DoomPartialEntry should not attempt to doom an already doomed entry.

net/http/mock_http_cache.cc

Index: net/http/mock_http_cache.cc
diff --git a/net/http/mock_http_cache.cc b/net/http/mock_http_cache.cc
index 514cc4208f82c79b3cafb876ef027716fd69b09f..920b866dac787cb8839df1f21741d16c0976f3c3 100644
--- a/net/http/mock_http_cache.cc
+++ b/net/http/mock_http_cache.cc
@@ -74,7 +74,9 @@ MockDiskEntry::MockDiskEntry(const std::string& key)
       fail_sparse_requests_(false),
       busy_(false),
       delayed_(false),
-      cancel_(false) {
+      cancel_(false),
+      defer_op_(DEFER_NONE),
+      resume_return_code_(0) {
   test_mode_ = GetTestModeForEntry(key);
 }
 
@@ -125,10 +127,26 @@ int MockDiskEntry::ReadData(int index,
   if (MockHttpCache::GetTestMode(test_mode_) & TEST_MODE_SYNC_CACHE_READ)
     return num;
 
+  // Pause and resume.
+  if (defer_op_ == DEFER_READ) {
+    defer_op_ = DEFER_NONE;
+    resume_callback_ = callback;
+    resume_return_code_ = num;
+    return ERR_IO_PENDING;
+  }
+
   CallbackLater(callback, num);
   return ERR_IO_PENDING;
 }
 
+int MockDiskEntry::ResumeCacheOperation() {
+  DCHECK(!resume_callback_.is_null());
+  CallbackLater(resume_callback_, resume_return_code_);
+  resume_callback_.Reset();
+  resume_return_code_ = 0;
+  return ERR_IO_PENDING;
+}
+
 int MockDiskEntry::WriteData(int index,
                              int offset,
                              IOBuffer* buf,
@@ -376,7 +394,9 @@ MockDiskCache::MockDiskCache()
       fail_requests_(false),
       soft_failures_(false),
       double_create_check_(true),
-      fail_sparse_requests_(false) {}
+      fail_sparse_requests_(false),
+      defer_op_(DEFER_NONE),
+      resume_return_code_(0) {}
 
 MockDiskCache::~MockDiskCache() {
   ReleaseAll();
@@ -402,7 +422,12 @@ int MockDiskCache::OpenEntry(const std::string& key,
     return ERR_CACHE_OPEN_FAILURE;
 
   if (it->second->is_doomed()) {
-    it->second->Release();
+    // It's possible that the entry was doomed directly by invoking

[jkarlin, 2017/07/12 16:15:54]

There is a lot of new code here to track doomed entries so that they can later
be resumed by the test.

This is why I suggested that when setting the defer, the test passes a callback.
The entry can then run the callback and pass the test a closure to run when the
test wants the entry to resume. The closure would have a ref to the entry and
run the resume function.

That way the MockDiskCache doesn't need to keep track of doomed entries since
the test calls the entry directly.

[shivanisha, 2017/07/12 17:56:31]

Keeping track of doomed_entries seems kind of good to have. The passing of entry
to the test seems to require more work in the test for every defer-resume and
less consistent in terms of layering since it passes an entry reference back to
the test. WDYT?

[shivanisha, 2017/07/13 14:47:26]

Let me know if you prefer to have the closure approach or the doomed_entries_
approach is fine.

+    // MockDiskEntry::Doom and thus was not inserted into the doomed_entries_
+    // map. Insert it now.
+    if (doomed_entries_.count(key))
+      doomed_entries_[key]->Release();
+    doomed_entries_[key] = it->second;
     entries_.erase(it);
     return ERR_CACHE_OPEN_FAILURE;
   }
@@ -437,7 +462,12 @@ int MockDiskCache::CreateEntry(const std::string& key,
       else
         return ERR_CACHE_CREATE_FAILURE;
     }
-    it->second->Release();
+    // It's possible that the entry was doomed directly by invoking
+    // MockDiskEntry::Doom and thus was not inserted into the doomed_entries_
+    // map. Insert it now.
+    if (doomed_entries_.count(key))
+      doomed_entries_[key]->Release();
+    doomed_entries_[key] = it->second;
     entries_.erase(it);
   }
 
