summaryrefslogtreecommitdiffstats
path: root/chromium/base/memory/shared_memory_unittest.cc
blob: 4d49c36f13656d45445f2d69318158b9899a5fac (plain)
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
681
682
683
684
685
686
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/shared_memory.h"
#include "base/process/kill.h"
#include "base/rand_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/sys_info.h"
#include "base/test/multiprocess_test.h"
#include "base/threading/platform_thread.h"
#include "base/time/time.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/multiprocess_func_list.h"

#if defined(OS_MACOSX)
#include "base/mac/scoped_nsautorelease_pool.h"
#endif

#if defined(OS_POSIX)
#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#endif

#if defined(OS_WIN)
#include "base/win/scoped_handle.h"
#endif

static const int kNumThreads = 5;
#if !defined(OS_IOS)  // iOS does not allow multiple processes.
static const int kNumTasks = 5;
#endif

namespace base {

namespace {

// Each thread will open the shared memory.  Each thread will take a different 4
// byte int pointer, and keep changing it, with some small pauses in between.
// Verify that each thread's value in the shared memory is always correct.
class MultipleThreadMain : public PlatformThread::Delegate {
 public:
  explicit MultipleThreadMain(int16 id) : id_(id) {}
  virtual ~MultipleThreadMain() {}

  static void CleanUp() {
    SharedMemory memory;
    memory.Delete(s_test_name_);
  }

  // PlatformThread::Delegate interface.
  virtual void ThreadMain() OVERRIDE {
#if defined(OS_MACOSX)
    mac::ScopedNSAutoreleasePool pool;
#endif
    const uint32 kDataSize = 1024;
    SharedMemory memory;
    bool rv = memory.CreateNamedDeprecated(s_test_name_, true, kDataSize);
    EXPECT_TRUE(rv);
    rv = memory.Map(kDataSize);
    EXPECT_TRUE(rv);
    int *ptr = static_cast<int*>(memory.memory()) + id_;
    EXPECT_EQ(0, *ptr);

    for (int idx = 0; idx < 100; idx++) {
      *ptr = idx;
      PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(1));
      EXPECT_EQ(*ptr, idx);
    }
    // Reset back to 0 for the next test that uses the same name.
    *ptr = 0;

    memory.Close();
  }

 private:
  int16 id_;

  static const char* const s_test_name_;

  DISALLOW_COPY_AND_ASSIGN(MultipleThreadMain);
};

const char* const MultipleThreadMain::s_test_name_ =
    "SharedMemoryOpenThreadTest";

// TODO(port):
// This test requires the ability to pass file descriptors between processes.
// We haven't done that yet in Chrome for POSIX.
#if defined(OS_WIN)
// Each thread will open the shared memory.  Each thread will take the memory,
// and keep changing it while trying to lock it, with some small pauses in
// between. Verify that each thread's value in the shared memory is always
// correct.
class MultipleLockThread : public PlatformThread::Delegate {
 public:
  explicit MultipleLockThread(int id) : id_(id) {}
  virtual ~MultipleLockThread() {}

  // PlatformThread::Delegate interface.
  virtual void ThreadMain() OVERRIDE {
    const uint32 kDataSize = sizeof(int);
    SharedMemoryHandle handle = NULL;
    {
      SharedMemory memory1;
      EXPECT_TRUE(memory1.CreateNamedDeprecated(
          "SharedMemoryMultipleLockThreadTest", true, kDataSize));
      EXPECT_TRUE(memory1.ShareToProcess(GetCurrentProcess(), &handle));
      // TODO(paulg): Implement this once we have a posix version of
      // SharedMemory::ShareToProcess.
      EXPECT_TRUE(true);
    }

    SharedMemory memory2(handle, false);
    EXPECT_TRUE(memory2.Map(kDataSize));
    volatile int* const ptr = static_cast<int*>(memory2.memory());

    for (int idx = 0; idx < 20; idx++) {
      memory2.LockDeprecated();
      int i = (id_ << 16) + idx;
      *ptr = i;
      PlatformThread::Sleep(TimeDelta::FromMilliseconds(1));
      EXPECT_EQ(*ptr, i);
      memory2.UnlockDeprecated();
    }

    memory2.Close();
  }

 private:
  int id_;

