Disk cache: switch stress_cache to perform fully async operations to

get a more realistic environmenrt.

BUG=none

Review URL: https://codereview.chromium.org/1351223002

Cr-Commit-Position: refs/heads/master@{#350237}

1 files changed, 205 insertions, 56 deletions

diff --git a/net/tools/stress_cache/stress_cache.cc b/net/tools/stress_cache/stress_cache.cc
index 0706d4c..29ddff2 100644
--- a/net/tools/stress_cache/stress_cache.cc
+++ b/net/tools/stress_cache/stress_cache.cc
@@ -19,6 +19,7 @@
 
 #include "base/at_exit.h"
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
 #include "base/files/file_path.h"
@@ -28,6 +29,7 @@
 #include "base/path_service.h"
 #include "base/process/launch.h"
 #include "base/process/process.h"
+#include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ -98,6 +100,197 @@ std::string GenerateStressKey() {
   return std::string(key);
 }
 
+// kNumKeys is meant to be enough to have about 3x or 4x iterations before
+// the process crashes.
+#ifdef NDEBUG
+const int kNumKeys = 4000;
+#else
+const int kNumKeys = 1200;
+#endif
+const int kNumEntries = 30;
+const int kBufferSize = 2000;
+const int kReadSize = 20;
+
+// Things that an entry can be doing.
+enum Operation { NONE, OPEN, CREATE, READ, WRITE, DOOM };
+
+// This class encapsulates a cache entry and the operations performed on that
+// entry. An entry is opened or created as needed, the current content is then
+// verified and then something is written to the entry. At that point, the
+// |state_| becomes NONE again, waiting for another write, unless the entry is
+// closed or deleted.
+class EntryWrapper {
+ public:
+  EntryWrapper() : entry_(nullptr), state_(NONE) {
+    buffer_ = new net::IOBuffer(kBufferSize);
+    memset(buffer_->data(), 'k', kBufferSize);
+  }
+
+  Operation state() const { return state_; }
+
+  void DoOpen(int key);
+
+ private:
+  void OnOpenDone(int key, int result);
+  void DoRead();
+  void OnReadDone(int result);
+  void DoWrite();
+  void OnWriteDone(int size, int result);
+  void DoDelete(const std::string& key);
+  void OnDeleteDone(int result);
+  void DoIdle();
+
+  disk_cache::Entry* entry_;
+  Operation state_;
+  scoped_refptr<net::IOBuffer> buffer_;
+};
+
+// The data that the main thread is working on.
+struct Data {
+  Data() : pendig_operations(0), writes(0), iteration(0), cache(nullptr) {}
+
+  int pendig_operations;  // Counter of simultaneous operations.
+  int writes;             // How many writes since this iteration started.
+  int iteration;          // The iteration (number of crashes).
+  disk_cache::BackendImpl* cache;
+  std::string keys[kNumKeys];
+  EntryWrapper entries[kNumEntries];
+};
+
+Data* g_data = nullptr;
+
+void EntryWrapper::DoOpen(int key) {
+  DCHECK_EQ(state_, NONE);
+  if (entry_)
+    return DoRead();
+
+  state_ = OPEN;
+  int rv = g_data->cache->OpenEntry(
+      g_data->keys[key], &entry_,
+      base::Bind(&EntryWrapper::OnOpenDone, base::Unretained(this), key));
+  if (rv != net::ERR_IO_PENDING)
+    OnOpenDone(key, rv);
+}
+
+void EntryWrapper::OnOpenDone(int key, int result) {
+  if (result == net::OK)
+    return DoRead();
+
+  CHECK_EQ(state_, OPEN);
+  state_ = CREATE;
+  result = g_data->cache->CreateEntry(
+      g_data->keys[key], &entry_,
+      base::Bind(&EntryWrapper::OnOpenDone, base::Unretained(this), key));
+  if (result != net::ERR_IO_PENDING)
+    OnOpenDone(key, result);
+}
+
+void EntryWrapper::DoRead() {
+  int current_size = entry_->GetDataSize(0);
