Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(540)

Unified Diff: net/http/http_cache_transaction.cc

Issue 2721933002: HttpCache::Transaction layer allowing parallel validation (Closed)
Patch Set: Fixed data race Created 3 years, 8 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
Index: net/http/http_cache_transaction.cc
diff --git a/net/http/http_cache_transaction.cc b/net/http/http_cache_transaction.cc
index 518944650747e6a3dc7f39c58b4b4d7cb1610758..48852bf7d33a18522b39afc147f1422f0aac566b 100644
--- a/net/http/http_cache_transaction.cc
+++ b/net/http/http_cache_transaction.cc
@@ -156,6 +156,7 @@ HttpCache::Transaction::Transaction(RequestPriority priority, HttpCache* cache)
new_entry_(NULL),
new_response_(NULL),
mode_(NONE),
+ original_mode_(NONE),
reading_(false),
invalid_range_(false),
truncated_(false),
@@ -196,16 +197,12 @@ HttpCache::Transaction::~Transaction() {
if (cache_) {
if (entry_) {
- bool cancel_request = reading_ && response_.headers.get();
- if (cancel_request) {
- if (partial_) {
- entry_->disk_entry->CancelSparseIO();
- } else {
- cancel_request &= (response_.headers->response_code() == 200);
- }
- }
+ bool writing_incomplete = cache_->IsTransactionWritingIncomplete(
+ entry_, this, request_->method);
+ if (writing_incomplete && partial_)
+ entry_->disk_entry->CancelSparseIO();
- cache_->DoneWithEntry(entry_, this, cancel_request);
+ cache_->DoneWithEntry(entry_, this, writing_incomplete);
} else if (cache_pending_) {
cache_->RemovePendingTransaction(this);
}
@@ -565,6 +562,12 @@ void HttpCache::Transaction::GetConnectionAttempts(
old_connection_attempts_.end());
}
+void HttpCache::Transaction::SetValidatingCannotProceed() {
+ DCHECK(!reading_);
+ next_state_ = STATE_HEADERS_PHASE_CANNOT_PROCEED;
+ entry_ = nullptr;
+}
+
size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// TODO(xunjieli): Consider improving the coverage. crbug.com/669108.
return 0;
@@ -579,7 +582,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// GetBackend* -> InitEntry -> OpenEntry* -> CreateEntry* -> AddToEntry* ->
// SendRequest* -> SuccessfulSendRequest -> OverwriteCachedResponse ->
// CacheWriteResponse* -> TruncateCachedData* -> TruncateCachedMetadata* ->
-// PartialHeadersReceived
+// PartialHeadersReceived -> FinishHeaders*
//
// Read():
// NetworkRead* -> CacheWriteData*
@@ -588,7 +591,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// Start():
// GetBackend* -> InitEntry -> OpenEntry* -> AddToEntry* -> CacheReadResponse*
// -> CacheDispatchValidation -> BeginPartialCacheValidation() ->
-// BeginCacheValidation() -> SetupEntryForRead()
+// BeginCacheValidation() -> SetupEntryForRead() -> FinishHeaders*
//
// Read():
// CacheReadData*
@@ -600,7 +603,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// BeginCacheValidation() -> SendRequest* -> SuccessfulSendRequest ->
// UpdateCachedResponse -> CacheWriteUpdatedResponse* ->
// UpdateCachedResponseComplete -> OverwriteCachedResponse ->
-// PartialHeadersReceived
+// PartialHeadersReceived -> FinishHeaders*
//
// Read():
// CacheReadData*
@@ -611,7 +614,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// -> CacheDispatchValidation -> BeginPartialCacheValidation() ->
// BeginCacheValidation() -> SendRequest* -> SuccessfulSendRequest ->
// OverwriteCachedResponse -> CacheWriteResponse* -> DoTruncateCachedData* ->
-// TruncateCachedMetadata* -> PartialHeadersReceived
+// TruncateCachedMetadata* -> PartialHeadersReceived -> FinishHeaders*
//
// Read():
