Revert "Fix bug in reservation monitoring."

This reverts commit c072c8c7.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 845219 as the
culprit for failures in the build cycles as shown on:
https://analysis.chromium.org/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtL2MwNzJjOGM3NDZlYjA5OWYzNzE5MGU0YzZjNWEzOWM0Yzk0N2I2OGUM

Sample Failed Build: https://ci.chromium.org/b/8857563414825836112

Sample Failed Step: bf_cache_unit_tests

Original change's description:
> Fix bug in reservation monitoring.
> 
> In ScopedReservation destructor did Reserve instead of Discard!
> This is now fixed, and unit tests provided for this and other cases.
> Also, Storage tests now verify that all memory has been released after
> the storage is reset.
> 
> Bug: b:174509632
> Change-Id: Ic3594f569f53c103d6ae9c6a73bd030c5f25d698
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2638220
> Commit-Queue: Zach Trudo <zatrudo@google.com>
> Reviewed-by: Zach Trudo <zatrudo@google.com>
> Auto-Submit: Leonid Baraz <lbaraz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#845219}


Change-Id: I453d14fd867294c134b72a40331ffd98a7a6e12c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: b:174509632
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2639575
Cr-Commit-Position: refs/heads/master@{#845259}

chrome/browser/policy/messaging_layer/storage/resources/resource_interface.cc

@@ -27,7 +27,7 @@ bool ScopedReservation::reserved() const {
 
 ScopedReservation::~ScopedReservation() {
   if (reserved()) {
-    resource_interface_->Discard(size_.value());
+    resource_interface_->Reserve(size_.value());
   }
 }
 

chrome/browser/policy/messaging_layer/storage/resources/resource_interface_unittest.cc

-// Copyright 2020 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 <cstdint>
-
-#include "chrome/browser/policy/messaging_layer/storage/resources/resource_interface.h"
-
-#include "base/task/post_task.h"
-#include "base/task_runner.h"
-#include "base/test/task_environment.h"
-#include "testing/gmock/include/gmock/gmock.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-using ::testing::Eq;
-
-namespace reporting {
-namespace {
-
-class TestCallbackWaiter {
- public:
-  TestCallbackWaiter() = default;
-  TestCallbackWaiter(const TestCallbackWaiter& other) = delete;
-  TestCallbackWaiter& operator=(const TestCallbackWaiter& other) = delete;
-
-  void Attach() {
-    const size_t old_counter = counter_.fetch_add(1);
-    DCHECK_GT(old_counter, 0u) << "Cannot attach when already being released";
-  }
-
-  void Signal() {
-    const size_t old_counter = counter_.fetch_sub(1);
-    DCHECK_GT(old_counter, 0u) << "Already being released";
-    if (old_counter == 1u) {
-      // Dropped last owner.
-      run_loop_.Quit();
-    }
-  }
-
-  void Wait() {
-    Signal();  // Rid of the constructor's ownership.
-    run_loop_.Run();
-  }
-
- private:
-  std::atomic<size_t> counter_{1};  // Onwed by constructor.
-  base::RunLoop run_loop_;
-};
-
-class ResourceInterfaceTest
-    : public ::testing::TestWithParam<ResourceInterface*> {
- protected:
-  ResourceInterface* resource_interface() const { return GetParam(); }
-
- private:
-  base::test::TaskEnvironment task_environment_;
-};
-
-TEST_P(ResourceInterfaceTest, NestedReservationTest) {
-  uint64_t size = resource_interface()->GetTotal();
-  while ((size / 2) > 0u) {
-    size /= 2;
-    EXPECT_TRUE(resource_interface()->Reserve(size));
-  }
-
-  for (; size < resource_interface()->GetTotal(); size *= 2) {
-    resource_interface()->Discard(size);
-  }
-
-  EXPECT_THAT(resource_interface()->GetUsed(), Eq(0u));
-}
-
-TEST_P(ResourceInterfaceTest, SimultaneousReservationTest) {
-  uint64_t size = resource_interface()->GetTotal();
-
-  // Schedule reservations.
-  TestCallbackWaiter reserve_waiter;
-  while ((size / 2) > 0u) {
-    size /= 2;
-    reserve_waiter.Attach();
-    base::ThreadPool::PostTask(
-        FROM_HERE, {base::TaskPriority::BEST_EFFORT},
-        base::BindOnce(
-            [](size_t size, ResourceInterface* resource_interface,
-               TestCallbackWaiter* waiter) {
-              EXPECT_TRUE(resource_interface->Reserve(size));
-              waiter->Signal();
-            },
-            size, resource_interface(), &reserve_waiter));
-  }
-  reserve_waiter.Wait();
-
-  // Schedule discards.
-  TestCallbackWaiter discard_waiter;
-  for (; size < resource_interface()->GetTotal(); size *= 2) {
-    discard_waiter.Attach();
-    base::ThreadPool::PostTask(
-        FROM_HERE, {base::TaskPriority::BEST_EFFORT},
-        base::BindOnce(
-            [](size_t size, ResourceInterface* resource_interface,
-               TestCallbackWaiter* waiter) {
-              resource_interface->Discard(size);
-              waiter->Signal();
-            },
-            size, resource_interface(), &discard_waiter));
-  }
-  discard_waiter.Wait();
-
-  EXPECT_THAT(resource_interface()->GetUsed(), Eq(0u));
-}
-
-TEST_P(ResourceInterfaceTest, SimultaneousScopedReservationTest) {
-  uint64_t size = resource_interface()->GetTotal();
-  TestCallbackWaiter waiter;
-  while ((size / 2) > 0u) {
-    size /= 2;
-    waiter.Attach();
-    base::ThreadPool::PostTask(
-        FROM_HERE, {base::TaskPriority::BEST_EFFORT},
-        base::BindOnce(
-            [](size_t size, ResourceInterface* resource_interface,
-               TestCallbackWaiter* waiter) {
-              { ScopedReservation(size, resource_interface); }
-              waiter->Signal();
-            },
-            size, resource_interface(), &waiter));
-  }
-  waiter.Wait();
-  EXPECT_THAT(resource_interface()->GetUsed(), Eq(0u));
-}
-
-TEST_P(ResourceInterfaceTest, ReservationOverMaxTest) {
-  EXPECT_FALSE(
-      resource_interface()->Reserve(resource_interface()->GetTotal() + 1));
-  EXPECT_TRUE(resource_interface()->Reserve(resource_interface()->GetTotal()));
-  resource_interface()->Discard(resource_interface()->GetTotal());
-  EXPECT_THAT(resource_interface()->GetUsed(), Eq(0u));
-}
-
-TEST_P(ResourceInterfaceTest, DiscardMoreThenReservedDeathTest) {
-  EXPECT_TRUE(
-      resource_interface()->Reserve(resource_interface()->GetTotal() / 2));
-  EXPECT_DEATH(resource_interface()->Discard(resource_interface()->GetTotal()),
-               "Check failed");
-}
-
-INSTANTIATE_TEST_SUITE_P(VariousResources,
-                         ResourceInterfaceTest,
-                         testing::Values(GetMemoryResource(),
-                                         GetDiskResource()));
-
-}  // namespace
-}  // namespace reporting

