Mercurial > jwe > octave
changeset 25044:b6aea95a7bf9 stable
store graphics object in Qt backend to avoid crash (bug #53487, #53500)
* Figure.cc (Figure::update): Return early if window doesn't exist.
* Object.h, Object.cc (Object::m_go): New data member.
(Object::object): Return m_go instead of using gh_manager to find it.
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Wed, 28 Mar 2018 17:36:40 -0400 |
| parents | ba5af45bbfc4 |
| children | 135cc24efe4c a4c687fec320 |
| files | libgui/graphics/Figure.cc libgui/graphics/Object.cc libgui/graphics/Object.h |
| diffstat | 3 files changed, 22 insertions(+), 2 deletions(-) [+] |
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--- a/libgui/graphics/Figure.cc Wed Mar 28 21:46:11 2018 +0200 +++ b/libgui/graphics/Figure.cc Wed Mar 28 17:36:40 2018 -0400 @@ -438,6 +438,10 @@ QMainWindow *win = qWidget<QMainWindow> (); + // If the window doesn't exist, there's nothing we can do. + if (! win) + return; + m_blockUpdates = true; switch (pId)
--- a/libgui/graphics/Object.cc Wed Mar 28 21:46:11 2018 +0200 +++ b/libgui/graphics/Object.cc Wed Mar 28 17:36:40 2018 -0400 @@ -35,7 +35,7 @@ { Object::Object (const graphics_object& go, QObject *obj) - : QObject (), m_handle (go.get_handle ()), m_qobject (nullptr) + : QObject (), m_go (go), m_handle (go.get_handle ()), m_qobject (nullptr) { gh_manager::auto_lock lock (false); @@ -78,7 +78,7 @@ "accessing graphics object (h=%g) without a valid lock!!!", m_handle.value ()); - return gh_manager::get_object (m_handle); + return m_go; } void
--- a/libgui/graphics/Object.h Wed Mar 28 21:46:11 2018 +0200 +++ b/libgui/graphics/Object.h Wed Mar 28 17:36:40 2018 -0400 @@ -97,7 +97,23 @@ virtual void beingDeleted (void); protected: + + // Store the graphics object directly so that it will exist when + // we need it. Previously, it was possible for the graphics + // backend to get a handle to a figure, then have the interpreter + // thread delete the corresponding object before the backend (GUI) + // thread had a chance to display it. It should be OK to store + // this object and use it in both threads (graphics_object uses a + // std::shared_ptr) provided that we protect access with mutex locks. + graphics_object m_go; + + // Handle to the graphics object. This may be redundant now. + // Also, the whole ObjectProxy thing may not need to store a + // pointer now? Maybe we can just have a lookup table from figure + // handle to Object? What does the FLTK toolkit do? Why does + // this seem to be so complicated? graphics_handle m_handle; + QObject *m_qobject; };