// NetworkRead* -> CacheWriteData*
@@ -625,7 +628,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// BeginCacheValidation() -> SendRequest* -> SuccessfulSendRequest ->
// UpdateCachedResponse -> CacheWriteUpdatedResponse* ->
// UpdateCachedResponseComplete -> OverwriteCachedResponse ->
-// PartialHeadersReceived
+// PartialHeadersReceived -> FinishHeaders*
//
// Read() 1:
// NetworkRead* -> CacheWriteData*
@@ -666,7 +669,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// GetBackend* -> InitEntry -> OpenEntry* -> AddToEntry* -> CacheReadResponse*
// -> CacheDispatchValidation -> BeginPartialCacheValidation() ->
// BeginCacheValidation() -> SendRequest* -> SuccessfulSendRequest ->
-// OverwriteCachedResponse
+// OverwriteCachedResponse -> FinishHeaders*
//
// 10. HEAD. Sparse entry, partially cached:
// Serve the request from the cache, as long as it doesn't require
@@ -691,7 +694,7 @@ size_t HttpCache::Transaction::EstimateMemoryUsage() const {
// GetBackend* -> InitEntry -> OpenEntry* -> AddToEntry* -> CacheReadResponse*
// -> CacheToggleUnusedSincePrefetch* -> CacheDispatchValidation ->
// BeginPartialCacheValidation() -> BeginCacheValidation() ->
-// SetupEntryForRead()
+// SetupEntryForRead() -> FinishHeaders*
//
// Read():
// CacheReadData*
@@ -705,8 +708,9 @@ int HttpCache::Transaction::DoLoop(int result) {
DCHECK(!in_do_loop_);
int rv = result;
+ State state = next_state_;
do {
- State state = next_state_;
+ state = next_state_;
next_state_ = STATE_UNSET;
base::AutoReset<bool> scoped_in_do_loop(&in_do_loop_, true);
@@ -843,6 +847,15 @@ int HttpCache::Transaction::DoLoop(int result) {
case STATE_CACHE_READ_METADATA_COMPLETE:
rv = DoCacheReadMetadataComplete(rv);
break;
+ case STATE_HEADERS_PHASE_CANNOT_PROCEED:
+ rv = DoHeadersPhaseCannotProceed();
+ break;
+ case STATE_FINISH_HEADERS:
+ rv = DoFinishHeaders(rv);
+ break;
+ case STATE_FINISH_HEADERS_COMPLETE:
+ rv = DoFinishHeadersComplete(rv);
+ break;
case STATE_NETWORK_READ:
DCHECK_EQ(OK, rv);
rv = DoNetworkRead();
@@ -879,8 +892,13 @@ int HttpCache::Transaction::DoLoop(int result) {
} while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
+ // Assert Start() state machine's allowed last state in successful cases when
+ // caching is happening.
+ DCHECK(reading_ || rv != OK || !entry_ ||
+ state == STATE_FINISH_HEADERS_COMPLETE);
+
if (rv != ERR_IO_PENDING && !callback_.is_null()) {
- read_buf_ = NULL; // Release the buffer before invoking the callback.
+ read_buf_ = nullptr; // Release the buffer before invoking the callback.
base::ResetAndReturn(&callback_).Run(rv);
}
@@ -907,7 +925,7 @@ int HttpCache::Transaction::DoGetBackendComplete(int result) {
if (effective_load_flags_ & LOAD_ONLY_FROM_CACHE) {
if (effective_load_flags_ & LOAD_BYPASS_CACHE) {
// The client has asked for nonsense.
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
mode_ = READ;
@@ -946,7 +964,7 @@ int HttpCache::Transaction::DoGetBackendComplete(int result) {
// If must use cache, then we must fail. This can happen for back/forward
// navigations to a page generated via a form post.
if (!(mode_ & READ) && effective_load_flags_ & LOAD_ONLY_FROM_CACHE) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
@@ -963,6 +981,9 @@ int HttpCache::Transaction::DoGetBackendComplete(int result) {
// This is only set if we have something to do with the response.
range_requested_ = (partial_.get() != NULL);
+ // mode_ may change later, save the initial mode in case we need to restart
+ // this request.
