foundationdb/fdbrpc/AsyncFileNonDurable.actor.h

/*
 * AsyncFileNonDurable.actor.h
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * 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.
 */

#pragma once

// When actually compiled (NO_INTELLISENSE), include the generated version of this file.  In intellisense use the source
// version.
#if defined(NO_INTELLISENSE) && !defined(FLOW_ASYNCFILENONDURABLE_ACTOR_G_H)
#define FLOW_ASYNCFILENONDURABLE_ACTOR_G_H
#include "fdbrpc/AsyncFileNonDurable.actor.g.h"
#elif !defined(FLOW_ASYNCFILENONDURABLE_ACTOR_H)
#define FLOW_ASYNCFILENONDURABLE_ACTOR_H

#include "flow/flow.h"
#include "fdbrpc/IAsyncFile.h"
#include "flow/ActorCollection.h"
#include "fdbrpc/simulator.h"
#include "fdbrpc/TraceFileIO.h"
#include "fdbrpc/RangeMap.h"
#include "flow/actorcompiler.h" // This must be the last #include.

#undef max
#undef min

ACTOR Future<Void> sendOnProcess(ISimulator::ProcessInfo* process, Promise<Void> promise, TaskPriority taskID);
ACTOR Future<Void> sendErrorOnProcess(ISimulator::ProcessInfo* process,
                                      Promise<Void> promise,
                                      Error e,
                                      TaskPriority taskID);

ACTOR template <class T>
Future<T> sendErrorOnShutdown(Future<T> in) {
	choose {
		when(wait(success(g_simulator.getCurrentProcess()->shutdownSignal.getFuture()))) {
			throw io_error().asInjectedFault();
		}
		when(T rep = wait(in)) { return rep; }
	}
}

class AsyncFileDetachable final : public IAsyncFile, public ReferenceCounted<AsyncFileDetachable> {
private:
	Reference<IAsyncFile> file;
	Future<Void> shutdown;

public:
	explicit AsyncFileDetachable(Reference<IAsyncFile> file) : file(file) { shutdown = doShutdown(this); }

	ACTOR Future<Void> doShutdown(AsyncFileDetachable* self) {
		wait(success(g_simulator.getCurrentProcess()->shutdownSignal.getFuture()));
		self->file = Reference<IAsyncFile>();
		return Void();
	}

	ACTOR static Future<Reference<IAsyncFile>> open(Future<Reference<IAsyncFile>> wrappedFile) {
		choose {
			when(wait(success(g_simulator.getCurrentProcess()->shutdownSignal.getFuture()))) {
				throw io_error().asInjectedFault();
			}
			when(Reference<IAsyncFile> f = wait(wrappedFile)) { return makeReference<AsyncFileDetachable>(f); }
		}
	}

	void addref() override { ReferenceCounted<AsyncFileDetachable>::addref(); }
	void delref() override { ReferenceCounted<AsyncFileDetachable>::delref(); }

	Future<int> read(void* data, int length, int64_t offset) override {
		if (!file.getPtr() || g_simulator.getCurrentProcess()->shutdownSignal.getFuture().isReady())
			return io_error().asInjectedFault();
		return sendErrorOnShutdown(file->read(data, length, offset));
	}

	Future<Void> write(void const* data, int length, int64_t offset) override {
		if (!file.getPtr() || g_simulator.getCurrentProcess()->shutdownSignal.getFuture().isReady())
			return io_error().asInjectedFault();
		return sendErrorOnShutdown(file->write(data, length, offset));
	}

	Future<Void> truncate(int64_t size) override {
		if (!file.getPtr() || g_simulator.getCurrentProcess()->shutdownSignal.getFuture().isReady())
			return io_error().asInjectedFault();
		return sendErrorOnShutdown(file->truncate(size));
	}

	Future<Void> sync() override {
		if (!file.getPtr() || g_simulator.getCurrentProcess()->shutdownSignal.getFuture().isReady())
			return io_error().asInjectedFault();
		return sendErrorOnShutdown(file->sync());
	}

	Future<int64_t> size() const override {
		if (!file.getPtr() || g_simulator.getCurrentProcess()->shutdownSignal.getFuture().isReady())
			return io_error().asInjectedFault();
		return sendErrorOnShutdown(file->size());
	}

	int64_t debugFD() const override {
		if (!file.getPtr())
			throw io_error().asInjectedFault();
		return file->debugFD();
	}
	std::string getFilename() const override {
		if (!file.getPtr())
			throw io_error().asInjectedFault();
		return file->getFilename();
	}
};

