Whole installer

installer/src/installer-lib/process.cpp

+#include <stdexcept>
+#include <functional>
+#include <wctype.h>
+// <thread> is C++11, but implemented in VS2012
+#include <thread>
+
+#include "installer-lib.h"
+#include "process.h"
+
+//-------------------------------------------------------
+//-------------------------------------------------------
+bool process_by_any_exe_with_any_module::operator()( const PROCESSENTRY32W & process )
+{
+  if (processNames.find(process.szExeFile) != processNames.end())
+  {
+    if (moduleNames.empty())
+      return true;
+
+    Module_Snapshot ms(process.th32ProcessID);
+    const MODULEENTRY32W* me = ms.first();
+    while (me != 0)
+    {
+      if (moduleNames.find(me->szModule) != moduleNames.end())
+      {
+        return true;
+      }
+      me = ms.next();
+    }
+  }
+  return false;
+}
+
+//-------------------------------------------------------
+// creator_process
+//-------------------------------------------------------
+DWORD creator_process( HWND window )
+{
+  DWORD pid ;
+  DWORD r = GetWindowThreadProcessId( window, & pid ) ;
+  if ( r == 0 )
+  {
+    // Assert GetWindowThreadProcessId returned an error
+    // If the window handle is invalid, we end up here.
+    throw windows_api_error( "GetWindowThreadProcessId", r ) ;
+  }
+  return pid ;
+}
+
+//-------------------------------------------------------
+// send_message, send_endsession_messages
+//-------------------------------------------------------
+/**
+* Default process exit wait time (per message) 5000 ms
+*
+* 5 seconds is time that the system will wait before it considers a process non-responsive.
+*/
+static const unsigned int timeout = 5000 ;    // milliseconds
+
+/**
+* An function object to process the results of sending window messages in send_message.
+*
+* We are using send_message within a system iteration over windows.
+* The system has its own convention for continuing/breaking the iteration.
+* This convention is assured consistently in send_message, which also provides default behavior.
+* This class provides the base for any variation from the default behavior.
+*/
+struct message_accumulator
+  : public std::binary_function< DWORD_PTR, bool, bool >
+{
+  virtual result_type operator()( first_argument_type result, second_argument_type return_value ) = 0 ;
+  virtual ~message_accumulator() {} ;
+} ;
+
+/**
+* Iteration action to send a message to a window and accumulate results.
+*
+* An error sending the message is not a failure for the function a whole.
+* The goal is to close the process, and if the window is no longer present, then the process may have already closed.
+* Therefore, we're ignoring both the return value and the result.
+*/
+class send_message
+{
+  UINT message ;                ///< Message type for windows message
+  WPARAM p1 ;                   ///< Generic parameter 1 for windows message
+  LPARAM p2 ;                   ///< Generic parameter 2 for windows message
+  message_accumulator * f ;     ///< Processor for results of sending the message.
+
+public:
+  /**
+  * Full contructor gathers message parameters and a message accumulator.
+  */
+  send_message( UINT message, WPARAM p1, LPARAM p2, message_accumulator & f )
+    : message( message ), p1( p1 ), p2( p2 ), f( & f )
+  {}
+
+  /**
+  * Abbreviated contructor gathers only message parameters.
+  * The message accumulator is absent.
+  */
+  send_message( UINT message, WPARAM p1, LPARAM p2 )
+    : message( message ), p1( p1 ), p2( p2 ), f( 0 )
+  {}
+
+  /*
+  * Enumeration function applied to each window.
+  */
+  bool operator()( HWND window )
+  {
+    DWORD_PTR result ;
+    LRESULT rv = SendMessageTimeoutW( window, message, p1, p2, SMTO_BLOCK, timeout, & result ) ;
+    /*
+    * If we have no message accumulator, the default behavior is to iterate everything.
+    * If we do have one, we delegate to it the decision whether to break or to continue.
+    */
+    if ( ! f )
+    {
+      return true ;
+    }
+    return ( * f )( result, (rv != 0) ) ;
+  }
+} ;
+
+/**
+* Send WM_QUERYENDSESSION and WM_ENDSESSION to a window.
+*
+* This window processor tries to shut down each application individually.
+* The alternative, gathering all the query results first and only then ending sessions, cannot be done with a single window enumeration.
+*/
+class send_endsession_messages
+{
+public:
+  /*
+  * Enumeration function applied to each window.
+  */
+  bool operator()( HWND window )
+  {
+    DWORD_PTR result ;
+    if ( ! SendMessageTimeoutW( window, WM_QUERYENDSESSION, 0, ENDSESSION_CLOSEAPP, SMTO_BLOCK, timeout, & result ) )
+    {
+      // Assert sending the message failed
+      // Ignore failure, just as with send_message().
+      return true ;
+    }
+    // Assert result is FALSE if the process has refused notice that it should shut down.
