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/* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
#include "vio_priv.h"
#if !defined(EMBEDDED_LIBRARY)
size_t vio_read_shared_memory(Vio *vio, uchar *buf, size_t size)
{
size_t length;
size_t remain_local;
char *current_position;
HANDLE events[2];
DWORD timeout;
DBUG_ENTER("vio_read_shared_memory");
remain_local= size;
current_position= buf;
timeout= vio->read_timeout >= 0 ? vio->read_timeout : INFINITE;
events[0]= vio->event_server_wrote;
events[1]= vio->event_conn_closed;
do
{
if (vio->shared_memory_remain == 0)
{
DWORD wait_status;
wait_status= WaitForMultipleObjects(array_elements(events), events,
FALSE, timeout);
/*
WaitForMultipleObjects can return next values:
WAIT_OBJECT_0+0 - event from vio->event_server_wrote
WAIT_OBJECT_0+1 - event from vio->event_conn_closed.
We can't read anything
WAIT_ABANDONED_0 and WAIT_TIMEOUT - fail. We can't read anything
*/
if (wait_status != WAIT_OBJECT_0)
{
/*
If wait_status is WAIT_TIMEOUT, set error code to indicate a
timeout error. If vio->event_conn_closed was set, use an EOF
condition (return value of zero) to indicate that the operation
has been aborted.
*/
if (wait_status == WAIT_TIMEOUT)
SetLastError(SOCKET_ETIMEDOUT);
else if (wait_status == (WAIT_OBJECT_0 + 1))
DBUG_RETURN(0);
DBUG_RETURN(-1);
}
vio->shared_memory_pos= vio->handle_map;
vio->shared_memory_remain= uint4korr(vio->shared_memory_pos);
vio->shared_memory_pos+= 4;
}
length= size;
if (vio->shared_memory_remain < length)
length= vio->shared_memory_remain;
if (length > remain_local)
length= remain_local;
memcpy(current_position, vio->shared_memory_pos, length);
vio->shared_memory_remain-= length;
vio->shared_memory_pos+= length;
current_position+= length;
remain_local-= length;
if (!vio->shared_memory_remain)
{
if (!SetEvent(vio->event_client_read))
DBUG_RETURN(-1);
}
} while (remain_local);
length= size;
DBUG_RETURN(length);
}
size_t vio_write_shared_memory(Vio *vio, const uchar *buf, size_t size)
{
size_t length, remain, sz;
HANDLE pos;
const uchar *current_position;
HANDLE events[2];
DWORD timeout;
DBUG_ENTER("vio_write_shared_memory");
remain= size;
current_position= buf;
timeout= vio->write_timeout >= 0 ? vio->write_timeout : INFINITE;
events[0]= vio->event_server_read;
events[1]= vio->event_conn_closed;
while (remain != 0)
{
DWORD wait_status;
wait_status= WaitForMultipleObjects(array_elements(events), events,
FALSE, timeout);
if (wait_status != WAIT_OBJECT_0)
{
/* Set error code to indicate a timeout error or disconnect. */
if (wait_status == WAIT_TIMEOUT)
SetLastError(SOCKET_ETIMEDOUT);
else
SetLastError(ERROR_GRACEFUL_DISCONNECT);
DBUG_RETURN((size_t) -1);
}
sz= (remain > shared_memory_buffer_length ? shared_memory_buffer_length :
remain);
int4store(vio->handle_map, (uint32)sz);
pos= vio->handle_map + 4;
memcpy(pos, current_position, sz);
remain-= sz;
current_position+= sz;
if (!SetEvent(vio->event_client_wrote))
DBUG_RETURN((size_t) -1);
}
length= size;
DBUG_RETURN(length);
}
my_bool vio_is_connected_shared_memory(Vio *vio)
{
return (WaitForSingleObject(vio->event_conn_closed, 0) != WAIT_OBJECT_0);
}
void vio_delete_shared_memory(Vio *vio)
{
DBUG_ENTER("vio_delete_shared_memory");
if (!vio)
DBUG_VOID_RETURN;
if (vio->inactive == FALSE)
vio->vioshutdown(vio);
/*
Close all handlers. UnmapViewOfFile and CloseHandle return non-zero
result if they are success.
*/
if (UnmapViewOfFile(vio->handle_map) == 0)
DBUG_PRINT("vio_error", ("UnmapViewOfFile() failed"));
if (CloseHandle(vio->event_server_wrote) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->esw) failed"));
if (CloseHandle(vio->event_server_read) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->esr) failed"));
if (CloseHandle(vio->event_client_wrote) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->ecw) failed"));
if (CloseHandle(vio->event_client_read) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->ecr) failed"));
if (CloseHandle(vio->handle_file_map) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->hfm) failed"));
if (CloseHandle(vio->event_conn_closed) == 0)
DBUG_PRINT("vio_error", ("CloseHandle(vio->ecc) failed"));
vio_delete(vio);
DBUG_VOID_RETURN;
}
/*
When "kill connection xx" is executed on an arbitrary thread it calls
THD::shutdown_active_vio() on the THD referred to by xx. Since the
thread serving the connection xx might be in the middle of a vio_read
or vio_write, we cannot unmap the shared memory here.
Therefore we here just signal the connection_closed event and give
the thread servicing connection xx a chance to gracefully exit.
All handles are closed and the VIO is cleaned up when vio_delete() is
called and this completes the vio cleanup operation in its entirety.
*/
int vio_shutdown_shared_memory(Vio * vio)
{
DBUG_ENTER("vio_shutdown_shared_memory");
if (vio->inactive == FALSE)
{
/*
Set event_conn_closed for notification of both client and server that
connection is closed
*/
SetEvent(vio->event_conn_closed);
}
vio->inactive= TRUE;
vio->mysql_socket= MYSQL_INVALID_SOCKET;
DBUG_RETURN(0);
}
#endif /* #if !defined(!EMBEDDED_LIBRARY) */
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