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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // This is a simple application that stress-tests the crash recovery of the disk
      6 // cache. The main application starts a copy of itself on a loop, checking the
      7 // exit code of the child process. When the child dies in an unexpected way,
      8 // the main application quits.
      9 
     10 // The child application has two threads: one to exercise the cache in an
     11 // infinite loop, and another one to asynchronously kill the process.
     12 
     13 // A regular build should never crash.
     14 // To test that the disk cache doesn't generate critical errors with regular
     15 // application level crashes, edit stress_support.h.
     16 
     17 #include <string>
     18 #include <vector>
     19 
     20 #include "base/at_exit.h"
     21 #include "base/bind.h"
     22 #include "base/command_line.h"
     23 #include "base/debug/debugger.h"
     24 #include "base/files/file_path.h"
     25 #include "base/logging.h"
     26 #include "base/message_loop/message_loop.h"
     27 #include "base/path_service.h"
     28 #include "base/process/kill.h"
     29 #include "base/process/launch.h"
     30 #include "base/process/process_handle.h"
     31 #include "base/strings/string_number_conversions.h"
     32 #include "base/strings/string_util.h"
     33 #include "base/strings/utf_string_conversions.h"
     34 #include "base/threading/platform_thread.h"
     35 #include "base/threading/thread.h"
     36 #include "net/base/io_buffer.h"
     37 #include "net/base/net_errors.h"
     38 #include "net/base/test_completion_callback.h"
     39 #include "net/disk_cache/backend_impl.h"
     40 #include "net/disk_cache/disk_cache.h"
     41 #include "net/disk_cache/disk_cache_test_util.h"
     42 #include "net/disk_cache/stress_support.h"
     43 #include "net/disk_cache/trace.h"
     44 
     45 #if defined(OS_WIN)
     46 #include "base/logging_win.h"
     47 #endif
     48 
     49 using base::Time;
     50 
     51 const int kError = -1;
     52 const int kExpectedCrash = 100;
     53 
     54 // Starts a new process.
     55 int RunSlave(int iteration) {
     56   base::FilePath exe;
     57   PathService::Get(base::FILE_EXE, &exe);
     58 
     59   CommandLine cmdline(exe);
     60   cmdline.AppendArg(base::IntToString(iteration));
     61 
     62   base::ProcessHandle handle;
     63   if (!base::LaunchProcess(cmdline, base::LaunchOptions(), &handle)) {
     64     printf("Unable to run test\n");
     65     return kError;
     66   }
     67 
     68   int exit_code;
     69   if (!base::WaitForExitCode(handle, &exit_code)) {
     70     printf("Unable to get return code\n");
     71     return kError;
     72   }
     73   return exit_code;
     74 }
     75 
     76 // Main loop for the master process.
     77 int MasterCode() {
     78   for (int i = 0; i < 100000; i++) {
     79     int ret = RunSlave(i);
     80     if (kExpectedCrash != ret)
     81       return ret;
     82   }
     83 
     84   printf("More than enough...\n");
     85 
     86   return 0;
     87 }
     88 
     89 // -----------------------------------------------------------------------
     90 
     91 std::string GenerateStressKey() {
     92   char key[20 * 1024];
     93   size_t size = 50 + rand() % 20000;
     94   CacheTestFillBuffer(key, size, true);
     95 
     96   key[size - 1] = '\0';
     97   return std::string(key);
     98 }
     99 
    100 // This thread will loop forever, adding and removing entries from the cache.
    101 // iteration is the current crash cycle, so the entries on the cache are marked
    102 // to know which instance of the application wrote them.
    103 void StressTheCache(int iteration) {
    104   int cache_size = 0x2000000;  // 32MB.
    105   uint32 mask = 0xfff;  // 4096 entries.
    106 
    107   base::FilePath path;
    108   PathService::Get(base::DIR_TEMP, &path);
    109   path = path.AppendASCII("cache_test_stress");
    110 
    111   base::Thread cache_thread("CacheThread");
    112   if (!cache_thread.StartWithOptions(
    113           base::Thread::Options(base::MessageLoop::TYPE_IO, 0)))
    114     return;
    115 
    116   disk_cache::BackendImpl* cache =
    117       new disk_cache::BackendImpl(path, mask,
    118                                   cache_thread.message_loop_proxy().get(),
    119                                   NULL);
    120   cache->SetMaxSize(cache_size);
    121   cache->SetFlags(disk_cache::kNoLoadProtection);
    122 
    123   net::TestCompletionCallback cb;
    124   int rv = cache->Init(cb.callback());
    125 
    126   if (cb.GetResult(rv) != net::OK) {
    127     printf("Unable to initialize cache.\n");
    128     return;
    129   }
    130   printf("Iteration %d, initial entries: %d\n", iteration,
    131          cache->GetEntryCount());
    132 
    133   int seed = static_cast<int>(Time::Now().ToInternalValue());
    134   srand(seed);
    135 
    136   // kNumKeys is meant to be enough to have about 3x or 4x iterations before
    137   // the process crashes.