+    if ( ! result )
+    {
+      /*
+      * Returning false terminates iteration over windows.
+      * Since this process is refusing to shut down, we can't close all the processes and the operation fails.
+      */
+      return false ;
+    }
+    SendMessageTimeoutW( window, WM_ENDSESSION, 0, ENDSESSION_CLOSEAPP, SMTO_BLOCK, timeout, 0 ) ;
+    return true ;
+  }
+} ;
+
+/**
+* Accumulator for query-endsession message.
+*
+* Implements a conditional-conjunction of the query results.
+* All answers must be true in order for this result to be true,
+*   and the calculation is terminated at the first answer 'false'.
+* As usual, errors sending messages are ignored.
+*/
+struct endsession_accumulator :
+  public message_accumulator
+{
+  bool permit_end_session ; ///< Accumulator variable yields final result.
+
+  /**
+  * Enumeration function applied to each window.
+  */
+  bool operator()( DWORD_PTR result, bool return_value )
+  {
+    if ( ( ! return_value ) || result )
+    {
+      // 1. If the result is true, then the process will permit WM_ENDSESSION
+      // 2. An error sending the message counts as "no new information"
+      return true ;
+    }
+    // The first false is the result of the calculation.
+    // The second false means to terminate enumeration early.
+    permit_end_session = false ;
+    return false ;
+  }
+
+  /**
+  * Ordinary constructor.
+  */
+  endsession_accumulator()
+    : permit_end_session( true )
+  {}
+} ;
+
+//-------------------------------------------------------
+// Process_Closer
+//-------------------------------------------------------
+/**
+* Shut down all the processes in the pid_list.
+*
+* The method used here uses blocking system calls to send messages to target processes.
+* Message processing delays, therefore, are sequential and the total delay is their sum.
+* Windows has non-blocking message calls available, and using a multi-threaded implementation would shorten that delay.
+* The code, hwoever, is significantly simpler without multi-threading.
+* The present use of this method is not closing dozens of applications, so delay performance is not critical.
+*
+* \return
+*   The negation of is_running.
+*   If is_running() was true at the beginning, then this function will have run refresh() before returning.
+*
+* \sa
+*   - MSDN [WM_QUERYENDSESSION message](http://msdn.microsoft.com/en-us/library/windows/desktop/aa376890%28v=vs.85%29.aspx)
+*   - MSDN [WM_ENDSESSION message](http://msdn.microsoft.com/en-us/library/windows/desktop/aa376889%28v=vs.85%29.aspx)
+*/
+bool Process_Closer::shut_down()
+{
+  /*
+  * If we're not running, we don't need to shut down.
+  */
+  if ( ! is_running() )
+  {
+    return true ;
+  }
+
+  /*
+  * Shutting down is a structure as an escalating series of attempts to shut down.
+  * After each one, we wait to see if the shut down has completed.
+  * Even though we're using a blocking call to send messages, applications need not block before exiting.
+  * Internet Explorer, in particular, does not.
+  *
+  * Note that termination occurs inside the default case within the switch statement
+  */
+  for ( unsigned int stage = 1 ; ; ++ stage )
+  {
+    // Assert is_running()
+    switch( stage )
+    {
+    case 1 :
+      /*
+      * Send WM_QUERYENDSESSION to every admissible window.
+      * Send WM_ENDSESSION if all processes are ready to shut down.
+      * We try this technique first, since this allows an application to restore its application state when it starts up again.
+      */
+      {
+        endsession_accumulator acc ;
+        send_message m1( WM_QUERYENDSESSION, 0, ENDSESSION_CLOSEAPP, acc ) ;
+        iterate_our_windows( m1 ) ;
+
+        if ( acc.permit_end_session )
+        {
+          send_message m2( WM_ENDSESSION, 0, 0 ) ;
+          iterate_our_windows( m2 ) ;
+        }
+      }
+      break ;
+
+    case 2 :
+      {
+        /*
+        * Send WM_QUERYENDSESSION and WM_ENDSESSION to every admissible window singly, not accumulating results.
+        */
+        send_endsession_messages m ;
+        iterate_our_windows( m ) ;
+      }
+      break ;
+
+    case 3 :
+      {
+        /*
+        * Send WM_CLOSE to every admissible window.
+        */
+        send_message m( WM_CLOSE, 0, 0 ) ;
+        iterate_our_windows( m ) ;
+      }
+      break ;
+
+    default :
+      /*
+      * We're out of ways to try to shut down.
+      */
+      return false ;
+    }
+
+    /*
+    * Wait loop.
+    */
+    for ( unsigned int j = 0 ; j < 50 ; ++ j )
+    {
+      std::this_thread::sleep_for( std::chrono::milliseconds( 100 ) ) ;
+      refresh() ;
+      if ( ! is_running() )
+      {
+        return true ;
+      }
+    }
+    // Assert is_running()
+  }
+  // No control path leaves the for-loop.
+} ;
+