1 files changed, 178 insertions, 0 deletions

diff --git a/mtp/ffs/AsyncIO.cpp b/mtp/ffs/AsyncIO.cpp
new file mode 100644
index 000000000..eb97a98a2
--- /dev/null
+++ b/mtp/ffs/AsyncIO.cpp
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2016 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 <android-base/logging.h>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <queue>
+
+#include "AsyncIO.h"
+
+void read_func(struct aiocb *aiocbp) {
+	aiocbp->ret = TEMP_FAILURE_RETRY(pread(aiocbp->aio_fildes,
+				aiocbp->aio_buf, aiocbp->aio_nbytes, aiocbp->aio_offset));
+	if (aiocbp->ret == -1) aiocbp->error = errno;
+}
+
+void write_func(struct aiocb *aiocbp) {
+	aiocbp->ret = TEMP_FAILURE_RETRY(pwrite(aiocbp->aio_fildes,
+				aiocbp->aio_buf, aiocbp->aio_nbytes, aiocbp->aio_offset));
+	if (aiocbp->ret == -1) aiocbp->error = errno;
+}
+
+void splice_read_func(struct aiocb *aiocbp) {
+	loff_t long_offset = aiocbp->aio_offset;
+	aiocbp->ret = TEMP_FAILURE_RETRY(splice(aiocbp->aio_fildes,
+				&long_offset, aiocbp->aio_sink,
+				NULL, aiocbp->aio_nbytes, 0));
+	if (aiocbp->ret == -1) aiocbp->error = errno;
+}
+
+void splice_write_func(struct aiocb *aiocbp) {
+	loff_t long_offset = aiocbp->aio_offset;
+	aiocbp->ret = TEMP_FAILURE_RETRY(splice(aiocbp->aio_fildes, NULL,
+				aiocbp->aio_sink, &long_offset,
+				aiocbp->aio_nbytes, 0));
+	if (aiocbp->ret == -1) aiocbp->error = errno;
+}
+
+std::queue<std::unique_ptr<struct aiocb>> queue;
+std::mutex queue_lock;
+std::condition_variable queue_cond;
+std::condition_variable write_cond;
+int done = 1;
+void splice_write_pool_func(int) {
+	while(1) {
+		std::unique_lock<std::mutex> lk(queue_lock);
+		queue_cond.wait(lk, []{return !queue.empty() || done;});
+		if (queue.empty() && done) {
+			return;
+		}
+		std::unique_ptr<struct aiocb> aiocbp = std::move(queue.front());
+		queue.pop();
+		lk.unlock();
+		write_cond.notify_one();
+		splice_write_func(aiocbp.get());
+		close(aiocbp->aio_fildes);
+	}
+}
+
+void write_pool_func(int) {
+	while(1) {
+		std::unique_lock<std::mutex> lk(queue_lock);
+		queue_cond.wait(lk, []{return !queue.empty() || done;});
+		if (queue.empty() && done) {
+			return;
+		}
+		std::unique_ptr<struct aiocb> aiocbp = std::move(queue.front());
+		queue.pop();
+		lk.unlock();
+		write_cond.notify_one();
+		aiocbp->ret = TEMP_FAILURE_RETRY(pwrite(aiocbp->aio_fildes,
+					aiocbp->aio_pool_buf.get(), aiocbp->aio_nbytes, aiocbp->aio_offset));
+		if (aiocbp->ret == -1) aiocbp->error = errno;
+	}
+}
+
+constexpr int NUM_THREADS = 1;
+constexpr int MAX_QUEUE_SIZE = 10;
+std::thread pool[NUM_THREADS];
+
+aiocb::~aiocb() {
+	CHECK(!thread.joinable());
+}
+
+void aio_pool_init(void(f)(int)) {
+	CHECK(done == 1);
+	done = 0;
+	for (int i = 0; i < NUM_THREADS; i++) {
+		pool[i] = std::thread(f, i);
+	}
+}
+
+void aio_pool_splice_init() {
+	aio_pool_init(splice_write_pool_func);
+}
+
+void aio_pool_write_init() {
+	aio_pool_init(write_pool_func);
+}
+
+void aio_pool_end() {
+	done = 1;
+	for (int i = 0; i < NUM_THREADS; i++) {
+		std::unique_lock<std::mutex> lk(queue_lock);
+		lk.unlock();
+		queue_cond.notify_one();
+	}
+
+	for (int i = 0; i < NUM_THREADS; i++) {
+		pool[i].join();
+	}
+}
+
+// used for both writes and splices depending on which init was used before.
+int aio_pool_write(struct aiocb *aiocbp) {
+	std::unique_lock<std::mutex> lk(queue_lock);
+	write_cond.wait(lk, []{return queue.size() < MAX_QUEUE_SIZE;});
+	queue.push(std::unique_ptr<struct aiocb>(aiocbp));
+	lk.unlock();
+	queue_cond.notify_one();
+	return 0;
+}
+
+int aio_read(struct aiocb *aiocbp) {
+	aiocbp->thread = std::thread(read_func, aiocbp);
+	return 0;
+}
+
+int aio_write(struct aiocb *aiocbp) {
+	aiocbp->thread = std::thread(write_func, aiocbp);
+	return 0;
+}
+
+int aio_splice_read(struct aiocb *aiocbp) {
+	aiocbp->thread = std::thread(splice_read_func, aiocbp);
+	return 0;
+}
+
+int aio_splice_write(struct aiocb *aiocbp) {
+	aiocbp->thread = std::thread(splice_write_func, aiocbp);
+	return 0;
+}
+
+int aio_error(const struct aiocb *aiocbp) {
+	return aiocbp->error;
+}
+
+ssize_t aio_return(struct aiocb *aiocbp) {
+	return aiocbp->ret;
+}
+
+int aio_suspend(struct aiocb *aiocbp[], int n,
+		const struct timespec *) {
+	for (int i = 0; i < n; i++) {
+		aiocbp[i]->thread.join();
+	}
+	return 0;
+}
+
+int aio_cancel(int, struct aiocb *) {
+	// Not implemented
+	return -1;
+}
+