| //*************************************************************** // From the book "Win32 System Services: The Heart of Windows NT" // by Marshall Brain // Published by Prentice Hall file:// // This code implements a simple mailslot server (receiver) that // uses polling. file://*************************************************************** // sms_recv.cpp #include #include int main() { char toDisptxt[80]; HANDLE hSMS_Slot; DWORD nextSize; DWORD Msgs; DWORD NumBytesRead; BOOL Status; /* Create a mailslot for receiving messages */ hSMS_Slot=CreateMailslot("\\\\.\\mailslot\\sms", 0, 0, (LPSECURITY_ATTRIBUTES) NULL); /* Check and see if the mailslot was created */ if (hSMS_Slot == INVALID_HANDLE_VALUE) { cerr << "ERROR: Unable to create mailslot " << GetLastError() << endl; return (1); } /* Repeatedly check for messages until the program is terminated */ while(1) { Status=GetMailslotInfo(hSMS_Slot, (LPDWORD) NULL, &nextSize, &Msgs, (LPDWORD) NULL); if (!Status) { cerr << "ERROR: Unable to get status. " << GetLastError() << endl; CloseHandle(hSMS_Slot); return (1); } /* If messages are available, then get them */ if (Msgs) { /* Read the message and check to see if read was successful */ if (!ReadFile(hSMS_Slot, toDisptxt, nextSize, &NumBytesRead, (LPOVERLAPPED) NULL)) { cerr << "ERROR: Unable to read from mailslot " << GetLastError() << endl; CloseHandle(hSMS_Slot); return (1); } /* Display the Message */ cout << toDisptxt << endl; } else /* Check for new messages twice a second */ Sleep(500); } /* while */ } |
