/*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* limitations under the License.
*/
-#include "folly/experimental/io/AsyncIO.h"
+#include <folly/experimental/io/AsyncIO.h>
#include <sys/eventfd.h>
-#include <unistd.h>
#include <cerrno>
+#include <ostream>
#include <stdexcept>
#include <string>
-#include <fstream>
#include <boost/intrusive/parent_from_member.hpp>
#include <glog/logging.h>
-#include "folly/Exception.h"
-#include "folly/Format.h"
-#include "folly/Likely.h"
-#include "folly/String.h"
+#include <folly/Exception.h>
+#include <folly/Format.h>
+#include <folly/Likely.h>
+#include <folly/String.h>
+#include <folly/portability/Unistd.h>
namespace folly {
}
}
+void AsyncIOOp::cancel() {
+ DCHECK_EQ(state_, State::PENDING);
+ state_ = State::CANCELED;
+}
+
ssize_t AsyncIOOp::result() const {
CHECK_EQ(state_, State::COMPLETED);
return result_;
state_ = State::INITIALIZED;
}
-AsyncIO::AsyncIO(size_t capacity, PollMode pollMode)
- : ctx_(0),
- ctxSet_(false),
- pending_(0),
- capacity_(capacity),
- pollFd_(-1) {
+AsyncIO::AsyncIO(size_t capacity, PollMode pollMode) : capacity_(capacity) {
CHECK_GT(capacity_, 0);
completed_.reserve(capacity_);
if (pollMode == POLLABLE) {
}
void AsyncIO::decrementPending() {
- ssize_t p = pending_.fetch_add(-1, std::memory_order_acq_rel);
+ auto p = pending_.fetch_add(-1, std::memory_order_acq_rel);
DCHECK_GE(p, 1);
}
initializeContext(); // on demand
// We can increment past capacity, but we'll clean up after ourselves.
- ssize_t p = pending_.fetch_add(1, std::memory_order_acq_rel);
+ auto p = pending_.fetch_add(1, std::memory_order_acq_rel);
if (p >= capacity_) {
decrementPending();
throw std::range_error("AsyncIO: too many pending requests");
decrementPending();
throwSystemErrorExplicit(-rc, "AsyncIO: io_submit failed");
}
+ submitted_++;
DCHECK_EQ(rc, 1);
op->start();
}
Range<AsyncIO::Op**> AsyncIO::wait(size_t minRequests) {
CHECK(ctx_);
CHECK_EQ(pollFd_, -1) << "wait() only allowed on non-pollable object";
- ssize_t p = pending_.load(std::memory_order_acquire);
+ auto p = pending_.load(std::memory_order_acquire);
CHECK_LE(minRequests, p);
- return doWait(minRequests, p);
+ return doWait(WaitType::COMPLETE, minRequests, p, completed_);
+}
+
+Range<AsyncIO::Op**> AsyncIO::cancel() {
+ CHECK(ctx_);
+ auto p = pending_.load(std::memory_order_acquire);
+ return doWait(WaitType::CANCEL, p, p, canceled_);
}
Range<AsyncIO::Op**> AsyncIO::pollCompleted() {
DCHECK_LE(numEvents, pending_);
// Don't reap more than numEvents, as we've just reset the counter to 0.
- return doWait(numEvents, numEvents);
+ return doWait(WaitType::COMPLETE, numEvents, numEvents, completed_);
}
-Range<AsyncIO::Op**> AsyncIO::doWait(size_t minRequests, size_t maxRequests) {
+Range<AsyncIO::Op**> AsyncIO::doWait(
+ WaitType type,
+ size_t minRequests,
+ size_t maxRequests,
+ std::vector<Op*>& result) {
io_event events[maxRequests];
- int count;
+
+ // Unfortunately, Linux AIO doesn't implement io_cancel, so even for
+ // WaitType::CANCEL we have to wait for IO completion.
+ size_t count = 0;
do {
- // Wait forever
- count = io_getevents(ctx_, minRequests, maxRequests, events, nullptr);
- } while (count == -EINTR);
- checkKernelError(count, "AsyncIO: io_getevents failed");
- DCHECK_GE(count, minRequests); // the man page says so
+ int ret;
+ do {
+ // GOTCHA: io_getevents() may returns less than min_nr results if
+ // interrupted after some events have been read (if before, -EINTR
+ // is returned).
+ ret = io_getevents(ctx_,
+ minRequests - count,
+ maxRequests - count,
+ events + count,
+ /* timeout */ nullptr); // wait forever
+ } while (ret == -EINTR);
+ // Check as may not be able to recover without leaking events.
+ CHECK_GE(ret, 0) << "AsyncIO: io_getevents failed with error "
+ << errnoStr(-ret);
+ count += ret;
+ } while (count < minRequests);
DCHECK_LE(count, maxRequests);
- completed_.clear();
- if (count == 0) {
- return folly::Range<Op**>();
- }
-
+ result.clear();
for (size_t i = 0; i < count; ++i) {
DCHECK(events[i].obj);
Op* op = boost::intrusive::get_parent_from_member(
events[i].obj, &AsyncIOOp::iocb_);
decrementPending();
- op->complete(events[i].res);
- completed_.push_back(op);
+ switch (type) {
+ case WaitType::COMPLETE:
+ op->complete(events[i].res);
+ break;
+ case WaitType::CANCEL:
+ op->cancel();
+ break;
+ }
+ result.push_back(op);
}
- return folly::Range<Op**>(&completed_.front(), count);
+ return range(result);
}
AsyncIOQueue::AsyncIOQueue(AsyncIO* asyncIO)
maybeDequeue();
}
-void AsyncIOQueue::onCompleted(AsyncIOOp* op) {
- maybeDequeue();
-}
+void AsyncIOQueue::onCompleted(AsyncIOOp* /* op */) { maybeDequeue(); }
void AsyncIOQueue::maybeDequeue() {
while (!queue_.empty() && asyncIO_->pending() < asyncIO_->capacity()) {
// Interpose our completion callback
auto& nextCb = op->notificationCallback();
- op->setNotificationCallback([this, nextCb](AsyncIOOp* op) {
- this->onCompleted(op);
- if (nextCb) nextCb(op);
+ op->setNotificationCallback([this, nextCb](AsyncIOOp* op2) {
+ this->onCompleted(op2);
+ if (nextCb) nextCb(op2);
});
asyncIO_->submit(op);
X(AsyncIOOp::State::INITIALIZED);
X(AsyncIOOp::State::PENDING);
X(AsyncIOOp::State::COMPLETED);
+ X(AsyncIOOp::State::CANCELED);
}
return "<INVALID AsyncIOOp::State>";
}
switch (cb.aio_lio_opcode) {
case IO_CMD_PREAD:
case IO_CMD_PWRITE:
- os << folly::format("buf={}, off={}, size={}, ",
- cb.u.c.buf, cb.u.c.nbytes, cb.u.c.offset);
+ os << folly::format("buf={}, offset={}, nbytes={}, ",
+ cb.u.c.buf, cb.u.c.offset, cb.u.c.nbytes);
+ break;
default:
os << "[TODO: write debug string for "
<< iocbCmdToString(cb.aio_lio_opcode) << "] ";
+ break;
}
return os;
}
if (op.state_ == AsyncIOOp::State::COMPLETED) {
- os << "result=" << op.result_ << ", ";
+ os << "result=" << op.result_;
+ if (op.result_ < 0) {
+ os << " (" << errnoStr(-op.result_) << ')';
+ }
+ os << ", ";
}
return os << "}";
}
} // namespace folly
-
projects / folly.git / blobdiff