// An async file implementation which wraps another async file and will randomly destroy sectors that it is writing when
// killed This is used to simulate a power failure which prevents all written data from being persisted to disk
class AsyncFileNonDurable final : public IAsyncFile, public ReferenceCounted<AsyncFileNonDurable> {
public:
	UID id;
	std::string filename;

	// For files that use atomic write and create, they are initially created with an extra suffix
	std::string initialFilename;

	// An approximation of the size of the file; .size() should be used instead of this variable in most cases
	mutable int64_t approximateSize;

	// The address of the machine that opened the file
	NetworkAddress openedAddress;

	bool aio;

private:
	// The wrapped IAsyncFile
	Reference<IAsyncFile> file;

	// The maximum amount of time a write is delayed before being passed along to the underlying file
	double maxWriteDelay;

	// Modifications which haven't been pushed to file, mapped by the location in the file that is being modified.
	// Be sure to update minSizeAfterPendingModifications when modifying pendingModifications.
	RangeMap<uint64_t, Future<Void>> pendingModifications;
	// The size of the file after the set of pendingModifications completes,
	// (the set pending at the time of reading this member). Must be updated in
	// lockstep with any inserts into the pendingModifications map. Tracking
	// this variable is necessary so that we can know the range of the file a
	// truncate is modifying, so we can insert it into the pendingModifications
	// map. Until minSizeAfterPendingModificationsIsExact is true, this is only a lower bound.
	mutable int64_t minSizeAfterPendingModifications = 0;
	mutable bool minSizeAfterPendingModificationsIsExact = false;

	// Will be blocked whenever kill is running
	Promise<Void> killed;
	Promise<Void> killComplete;

	// Used by sync (and kill) to force writes which have not yet been passed along.
	// If true is sent, then writes will be durable.  If false, then they may not be durable.
	Promise<bool> startSyncPromise;

	// The performance parameters of the simulated disk
	Reference<DiskParameters> diskParameters;

	// Set to true the first time sync is called on the file
	bool hasBeenSynced;

	// Used to describe what corruption is allowed by the file as well as the type of corruption being used on a
	// particular page
	enum KillMode { NO_CORRUPTION = 0, DROP_ONLY = 1, FULL_CORRUPTION = 2 };

	// Limits what types of corruption are applied to writes from this file
	KillMode killMode;

	ActorCollection
	    reponses; // cannot call getResult on this actor collection, since the actors will be on different processes

	AsyncFileNonDurable(const std::string& filename,
	                    const std::string& initialFilename,
	                    Reference<IAsyncFile> file,
	                    Reference<DiskParameters> diskParameters,
	                    NetworkAddress openedAddress,
	                    bool aio)
	  : filename(filename), initialFilename(initialFilename), approximateSize(0), openedAddress(openedAddress),
	    aio(aio), file(file), pendingModifications(uint64_t(-1)), diskParameters(diskParameters), reponses(false) {

		// This is only designed to work in simulation
		ASSERT(g_network->isSimulated());
		this->id = deterministicRandom()->randomUniqueID();

		//TraceEvent("AsyncFileNonDurable_Create", id).detail("Filename", filename);
		maxWriteDelay = FLOW_KNOBS->NON_DURABLE_MAX_WRITE_DELAY;
		hasBeenSynced = false;

		killMode = (KillMode)deterministicRandom()->randomInt(1, 3);
		//TraceEvent("AsyncFileNonDurable_CreateEnd", id).detail("Filename", filename).backtrace();
	}

public:
	static std::map<std::string, Future<Void>> filesBeingDeleted;

	// Creates a new AsyncFileNonDurable which wraps the provided IAsyncFile
	ACTOR static Future<Reference<IAsyncFile>> open(std::string filename,
	                                                std::string actualFilename,
	                                                Future<Reference<IAsyncFile>> wrappedFile,
	                                                Reference<DiskParameters> diskParameters,
	                                                bool aio) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		state Future<Void> shutdown = success(currentProcess->shutdownSignal.getFuture());

		//TraceEvent("AsyncFileNonDurableOpenBegin").detail("Filename", filename).detail("Addr", g_simulator.getCurrentProcess()->address);
		wait(g_simulator.onMachine(currentProcess));
		try {
			wait(success(wrappedFile) || shutdown);

			if (shutdown.isReady())
				throw io_error().asInjectedFault();

			state Reference<IAsyncFile> file = wrappedFile.get();