  DISALLOW_COPY_AND_ASSIGN(MultipleLockThread);
};
#endif

}  // namespace

// Android doesn't support SharedMemory::Open/Delete/
// CreateNamedDeprecated(openExisting=true)
#if !defined(OS_ANDROID)
TEST(SharedMemoryTest, OpenClose) {
  const uint32 kDataSize = 1024;
  std::string test_name = "SharedMemoryOpenCloseTest";

  // Open two handles to a memory segment, confirm that they are mapped
  // separately yet point to the same space.
  SharedMemory memory1;
  bool rv = memory1.Delete(test_name);
  EXPECT_TRUE(rv);
  rv = memory1.Delete(test_name);
  EXPECT_TRUE(rv);
  rv = memory1.Open(test_name, false);
  EXPECT_FALSE(rv);
  rv = memory1.CreateNamedDeprecated(test_name, false, kDataSize);
  EXPECT_TRUE(rv);
  rv = memory1.Map(kDataSize);
  EXPECT_TRUE(rv);
  SharedMemory memory2;
  rv = memory2.Open(test_name, false);
  EXPECT_TRUE(rv);
  rv = memory2.Map(kDataSize);
  EXPECT_TRUE(rv);
  EXPECT_NE(memory1.memory(), memory2.memory());  // Compare the pointers.

  // Make sure we don't segfault. (it actually happened!)
  ASSERT_NE(memory1.memory(), static_cast<void*>(NULL));
  ASSERT_NE(memory2.memory(), static_cast<void*>(NULL));

  // Write data to the first memory segment, verify contents of second.
  memset(memory1.memory(), '1', kDataSize);
  EXPECT_EQ(memcmp(memory1.memory(), memory2.memory(), kDataSize), 0);

  // Close the first memory segment, and verify the second has the right data.
  memory1.Close();
  char *start_ptr = static_cast<char *>(memory2.memory());
  char *end_ptr = start_ptr + kDataSize;
  for (char* ptr = start_ptr; ptr < end_ptr; ptr++)
    EXPECT_EQ(*ptr, '1');

  // Close the second memory segment.
  memory2.Close();

  rv = memory1.Delete(test_name);
  EXPECT_TRUE(rv);
  rv = memory2.Delete(test_name);
  EXPECT_TRUE(rv);
}

TEST(SharedMemoryTest, OpenExclusive) {
  const uint32 kDataSize = 1024;
  const uint32 kDataSize2 = 2048;
  std::ostringstream test_name_stream;
  test_name_stream << "SharedMemoryOpenExclusiveTest."
                   << Time::Now().ToDoubleT();
  std::string test_name = test_name_stream.str();

  // Open two handles to a memory segment and check that
  // open_existing_deprecated works as expected.
  SharedMemory memory1;
  bool rv = memory1.CreateNamedDeprecated(test_name, false, kDataSize);
  EXPECT_TRUE(rv);

  // Memory1 knows it's size because it created it.
  EXPECT_EQ(memory1.requested_size(), kDataSize);

  rv = memory1.Map(kDataSize);
  EXPECT_TRUE(rv);

  // The mapped memory1 must be at least the size we asked for.
  EXPECT_GE(memory1.mapped_size(), kDataSize);

  // The mapped memory1 shouldn't exceed rounding for allocation granularity.
  EXPECT_LT(memory1.mapped_size(),
            kDataSize + base::SysInfo::VMAllocationGranularity());

  memset(memory1.memory(), 'G', kDataSize);

  SharedMemory memory2;
  // Should not be able to create if openExisting is false.
  rv = memory2.CreateNamedDeprecated(test_name, false, kDataSize2);
  EXPECT_FALSE(rv);

  // Should be able to create with openExisting true.
  rv = memory2.CreateNamedDeprecated(test_name, true, kDataSize2);
  EXPECT_TRUE(rv);

  // Memory2 shouldn't know the size because we didn't create it.
  EXPECT_EQ(memory2.requested_size(), 0U);

  // We should be able to map the original size.
  rv = memory2.Map(kDataSize);
  EXPECT_TRUE(rv);

  // The mapped memory2 must be at least the size of the original.
  EXPECT_GE(memory2.mapped_size(), kDataSize);

  // The mapped memory2 shouldn't exceed rounding for allocation granularity.
  EXPECT_LT(memory2.mapped_size(),
            kDataSize2 + base::SysInfo::VMAllocationGranularity());

