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/***************************************************************************
* lib/io/linuxaio_request.cpp
*
* Part of the STXXL. See http://stxxl.sourceforge.net
*
* Copyright (C) 2011 Johannes Singler <singler@kit.edu>
* Copyright (C) 2014 Timo Bingmann <tb@panthema.net>
*
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
**************************************************************************/
#include <stxxl/bits/io/linuxaio_request.h>
#if STXXL_HAVE_LINUXAIO_FILE
#include <stxxl/bits/io/disk_queues.h>
#include <stxxl/bits/verbose.h>
#include <stxxl/bits/common/error_handling.h>
#include <unistd.h>
#include <sys/syscall.h>
STXXL_BEGIN_NAMESPACE
void linuxaio_request::completed(bool posted, bool canceled)
{
STXXL_VERBOSE_LINUXAIO("linuxaio_request[" << this << "] completed(" <<
posted << "," << canceled << ")");
if (!canceled)
{
if (m_type == READ)
stats::get_instance()->read_finished();
else
stats::get_instance()->write_finished();
}
else if (posted)
{
if (m_type == READ)
stats::get_instance()->read_canceled(m_bytes);
else
stats::get_instance()->write_canceled(m_bytes);
}
request_with_state::completed(canceled);
}
void linuxaio_request::fill_control_block()
{
linuxaio_file* af = dynamic_cast<linuxaio_file*>(m_file);
memset(&cb, 0, sizeof(cb));
// indirection, so the I/O system retains a counting_ptr reference
cb.aio_data = reinterpret_cast<__u64>(new request_ptr(this));
cb.aio_fildes = af->file_des;
cb.aio_lio_opcode = (m_type == READ) ? IOCB_CMD_PREAD : IOCB_CMD_PWRITE;
cb.aio_reqprio = 0;
cb.aio_buf = static_cast<__u64>((unsigned long)(m_buffer));
cb.aio_nbytes = m_bytes;
cb.aio_offset = m_offset;
}
//! Submits an I/O request to the OS
//! \returns false if submission fails
bool linuxaio_request::post()
{
STXXL_VERBOSE_LINUXAIO("linuxaio_request[" << this << "] post()");
fill_control_block();
iocb* cb_pointer = &cb;
// io_submit might considerable time, so we have to remember the current
// time before the call.
double now = timestamp();
linuxaio_queue* queue = dynamic_cast<linuxaio_queue*>(
disk_queues::get_instance()->get_queue(m_file->get_queue_id())
);
long success = syscall(SYS_io_submit, queue->get_io_context(), 1, &cb_pointer);
if (success == 1)
{
if (m_type == READ)
stats::get_instance()->read_started(m_bytes, now);
else
stats::get_instance()->write_started(m_bytes, now);
}
else if (success == -1 && errno != EAGAIN)
STXXL_THROW_ERRNO(io_error, "linuxaio_request::post"
" io_submit()");
return success == 1;
}
//! Cancel the request
//!
//! Routine is called by user, as part of the request interface.
bool linuxaio_request::cancel()
{
STXXL_VERBOSE_LINUXAIO("linuxaio_request[" << this << "] cancel()");
if (!m_file) return false;
request_ptr req(this);
linuxaio_queue* queue = dynamic_cast<linuxaio_queue*>(
disk_queues::get_instance()->get_queue(m_file->get_queue_id())
);
return queue->cancel_request(req);
}
//! Cancel already posted request
bool linuxaio_request::cancel_aio()
{
STXXL_VERBOSE_LINUXAIO("linuxaio_request[" << this << "] cancel_aio()");
if (!m_file) return false;
io_event event;
linuxaio_queue* queue = dynamic_cast<linuxaio_queue*>(
disk_queues::get_instance()->get_queue(m_file->get_queue_id())
);
long result = syscall(SYS_io_cancel, queue->get_io_context(), &cb, &event);
if (result == 0) //successfully canceled
queue->handle_events(&event, 1, true);
return result == 0;
}
STXXL_END_NAMESPACE
#endif // #if STXXL_HAVE_LINUXAIO_FILE
// vim: et:ts=4:sw=4
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