+ original_mode_ = mode_;
return OK;
}
@@ -971,7 +992,7 @@ int HttpCache::Transaction::DoInitEntry() {
DCHECK(!new_entry_);
if (!cache_.get()) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_UNEXPECTED;
}
@@ -1008,7 +1029,7 @@ int HttpCache::Transaction::DoOpenEntryComplete(int result) {
}
if (result == ERR_CACHE_RACE) {
- TransitionToState(STATE_INIT_ENTRY);
+ TransitionToState(STATE_HEADERS_PHASE_CANNOT_PROCEED);
return OK;
}
@@ -1034,7 +1055,7 @@ int HttpCache::Transaction::DoOpenEntryComplete(int result) {
// The entry does not exist, and we are not permitted to create a new entry,
// so we must fail.
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
@@ -1053,8 +1074,9 @@ int HttpCache::Transaction::DoDoomEntryComplete(int result) {
net_log_.EndEventWithNetErrorCode(NetLogEventType::HTTP_CACHE_DOOM_ENTRY,
result);
cache_pending_ = false;
- TransitionToState(result == ERR_CACHE_RACE ? STATE_INIT_ENTRY
- : STATE_CREATE_ENTRY);
+ TransitionToState(result == ERR_CACHE_RACE
+ ? STATE_HEADERS_PHASE_CANNOT_PROCEED
+ : STATE_CREATE_ENTRY);
return OK;
}
@@ -1081,7 +1103,7 @@ int HttpCache::Transaction::DoCreateEntryComplete(int result) {
break;
case ERR_CACHE_RACE:
- TransitionToState(STATE_INIT_ENTRY);
+ TransitionToState(STATE_HEADERS_PHASE_CANNOT_PROCEED);
break;
default:
@@ -1162,13 +1184,13 @@ int HttpCache::Transaction::DoAddToEntryComplete(int result) {
new_entry_ = NULL;
if (result == ERR_CACHE_RACE) {
- TransitionToState(STATE_INIT_ENTRY);
+ TransitionToState(STATE_HEADERS_PHASE_CANNOT_PROCEED);
return OK;
}
if (result == ERR_CACHE_LOCK_TIMEOUT) {
if (mode_ == READ) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
@@ -1182,12 +1204,15 @@ int HttpCache::Transaction::DoAddToEntryComplete(int result) {
return OK;
}
- open_entry_last_used_ = entry_->disk_entry->GetLastUsed();
+ // Access timestamp for histograms only if entry is already written, to avoid
+ // data race since cache thread can also access this.
+ if (!cache_->IsWritingInProgress(entry_))
+ open_entry_last_used_ = entry_->disk_entry->GetLastUsed();
// TODO(jkarlin): We should either handle the case or DCHECK.
if (result != OK) {
NOTREACHED();
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return result;
}
@@ -1226,29 +1251,31 @@ int HttpCache::Transaction::DoCacheReadResponseComplete(int result) {
return OnCacheReadError(result, true);
}
- int current_size = entry_->disk_entry->GetDataSize(kResponseContentIndex);
- int64_t full_response_length = response_.headers->GetContentLength();
-
- // Some resources may have slipped in as truncated when they're not.
- if (full_response_length == current_size)
- truncated_ = false;
-
- // The state machine's handling of StopCaching unfortunately doesn't deal well
- // with resources that are larger than 2GB when there is a truncated or sparse
- // cache entry. While the state machine is reworked to resolve this, the
- // following logic is put in place to defer such requests to the network. The
- // cache should not be storing multi gigabyte resources. See
- // http://crbug.com/89567.