			// If we are in the process of deleting a file, we can't let someone else modify it at the same time.  We
			// therefore block the creation of new files until deletion is complete
			state std::map<std::string, Future<Void>>::iterator deletedFile = filesBeingDeleted.find(filename);
			if (deletedFile != filesBeingDeleted.end()) {
				//TraceEvent("AsyncFileNonDurableOpenWaitOnDelete1").detail("Filename", filename);
				wait(deletedFile->second || shutdown);
				//TraceEvent("AsyncFileNonDurableOpenWaitOnDelete2").detail("Filename", filename);
				if (shutdown.isReady())
					throw io_error().asInjectedFault();
				wait(g_simulator.onProcess(currentProcess, currentTaskID));
			}

			state Reference<AsyncFileNonDurable> nonDurableFile(
			    new AsyncFileNonDurable(filename, actualFilename, file, diskParameters, currentProcess->address, aio));

			// Causes the approximateSize member to be set
			state Future<int64_t> sizeFuture = nonDurableFile->size();
			wait(success(sizeFuture) || shutdown);

			if (shutdown.isReady())
				throw io_error().asInjectedFault();

			//TraceEvent("AsyncFileNonDurableOpenComplete").detail("Filename", filename);

			wait(g_simulator.onProcess(currentProcess, currentTaskID));

			return nonDurableFile;
		} catch (Error& e) {
			state Error err = e;
			std::string currentFilename =
			    (wrappedFile.isReady() && !wrappedFile.isError()) ? wrappedFile.get()->getFilename() : actualFilename;
			currentProcess->machine->openFiles.erase(currentFilename);
			//TraceEvent("AsyncFileNonDurableOpenError").error(e, true).detail("Filename", filename).detail("Address", currentProcess->address).detail("Addr", g_simulator.getCurrentProcess()->address);
			wait(g_simulator.onProcess(currentProcess, currentTaskID));
			throw err;
		}
	}

	~AsyncFileNonDurable() override {
		//TraceEvent("AsyncFileNonDurable_Destroy", id).detail("Filename", filename);
	}

	void addref() override { ReferenceCounted<AsyncFileNonDurable>::addref(); }

	void delref() override {
		if (delref_no_destroy()) {
			if (filesBeingDeleted.count(filename) == 0) {
				//TraceEvent("AsyncFileNonDurable_StartDelete", id).detail("Filename", filename);
				Future<Void> deleteFuture = deleteFile(this);
				if (!deleteFuture.isReady())
					filesBeingDeleted[filename] = deleteFuture;
			}

			removeOpenFile(filename, this);
			if (initialFilename != filename) {
				removeOpenFile(initialFilename, this);
			}
		}
	}

	// Removes a file from the openFiles map
	static void removeOpenFile(std::string filename, AsyncFileNonDurable* file) {
		auto& openFiles = g_simulator.getCurrentProcess()->machine->openFiles;

		auto iter = openFiles.find(filename);

		// Various actions (e.g. simulated delete) can remove a file from openFiles prematurely, so it may already
		// be gone. Renamed files (from atomic write and create) will also be present under only one of the two
		// names.
		if (iter != openFiles.end()) {
			// even if the filename exists, it doesn't mean that it references the same file. It could be that the
			// file was renamed and later a file with the same name was opened.
			if (iter->second.getPtrIfReady().orDefault(nullptr) == file) {
				openFiles.erase(iter);
			}
		}
	}

	// Passes along reads straight to the underlying file, waiting for any outstanding changes that could affect the
	// results
	Future<int> read(void* data, int length, int64_t offset) override { return read(this, data, length, offset); }

	// Writes data to the file.  Writes are delayed a random amount of time before being
	// passed to the underlying file
	Future<Void> write(void const* data, int length, int64_t offset) override {
		//TraceEvent("AsyncFileNonDurable_Write", id).detail("Filename", filename).detail("Offset", offset).detail("Length", length);
		if (length == 0) {
			TraceEvent(SevWarnAlways, "AsyncFileNonDurable_EmptyModification", id).detail("Filename", filename);
			return Void();
		}

		debugFileSet("AsyncFileNonDurableWrite", filename, data, offset, length);

		Promise<Void> writeStarted;
		Promise<Future<Void>> writeEnded;
		writeEnded.send(write(this, writeStarted, writeEnded.getFuture(), data, length, offset));
		return writeStarted.getFuture();
	}

	// Truncates the file.  Truncates are delayed a random amount of time before being
	// passed to the underlying file
	Future<Void> truncate(int64_t size) override {
		//TraceEvent("AsyncFileNonDurable_Truncate", id).detail("Filename", filename).detail("Offset", size);
		debugFileTruncate("AsyncFileNonDurableTruncate", filename, size);