  // Verify that opening memory2 didn't truncate or delete memory 1.
  char *start_ptr = static_cast<char *>(memory2.memory());
  char *end_ptr = start_ptr + kDataSize;
  for (char* ptr = start_ptr; ptr < end_ptr; ptr++) {
    EXPECT_EQ(*ptr, 'G');
  }

  memory1.Close();
  memory2.Close();

  rv = memory1.Delete(test_name);
  EXPECT_TRUE(rv);
}
#endif

// Create a set of N threads to each open a shared memory segment and write to
// it. Verify that they are always reading/writing consistent data.
TEST(SharedMemoryTest, MultipleThreads) {
  MultipleThreadMain::CleanUp();
  // On POSIX we have a problem when 2 threads try to create the shmem
  // (a file) at exactly the same time, since create both creates the
  // file and zerofills it.  We solve the problem for this unit test
  // (make it not flaky) by starting with 1 thread, then
  // intentionally don't clean up its shmem before running with
  // kNumThreads.

  int threadcounts[] = { 1, kNumThreads };
  for (size_t i = 0; i < arraysize(threadcounts); i++) {
    int numthreads = threadcounts[i];
    scoped_ptr<PlatformThreadHandle[]> thread_handles;
    scoped_ptr<MultipleThreadMain*[]> thread_delegates;

    thread_handles.reset(new PlatformThreadHandle[numthreads]);
    thread_delegates.reset(new MultipleThreadMain*[numthreads]);

    // Spawn the threads.
    for (int16 index = 0; index < numthreads; index++) {
      PlatformThreadHandle pth;
      thread_delegates[index] = new MultipleThreadMain(index);
      EXPECT_TRUE(PlatformThread::Create(0, thread_delegates[index], &pth));
      thread_handles[index] = pth;
    }

    // Wait for the threads to finish.
    for (int index = 0; index < numthreads; index++) {
      PlatformThread::Join(thread_handles[index]);
      delete thread_delegates[index];
    }
  }
  MultipleThreadMain::CleanUp();
}

// TODO(port): this test requires the MultipleLockThread class
// (defined above), which requires the ability to pass file
// descriptors between processes.  We haven't done that yet in Chrome
// for POSIX.
#if defined(OS_WIN)
// Create a set of threads to each open a shared memory segment and write to it
// with the lock held. Verify that they are always reading/writing consistent
// data.
TEST(SharedMemoryTest, Lock) {
  PlatformThreadHandle thread_handles[kNumThreads];
  MultipleLockThread* thread_delegates[kNumThreads];

  // Spawn the threads.
  for (int index = 0; index < kNumThreads; ++index) {
    PlatformThreadHandle pth;
    thread_delegates[index] = new MultipleLockThread(index);
    EXPECT_TRUE(PlatformThread::Create(0, thread_delegates[index], &pth));
    thread_handles[index] = pth;
  }

  // Wait for the threads to finish.
  for (int index = 0; index < kNumThreads; ++index) {
    PlatformThread::Join(thread_handles[index]);
    delete thread_delegates[index];
  }
}
#endif

// Allocate private (unique) shared memory with an empty string for a
// name.  Make sure several of them don't point to the same thing as
// we might expect if the names are equal.
TEST(SharedMemoryTest, AnonymousPrivate) {
  int i, j;
  int count = 4;
  bool rv;
  const uint32 kDataSize = 8192;

  scoped_ptr<SharedMemory[]> memories(new SharedMemory[count]);
  scoped_ptr<int*[]> pointers(new int*[count]);
  ASSERT_TRUE(memories.get());
  ASSERT_TRUE(pointers.get());

  for (i = 0; i < count; i++) {
    rv = memories[i].CreateAndMapAnonymous(kDataSize);
    EXPECT_TRUE(rv);
    int *ptr = static_cast<int*>(memories[i].memory());
    EXPECT_TRUE(ptr);
    pointers[i] = ptr;
  }

  for (i = 0; i < count; i++) {
    // zero out the first int in each except for i; for that one, make it 100.
    for (j = 0; j < count; j++) {
      if (i == j)
        pointers[j][0] = 100;
      else
        pointers[j][0] = 0;
    }
    // make sure there is no bleeding of the 100 into the other pointers
    for (j = 0; j < count; j++) {
      if (i == j)
        EXPECT_EQ(100, pointers[j][0]);
      else
        EXPECT_EQ(0, pointers[j][0]);
    }
  }

  for (int i = 0; i < count; i++) {
    memories[i].Close();
  }
}

TEST(SharedMemoryTest, ShareReadOnly) {
  StringPiece contents = "Hello World";