+  if (!current_size)
+    return DoWrite();
+
+  state_ = READ;
+  memset(buffer_->data(), 'k', kReadSize);
+  int rv = entry_->ReadData(
+      0, 0, buffer_.get(), kReadSize,
+      base::Bind(&EntryWrapper::OnReadDone, base::Unretained(this)));
+  if (rv != net::ERR_IO_PENDING)
+    OnReadDone(rv);
+}
+
+void EntryWrapper::OnReadDone(int result) {
+  DCHECK_EQ(state_, READ);
+  CHECK_EQ(result, kReadSize);
+  CHECK_EQ(0, memcmp(buffer_->data(), "Write: ", 7));
+  DoWrite();
+}
+
+void EntryWrapper::DoWrite() {
+  bool truncate = (rand() % 2 == 0);
+  int size = kBufferSize - (rand() % 20) * kBufferSize / 20;
+  state_ = WRITE;
+  base::snprintf(buffer_->data(), kBufferSize,
+                 "Write: %d iter: %d, size: %d, truncate: %d     ",
+                 g_data->writes, g_data->iteration, size, truncate ? 1 : 0);
+  int rv = entry_->WriteData(
+      0, 0, buffer_.get(), size,
+      base::Bind(&EntryWrapper::OnWriteDone, base::Unretained(this), size),
+      truncate);
+  if (rv != net::ERR_IO_PENDING)
+    OnWriteDone(size, rv);
+}
+
+void EntryWrapper::OnWriteDone(int size, int result) {
+  DCHECK_EQ(state_, WRITE);
+  CHECK_EQ(size, result);
+  if (!(g_data->writes++ % 100))
+    printf("Entries: %d    \r", g_data->writes);
+
+  int random = rand() % 100;
+  std::string key = entry_->GetKey();
+  if (random > 90)
+    return DoDelete(key);  // 10% delete then close.
+
+  if (random > 60) {  // 20% close.
+    entry_->Close();
+    entry_ = nullptr;
+  }
+
+  if (random > 80)
+    return DoDelete(key);  // 10% close then delete.
+
+  DoIdle();  // 60% do another write later.
+}
+
+void EntryWrapper::DoDelete(const std::string& key) {
+  state_ = DOOM;
+  int rv = g_data->cache->DoomEntry(
+      key, base::Bind(&EntryWrapper::OnDeleteDone, base::Unretained(this)));
+  if (rv != net::ERR_IO_PENDING)
+    OnDeleteDone(rv);
+}
+
+void EntryWrapper::OnDeleteDone(int result) {
+  DCHECK_EQ(state_, DOOM);
+  if (entry_) {
+    entry_->Close();
+    entry_ = nullptr;
+  }
+  DoIdle();
+}
+
+void LoopTask();
+
+void EntryWrapper::DoIdle() {
+  state_ = NONE;
+  g_data->pendig_operations--;
+  DCHECK(g_data->pendig_operations);
+  base::MessageLoop::current()->task_runner()->PostTask(FROM_HERE,
+                                                        base::Bind(&LoopTask));
+}
+
+// The task that keeps the main thread busy. Whenever an entry becomes idle this
+// task is executed again.
+void LoopTask() {
+  if (g_data->pendig_operations >= kNumEntries)
+    return;
+
+  int slot = rand() % kNumEntries;
+  if (g_data->entries[slot].state() == NONE) {
+    // Each slot will have some keys assigned to it so that the same entry will
+    // not be open by two slots, which means that the state is well known at
+    // all times.
+    int keys_per_entry = kNumKeys / kNumEntries;
+    int key = rand() % keys_per_entry + keys_per_entry * slot;
+    g_data->pendig_operations++;
+    g_data->entries[slot].DoOpen(key);
+  }
+
+  base::MessageLoop::current()->task_runner()->PostTask(FROM_HERE,
+                                                        base::Bind(&LoopTask));
+}
+
 // This thread will loop forever, adding and removing entries from the cache.
 // iteration is the current crash cycle, so the entries on the cache are marked
 // to know which instance of the application wrote them.
@@ -114,76 +307,32 @@ void StressTheCache(int iteration) {
           base::Thread::Options(base::MessageLoop::TYPE_IO, 0)))
     return;
 