		Promise<Void> truncateStarted;
		Promise<Future<Void>> truncateEnded;
		truncateEnded.send(truncate(this, truncateStarted, truncateEnded.getFuture(), size));
		return truncateStarted.getFuture();
	}

	// Fsyncs the file.  This allows all delayed modifications to the file to complete before
	// syncing the underlying file
	Future<Void> sync() override {
		//TraceEvent("AsyncFileNonDurable_Sync", id).detail("Filename", filename);
		Future<Void> syncFuture = sync(this, true);
		reponses.add(syncFuture);
		return syncFuture;
	}

	// Passes along size requests to the underlying file, augmenting with any writes past the end of the file
	Future<int64_t> size() const override { return size(this); }

	int64_t debugFD() const override { return file->debugFD(); }

	std::string getFilename() const override { return file->getFilename(); }

	// Forces a non-durable sync (some writes are not made or made incorrectly)
	// This is used when the file should 'die' without first completing its operations
	//(e.g. to simulate power failure)
	Future<Void> kill() {
		TraceEvent("AsyncFileNonDurable_Kill", id).detail("Filename", filename);
		TEST(true); // AsyncFileNonDurable was killed
		return sync(this, false);
	}

private:
	// Returns a future that is used to ensure the waiter ends up on the main thread
	Future<Void> returnToMainThread() {
		Promise<Void> p;
		Future<Void> f = p.getFuture();
		g_network->onMainThread(std::move(p), g_network->getCurrentTask());
		return f;
	}

	// Gets existing modifications that overlap the specified range.  Optionally inserts a new modification into the map
	std::vector<Future<Void>> getModificationsAndInsert(int64_t offset,
	                                                    int64_t length,
	                                                    bool insertModification = false,
	                                                    Future<Void> value = Void()) {
		auto modification = RangeMapRange<uint64_t>(offset, length >= 0 ? offset + length : uint64_t(-1));
		auto priorModifications = pendingModifications.intersectingRanges(modification);

		// Aggregate existing modifications in this range
		std::vector<Future<Void>> modificationFutures;
		for (auto itr = priorModifications.begin(); itr != priorModifications.end(); ++itr) {
			if (itr.value().isValid() && (!itr.value().isReady() || itr.value().isError())) {
				modificationFutures.push_back(itr.value());
			}
		}

		// Add the modification if we are doing a write or truncate
		if (insertModification)
			pendingModifications.insert(modification, value);

		return modificationFutures;
	}

	// Checks if the file is killed.  If so, then the current sync is completed if running and then an error is thrown
	ACTOR static Future<Void> checkKilled(AsyncFileNonDurable const* self, std::string context) {
		if (self->killed.isSet()) {
			//TraceEvent("AsyncFileNonDurable_KilledInCheck", self->id).detail("In", context).detail("Filename", self->filename);
			wait(self->killComplete.getFuture());
			TraceEvent("AsyncFileNonDurable_KilledFileOperation", self->id)
			    .detail("In", context)
			    .detail("Filename", self->filename);
			TEST(true); // AsyncFileNonDurable operation killed
			throw io_error().asInjectedFault();
		}

		return Void();
	}

	// Passes along reads straight to the underlying file, waiting for any outstanding changes that could affect the
	// results
	ACTOR Future<int> onRead(AsyncFileNonDurable* self, void* data, int length, int64_t offset) {
		wait(checkKilled(self, "Read"));
		vector<Future<Void>> priorModifications = self->getModificationsAndInsert(offset, length);
		wait(waitForAll(priorModifications));
		state Future<int> readFuture = self->file->read(data, length, offset);
		wait(success(readFuture) || self->killed.getFuture());

		// throws if we were killed
		wait(checkKilled(self, "ReadEnd"));

		debugFileCheck("AsyncFileNonDurableRead", self->filename, data, offset, length);

		// if(g_simulator.getCurrentProcess()->rebooting)
		//TraceEvent("AsyncFileNonDurable_ReadEnd", self->id).detail("Filename", self->filename);

		return readFuture.get();
	}

	ACTOR Future<int> read(AsyncFileNonDurable* self, void* data, int length, int64_t offset) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		wait(g_simulator.onMachine(currentProcess));

		try {
			state int rep = wait(self->onRead(self, data, length, offset));
			wait(g_simulator.onProcess(currentProcess, currentTaskID));

			return rep;
		} catch (Error& e) {
			state Error err = e;
			wait(g_simulator.onProcess(currentProcess, currentTaskID));
			throw err;
		}
	}