- if ((truncated_ || response_.headers->response_code() == 206) &&
- !range_requested_ &&
- full_response_length > std::numeric_limits<int32_t>::max()) {
- // Does not release the cache entry. If another transaction wants to use
- // this cache entry while this transaction is active, the second transaction
- // will fall back to the network after the timeout.
- DCHECK(!partial_);
- mode_ = NONE;
- TransitionToState(STATE_SEND_REQUEST);
- return OK;
+ if (!cache_->IsWritingInProgress(entry_)) {
Randy Smith (Not in Mondays) 2017/04/19 17:26:34 This scares me. Does this mean that we are openin
jkarlin 2017/04/20 15:05:29 Needs a comment so that we understand why we can't
shivanisha 2017/04/21 23:06:00 Talked with asanka@ yesterday about this and here
+ int current_size = entry_->disk_entry->GetDataSize(kResponseContentIndex);
+ int64_t full_response_length = response_.headers->GetContentLength();
+
+ // Some resources may have slipped in as truncated when they're not.
+ if (full_response_length == current_size)
+ truncated_ = false;
+
+ // The state machine's handling of StopCaching unfortunately doesn't deal
+ // well with resources that are larger than 2GB when there is a truncated or
+ // sparse cache entry. While the state machine is reworked to resolve this,
+ // the following logic is put in place to defer such requests to the
+ // network. The cache should not be storing multi gigabyte resources. See
+ // http://crbug.com/89567.
+ if ((truncated_ || response_.headers->response_code() == 206) &&
+ !range_requested_ &&
+ full_response_length > std::numeric_limits<int32_t>::max()) {
+ // Does not release the cache entry. If another transaction wants to use
+ // this cache entry while this transaction is active, the second
+ // transaction will fall back to the network after the timeout.
+ DCHECK(!partial_);
+ mode_ = NONE;
+ TransitionToState(STATE_SEND_REQUEST);
+ return OK;
+ }
}
if (response_.unused_since_prefetch !=
@@ -1330,7 +1357,7 @@ int HttpCache::Transaction::DoCacheQueryData() {
int HttpCache::Transaction::DoCacheQueryDataComplete(int result) {
DCHECK_EQ(OK, result);
if (!cache_.get()) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_UNEXPECTED;
}
@@ -1340,7 +1367,7 @@ int HttpCache::Transaction::DoCacheQueryDataComplete(int result) {
// We may end up here multiple times for a given request.
int HttpCache::Transaction::DoStartPartialCacheValidation() {
if (mode_ == NONE) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -1357,12 +1384,12 @@ int HttpCache::Transaction::DoCompletePartialCacheValidation(int result) {
cache_->DoneReadingFromEntry(entry_, this);
entry_ = NULL;
}
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return result;
}
if (result < 0) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return result;
}
@@ -1388,7 +1415,7 @@ int HttpCache::Transaction::DoSendRequest() {
int rv =
cache_->network_layer_->CreateTransaction(priority_, &network_trans_);
if (rv != OK) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return rv;
}
network_trans_->SetBeforeNetworkStartCallback(before_network_start_callback_);
@@ -1410,7 +1437,7 @@ int HttpCache::Transaction::DoSendRequest() {
int HttpCache::Transaction::DoSendRequestComplete(int result) {
TRACE_EVENT0("io", "HttpCacheTransaction::DoSendRequestComplete");
if (!cache_.get()) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_UNEXPECTED;
}
@@ -1441,7 +1468,7 @@ int HttpCache::Transaction::DoSendRequestComplete(int result) {
DoneWritingToEntry(true);
}
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return result;
}
@@ -1455,7 +1482,7 @@ int HttpCache::Transaction::DoSuccessfulSendRequest() {
new_response->headers->response_code() == 407) {
SetAuthResponse(*new_response);
if (!reading_) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -1480,7 +1507,7 @@ int HttpCache::Transaction::DoSuccessfulSendRequest() {
mode_ = NONE;
partial_.reset();
ResetNetworkTransaction();
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_AUTH_FAILURE_AFTER_READ;
}
@@ -1518,7 +1545,7 @@ int HttpCache::Transaction::DoSuccessfulSendRequest() {
int ret = cache_->DoomEntry(cache_key_, NULL);
DCHECK_EQ(OK, ret);
}
- cache_->DoneWritingToEntry(entry_, true);
+ cache_->DoneWritingToEntry(entry_, true, this);
entry_ = NULL;
mode_ = NONE;
}
@@ -1536,7 +1563,7 @@ int HttpCache::Transaction::DoSuccessfulSendRequest() {
(request_->method == "GET" || request_->method == "POST")) {
// If there is an active entry it may be destroyed with this transaction.
