multithreading programming
I am sharing a static array between a number of System.Threading.Timer simultaneously. This array is accessed only by the first timer thread & second timer will not accessed this array. An exception is displayed: "error can not evaluate expression a native frame is on top of the call stack in c#"
please reply
project code:
public partial class OPC_server : DevExpress.XtraEditors.XtraForm
{
private System.Threading.Timer timer1;
private System.Threading.Timer timer2;
parameter param = new parameter();//another class
private static readonly object myLockHolder = new object();
private static readonly object myLockHolder1 = new object();
public static OpcServer[] _opcServer;
private void OPC_server_Load(object sender, EventArgs e)
{
getconnectedOPC();
}
public void getconnectedOPC()
{
ds = opcconn.GetOPCServerInfo();
int i=0;
DataTable dtOPC=new DataTable();
if (ds.Tables[0].Rows.Count != 0 || ds.Tables[0] != null)
{
dtOPC = ds.Tables[0].Copy();
_opcServer = new OpcServer[dtOPC.Rows.Count];
TimeSpan delayTime = new TimeSpan(0, 0, 1);
TimeSpan intervalTime = new TimeSpan(0, 0, 0, 0, 450);
foreach (DataRow row in dtOPC.Rows)
{
if (i <= dtOPC.Rows.Count)
{
//connetion(row);
getconnect(i, row, dtOPC.Rows.Count);
i++;
}
}
connetion(dtOPC.Rows.Count);
}
}
//connecting the server
public void getconnect(int conn, DataRow r,int rows)
{
DataSet ds2=new DataSet();
DataTable dt2 = new DataTable();
try
{
string machinename = Convert.ToString(r["OPCIPAddress"]);
string servername = Convert.ToString(r["OPCName"]);
_opcServer[conn] = new OpcServer();
int i = _opcServer[conn].Connect(machinename, servername);
if (i == 0)
{
opcconn.update("true", servername);
writelog(servername, "connected");
}
else
{
opcconn.update("false", servername);
writelog(servername, "disconnected");
}
}
catch (OPCException e)
{
servername = Convert.ToString(r["OPCName"]);
opcconn.update("false", servername);
writelog(servername, e.Message.ToString());
}
catch (ApplicationException e)
{
servername = Convert.ToString(r["OPCName"]);
opcconn.update("false", servername);
writelog(servername, "No instance server");
}
}
public void connetion(object state)
{
int k ,i,q=0;
k = (System.Int32)state;
DataSet dsgroup=new DataSet();
while(j < k)
{
try
{
bool val;
HRESULTS re;
SrvStatus status;
DateTime dt;
i = _opcServer[j].GetStatus(out status);
if (HRESULTS.Failed(i))
{
try
{
opcconn.update("false", _opcServer[j].ServerName.ToString());
string IP = opcconn.search(_opcServer[j].Serv开发者_如何学JAVAerName.ToString());
_opcServer[j].Connect(IP, _opcServer[j].ServerName.ToString());
opcconn.update("true", _opcServer[j].ServerName.ToString());
j++;
}
catch
{
opcconn.update("false", _opcServer[j].ServerName.ToString());
j++;
}
}
else
{
val = HRESULTS.Succeeded(i);
dsgroup = grpclass.getgroupinfo(j + 1);
if (dsgroup.Tables[0].Rows.Count != 0)
{
grpdt = new DataTable();
grpdt = dsgroup.Tables[0].Copy();
foreach (DataRow Row in grpdt.Rows)
{
if (groupcnt <= 128)
{
if (cntgroup < grpdt.Rows.Count)
{
grp = _opcServer[j].AddGroup((Convert.ToString(Row["GroupName"])), (Convert.ToBoolean(Row["setactive"])), (Convert.ToInt32(Row["refreshRate"])), 1);
ds1 = param.getparameter1(Convert.ToInt32(Row["groupID"]));
if (ds1.Tables[0].Rows.Count != 0)
{
dt1 = ds1.Tables[0].Copy();
int tq = 0;
item1 = new OPCItemDef[dt1.Rows.Count];
int clienthandle = 1;
foreach (DataRow r in dt1.Rows)
{
if (tq < item1.Length)
{
