Rewrite wxExecute() implementation under Unix.

[wxWidgets.git] / include / wx / unix / private / executeiohandler.h

diff --git a/include/wx/unix/private/executeiohandler.h b/include/wx/unix/private/executeiohandler.h
new file mode 100644 (file)
index 0000000..ffee30b
--- /dev/null
+++ b/include/wx/unix/private/executeiohandler.h
@@ -0,0 +1,137 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/unix/private/executeiohandler.h
+// Purpose:     IO handler class for the FD used by wxExecute() under Unix
+// Author:      Rob Bresalier, Vadim Zeitlin
+// Created:     2013-01-06
+// RCS-ID:      $Id$
+// Copyright:   (c) 2013 Rob Bresalier, Vadim Zeitlin
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_UNIX_PRIVATE_EXECUTEIOHANDLER_H_
+#define _WX_UNIX_PRIVATE_EXECUTEIOHANDLER_H_
+
+#include "wx/private/streamtempinput.h"
+
+// This class handles IO events on the pipe FD connected to the child process
+// stdout/stderr and is used by wxExecute().
+//
+// Currently it can derive from either wxEventLoopSourceHandler or
+// wxFDIOHandler depending on the kind of dispatcher/event loop it is used
+// with. In the future, when we get rid of wxFDIOHandler entirely, it will
+// derive from wxEventLoopSourceHandler only.
+template <class T>
+class wxExecuteIOHandlerBase : public T
+{
+public:
+    wxExecuteIOHandlerBase(int fd, wxStreamTempInputBuffer& buf)
+        : m_fd(fd),
+          m_buf(buf)
+    {
+        m_callbackDisabled = false;
+    }
+
+    // Called when the associated descriptor is available for reading.
+    virtual void OnReadWaiting()
+    {
+        // Sync process, process all data coming at us from the pipe so that
+        // the pipe does not get full and cause a deadlock situation.
+        m_buf.Update();
+
+        if ( m_buf.Eof() )
+            DisableCallback();
+    }
+
+    // These methods are never called as we only monitor the associated FD for
+    // reading, but we still must implement them as they're pure virtual in the
+    // base class.
+    virtual void OnWriteWaiting() { }
+    virtual void OnExceptionWaiting() { }
+
+    // Disable any future calls to our OnReadWaiting(), can be called when
+    // we're sure that no more input is forthcoming.
+    void DisableCallback()
+    {
+        if ( !m_callbackDisabled )
+        {
+            m_callbackDisabled = true;
+
+            DoDisable();
+        }
+    }
+
+protected:
+    const int m_fd;
+
+private:
+    virtual void DoDisable() = 0;
+
+    wxStreamTempInputBuffer& m_buf;
+
+    // If true, DisableCallback() had been already called.
+    bool m_callbackDisabled;
+
+    wxDECLARE_NO_COPY_CLASS(wxExecuteIOHandlerBase);
+};
+
+// This is the version used with wxFDIODispatcher, which must be passed to the
+// ctor in order to register this handler with it.
+class wxExecuteFDIOHandler : public wxExecuteIOHandlerBase<wxFDIOHandler>
+{
+public:
+    wxExecuteFDIOHandler(wxFDIODispatcher& dispatcher,
+                         int fd,
+                         wxStreamTempInputBuffer& buf)
+        : wxExecuteIOHandlerBase<wxFDIOHandler>(fd, buf),
+          m_dispatcher(dispatcher)
+    {
+        dispatcher.RegisterFD(fd, this, wxFDIO_INPUT);
+    }
+
+    virtual ~wxExecuteFDIOHandler()
+    {
+        DisableCallback();
+    }
+
+private:
+    virtual void DoDisable()
+    {
+        m_dispatcher.UnregisterFD(m_fd);
+    }
+
+    wxFDIODispatcher& m_dispatcher;
+
+    wxDECLARE_NO_COPY_CLASS(wxExecuteFDIOHandler);
+};
+
+// And this is the version used with an event loop. As AddSourceForFD() is
+// static, we don't require passing the event loop to the ctor but an event
+// loop must be running to handle our events.
+class wxExecuteEventLoopSourceHandler
+    : public wxExecuteIOHandlerBase<wxEventLoopSourceHandler>
+{
+public:
+    wxExecuteEventLoopSourceHandler(int fd, wxStreamTempInputBuffer& buf)
+        : wxExecuteIOHandlerBase<wxEventLoopSourceHandler>(fd, buf)
+    {
+        m_source = wxEventLoop::AddSourceForFD(fd, this, wxEVENT_SOURCE_INPUT);
+    }
+
+    virtual ~wxExecuteEventLoopSourceHandler()
+    {
+        DisableCallback();
+    }
+
+private:
+    virtual void DoDisable()
+    {
+        delete m_source;
+        m_source = NULL;
+    }
+
+    wxEventLoopSource* m_source;
+
+    wxDECLARE_NO_COPY_CLASS(wxExecuteEventLoopSourceHandler);
+};
+
+#endif // _WX_UNIX_PRIVATE_EXECUTEIOHANDLER_H_