	// Delays writes a random amount of time before passing them through to the underlying file.
	// If a kill interrupts the delay, then the output could be the correct write, part of the write,
	// or none of the write.  It may also corrupt parts of sectors which have not been written correctly
	ACTOR Future<Void> write(AsyncFileNonDurable* self,
	                         Promise<Void> writeStarted,
	                         Future<Future<Void>> ownFuture,
	                         void const* data,
	                         int length,
	                         int64_t offset) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		wait(g_simulator.onMachine(currentProcess));

		state double delayDuration =
		    g_simulator.speedUpSimulation ? 0.0001 : (deterministicRandom()->random01() * self->maxWriteDelay);
		state Standalone<StringRef> dataCopy(StringRef((uint8_t*)data, length));

		state Future<bool> startSyncFuture = self->startSyncPromise.getFuture();

		try {
			//TraceEvent("AsyncFileNonDurable_Write", self->id).detail("Delay", delayDuration).detail("Filename", self->filename).detail("WriteLength", length).detail("Offset", offset);
			wait(checkKilled(self, "Write"));

			Future<Void> writeEnded = wait(ownFuture);
			std::vector<Future<Void>> priorModifications =
			    self->getModificationsAndInsert(offset, length, true, writeEnded);
			self->minSizeAfterPendingModifications = std::max(self->minSizeAfterPendingModifications, offset + length);

			if (BUGGIFY_WITH_PROB(0.001) && !g_simulator.speedUpSimulation)
				priorModifications.push_back(
				    delay(deterministicRandom()->random01() * FLOW_KNOBS->MAX_PRIOR_MODIFICATION_DELAY) ||
				    self->killed.getFuture());
			else
				priorModifications.push_back(waitUntilDiskReady(self->diskParameters, length) ||
				                             self->killed.getFuture());

			wait(waitForAll(priorModifications));

			self->approximateSize = std::max(self->approximateSize, length + offset);

			self->reponses.add(sendOnProcess(currentProcess, writeStarted, currentTaskID));
		} catch (Error& e) {
			self->reponses.add(sendErrorOnProcess(currentProcess, writeStarted, e, currentTaskID));
			throw;
		}

		//TraceEvent("AsyncFileNonDurable_WriteDoneWithPreviousMods", self->id).detail("Delay", delayDuration).detail("Filename", self->filename).detail("WriteLength", length).detail("Offset", offset);

		// Wait a random amount of time or until a sync/kill is issued
		state bool saveDurable = true;
		choose {
			when(wait(delay(delayDuration))) {}
			when(bool durable = wait(startSyncFuture)) { saveDurable = durable; }
		}

		debugFileCheck("AsyncFileNonDurableWriteAfterWait", self->filename, dataCopy.begin(), offset, length);

		// In AIO mode, only page-aligned writes are supported
		ASSERT(!self->aio || (offset % 4096 == 0 && length % 4096 == 0));

		// Non-durable writes should introduce errors at the page level and corrupt at the sector level
		// Otherwise, we can perform the entire write at once
		int diskPageLength = saveDurable ? length : 4096;
		int diskSectorLength = saveDurable ? length : 512;

		vector<Future<Void>> writeFutures;
		for (int writeOffset = 0; writeOffset < length;) {
			// Number of bytes until the next diskPageLength file offset within the write or the end of the write.
			int pageLength = diskPageLength;
			if (!self->aio && !saveDurable) {
				// If not in AIO mode, and the save is not durable, then we can't perform the entire write all at once
				// and the first and last pages touched by the write could be partial.
				pageLength = std::min<int64_t>((int64_t)length - writeOffset,
				                               diskPageLength - ((offset + writeOffset) % diskPageLength));
			}

			// choose a random action to perform on this page write (write correctly, corrupt, or don't write)
			KillMode pageKillMode = (KillMode)deterministicRandom()->randomInt(0, self->killMode + 1);

			for (int pageOffset = 0; pageOffset < pageLength;) {
				// Number of bytes until the next diskSectorLength file offset within the write or the end of the write.
				int sectorLength = diskSectorLength;
				if (!self->aio && !saveDurable) {
					// If not in AIO mode, and the save is not durable, then we can't perform the entire write all at
					// once and the first and last sectors touched by the write could be partial.
					sectorLength =
					    std::min<int64_t>((int64_t)length - (writeOffset + pageOffset),
					                      diskSectorLength - ((offset + writeOffset + pageOffset) % diskSectorLength));
				}