item1[tq] = new OPCItemDef(Convert.ToString(r["param_ID"]), Convert.ToBoolean(r["active"]), clienthandle, VarEnum.VT_EMPTY);
++clienthandle;
tq++;
}
}
int y = grp.AddItems(item1, out addRslt);
// thread started like each group assign one thread
OPCthread(Row, groupcnt);
groupcnt++;
cntgroup++;
}
}
}
}
}
cntgroup = 0;
j++;
}
}
catch (OPCException)
{
string servername = opcconn.getserver(j + 1);
string IPadd = opcconn.search(servername);
_opcServer[j].Connect(IPadd, servername);
}
catch (IndexOutOfRangeException)
{
j = 0;
}
catch (InvalidCastException e)
{
try
{
// writelog1(_opcServer[j].ServerName.ToString(), "disconnected");
opcconn.update("false", _opcServer[j].ServerName.ToString());
string IP = opcconn.search(_opcServer[j].ServerName.ToString());
_opcServer[j].Connect(IP, _opcServer[j].ServerName.ToString());
opcconn.update("true", _opcServer[j].ServerName.ToString());
j++;
}
catch
{
// writelog1(_opcServer[j].ServerName.ToString(), "connection failed");
opcconn.update("true", _opcServer[j].ServerName.ToString());
j++;
}
}
catch (ArgumentOutOfRangeException)
{
j = 0;
}
catch (NullReferenceException)
{
try
{
// writelog1("server'" + j + "' ", "no server instance");
OPC1 = opcconn.getserver(j + 1);
string IPA = opcconn.search(OPC1);
_opcServer[j].Connect(IPA, OPC1);
opcconn.update("true", OPC1);
writelog(OPC1, "connected");
j++;
}
catch (OPCException e)
{
opcconn.update("false", OPC1);
writelog(OPC1, e.Message.ToString());
j++;
}
catch (ApplicationException e)
{
opcconn.update("false", OPC1);
writelog(OPC1, "No instance server");
j++;
}
}
}
}
public void OPCthread(DataRow r2,int timerinfo)
{
if (timerinfo == 0)
{
int rer = Convert.ToInt32(r2["refreshRate"]);//at least 1 second
TimeSpan dueTime = new TimeSpan(0, 0,0,0,rer);
TimeSpan interval = new TimeSpan(0, 0, 0 ,0 ,rer);
timer1 = new System.Threading.Timer(register, r2, dueTime,interval);
}
else if (timerinfo == 1)
{
TimeSpan dueTime;
TimeSpan interval;
int rer1 = Convert.ToInt32(r2["refreshRate"]);
dueTime = new TimeSpan(0, 0, 0, 0, rer1);
interval = new TimeSpan(0, 0, 0, 0, rer1);
timer2 = new System.Threading.Timer(register1, r2, dueTime, interval);
}
}
public void register(object row1)
{
try
{
lock (myLockHolder)
{
int cnt = 0, cnt1 = 0;
ItemValue[] rVals;
OPCItemDef[] item;
OpcServer srv = new OpcServer();
string[] array;
//SrvStatus status1;
DataSet paramds = new DataSet();
DataTable paramdt = new DataTable();
DataRow dt = (System.Data.DataRow)row1;
int serverID = Convert.ToInt32(dt["OPCServerID"]);
paramds = param.getparameter(Convert.ToInt32(dt["groupID"]));
if (Convert.ToBoolean(dt["setactive"]) == true)
{
if (paramds != null && paramds.Tables[0].Rows.Count != 0)
{
paramdt = paramds.Tables[0].Copy();
int tq = 0;
item = new OPCItemDef[paramdt.Rows.Count];
int clienthandle = 1;
foreach (DataRow r in paramdt.Rows)
{
if (tq < item.Length)
{
item[tq] = new OPCItemDef(Convert.ToString(r["param_ID"]), Convert.ToBoolean(r["active"]), clienthandle, VarEnum.VT_EMPTY);
++clienthandle;
tq++;
}
}
array = new string[item.Length];
cnt1 = 0;
while (cnt1 < array.Length)
{
array[cnt1] = item[cnt1].ItemID;
cnt1++;
}
rVals = _opcServer[serverID - 1].Read(array, Convert.ToInt32(dt["refreshRate"]));
//this line i got the exception when i checking the value of the _opcserver varible in locals the it will be display as "error can not evaluate expression a native frame is on top of the call stack in c#" & thread will stop the execution.