  SharedMemory writable_shmem;
  SharedMemoryCreateOptions options;
  options.size = contents.size();
  options.share_read_only = true;
  ASSERT_TRUE(writable_shmem.Create(options));
  ASSERT_TRUE(writable_shmem.Map(options.size));
  memcpy(writable_shmem.memory(), contents.data(), contents.size());
  EXPECT_TRUE(writable_shmem.Unmap());

  SharedMemoryHandle readonly_handle;
  ASSERT_TRUE(writable_shmem.ShareReadOnlyToProcess(GetCurrentProcessHandle(),
                                                    &readonly_handle));
  SharedMemory readonly_shmem(readonly_handle, /*readonly=*/true);

  ASSERT_TRUE(readonly_shmem.Map(contents.size()));
  EXPECT_EQ(contents,
            StringPiece(static_cast<const char*>(readonly_shmem.memory()),
                        contents.size()));
  EXPECT_TRUE(readonly_shmem.Unmap());

  // Make sure the writable instance is still writable.
  ASSERT_TRUE(writable_shmem.Map(contents.size()));
  StringPiece new_contents = "Goodbye";
  memcpy(writable_shmem.memory(), new_contents.data(), new_contents.size());
  EXPECT_EQ(new_contents,
            StringPiece(static_cast<const char*>(writable_shmem.memory()),
                        new_contents.size()));

  // We'd like to check that if we send the read-only segment to another
  // process, then that other process can't reopen it read/write.  (Since that
  // would be a security hole.)  Setting up multiple processes is hard in a
  // unittest, so this test checks that the *current* process can't reopen the
  // segment read/write.  I think the test here is stronger than we actually
  // care about, but there's a remote possibility that sending a file over a
  // pipe would transform it into read/write.
  SharedMemoryHandle handle = readonly_shmem.handle();

#if defined(OS_ANDROID)
  // The "read-only" handle is still writable on Android:
  // http://crbug.com/320865
  (void)handle;
#elif defined(OS_POSIX)
  EXPECT_EQ(O_RDONLY, fcntl(handle.fd, F_GETFL) & O_ACCMODE)
      << "The descriptor itself should be read-only.";

  errno = 0;
  void* writable = mmap(
      NULL, contents.size(), PROT_READ | PROT_WRITE, MAP_SHARED, handle.fd, 0);
  int mmap_errno = errno;
  EXPECT_EQ(MAP_FAILED, writable)
      << "It shouldn't be possible to re-mmap the descriptor writable.";
  EXPECT_EQ(EACCES, mmap_errno) << strerror(mmap_errno);
  if (writable != MAP_FAILED)
    EXPECT_EQ(0, munmap(writable, readonly_shmem.mapped_size()));

#elif defined(OS_WIN)
  EXPECT_EQ(NULL, MapViewOfFile(handle, FILE_MAP_WRITE, 0, 0, 0))
      << "Shouldn't be able to map memory writable.";

  HANDLE temp_handle;
  BOOL rv = ::DuplicateHandle(GetCurrentProcess(),
                              handle,
                              GetCurrentProcess,
                              &temp_handle,
                              FILE_MAP_ALL_ACCESS,
                              false,
                              0);
  EXPECT_EQ(FALSE, rv)
      << "Shouldn't be able to duplicate the handle into a writable one.";
  if (rv)
    base::win::ScopedHandle writable_handle(temp_handle);
#else
#error Unexpected platform; write a test that tries to make 'handle' writable.
#endif  // defined(OS_POSIX) || defined(OS_WIN)
}

TEST(SharedMemoryTest, ShareToSelf) {
  StringPiece contents = "Hello World";

  SharedMemory shmem;
  ASSERT_TRUE(shmem.CreateAndMapAnonymous(contents.size()));
  memcpy(shmem.memory(), contents.data(), contents.size());
  EXPECT_TRUE(shmem.Unmap());