				// If saving durable, then perform the write correctly.  Otherwise, perform the write correcly with a
				// probability of 1/3. If corrupting the write, then this sector will be written correctly with a 1/4
				// chance
				if (saveDurable || pageKillMode == NO_CORRUPTION ||
				    (pageKillMode == FULL_CORRUPTION && deterministicRandom()->random01() < 0.25)) {
					// if (!saveDurable) TraceEvent(SevInfo, "AsyncFileNonDurableWrite", self->id).detail("Filename",
					// self->filename).detail("Offset", offset+writeOffset+pageOffset).detail("Length", sectorLength);
					writeFutures.push_back(self->file->write(
					    dataCopy.begin() + writeOffset + pageOffset, sectorLength, offset + writeOffset + pageOffset));
				}

				// If the write is not durable, then the write will either be corrupted or not written at all.  If
				// corrupted, there is 1/4 chance that a given sector will not be written
				else if (pageKillMode == FULL_CORRUPTION && deterministicRandom()->random01() < 0.66667) {
					// The incorrect part of the write can be the rightmost bytes (side = 0), the leftmost bytes (side =
					// 1), or the entire write (side = 2)
					int side = deterministicRandom()->randomInt(0, 3);

					// There is a 1/2 chance that a bad write will have garbage written into its bad portion
					// The chance is increased to 1 if the entire write is bad
					bool garbage = side == 2 || deterministicRandom()->random01() < 0.5;

					int64_t goodStart = 0;
					int64_t goodEnd = sectorLength;
					int64_t badStart = 0;
					int64_t badEnd = sectorLength;

					if (side == 0) {
						goodEnd = deterministicRandom()->randomInt(0, sectorLength);
						badStart = goodEnd;
					} else if (side == 1) {
						badEnd = deterministicRandom()->randomInt(0, sectorLength);
						goodStart = badEnd;
					} else
						goodEnd = 0;

					// Write randomly generated bytes, if required
					if (garbage && badStart != badEnd) {
						uint8_t* badData = const_cast<uint8_t*>(&dataCopy.begin()[badStart + writeOffset + pageOffset]);
						for (int i = 0; i < badEnd - badStart; i += sizeof(uint32_t)) {
							uint32_t val = deterministicRandom()->randomUInt32();
							memcpy(&badData[i], &val, std::min(badEnd - badStart - i, (int64_t)sizeof(uint32_t)));
						}

						writeFutures.push_back(self->file->write(dataCopy.begin() + writeOffset + pageOffset,
						                                         sectorLength,
						                                         offset + writeOffset + pageOffset));
						debugFileSet("AsyncFileNonDurableBadWrite",
						             self->filename,
						             dataCopy.begin() + writeOffset + pageOffset,
						             offset + writeOffset + pageOffset,
						             sectorLength);
					} else if (goodStart != goodEnd)
						writeFutures.push_back(
						    self->file->write(dataCopy.begin() + goodStart + writeOffset + pageOffset,
						                      goodEnd - goodStart,
						                      goodStart + offset + writeOffset + pageOffset));

					TraceEvent("AsyncFileNonDurable_BadWrite", self->id)
					    .detail("Offset", offset + writeOffset + pageOffset)
					    .detail("Length", sectorLength)
					    .detail("GoodStart", goodStart)
					    .detail("GoodEnd", goodEnd)
					    .detail("HasGarbage", garbage)
					    .detail("Side", side)
					    .detail("Filename", self->filename);
					TEST(true); // AsyncFileNonDurable bad write
				} else {
					TraceEvent("AsyncFileNonDurable_DroppedWrite", self->id)
					    .detail("Offset", offset + writeOffset + pageOffset)
					    .detail("Length", sectorLength)
					    .detail("Filename", self->filename);
					TEST(true); // AsyncFileNonDurable dropped write
				}

				pageOffset += sectorLength;
			}

			writeOffset += pageLength;
		}

		wait(waitForAll(writeFutures));
		//TraceEvent("AsyncFileNonDurable_WriteDone", self->id).detail("Delay", delayDuration).detail("Filename", self->filename).detail("WriteLength", length).detail("Offset", offset);
		return Void();
	}

	// Delays truncates a random amount of time before passing them through to the underlying file.
	// If a kill interrupts the delay, then the truncate may or may not be performed
	ACTOR Future<Void> truncate(AsyncFileNonDurable* self,
	                            Promise<Void> truncateStarted,
	                            Future<Future<Void>> ownFuture,
	                            int64_t size) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		wait(g_simulator.onMachine(currentProcess));

		state double delayDuration =
		    g_simulator.speedUpSimulation ? 0.0001 : (deterministicRandom()->random01() * self->maxWriteDelay);
		state Future<bool> startSyncFuture = self->startSyncPromise.getFuture();

		try {
			//TraceEvent("AsyncFileNonDurable_Truncate", self->id).detail("Delay", delayDuration).detail("Filename", self->filename);
			wait(checkKilled(self, "Truncate"));

			state Future<Void> truncateEnded = wait(ownFuture);