SetResponse(*new_response_);
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -1624,7 +1651,6 @@ int HttpCache::Transaction::DoUpdateCachedResponseComplete(int result) {
} else if (entry_ && !handling_206_) {
DCHECK_EQ(READ_WRITE, mode_);
if (!partial_ || partial_->IsLastRange()) {
- cache_->ConvertWriterToReader(entry_);
mode_ = READ;
}
// We no longer need the network transaction, so destroy it.
@@ -1662,7 +1688,7 @@ int HttpCache::Transaction::DoOverwriteCachedResponse() {
DoneWritingToEntry(false);
mode_ = NONE;
new_response_ = NULL;
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -1683,6 +1709,19 @@ int HttpCache::Transaction::DoOverwriteCachedResponse() {
int HttpCache::Transaction::DoCacheWriteResponse() {
TRACE_EVENT0("io", "HttpCacheTransaction::DoCacheWriteResponse");
TransitionToState(STATE_CACHE_WRITE_RESPONSE_COMPLETE);
+
+ // Invalidate any current entry with a successful response if this transaction
+ // cannot write to this entry. This transaction then continues to read from
+ // the network without writing to the backend.
+ if (entry_ && response_.headers &&
+ !cache_->CanTransactionWriteResponseHeaders(
+ entry_, this, response_.headers->response_code())) {
+ cache_->DoneWritingToEntry(entry_, false, this);
+ entry_ = nullptr;
+ mode_ = NONE;
+ return OK;
+ }
+
return WriteResponseInfoToEntry(truncated_);
}
@@ -1744,10 +1783,12 @@ int HttpCache::Transaction::DoPartialHeadersReceived() {
new_response_ = NULL;
if (!partial_) {
- if (entry_ && entry_->disk_entry->GetDataSize(kMetadataIndex))
+ if (entry_ && entry_->disk_entry->GetDataSize(kMetadataIndex)) {
TransitionToState(STATE_CACHE_READ_METADATA);
- else
- TransitionToState(STATE_NONE);
+ } else {
+ DCHECK(!reading_);
+ TransitionToState(STATE_FINISH_HEADERS);
+ }
return OK;
}
@@ -1761,13 +1802,63 @@ int HttpCache::Transaction::DoPartialHeadersReceived() {
// We are about to return the headers for a byte-range request to the user,
// so let's fix them.
partial_->FixResponseHeaders(response_.headers.get(), true);
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
} else {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
}
return OK;
}
+int HttpCache::Transaction::DoHeadersPhaseCannotProceed() {
+ // If its the Start state machine and it cannot proceed due to a cache
+ // failure, restart this transaction.
+ DCHECK(!reading_);
+ TransitionToState(STATE_INIT_ENTRY);
+ cache_entry_status_ = CacheEntryStatus::ENTRY_UNDEFINED;
+ entry_ = nullptr;
+ mode_ = original_mode_;
+ if (network_trans_)
+ network_trans_.reset();
+ return OK;
+}
+
+int HttpCache::Transaction::DoFinishHeaders(int result) {
+ if (!entry_ || result != OK) {
+ TransitionToState(STATE_NONE);
+ return result;
+ }
+
+ TransitionToState(STATE_FINISH_HEADERS_COMPLETE);
+
+ // If it was an auth failure or 416, this transaction should continue to be
+ // headers_transaction till consumer takes an action, so no need to do
+ // anything now.