  SharedMemoryHandle shared_handle;
  ASSERT_TRUE(shmem.ShareToProcess(GetCurrentProcessHandle(), &shared_handle));
  SharedMemory shared(shared_handle, /*readonly=*/false);

  ASSERT_TRUE(shared.Map(contents.size()));
  EXPECT_EQ(
      contents,
      StringPiece(static_cast<const char*>(shared.memory()), contents.size()));

  ASSERT_TRUE(shmem.ShareToProcess(GetCurrentProcessHandle(), &shared_handle));
  SharedMemory readonly(shared_handle, /*readonly=*/true);

  ASSERT_TRUE(readonly.Map(contents.size()));
  EXPECT_EQ(contents,
            StringPiece(static_cast<const char*>(readonly.memory()),
                        contents.size()));
}

TEST(SharedMemoryTest, MapAt) {
  ASSERT_TRUE(SysInfo::VMAllocationGranularity() >= sizeof(uint32));
  const size_t kCount = SysInfo::VMAllocationGranularity();
  const size_t kDataSize = kCount * sizeof(uint32);

  SharedMemory memory;
  ASSERT_TRUE(memory.CreateAndMapAnonymous(kDataSize));
  uint32* ptr = static_cast<uint32*>(memory.memory());
  ASSERT_NE(ptr, static_cast<void*>(NULL));

  for (size_t i = 0; i < kCount; ++i) {
    ptr[i] = i;
  }

  memory.Unmap();

  off_t offset = SysInfo::VMAllocationGranularity();
  ASSERT_TRUE(memory.MapAt(offset, kDataSize - offset));
  offset /= sizeof(uint32);
  ptr = static_cast<uint32*>(memory.memory());
  ASSERT_NE(ptr, static_cast<void*>(NULL));
  for (size_t i = offset; i < kCount; ++i) {
    EXPECT_EQ(ptr[i - offset], i);
  }
}

TEST(SharedMemoryTest, MapTwice) {
  const uint32 kDataSize = 1024;
  SharedMemory memory;
  bool rv = memory.CreateAndMapAnonymous(kDataSize);
  EXPECT_TRUE(rv);

  void* old_address = memory.memory();

  rv = memory.Map(kDataSize);
  EXPECT_FALSE(rv);
  EXPECT_EQ(old_address, memory.memory());
}

#if defined(OS_POSIX)
// Create a shared memory object, mmap it, and mprotect it to PROT_EXEC.
TEST(SharedMemoryTest, AnonymousExecutable) {
  const uint32 kTestSize = 1 << 16;

  SharedMemory shared_memory;
  SharedMemoryCreateOptions options;
  options.size = kTestSize;
  options.executable = true;

  EXPECT_TRUE(shared_memory.Create(options));
  EXPECT_TRUE(shared_memory.Map(shared_memory.requested_size()));

  EXPECT_EQ(0, mprotect(shared_memory.memory(), shared_memory.requested_size(),
                        PROT_READ | PROT_EXEC));
}

// Android supports a different permission model than POSIX for its "ashmem"
// shared memory implementation. So the tests about file permissions are not
// included on Android.
#if !defined(OS_ANDROID)

// Set a umask and restore the old mask on destruction.
class ScopedUmaskSetter {
 public:
  explicit ScopedUmaskSetter(mode_t target_mask) {
    old_umask_ = umask(target_mask);
  }
  ~ScopedUmaskSetter() { umask(old_umask_); }
 private:
  mode_t old_umask_;
  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedUmaskSetter);
};

// Create a shared memory object, check its permissions.
TEST(SharedMemoryTest, FilePermissionsAnonymous) {
  const uint32 kTestSize = 1 << 8;

  SharedMemory shared_memory;
  SharedMemoryCreateOptions options;
  options.size = kTestSize;
  // Set a file mode creation mask that gives all permissions.
  ScopedUmaskSetter permissive_mask(S_IWGRP | S_IWOTH);

  EXPECT_TRUE(shared_memory.Create(options));

  int shm_fd = shared_memory.handle().fd;
  struct stat shm_stat;
  EXPECT_EQ(0, fstat(shm_fd, &shm_stat));
  // Neither the group, nor others should be able to read the shared memory
  // file.
  EXPECT_FALSE(shm_stat.st_mode & S_IRWXO);
  EXPECT_FALSE(shm_stat.st_mode & S_IRWXG);
}