			// Need to know the size of the file directly before this truncate
			// takes effect to see what range it modifies.
			if (!self->minSizeAfterPendingModificationsIsExact) {
				wait(success(self->size()));
			}
			ASSERT(self->minSizeAfterPendingModificationsIsExact);
			int64_t beginModifiedRange = std::min(size, self->minSizeAfterPendingModifications);
			self->minSizeAfterPendingModifications = size;

			std::vector<Future<Void>> priorModifications =
			    self->getModificationsAndInsert(beginModifiedRange, /*through end of file*/ -1, true, truncateEnded);

			if (BUGGIFY_WITH_PROB(0.001))
				priorModifications.push_back(
				    delay(deterministicRandom()->random01() * FLOW_KNOBS->MAX_PRIOR_MODIFICATION_DELAY) ||
				    self->killed.getFuture());
			else
				priorModifications.push_back(waitUntilDiskReady(self->diskParameters, 0) || self->killed.getFuture());

			wait(waitForAll(priorModifications));

			self->approximateSize = size;

			self->reponses.add(sendOnProcess(currentProcess, truncateStarted, currentTaskID));
		} catch (Error& e) {
			self->reponses.add(sendErrorOnProcess(currentProcess, truncateStarted, e, currentTaskID));
			throw;
		}

		// Wait a random amount of time or until a sync/kill is issued
		state bool saveDurable = true;
		choose {
			when(wait(delay(delayDuration))) {}
			when(bool durable = wait(startSyncFuture)) { saveDurable = durable; }
		}

		if (g_network->check_yield(TaskPriority::DefaultYield)) {
			wait(delay(0, TaskPriority::DefaultYield));
		}

		// If performing a durable truncate, then pass it through to the file.  Otherwise, pass it through with a 1/2
		// chance
		if (saveDurable || self->killMode == NO_CORRUPTION || deterministicRandom()->random01() < 0.5)
			wait(self->file->truncate(size));
		else {
			TraceEvent("AsyncFileNonDurable_DroppedTruncate", self->id).detail("Size", size);
			TEST(true); // AsyncFileNonDurable dropped truncate
		}

		return Void();
	}

	// Waits for delayed modifications to the file to complete and then syncs the underlying file
	// If durable is false, then some of the delayed modifications will not be applied or will be
	// applied incorrectly
	ACTOR Future<Void> onSync(AsyncFileNonDurable* self, bool durable) {
		//TraceEvent("AsyncFileNonDurable_ImplSync", self->id).detail("Filename", self->filename).detail("Durable", durable);
		ASSERT(durable || !self->killed.isSet()); // this file is kill()ed only once

		if (durable) {
			self->hasBeenSynced = true;
			wait(waitUntilDiskReady(self->diskParameters, 0, true) || self->killed.getFuture());
		}

		wait(checkKilled(self, durable ? "Sync" : "Kill"));

		if (!durable)
			self->killed.send(Void());

		// Get all outstanding modifications
		std::vector<Future<Void>> outstandingModifications;
		std::vector<RangeMapRange<uint64_t>> stillPendingModifications;

		auto rangeItr = self->pendingModifications.ranges();
		for (auto itr = rangeItr.begin(); itr != rangeItr.end(); ++itr) {
			if (itr.value().isValid() && (!itr->value().isReady() || itr->value().isError())) {
				outstandingModifications.push_back(itr->value());

				if (!itr.value().isReady())
					stillPendingModifications.push_back(itr->range());
			}
		}

		Future<Void> allModifications = waitForAll(outstandingModifications);
		// Clear out the pending modifications map of all completed modifications
		self->pendingModifications.insert(RangeMapRange<uint64_t>(0, -1), Void());
		for (auto itr = stillPendingModifications.begin(); itr != stillPendingModifications.end(); ++itr)
			self->pendingModifications.insert(
			    *itr, success(allModifications)); // waitForAll cannot wait on the same future more than once, so wrap
			                                      // the future with success

		// Signal all modifications to end their delay and reset the startSyncPromise
		Promise<bool> startSyncPromise = self->startSyncPromise;
		self->startSyncPromise = Promise<bool>();

		// Writes will be durable in a kill with a 10% probability
		state bool writeDurable = durable || deterministicRandom()->random01() < 0.1;
		startSyncPromise.send(writeDurable);

