[PATCH v2] Don't add window duplicates to tui_windows
Hannes Domani
ssbssa@yahoo.de
Mon Jan 25 17:31:35 GMT 2021
Am Montag, 25. Januar 2021, 17:19:16 MEZ hat Andrew Burgess <andrew.burgess@embecosm.com> Folgendes geschrieben:
> * Hannes Domani via Gdb-patches <gdb-patches@sourceware.org> [2021-01-05 14:55:49 +0100]:
>
> > Otherwise, each time a window size is changed with 'winheight', all windows
> > are duplicated, and when done multiple times, slows down redrawing.
> >
> > gdb/ChangeLog:
> >
> > 2021-01-05 Hannes Domani <ssbssa@yahoo.de>
> >
> > * tui/tui-layout.c (tui_apply_current_layout): Add add_window
> > argument to apply function.
> > (tui_layout_window::apply): Likewise.
> > (tui_layout_split::adjust_size): Likewise.
> > (tui_layout_split::apply): Likewise.
> > * tui/tui-layout.h (class tui_layout_base): Likewise.
> > (class tui_layout_window): Likewise.
> > (class tui_layout_split): Likewise.
> > ---
> > v2:
> > - Use new add_window argument to decide if window should be added to
> > tui_windows.
> > ---
> > gdb/tui/tui-layout.c | 19 ++++++++++++-------
> > gdb/tui/tui-layout.h | 7 ++++---
> > 2 files changed, 16 insertions(+), 10 deletions(-)
> >
> > diff --git a/gdb/tui/tui-layout.c b/gdb/tui/tui-layout.c
> > index d6e299b00f1..fc1b65d8799 100644
> > --- a/gdb/tui/tui-layout.c
> > +++ b/gdb/tui/tui-layout.c
> > @@ -85,7 +85,7 @@ tui_apply_current_layout ()
> > for (tui_win_info *win_info : saved_tui_windows)
> > win_info->make_visible (false);
> >
> > - applied_layout->apply (0, 0, tui_term_width (), tui_term_height ());
> > + applied_layout->apply (0, 0, tui_term_width (), tui_term_height (), true);
> >
> > /* Keep the list of internal windows up-to-date. */
> > for (int win_type = SRC_WIN; (win_type < MAX_MAJOR_WINDOWS); win_type++)
> > @@ -416,7 +416,8 @@ tui_layout_window::clone () const
> > /* See tui-layout.h. */
> >
> > void
> > -tui_layout_window::apply (int x_, int y_, int width_, int height_)
> > +tui_layout_window::apply (int x_, int y_, int width_, int height_,
> > + bool add_window)
> > {
> > x = x_;
> > y = y_;
> > @@ -424,7 +425,8 @@ tui_layout_window::apply (int x_, int y_, int width_, int height_)
> > height = height_;
> > gdb_assert (m_window != nullptr);
> > m_window->resize (height, width, x, y);
> > - tui_windows.push_back (m_window);
> > + if (add_window)
> > + tui_windows.push_back (m_window);
> > }
>
> I wondered if there was a solution to this problem that would remove
> the need to update some global state from the ::apply function.
>
> I came up with the patch below. What do you think?
I think this is fine, I only have one question below.
> This also includes a test that covers this issue, when I run the test
> under valgrind it highlights that GDB tries to free the same object
> multiple times.
>
> Thanks,
> Andrew
>
>
> ---
>
> commit 3d47fcb70e234d08ab2e47c1527bca081846b8ee
> Author: Andrew Burgess <andrew.burgess@embecosm.com>
> Date: Mon Jan 25 15:46:58 2021 +0000
>
> gdb/tui: don't add windows to global list from tui_layout:window::apply
>
> This commit was inspired by this mailing list patch:
>
> https://sourceware.org/pipermail/gdb-patches/2021-January/174713.html
>
> Currently, calling tui_layout_window::apply will add the window from
> the layout object to the global tui_windows list.
>
> Unfortunately, when the user runs the 'winheight' command, this calls
> tui_adjust_window_height, which calls the tui_layout_base::adjust_size
> function, which can then call tui_layout_base::apply. The consequence
> of this is that when the user does 'winheight' duplicate copies of a
> window can be added to the global tui_windows list.
>
> The original patch fixed this by changing the apply function to only
> update the global list some of the time.
>
> This patch takes a different approach. The apply function no longer
> updates the global tui_windows list. Instead a new virtual function
> is added to tui_layout_base which is used to gather all the currently
> applied windows into a vector. Finally tui_apply_current_layout is
> updated to make use of this new function to update the tui_windows
> list.
>
> The benefits I see in this approach are, (a) the apply function now no
> longer touches global state, this solves the immediate problem,
> and (b) now that tui_windows is updated directly in the function
> tui_apply_current_layout, we can drop the saved_tui_windows global.
>
> gdb/ChangeLog:
>
> * tui-layout.c (saved_tui_windows): Delete.
> (tui_apply_current_layout): Don't make use of saved_tui_windows,
> call new get_windows member function instead.
> (tui_get_window_by_name): Check in tui_windows.
> (tui_layout_window::apply): Don't add to tui_windows.
> * tui-layout.h (tui_layout_base::get_windows): New member function.
> (tui_layout_window::get_windows): Likewise.
> (tui_layout_split::get_windows): Likewise.
>
> gdb/testsuite/ChangeLog:
>
> * gdb.tui/winheight.exp: Add more tests.
