Implement partial canonical Burst in NN util code

This CL adds a simple implementation of IBurst that dispatches calls to
an IPreparedModel object and changes
IPreparedModel::configureExecutionBurst to return this new object
(instead of returning an error).

This CL additionally defines an InvalidBurst class that returns errors
whenever it is used and a ResilientBurst class to recover an IBurst
object when it has died.

Bug: 177267324
Test: mma
Change-Id: I4c7e7ff4e6559aeb5e62c4fa02f2e751fef9d87d
Merged-In: I4c7e7ff4e6559aeb5e62c4fa02f2e751fef9d87d
(cherry picked from commit 44f324fb0d89ed896c9b0566ea632bddcfe69439)
diff --git a/neuralnetworks/utils/common/include/nnapi/hal/InvalidBurst.h b/neuralnetworks/utils/common/include/nnapi/hal/InvalidBurst.h
new file mode 100644
index 0000000..83e60b6
--- /dev/null
+++ b/neuralnetworks/utils/common/include/nnapi/hal/InvalidBurst.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_INVALID_BURST_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_INVALID_BURST_H
+
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include <memory>
+#include <optional>
+#include <utility>
+
+namespace android::hardware::neuralnetworks::utils {
+
+class InvalidBurst final : public nn::IBurst {
+  public:
+    OptionalCacheHold cacheMemory(const nn::Memory& memory) const override;
+
+    nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> execute(
+            const nn::Request& request, nn::MeasureTiming measure) const override;
+};
+
+}  // namespace android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_INVALID_BURST_H
diff --git a/neuralnetworks/utils/common/include/nnapi/hal/ResilientBurst.h b/neuralnetworks/utils/common/include/nnapi/hal/ResilientBurst.h
new file mode 100644
index 0000000..0df287f
--- /dev/null
+++ b/neuralnetworks/utils/common/include/nnapi/hal/ResilientBurst.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H
+
+#include <android-base/thread_annotations.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <utility>
+
+namespace android::hardware::neuralnetworks::utils {
+
+class ResilientBurst final : public nn::IBurst,
+                             public std::enable_shared_from_this<ResilientBurst> {
+    struct PrivateConstructorTag {};
+
+  public:
+    using Factory = std::function<nn::GeneralResult<nn::SharedBurst>()>;
+
+    static nn::GeneralResult<std::shared_ptr<const ResilientBurst>> create(Factory makeBurst);
+
+    ResilientBurst(PrivateConstructorTag tag, Factory makeBurst, nn::SharedBurst burst);
+
+    nn::SharedBurst getBurst() const;
+    nn::GeneralResult<nn::SharedBurst> recover(const nn::IBurst* failingBurst) const;
+
+    OptionalCacheHold cacheMemory(const nn::Memory& memory) const override;
+
+    nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> execute(
+            const nn::Request& request, nn::MeasureTiming measure) const override;
+
+  private:
+    const Factory kMakeBurst;
+    mutable std::mutex mMutex;
+    mutable nn::SharedBurst mBurst GUARDED_BY(mMutex);
+};
+
+}  // namespace android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_UTILS_COMMON_RESILIENT_BURST_H
diff --git a/neuralnetworks/utils/common/include/nnapi/hal/ResilientPreparedModel.h b/neuralnetworks/utils/common/include/nnapi/hal/ResilientPreparedModel.h
index 4014404..a6c1b19 100644
--- a/neuralnetworks/utils/common/include/nnapi/hal/ResilientPreparedModel.h
+++ b/neuralnetworks/utils/common/include/nnapi/hal/ResilientPreparedModel.h
@@ -30,7 +30,8 @@
 
 namespace android::hardware::neuralnetworks::utils {
 
-class ResilientPreparedModel final : public nn::IPreparedModel {
+class ResilientPreparedModel final : public nn::IPreparedModel,
+                                     public std::enable_shared_from_this<ResilientPreparedModel> {
     struct PrivateConstructorTag {};
 
   public:
@@ -62,6 +63,9 @@
     std::any getUnderlyingResource() const override;
 