-  disk_cache::BackendImpl* cache = new disk_cache::BackendImpl(
+  g_data = new Data();
+  g_data->iteration = iteration;
+  g_data->cache = new disk_cache::BackendImpl(
       path, mask, cache_thread.task_runner().get(), NULL);
-  cache->SetMaxSize(cache_size);
-  cache->SetFlags(disk_cache::kNoLoadProtection);
+  g_data->cache->SetMaxSize(cache_size);
+  g_data->cache->SetFlags(disk_cache::kNoLoadProtection);
 
   net::TestCompletionCallback cb;
-  int rv = cache->Init(cb.callback());
+  int rv = g_data->cache->Init(cb.callback());
 
   if (cb.GetResult(rv) != net::OK) {
     printf("Unable to initialize cache.\n");
     return;
   }
   printf("Iteration %d, initial entries: %d\n", iteration,
-         cache->GetEntryCount());
+         g_data->cache->GetEntryCount());
 
   int seed = static_cast<int>(Time::Now().ToInternalValue());
   srand(seed);
 
-  // kNumKeys is meant to be enough to have about 3x or 4x iterations before
-  // the process crashes.
-#ifdef NDEBUG
-  const int kNumKeys = 4000;
-#else
-  const int kNumKeys = 1200;
-#endif
-  const int kNumEntries = 30;
-  std::string keys[kNumKeys];
-  disk_cache::Entry* entries[kNumEntries] = {0};
+  for (int i = 0; i < kNumKeys; i++)
+    g_data->keys[i] = GenerateStressKey();
 
-  for (int i = 0; i < kNumKeys; i++) {
-    keys[i] = GenerateStressKey();
-  }
-
-  const int kSize = 20000;
-  scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(kSize));
-  memset(buffer->data(), 'k', kSize);
-
-  for (int i = 0;; i++) {
-    int slot = rand() % kNumEntries;
-    int key = rand() % kNumKeys;
-    bool truncate = (rand() % 2 == 0);
-    int size = kSize - (rand() % 20) * kSize / 20;
-
-    if (entries[slot])
-      entries[slot]->Close();
-
-    net::TestCompletionCallback cb;
-    rv = cache->OpenEntry(keys[key], &entries[slot], cb.callback());
-    if (cb.GetResult(rv) != net::OK) {
-      rv = cache->CreateEntry(keys[key], &entries[slot], cb.callback());
-      CHECK_EQ(net::OK, cb.GetResult(rv));
-    }
-
-    base::snprintf(buffer->data(), kSize,
-                   "i: %d iter: %d, size: %d, truncate: %d     ", i, iteration,
-                   size, truncate ? 1 : 0);
-    rv = entries[slot]->WriteData(0, 0, buffer.get(), size, cb.callback(),
-                                  truncate);
-    CHECK_EQ(size, cb.GetResult(rv));
-
-    if (rand() % 100 > 80) {
-      key = rand() % kNumKeys;
-      net::TestCompletionCallback cb2;
-      rv = cache->DoomEntry(keys[key], cb2.callback());
-      cb2.GetResult(rv);
-    }
-
-    if (!(i % 100))
-      printf("Entries: %d    \r", i);
-  }
+  base::MessageLoop::current()->task_runner()->PostTask(FROM_HERE,
+                                                        base::Bind(&LoopTask));
+  base::RunLoop().Run();
 }
 
 // We want to prevent the timer thread from killing the process while we are