Merge pull request #439 from mono-soc-2012/garyb/iconfix

[mono.git] / mcs / class / System.Data / System.Data.Odbc / OdbcCommand.cs

diff --git a/mcs/class/System.Data/System.Data.Odbc/OdbcCommand.cs b/mcs/class/System.Data/System.Data.Odbc/OdbcCommand.cs
index dc30bc0a3cc794399fbf42eb864ce6cd2793853e..ca4f4905c9d161ec62b4401fd101d3cef933e61a 100644 (file)
--- a/mcs/class/System.Data/System.Data.Odbc/OdbcCommand.cs
+++ b/mcs/class/System.Data/System.Data.Odbc/OdbcCommand.cs
@@ -67,6 +67,7 @@ namespace System.Data.Odbc
                bool designTimeVisible;
                bool prepared;
                IntPtr hstmt = IntPtr.Zero;
+               object generation = null; // validity of hstmt
 
                bool disposed;
                
@@ -132,23 +133,13 @@ namespace System.Data.Odbc
                }
 
                [OdbcDescriptionAttribute ("Time to wait for command to execute")]
-#if NET_1_0 || ONLY_1_1
-               [DefaultValue (DEFAULT_COMMAND_TIMEOUT)]
-#endif
-               public
-#if NET_2_0
-               override
-#endif
+               public override
                int CommandTimeout {
                        get { return timeout; }
                        set {
                                if (value < 0)
-#if NET_2_0
                                        throw new ArgumentException ("The property value assigned is less than 0.",
                                                "CommandTimeout");
-#else
-                                       throw new ArgumentException ("The property value assigned is less than 0.");
-#endif
                                timeout = value;
                        }
                }
@@ -353,10 +344,11 @@ namespace System.Data.Odbc
                        OdbcReturn ret;
 
                        if (hstmt != IntPtr.Zero)
+                               // Free the existing hstmt.  Also unlinks from the connection.
                                FreeStatement ();
-                       else
-                               Connection.Link (this);
-
+                       // Link this command to the connection.  The hstmt created below
+                       // only remains valid while generation == Connection.generation.
+                       generation = Connection.Link (this);
                        ret = libodbc.SQLAllocHandle (OdbcHandleType.Stmt, Connection.hDbc, ref hstmt);
                        if (ret != OdbcReturn.Success && ret != OdbcReturn.SuccessWithInfo)
                                throw connection.CreateOdbcException (OdbcHandleType.Dbc, Connection.hDbc);
@@ -376,18 +368,29 @@ namespace System.Data.Odbc
                        if (hstmt == IntPtr.Zero)
                                return;
 
+                       // Normally the command is unlinked from the connection, but during
+                       // OdbcConnection.Close() this would be pointless and (quadratically)
+                       // slow.
                        if (unlink)
                                Connection.Unlink (this);
 
-                       // free previously allocated handle.
-                       OdbcReturn ret = libodbc.SQLFreeStmt (hstmt, libodbc.SQLFreeStmtOptions.Close);
-                       if ((ret!=OdbcReturn.Success) && (ret!=OdbcReturn.SuccessWithInfo))
-                               throw connection.CreateOdbcException (OdbcHandleType.Stmt, hstmt);
+                       // Serialize with respect to the connection's own destruction
+                       lock(Connection) {
+                               // If the connection has already called SQLDisconnect then hstmt
+                               // may have already been freed, in which case it is not safe to
+                               // use.  Thus the generation check.
+                               if(Connection.Generation == generation) {
+                                       // free previously allocated handle.
+                                       OdbcReturn ret = libodbc.SQLFreeStmt (hstmt, libodbc.SQLFreeStmtOptions.Close);
+                                       if ((ret!=OdbcReturn.Success) && (ret!=OdbcReturn.SuccessWithInfo))
+                                               throw connection.CreateOdbcException (OdbcHandleType.Stmt, hstmt);
                        
-                       ret = libodbc.SQLFreeHandle ((ushort) OdbcHandleType.Stmt, hstmt);
-                       if (ret != OdbcReturn.Success && ret != OdbcReturn.SuccessWithInfo)
-                               throw connection.CreateOdbcException (OdbcHandleType.Stmt, hstmt);
-                       hstmt = IntPtr.Zero;
+                                       ret = libodbc.SQLFreeHandle ((ushort) OdbcHandleType.Stmt, hstmt);
+                                       if (ret != OdbcReturn.Success && ret != OdbcReturn.SuccessWithInfo)
+                                               throw connection.CreateOdbcException (OdbcHandleType.Stmt, hstmt);
+                               }
+                               hstmt = IntPtr.Zero;
+                       }
                }
                
                private void ExecSQL (CommandBehavior behavior, bool createReader, string sql)
@@ -449,7 +452,7 @@ namespace System.Data.Odbc
                            (CommandText.ToUpper().IndexOf("INSERT")!=-1) ||
                            (CommandText.ToUpper().IndexOf("DELETE")!=-1)) {
                                int numrows = 0;
-                               OdbcReturn ret = libodbc.SQLRowCount (hstmt, ref numrows);
+                               libodbc.SQLRowCount (hstmt, ref numrows);
                                records = numrows;
                        } else
                                records = -1;