   private:
+    bool isValidInternal() const EXCLUDES(mMutex);
+    nn::GeneralResult<nn::SharedBurst> configureExecutionBurstInternal() const;
+
     const Factory kMakePreparedModel;
     mutable std::mutex mMutex;
     mutable nn::SharedPreparedModel mPreparedModel GUARDED_BY(mMutex);
diff --git a/neuralnetworks/utils/common/src/InvalidBurst.cpp b/neuralnetworks/utils/common/src/InvalidBurst.cpp
new file mode 100644
index 0000000..4ca6603
--- /dev/null
+++ b/neuralnetworks/utils/common/src/InvalidBurst.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "InvalidBurst.h"
+
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include <memory>
+#include <optional>
+#include <utility>
+
+namespace android::hardware::neuralnetworks::utils {
+
+InvalidBurst::OptionalCacheHold InvalidBurst::cacheMemory(const nn::Memory& /*memory*/) const {
+    return nullptr;
+}
+
+nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> InvalidBurst::execute(
+        const nn::Request& /*request*/, nn::MeasureTiming /*measure*/) const {
+    return NN_ERROR() << "InvalidBurst";
+}
+
+}  // namespace android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/utils/common/src/ResilientBurst.cpp b/neuralnetworks/utils/common/src/ResilientBurst.cpp
new file mode 100644
index 0000000..0d3cb33
--- /dev/null
+++ b/neuralnetworks/utils/common/src/ResilientBurst.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ResilientBurst.h"
+
+#include <android-base/logging.h>
+#include <android-base/thread_annotations.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <utility>
+
+namespace android::hardware::neuralnetworks::utils {
+namespace {
+
+template <typename FnType>
+auto protect(const ResilientBurst& resilientBurst, const FnType& fn)
+        -> decltype(fn(*resilientBurst.getBurst())) {
+    auto burst = resilientBurst.getBurst();
+    auto result = fn(*burst);
+
+    // Immediately return if burst is not dead.
+    if (result.has_value() || result.error().code != nn::ErrorStatus::DEAD_OBJECT) {
+        return result;
+    }
+
+    // Attempt recovery and return if it fails.
+    auto maybeBurst = resilientBurst.recover(burst.get());
+    if (!maybeBurst.has_value()) {
+        auto [resultErrorMessage, resultErrorCode, resultOutputShapes] = std::move(result).error();
+        const auto& [recoveryErrorMessage, recoveryErrorCode] = maybeBurst.error();
+        return nn::error(resultErrorCode, std::move(resultOutputShapes))
+               << resultErrorMessage << ", and failed to recover dead burst object with error "
+               << recoveryErrorCode << ": " << recoveryErrorMessage;
+    }
+    burst = std::move(maybeBurst).value();
+
+    return fn(*burst);
+}
+
+}  // namespace
+
+nn::GeneralResult<std::shared_ptr<const ResilientBurst>> ResilientBurst::create(Factory makeBurst) {
+    if (makeBurst == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "utils::ResilientBurst::create must have non-empty makeBurst";
+    }
+    auto burst = NN_TRY(makeBurst());
+    CHECK(burst != nullptr);
+    return std::make_shared<ResilientBurst>(PrivateConstructorTag{}, std::move(makeBurst),
+                                            std::move(burst));
+}
+
+ResilientBurst::ResilientBurst(PrivateConstructorTag /*tag*/, Factory makeBurst,
+                               nn::SharedBurst burst)
+    : kMakeBurst(std::move(makeBurst)), mBurst(std::move(burst)) {
+    CHECK(kMakeBurst != nullptr);
+    CHECK(mBurst != nullptr);
+}
+
+nn::SharedBurst ResilientBurst::getBurst() const {
+    std::lock_guard guard(mMutex);
+    return mBurst;
+}
+
+nn::GeneralResult<nn::SharedBurst> ResilientBurst::recover(const nn::IBurst* failingBurst) const {
+    std::lock_guard guard(mMutex);
+
+    // Another caller updated the failing burst.
+    if (mBurst.get() != failingBurst) {
+        return mBurst;
+    }
+
+    mBurst = NN_TRY(kMakeBurst());
+    return mBurst;
+}
+
+ResilientBurst::OptionalCacheHold ResilientBurst::cacheMemory(const nn::Memory& memory) const {
+    return getBurst()->cacheMemory(memory);
+}
+
+nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> ResilientBurst::execute(
+        const nn::Request& request, nn::MeasureTiming measure) const {
+    const auto fn = [&request, measure](const nn::IBurst& burst) {
+        return burst.execute(request, measure);
+    };
+    return protect(*this, fn);
+}
+
+}  // namespace android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/utils/common/src/ResilientPreparedModel.cpp b/neuralnetworks/utils/common/src/ResilientPreparedModel.cpp
index faba996..5dd5f99 100644
--- a/neuralnetworks/utils/common/src/ResilientPreparedModel.cpp
+++ b/neuralnetworks/utils/common/src/ResilientPreparedModel.cpp
@@ -16,6 +16,9 @@
 
 #include "ResilientPreparedModel.h"
 
+#include "InvalidBurst.h"
+#include "ResilientBurst.h"
+
 #include <android-base/logging.h>
 #include <android-base/thread_annotations.h>
 #include <nnapi/IPreparedModel.h>
@@ -125,14 +128,34 @@
 }
 
 nn::GeneralResult<nn::SharedBurst> ResilientPreparedModel::configureExecutionBurst() const {
-    const auto fn = [](const nn::IPreparedModel& preparedModel) {
-        return preparedModel.configureExecutionBurst();
+#if 0
+    auto self = shared_from_this();
+    ResilientBurst::Factory makeBurst =
+            [preparedModel = std::move(self)]() -> nn::GeneralResult<nn::SharedBurst> {
+        return preparedModel->configureExecutionBurst();
     };
-    return protect(*this, fn);
+    return ResilientBurst::create(std::move(makeBurst));
+#else
+    return configureExecutionBurstInternal();
+#endif
 }
 
 std::any ResilientPreparedModel::getUnderlyingResource() const {
     return getPreparedModel()->getUnderlyingResource();
 }
 
+bool ResilientPreparedModel::isValidInternal() const {
+    return true;
+}
+
+nn::GeneralResult<nn::SharedBurst> ResilientPreparedModel::configureExecutionBurstInternal() const {
+    if (!isValidInternal()) {
+        return std::make_shared<const InvalidBurst>();
+    }
+    const auto fn = [](const nn::IPreparedModel& preparedModel) {
+        return preparedModel.configureExecutionBurst();
+    };
+    return protect(*this, fn);
+}
+
 }  // namespace android::hardware::neuralnetworks::utils