param.update(rVals, Convert.ToInt32(dt["groupID"]));
}
}
}
}
catch (ThreadAbortException) { }
finally { }
}
public void register1(object row2)
{
try
{
lock (myLockHolder1)
{
int cnt = 0, cnt11 = 0;
ItemValue[] rVals1;
OPCItemDef[] item1;
OpcServer srv1 = new OpcServer();
string[] array1;
DataSet paramds1 = new DataSet();
DataTable paramdt1 = new DataTable();
DataRow dt1 = (System.Data.DataRow)row2;
int serverID1 = Convert.ToInt32(dt1["OPCServerID"]);
// Boolean gstatus = grpclass.getstatus(Convert.ToInt32(dt["groupID"]));
paramds1 = param.getparameter2(Convert.ToInt32(dt1["groupID"]));
if (Convert.ToBoolean(dt1["setactive"]) == true)
{
if (paramds1 != null)
{
paramdt1 = paramds1.Tables[0].Copy();
int tq1 = 0;
item1 = new OPCItemDef[paramdt1.Rows.Count];
int clienthandle1 = 1;
foreach (DataRow r in paramdt1.Rows)
{
if (tq1 < item1.Length)
{
item1[tq1] = new OPCItemDef(Convert.ToString(r["param_ID"]), Convert.ToBoolean(r["active"]), clienthandle1, VarEnum.VT_EMPTY);
clienthandle1++;
tq1++;
}
}
array1 = new string[item1.Length];
cnt11 = 0;
while (cnt11 < array1.Length)
{
array1[cnt11] = item1[cnt11].ItemID;
cnt11++;
}
rvals = _opcServer[serverID1 - 1].Read(array1, Convert.ToInt32(dt1["refreshRate"]));//this line i got the exception when i checking the value of the _opcserver varible in locals the it will be display as "error can not evaluate expression a native frame is on top of the call stack in c#" & thread will stop the execution.
param.update1(rVals1, Convert.ToInt32(dt1["groupID"]));
}
}
}
}
catch { }
finally { }
}
The error you are seeing is not an Exception. The message you see is just letting you know that a native frame is on the top of the stack instead of a managed frame.
It's possible that the error you're seeing has nothing to do with the array - but it's difficult to tell without seeing some of your code.
There are two very common problems involved with multi-threaded programs. If I had to take a guess, you're getting an InvalidOperationException either because the "Object is currently in use" or because "Cross-thread operation not valid".
If the first is the case, you need to use something like:
lock (myObject)
{
// Alter myObject
}
see Locks.
And if the second is the case, you need to use something like:
Invoke(new MethodInvoker(delegate()
{
// Alter stuff in Forms/Controls
}));
see Invoke.
It would really help if you could post the exact Exception you're getting and the code which produces it.
Edit: You have posted a mountain of code to look through. It is very unhelpful. You say the line causing it is
rvals = _opcServer[serverID1 - 1].Read(array1, Convert.ToInt32(dt1["refreshRate"]));
but nowhere in your code can I see you have declared the variable _opcServer.
As I have already told you, the native frame message isn't an Exception and doesn't mean that there is anything wrong with your program! - it's simply the debugger telling you that it can't give you the values of the managed variables.
Please put this code around the line to identify which type of Exception you are getting, and tell me what the Exception is.
try
{
rvals = _opcServer[serverID1 - 1].Read(array1, Convert.ToInt32(dt1["refreshRate"]));
}
catch (System.Exception ex)
{
System.Windows.Forms.MessageBox.Show("Exception: " + ex.GetType().ToString() +
"\r\nMessage: " + ex.Message);
}
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