+ if (auth_response_.headers.get() ||
+ (new_response_ && new_response_->headers &&
+ new_response_->headers->response_code() == 416))
+ return OK;
+
+ // If there is no response body to be written or read, it does not need to
+ // wait.
+ if (request_->method == "HEAD")
+ return OK;
+
+ // If the transaction needs to wait because another transaction is still
+ // writing the response body, it will return ERR_IO_PENDING now and the
+ // io_callback_ will be invoked when the wait is done.
+ return cache_->DoneWithResponseHeaders(entry_, this);
+}
+
+int HttpCache::Transaction::DoFinishHeadersComplete(int rv) {
+ if (rv == ERR_CACHE_RACE) {
+ TransitionToState(STATE_HEADERS_PHASE_CANNOT_PROCEED);
+ return OK;
+ }
+
+ TransitionToState(STATE_NONE);
+ return rv;
+}
+
int HttpCache::Transaction::DoCacheReadMetadata() {
TRACE_EVENT0("io", "HttpCacheTransaction::DoCacheReadMetadata");
DCHECK(entry_);
@@ -1790,7 +1881,8 @@ int HttpCache::Transaction::DoCacheReadMetadataComplete(int result) {
result);
if (result != response_.metadata->size())
return OnCacheReadError(result, false);
- TransitionToState(STATE_NONE);
+
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -2087,18 +2179,18 @@ int HttpCache::Transaction::BeginCacheRead() {
// TODO(jkarlin): Either handle this case or DCHECK.
if (response_.headers->response_code() == 206 || partial_) {
NOTREACHED();
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
// We don't have the whole resource.
if (truncated_) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
if (RequiresValidation()) {
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return ERR_CACHE_MISS;
}
@@ -2108,7 +2200,7 @@ int HttpCache::Transaction::BeginCacheRead() {
if (entry_->disk_entry->GetDataSize(kMetadataIndex))
TransitionToState(STATE_CACHE_READ_METADATA);
else
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -2568,7 +2660,7 @@ int HttpCache::Transaction::SetupEntryForRead() {
partial_.reset();
}
}
- cache_->ConvertWriterToReader(entry_);
+
mode_ = READ;
if (request_->method == "HEAD")
@@ -2577,7 +2669,7 @@ int HttpCache::Transaction::SetupEntryForRead() {
if (entry_->disk_entry->GetDataSize(kMetadataIndex))
TransitionToState(STATE_CACHE_READ_METADATA);
else
- TransitionToState(STATE_NONE);
+ TransitionToState(STATE_FINISH_HEADERS);
return OK;
}
@@ -2656,7 +2748,7 @@ void HttpCache::Transaction::DoneWritingToEntry(bool success) {
RecordHistograms();
- cache_->DoneWritingToEntry(entry_, success);
+ cache_->DoneWritingToEntry(entry_, success, this);
entry_ = NULL;
mode_ = NONE; // switch to 'pass through' mode
}
@@ -2867,10 +2959,14 @@ void HttpCache::Transaction::RecordHistograms() {
cache_entry_status_ == CacheEntryStatus::ENTRY_CANT_CONDITIONALIZE);
int64_t freshness_periods_since_last_used = 0;
- if (stale_request) {
+ if (stale_request && !open_entry_last_used_.is_null()) {
+ // Note that we are not able to capture those transactions' histograms which
+ // when added to entry the response was being written by another transaction
+ // because getting the last used timestamp might lead to a data race in that
+ // case.
+
// For stale entries, record how many freshness periods have elapsed since
// the entry was last used.
- DCHECK(!open_entry_last_used_.is_null());
DCHECK(!stale_entry_freshness_.is_zero());
base::TimeDelta time_since_use = base::Time::Now() - open_entry_last_used_;
freshness_periods_since_last_used =

Powered by Google App Engine
This is Rietveld 408576698