		// Wait for outstanding writes to complete
		if (durable)
			wait(allModifications);
		else
			wait(success(errorOr(allModifications)));

		if (!durable) {
			// Sometimes sync the file if writes were made durably.  Before a file is first synced, it is stored in a
			// temporary file and then renamed to the correct location once sync is called.  By not calling sync, we
			// simulate a failure to fsync the directory storing the file
			if (self->hasBeenSynced && writeDurable && deterministicRandom()->random01() < 0.5) {
				TEST(true); // AsyncFileNonDurable kill was durable and synced
				wait(success(errorOr(self->file->sync())));
			}

			// Setting this promise could trigger the deletion of the AsyncFileNonDurable; after this none of its
			// members should be used
			//TraceEvent("AsyncFileNonDurable_ImplSyncEnd", self->id).detail("Filename", self->filename).detail("Durable", durable);
			self->killComplete.send(Void());
		}
		// A killed file cannot be allowed to report that it successfully synced
		else {
			wait(checkKilled(self, "SyncEnd"));
			wait(self->file->sync());
			//TraceEvent("AsyncFileNonDurable_ImplSyncEnd", self->id).detail("Filename", self->filename).detail("Durable", durable);
		}

		return Void();
	}

	ACTOR Future<Void> sync(AsyncFileNonDurable* self, bool durable) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		wait(g_simulator.onMachine(currentProcess));

		try {
			wait(self->onSync(self, durable));
			wait(g_simulator.onProcess(currentProcess, currentTaskID));

			return Void();
		} catch (Error& e) {
			state Error err = e;
			wait(g_simulator.onProcess(currentProcess, currentTaskID));
			throw err;
		}
	}

	// Passes along size requests to the underlying file, augmenting with any writes past the end of the file
	ACTOR static Future<int64_t> onSize(AsyncFileNonDurable const* self) {
		//TraceEvent("AsyncFileNonDurable_Size", self->id).detail("Filename", self->filename);
		wait(checkKilled(self, "Size"));
		state Future<int64_t> sizeFuture = self->file->size();
		wait(success(sizeFuture) || self->killed.getFuture());

		wait(checkKilled(self, "SizeEnd"));

		// Include any modifications which extend past the end of the file
		self->approximateSize = self->minSizeAfterPendingModifications =
		    std::max<int64_t>(sizeFuture.get(), self->minSizeAfterPendingModifications);
		self->minSizeAfterPendingModificationsIsExact = true;
		return self->approximateSize;
	}

	ACTOR static Future<int64_t> size(AsyncFileNonDurable const* self) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();

		wait(g_simulator.onMachine(currentProcess));

		try {
			state int64_t rep = wait(onSize(self));
			wait(g_simulator.onProcess(currentProcess, currentTaskID));

			return rep;
		} catch (Error& e) {
			state Error err = e;
			wait(g_simulator.onProcess(currentProcess, currentTaskID));
			throw err;
		}
	}

	// Finishes all outstanding actors on an AsyncFileNonDurable and then deletes it
	ACTOR Future<Void> deleteFile(AsyncFileNonDurable* self) {
		state ISimulator::ProcessInfo* currentProcess = g_simulator.getCurrentProcess();
		state TaskPriority currentTaskID = g_network->getCurrentTask();
		state std::string filename = self->filename;

		wait(g_simulator.onMachine(currentProcess));
		try {
			// Make sure all writes have gone through.
			Promise<bool> startSyncPromise = self->startSyncPromise;
			self->startSyncPromise = Promise<bool>();
			startSyncPromise.send(true);

			std::vector<Future<Void>> outstandingModifications;

			for (auto itr = self->pendingModifications.ranges().begin();
			     itr != self->pendingModifications.ranges().end();
			     ++itr)
				if (itr->value().isValid() && !itr->value().isReady())
					outstandingModifications.push_back(itr->value());

			// Ignore errors here so that all modifications can finish
			wait(waitForAllReady(outstandingModifications));

			// Make sure we aren't in the process of killing the file
			if (self->killed.isSet())
				wait(self->killComplete.getFuture());

			// Remove this file from the filesBeingDeleted map so that new files can be created with this filename
			g_simulator.getMachineByNetworkAddress(self->openedAddress)->closingFiles.erase(self->getFilename());
			g_simulator.getMachineByNetworkAddress(self->openedAddress)->deletingFiles.erase(self->getFilename());
			AsyncFileNonDurable::filesBeingDeleted.erase(self->filename);
			//TraceEvent("AsyncFileNonDurable_FinishDelete", self->id).detail("Filename", self->filename);

			delete self;
			return Void();
		} catch (Error& e) {
			state Error err = e;
			throw err;
		}
	}
};

#include "flow/unactorcompiler.h"
#endif