@@ -460,6 +490,14 @@ int MockDiskCache::CreateEntry(const std::string& key,
   if (GetTestModeForEntry(key) & TEST_MODE_SYNC_CACHE_START)
     return OK;
 
+  // Pause and resume.
+  if (defer_op_ == DEFER_CREATE) {
+    defer_op_ = DEFER_NONE;
+    resume_callback_ = callback;
+    resume_return_code_ = OK;
+    return ERR_IO_PENDING;
+  }
+
   CallbackLater(callback, OK);
   return ERR_IO_PENDING;
 }
@@ -469,7 +507,9 @@ int MockDiskCache::DoomEntry(const std::string& key,
   DCHECK(!callback.is_null());
   EntryMap::iterator it = entries_.find(key);
   if (it != entries_.end()) {
-    it->second->Release();
+    if (doomed_entries_.count(key))
+      doomed_entries_[key]->Release();
+    doomed_entries_[key] = it->second;
     entries_.erase(it);
     doomed_count_++;
   }
@@ -526,10 +566,13 @@ size_t MockDiskCache::DumpMemoryStats(
 }
 
 void MockDiskCache::ReleaseAll() {
-  EntryMap::iterator it = entries_.begin();
-  for (; it != entries_.end(); ++it)
-    it->second->Release();
+  for (auto entry : entries_)
+    entry.second->Release();
   entries_.clear();
+
+  for (auto doomed : doomed_entries_)
+    doomed.second->Release();
+  doomed_entries_.clear();
 }
 
 void MockDiskCache::CallbackLater(const CompletionCallback& callback,
@@ -539,10 +582,60 @@ void MockDiskCache::CallbackLater(const CompletionCallback& callback,
 }
 
 bool MockDiskCache::IsDiskEntryDoomed(const std::string& key) {
+  auto doomed_it = doomed_entries_.find(key);
+  if (doomed_it != doomed_entries_.end())
+    return true;
+
+  auto it = entries_.find(key);
+  if (it != entries_.end())
+    return it->second->is_doomed();
+
+  return false;
+}
+
+bool MockDiskCache::IsDiskEntryNotDoomed(const std::string& key) {
+  auto it = entries_.find(key);
+  if (it != entries_.end())
+    return !it->second->is_doomed();
+
+  return false;
+}
+
+int MockDiskCache::ResumeCacheOperation() {
+  DCHECK(!resume_callback_.is_null());
+  CallbackLater(resume_callback_, resume_return_code_);
+  resume_callback_.Reset();
+  resume_return_code_ = 0;
+  return ERR_IO_PENDING;
+}
+
+void MockDiskCache::SetDefer(const std::string& key, const DeferOp defer_op) {
   auto it = entries_.find(key);
   if (it == entries_.end())
-    return false;
-  return it->second->is_doomed();
+    return;
+  it->second->SetDefer(defer_op);
+}
+
+int MockDiskCache::ResumeCacheOperation(const std::string& key) {
+  auto it = entries_.find(key);
+  if (it != entries_.end())
+    return it->second->ResumeCacheOperation();
+
+  return ERR_UNEXPECTED;
+}
+
+int MockDiskCache::ResumeDoomedEntryCacheOperation(const std::string& key) {
+  auto doomed_it = doomed_entries_.find(key);
+  if (doomed_it != doomed_entries_.end())
+    return doomed_it->second->ResumeCacheOperation();
+
+  auto it = entries_.find(key);
+  if (it != entries_.end()) {
+    DCHECK(it->second->is_doomed());
+    return it->second->ResumeCacheOperation();
+  }
+
+  return ERR_UNEXPECTED;
 }
 
 //-----------------------------------------------------------------------------