>
> diff --git a/gdb/testsuite/gdb.tui/winheight.exp b/gdb/testsuite/gdb.tui/winheight.exp
> index 38fb29c3829..04de35d2f45 100644
> --- a/gdb/testsuite/gdb.tui/winheight.exp
> +++ b/gdb/testsuite/gdb.tui/winheight.exp
> @@ -36,3 +36,17 @@ Term::check_box "smaller source box" 0 0 80 10
>
> Term::command "winheight cmd -5"
> Term::check_box "larger source box" 0 0 80 15
> +
> +Term::command "winheight src -5"
> +Term::check_box "smaller source box again" 0 0 80 10
> +
> +Term::command "winheight src +5"
> +Term::check_box "larger source box again" 0 0 80 15
> +
> +# At one point we had a bug where adjusting the winheight would result
> +# in GDB keeping hold of duplicate window pointers, which it might
> +# then try to delete when the layout was changed. Running this test
> +# under valgrind would expose that bug.
> +Term::command "layout asm"
> +Term::check_box "check for asm window" 0 0 80 15
> +
> diff --git a/gdb/tui/tui-layout.c b/gdb/tui/tui-layout.c
> index d6e299b00f1..adb99852da2 100644
> --- a/gdb/tui/tui-layout.c
> +++ b/gdb/tui/tui-layout.c
> @@ -64,11 +64,6 @@ static tui_layout_split *asm_regs_layout;
> /* See tui-data.h. */
> std::vector<tui_win_info *> tui_windows;
>
> -/* When applying a layout, this is the list of all windows that were
> - in the previous layout. This is used to re-use windows when
> - changing a layout. */
> -static std::vector<tui_win_info *> saved_tui_windows;
> -
> /* See tui-layout.h. */
>
> void
> @@ -79,10 +74,7 @@ tui_apply_current_layout ()
>
> extract_display_start_addr (&gdbarch, &addr);
>
> - saved_tui_windows = std::move (tui_windows);
> - tui_windows.clear ();
> -
> - for (tui_win_info *win_info : saved_tui_windows)
> + for (tui_win_info *win_info : tui_windows)
> win_info->make_visible (false);
>
> applied_layout->apply (0, 0, tui_term_width (), tui_term_height ());
> @@ -96,25 +88,33 @@ tui_apply_current_layout ()
> /* This should always be made visible by a layout. */
> gdb_assert (TUI_CMD_WIN->is_visible ());
>
> + /* Get the new list of currently visible windows. */
> + std::vector<tui_win_info *> new_tui_windows;
> + applied_layout->get_windows (&new_tui_windows);
> +
> /* Now delete any window that was not re-applied. */
> tui_win_info *focus = tui_win_with_focus ();
> tui_win_info *locator = tui_locator_win_info_ptr ();
> - for (tui_win_info *win_info : saved_tui_windows)
> + for (tui_win_info *win_info : tui_windows)
> {
> if (!win_info->is_visible ())
> {
> + /* If we're about to delete the window with focus then don't.
> + This will be deleted later once we have selected an
> + alternative window to focus on. */
> if (focus == win_info)
> - tui_set_win_focus_to (tui_windows[0]);
> + tui_set_win_focus_to (new_tui_windows[0]);
> if (win_info != locator)
> delete win_info;
> }
> }
>
> + tui_windows.clear ();
Isn't this clear() redundant?
> + tui_windows = std::move (new_tui_windows);
> +
> if (gdbarch == nullptr && TUI_DISASM_WIN != nullptr)
> tui_get_begin_asm_address (&gdbarch, &addr);
> tui_update_source_windows_with_addr (gdbarch, addr);
> -
> - saved_tui_windows.clear ();
> }
>
> /* See tui-layout. */
> @@ -354,7 +354,7 @@ static std::unordered_map<std::string, window_factory> *known_window_types;
> static tui_win_info *
> tui_get_window_by_name (const std::string &name)
> {
> - for (tui_win_info *window : saved_tui_windows)
> + for (tui_win_info *window : tui_windows)
> if (name == window->name ())
> return window;
>
> @@ -424,7 +424,6 @@ tui_layout_window::apply (int x_, int y_, int width_, int height_)
> height = height_;
> gdb_assert (m_window != nullptr);
> m_window->resize (height, width, x, y);
> - tui_windows.push_back (m_window);
> }
>
> /* See tui-layout.h. */
> diff --git a/gdb/tui/tui-layout.h b/gdb/tui/tui-layout.h
> index 193f42de420..f89166eae37 100644
> --- a/gdb/tui/tui-layout.h
> +++ b/gdb/tui/tui-layout.h
> @@ -91,6 +91,9 @@ class tui_layout_base
> depth of this layout in the hierarchy (zero-based). */
> virtual void specification (ui_file *output, int depth) = 0;
>
> + /* Add all windows to the WINDOWS vector. */
> + virtual void get_windows (std::vector<tui_win_info *> *windows) = 0;
> +
> /* The most recent space allocation. */
> int x = 0;
> int y = 0;
> @@ -141,6 +144,12 @@ class tui_layout_window : public tui_layout_base
>
> void specification (ui_file *output, int depth) override;
>
> + /* See tui_layout_base::get_windows. */
> + void get_windows (std::vector<tui_win_info *> *windows) override
> + {
> + windows->push_back (m_window);
> + }
> +
> protected:
>
> void get_sizes (bool height, int *min_value, int *max_value) override;
> @@ -195,6 +204,13 @@ class tui_layout_split : public tui_layout_base
>
> void specification (ui_file *output, int depth) override;
>
> + /* See tui_layout_base::get_windows. */
> + void get_windows (std::vector<tui_win_info *> *windows) override
> + {
> + for (auto &item : m_splits)
> + item.layout->get_windows (windows);
> + }
> +
> protected:
>
> void get_sizes (bool height, int *min_value, int *max_value) override;
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