's the corner case that we waited for
// another thread that was doing the initialization, but that thread
// was canceled once_control is back to 0, and now we need to
// initialize in this thread. Fall through to the code below with the
// lock still taken.
} else if (*once_control != 0) {
// Unexpected value in once_control. Barf.
m.unlock();
return EINVAL;
}
// mark that we're initializing, and run the initialization routine.
*once_control = 1;
m.unlock();
init_routine();
// TODO: if init_routine() was canceled, return once_control back to 0!
m.lock();
*once_control = 2;
// wake up any other threads waiting for our initialization. We need to
// do this with the lock taken, as we are touching the waitlist.
for (struct waiter **p = &waiterlist; *p; p = &((*p)->next)) {
if ((*p)->once_control == once_control ) {
(*p)->thread->wake();
struct waiter *save = *p;
*p = (*p)->next;
free(save);
if (!*p) break;
}
}
m.unlock();
return 0;
}
// libstdc++ checks whether threads are compiled in using its
// __gthread_active_p(), which (when compiled on Linux) just verifies
// that pthread_cancel() is available. So we need it available, even
// we don't intend to actually use it.
int pthread_cancel(pthread_t thread)
{
WARN_STUBBED();
return ESRCH;
}
int pthread_detach(pthread_t thread)
{
pthread* p = pthread::from_libc(thread);
p->_thread.detach();
return 0;
}
int pthread_equal(pthread_t t1, pthread_t t2)
{
return t1 == t2;
}
int pthread_mutexattr_init(pthread_mutexattr_t *attr)
{
WARN_STUBBED();
return ENOMEM;
}
int pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *type)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_condattr_init(pthread_condattr_t *attr)
{
// We assume there's room for at least one byte in pthread_condattr_t
// and use this single byte to specify the clockid. The default is 0
// (which we take to signify CLOCK_REALTIME).
*reinterpret_cast<char*>(attr) = 0;
return 0;
}
int pthread_condattr_destroy(pthread_condattr_t *)
{
return 0;
}
int pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clockid)
{
char byte;
switch (clockid) {
case CLOCK_REALTIME:
byte = 0;
break;
case CLOCK_MONOTONIC:
byte = 1;
break;
default:
return EINVAL;
}
*reinterpret_cast<char*>(attr) = byte;
return 0;
}
int pthread_condattr_getclock(const pthread_condattr_t *__restrict attr,
clockid_t *__restrict clockid)
{
if (*reinterpret_cast<const char*>(attr)) {
*clockid = CLOCK_MONOTONIC;
} else {
*clockid = CLOCK_REALTIME;
}
return 0;
}
int pthread_condattr_setpshared(pthread_condattr_t *, int)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_condattr_getpshared(const pthread_condattr_t *__restrict, int *__restrict)
{
WARN_STUBBED();
return EINVAL;
}
void pthread_exit(void *retval)
{
WARN_STUBBED();
abort();
}
int sched_get_priority_max(int policy)
{
WARN_STUBBED();
return EINVAL;
}
int sched_get_priority_min(int policy)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_setschedparam(pthread_t thread, int policy,
const struct sched_param *param)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_getschedparam(pthread_t thread, int *policy,
struct sched_param *param)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_kill(pthread_t thread, int sig)
{
WARN_STUBBED();
return EINVAL;
}
int pthread_setname_np(pthread_t p, const char* name)
{
if (strlen(name) > 16) {
return ERANGE;
}
pthread::from_libc(p)->_thread.set_name(name);
return 0;
}