// Create a shared memory object, check its permissions.
TEST(SharedMemoryTest, FilePermissionsNamed) {
  const uint32 kTestSize = 1 << 8;

  SharedMemory shared_memory;
  SharedMemoryCreateOptions options;
  options.size = kTestSize;
  std::string shared_mem_name = "shared_perm_test-" + IntToString(getpid()) +
      "-" + Uint64ToString(RandUint64());
  options.name_deprecated = &shared_mem_name;
  // Set a file mode creation mask that gives all permissions.
  ScopedUmaskSetter permissive_mask(S_IWGRP | S_IWOTH);

  EXPECT_TRUE(shared_memory.Create(options));
  // Clean-up the backing file name immediately, we don't need it.
  EXPECT_TRUE(shared_memory.Delete(shared_mem_name));

  int shm_fd = shared_memory.handle().fd;
  struct stat shm_stat;
  EXPECT_EQ(0, fstat(shm_fd, &shm_stat));
  // Neither the group, nor others should have been able to open the shared
  // memory file while its name existed.
  EXPECT_FALSE(shm_stat.st_mode & S_IRWXO);
  EXPECT_FALSE(shm_stat.st_mode & S_IRWXG);
}
#endif  // !defined(OS_ANDROID)

#endif  // defined(OS_POSIX)

// Map() will return addresses which are aligned to the platform page size, this
// varies from platform to platform though.  Since we'd like to advertise a
// minimum alignment that callers can count on, test for it here.
TEST(SharedMemoryTest, MapMinimumAlignment) {
  static const int kDataSize = 8192;

  SharedMemory shared_memory;
  ASSERT_TRUE(shared_memory.CreateAndMapAnonymous(kDataSize));
  EXPECT_EQ(0U, reinterpret_cast<uintptr_t>(
      shared_memory.memory()) & (SharedMemory::MAP_MINIMUM_ALIGNMENT - 1));
  shared_memory.Close();
}

#if !defined(OS_IOS)  // iOS does not allow multiple processes.

// On POSIX it is especially important we test shmem across processes,
// not just across threads.  But the test is enabled on all platforms.
class SharedMemoryProcessTest : public MultiProcessTest {
 public:

  static void CleanUp() {
    SharedMemory memory;
    memory.Delete(s_test_name_);
  }

  static int TaskTestMain() {
    int errors = 0;
#if defined(OS_MACOSX)
    mac::ScopedNSAutoreleasePool pool;
#endif
    const uint32 kDataSize = 1024;
    SharedMemory memory;
    bool rv = memory.CreateNamedDeprecated(s_test_name_, true, kDataSize);
    EXPECT_TRUE(rv);
    if (rv != true)
      errors++;
    rv = memory.Map(kDataSize);
    EXPECT_TRUE(rv);
    if (rv != true)
      errors++;
    int *ptr = static_cast<int*>(memory.memory());

    for (int idx = 0; idx < 20; idx++) {
      memory.LockDeprecated();
      int i = (1 << 16) + idx;
      *ptr = i;
      PlatformThread::Sleep(TimeDelta::FromMilliseconds(10));
      if (*ptr != i)
        errors++;
      memory.UnlockDeprecated();
    }

    memory.Close();
    return errors;
  }

 private:
  static const char* const s_test_name_;
};

const char* const SharedMemoryProcessTest::s_test_name_ = "MPMem";

TEST_F(SharedMemoryProcessTest, Tasks) {
  SharedMemoryProcessTest::CleanUp();

  ProcessHandle handles[kNumTasks];
  for (int index = 0; index < kNumTasks; ++index) {
    handles[index] = SpawnChild("SharedMemoryTestMain");
    ASSERT_TRUE(handles[index]);
  }

  int exit_code = 0;
  for (int index = 0; index < kNumTasks; ++index) {
    EXPECT_TRUE(WaitForExitCode(handles[index], &exit_code));
    EXPECT_EQ(0, exit_code);
  }

  SharedMemoryProcessTest::CleanUp();
}

MULTIPROCESS_TEST_MAIN(SharedMemoryTestMain) {
  return SharedMemoryProcessTest::TaskTestMain();
}

#endif  // !OS_IOS

}  // namespace base