    138 #ifdef NDEBUG
    139   const int kNumKeys = 4000;
    140 #else
    141   const int kNumKeys = 1200;
    142 #endif
    143   const int kNumEntries = 30;
    144   std::string keys[kNumKeys];
    145   disk_cache::Entry* entries[kNumEntries] = {0};
    146 
    147   for (int i = 0; i < kNumKeys; i++) {
    148     keys[i] = GenerateStressKey();
    149   }
    150 
    151   const int kSize = 20000;
    152   scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(kSize));
    153   memset(buffer->data(), 'k', kSize);
    154 
    155   for (int i = 0;; i++) {
    156     int slot = rand() % kNumEntries;
    157     int key = rand() % kNumKeys;
    158     bool truncate = (rand() % 2 == 0);
    159     int size = kSize - (rand() % 20) * kSize / 20;
    160 
    161     if (entries[slot])
    162       entries[slot]->Close();
    163 
    164     net::TestCompletionCallback cb;
    165     rv = cache->OpenEntry(keys[key], &entries[slot], cb.callback());
    166     if (cb.GetResult(rv) != net::OK) {
    167       rv = cache->CreateEntry(keys[key], &entries[slot], cb.callback());
    168       CHECK_EQ(net::OK, cb.GetResult(rv));
    169     }
    170 
    171     base::snprintf(buffer->data(), kSize,
    172                    "i: %d iter: %d, size: %d, truncate: %d     ", i, iteration,
    173                    size, truncate ? 1 : 0);
    174     rv = entries[slot]->WriteData(0, 0, buffer.get(), size, cb.callback(),
    175                                   truncate);
    176     CHECK_EQ(size, cb.GetResult(rv));
    177 
    178     if (rand() % 100 > 80) {
    179       key = rand() % kNumKeys;
    180       net::TestCompletionCallback cb2;
    181       rv = cache->DoomEntry(keys[key], cb2.callback());
    182       cb2.GetResult(rv);
    183     }
    184 
    185     if (!(i % 100))
    186       printf("Entries: %d    \r", i);
    187   }
    188 }
    189 
    190 // We want to prevent the timer thread from killing the process while we are
    191 // waiting for the debugger to attach.
    192 bool g_crashing = false;
    193 
    194 // RunSoon() and CrashCallback() reference each other, unfortunately.
    195 void RunSoon(base::MessageLoop* target_loop);
    196 
    197 void CrashCallback() {
    198   // Keep trying to run.
    199   RunSoon(base::MessageLoop::current());
    200 
    201   if (g_crashing)
    202     return;
    203 
    204   if (rand() % 100 > 30) {
    205     printf("sweet death...\n");
    206 #if defined(OS_WIN)
    207     // Windows does more work on _exit() that we would like, so we use Kill.
    208     base::KillProcessById(base::GetCurrentProcId(), kExpectedCrash, false);
    209 #elif defined(OS_POSIX)
    210     // On POSIX, _exit() will terminate the process with minimal cleanup,
    211     // and it is cleaner than killing.
    212     _exit(kExpectedCrash);
    213 #endif
    214   }
    215 }
    216 
    217 void RunSoon(base::MessageLoop* target_loop) {
    218   const base::TimeDelta kTaskDelay = base::TimeDelta::FromSeconds(10);
    219   target_loop->PostDelayedTask(
    220       FROM_HERE, base::Bind(&CrashCallback), kTaskDelay);
    221 }
    222 
    223 // We leak everything here :)
    224 bool StartCrashThread() {
    225   base::Thread* thread = new base::Thread("party_crasher");
    226   if (!thread->Start())
    227     return false;
    228 
    229   RunSoon(thread->message_loop());
    230   return true;
    231 }
    232 
    233 void CrashHandler(const std::string& str) {
    234   g_crashing = true;
    235   base::debug::BreakDebugger();
    236 }
    237 
    238 bool MessageHandler(int severity, const char* file, int line,
    239                     size_t message_start, const std::string& str) {
    240   const size_t kMaxMessageLen = 48;
    241   char message[kMaxMessageLen];
    242   size_t len = std::min(str.length() - message_start, kMaxMessageLen - 1);
    243 
    244   memcpy(message, str.c_str() + message_start, len);
    245   message[len] = '\0';
    246 #if !defined(DISK_CACHE_TRACE_TO_LOG)
    247   disk_cache::Trace("%s", message);
    248 #endif
    249   return false;
    250 }
    251 
    252 // -----------------------------------------------------------------------
    253 
    254 #if defined(OS_WIN)
    255 // {B9A153D4-31C3-48e4-9ABF-D54383F14A0D}
    256 const GUID kStressCacheTraceProviderName = {
    257     0xb9a153d4, 0x31c3, 0x48e4,
    258         { 0x9a, 0xbf, 0xd5, 0x43, 0x83, 0xf1, 0x4a, 0xd } };
    259 #endif
    260 
    261 int main(int argc, const char* argv[]) {
    262   // Setup an AtExitManager so Singleton objects will be destructed.
    263   base::AtExitManager at_exit_manager;
    264 
    265   if (argc < 2)
    266     return MasterCode();
    267 
    268   logging::SetLogAssertHandler(CrashHandler);
    269   logging::SetLogMessageHandler(MessageHandler);
    270 
    271 #if defined(OS_WIN)
    272   logging::LogEventProvider::Initialize(kStressCacheTraceProviderName);
    273 #else
    274   CommandLine::Init(argc, argv);
    275   logging::LoggingSettings settings;
    276   settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
    277   logging::InitLogging(settings);
    278 #endif
    279 
    280   // Some time for the memory manager to flush stuff.
    281   base::PlatformThread::Sleep(base::TimeDelta::FromSeconds(3));
    282   base::MessageLoop message_loop(base::MessageLoop::TYPE_IO);
    283 
    284   char* end;
    285   long int iteration = strtol(argv[1], &end, 0);
    286 
    287   if (!StartCrashThread()) {
    288     printf("failed to start thread\n");
    289     return kError;
    290   }
    291 
    292   StressTheCache(iteration);
    293   return 0;
    294 }
    295