chrome/browser/policy/messaging_layer/storage/storage_queue.cc

@@ -139,8 +139,10 @@ StorageQueue::~StorageQueue() {
 
   // Stop upload timer.
   upload_timer_.AbandonAndStop();
-  // Close all opened files.
-  files_.clear();
+  // CLose all opened files.
+  for (auto& file : files_) {
+    file.second->Close();
+  }
 }
 
 Status StorageQueue::Init() {
@@ -1316,7 +1318,6 @@ StorageQueue::SingleFile::SingleFile(const base::FilePath& filename,
     : filename_(filename), size_(size) {}
 
 StorageQueue::SingleFile::~SingleFile() {
-  Close();
   handle_.reset();
 }
 
@@ -1354,10 +1355,8 @@ void StorageQueue::SingleFile::Close() {
   }
   handle_.reset();
   is_readonly_ = base::nullopt;
-  if (buffer_) {
-    buffer_.reset();
-    GetMemoryResource()->Discard(buffer_size_);
-  }
+  buffer_.reset();
+  GetMemoryResource()->Discard(buffer_size_);
 }
 
 Status StorageQueue::SingleFile::Delete() {

chrome/browser/policy/messaging_layer/storage/storage_queue_unittest.cc

@@ -15,9 +15,9 @@
 #include "base/optional.h"
 #include "base/strings/strcat.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/test/task_environment.h"
 #include "chrome/browser/policy/messaging_layer/encryption/test_encryption_module.h"
-#include "chrome/browser/policy/messaging_layer/storage/resources/resource_interface.h"
 #include "chrome/browser/policy/messaging_layer/storage/storage_configuration.h"
 #include "chrome/browser/policy/messaging_layer/util/status.h"
 #include "chrome/browser/policy/messaging_layer/util/statusor.h"
@@ -288,8 +288,6 @@ class StorageQueueTest : public ::testing::TestWithParam<size_t> {
   void ResetTestStorageQueue() {
     task_environment_.RunUntilIdle();
     storage_queue_.reset();
-    // Make sure all memory is deallocated.
-    ASSERT_THAT(GetMemoryResource()->GetUsed(), Eq(0u));
   }
 
   void InjectFailures(std::initializer_list<int64_t> seq_numbers) {

chrome/browser/policy/messaging_layer/storage/storage_unittest.cc

@@ -13,12 +13,12 @@
 #include "base/sequenced_task_runner.h"
 #include "base/strings/strcat.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/task_environment.h"
 #include "chrome/browser/policy/messaging_layer/encryption/decryption.h"
 #include "chrome/browser/policy/messaging_layer/encryption/encryption.h"
 #include "chrome/browser/policy/messaging_layer/encryption/test_encryption_module.h"
-#include "chrome/browser/policy/messaging_layer/storage/resources/resource_interface.h"
 #include "chrome/browser/policy/messaging_layer/storage/storage_configuration.h"
 #include "chrome/browser/policy/messaging_layer/util/status.h"
 #include "chrome/browser/policy/messaging_layer/util/status_macros.h"
@@ -493,8 +493,6 @@ class StorageTest
   void ResetTestStorage() {
     task_environment_.RunUntilIdle();
     storage_.reset();
-    // Make sure all memory is deallocated.
-    ASSERT_THAT(GetMemoryResource()->GetUsed(), Eq(0u));
     expect_to_need_key_ = false;
   }
 

chrome/test/BUILD.gn

@@ -3660,7 +3660,6 @@ test("unit_tests") {
     "../browser/policy/messaging_layer/public/report_client_unittest.cc",
     "../browser/policy/messaging_layer/public/report_queue_configuration_unittest.cc",
     "../browser/policy/messaging_layer/public/report_queue_unittest.cc",
-    "../browser/policy/messaging_layer/storage/resources/resource_interface_unittest.cc",
     "../browser/policy/messaging_layer/storage/storage_queue_unittest.cc",
     "../browser/policy/messaging_layer/storage/storage_unittest.cc",
     "../browser/policy/messaging_layer/storage/test_storage_module.cc",