From b06e5e2b9761d242d9269b091da9a98ec705d2b1 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Caol=C3=A1n=20McNamara?= <caolanm@redhat.com>

Date: Tue, 1 Jun 2021 13:20:43 +0100

Subject: [PATCH] gtk3: workaround missing gdk_threads_enter calls in external

 code

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with gtk3 file dialog. file, open, +other locations,

type davs://somewhere + return

 #0  0x00007ffff7a6e2a2 in raise () at /lib64/libc.so.6

 #1  0x00007ffff7a578a4 in abort () at /lib64/libc.so.6

 #2  0x00007ffff7a57789 in _nl_load_domain.cold () at /lib64/libc.so.6

 #3  0x00007ffff7a66a16 in  () at /lib64/libc.so.6

 #4  0x00007fffd9be7672 in GtkYieldMutex::ThreadsLeave() (this=0x513480) at vcl/unx/gtk3/gtkinst.cxx:354

 #5  0x00007fffd9be6a53 in GdkThreadsLeave() () at vcl/unx/gtk3/gtkinst.cxx:116

 #6  0x00007fffd947ac2d in gtk_dialog_run (dialog=0xa984310) at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkdialog.c:1397

 ^^^ this also (see #30) calls gdk_threads_leave before g_main_loop_run, but no gdk_threads_enter has been called, presumably emit_show_error_message should have called it (?) ^^^

 #7  0x00007fffd94a6dc6 in error_message_with_parent (detail=0xa97f9b0 "HTTP Error: Error resolving “nowhere”: Name or service not known", msg=<optimized out>, parent=<optimized out>)

     at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkfilechooserwidget.c:763

 #8  error_message (impl=<optimized out>, msg=<optimized out>, detail=0xa97f9b0 "HTTP Error: Error resolving “nowhere”: Name or service not known") at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkfilechooserwidget.c:786

 #9  0x00007fffe996ec2f in g_closure_invoke () at /lib64/libgobject-2.0.so.0

 #10 0x00007fffe998aea6 in signal_emit_unlocked_R () at /lib64/libgobject-2.0.so.0

 #11 0x00007fffe998c76a in g_signal_emit_valist () at /lib64/libgobject-2.0.so.0

 #12 0x00007fffe998c983 in g_signal_emit () at /lib64/libgobject-2.0.so.0

 #13 0x00007fffd9561fc7 in emit_show_error_message (secondary_message=0x7fffbc0566f0 "HTTP Error: Error resolving “nowhere”: Name or service not known", primary_message=<optimized out>, view=0x900a240)

     at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkplacesview.c:171

 #14 server_mount_ready_cb (source_file=0x7fffbc05b4c0, res=<optimized out>, user_data=0x900a240) at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkplacesview.c:1232

 #15 0x00007fffe9a64a7a in g_task_return_now () at /lib64/libgio-2.0.so.0

 #16 0x00007fffe9a64c7b in g_task_return () at /lib64/libgio-2.0.so.0

 #17 0x00007fffd80653b8 in mount_reply () at /usr/lib64/gio/modules/libgvfsdbus.so

 #18 0x00007fffe9a64a7a in g_task_return_now () at /lib64/libgio-2.0.so.0

 #19 0x00007fffe9a64c7b in g_task_return () at /lib64/libgio-2.0.so.0

 #20 0x00007fffe9acd2dd in reply_cb () at /lib64/libgio-2.0.so.0

 #21 0x00007fffe9a64a7a in g_task_return_now () at /lib64/libgio-2.0.so.0

 #22 0x00007fffe9a64c7b in g_task_return () at /lib64/libgio-2.0.so.0

 #23 0x00007fffe9ac4c34 in g_dbus_connection_call_done () at /lib64/libgio-2.0.so.0

 #24 0x00007fffe9a64a7a in g_task_return_now () at /lib64/libgio-2.0.so.0

 #25 0x00007fffe9a64abd in complete_in_idle_cb () at /lib64/libgio-2.0.so.0

 #26 0x00007fffe987074b in g_idle_dispatch () at /lib64/libglib-2.0.so.0

 #27 0x00007fffe98744cf in g_main_context_dispatch () at /lib64/libglib-2.0.so.0

 #28 0x00007fffe98c84e8 in g_main_context_iterate.constprop () at /lib64/libglib-2.0.so.0

 #29 0x00007fffe9873a93 in g_main_loop_run () at /lib64/libglib-2.0.so.0

 #30 0x00007fffd947ac37 in gtk_dialog_run (dialog=0x1604460) at /usr/src/debug/gtk3-3.24.29-1.fc34.x86_64/gtk/gtkdialog.c:1398

 ^^^ this will call gdk_threads_leave before g_main_loop_run, (gdk_threads_enter has been called earlier, and gdk_threads_enter will be called after g_main_loop_run) ^^^

 #31 0x00007fffd9bdbd96 in RunDialog::run() (this=0x9134f00) at vcl/unx/gtk3/fpicker/SalGtkPicker.cxx:199

 #32 0x00007fffd9bbf23f in SalGtkFilePicker::execute() (this=0x9004690) at vcl/unx/gtk3/fpicker/SalGtkFilePicker.cxx:953

 #33 0x00007ffff474741a in sfx2::FileDialogHelper_Impl::implDoExecute() (this=0x1667470) at sfx2/source/dialog/filedlghelper.cxx:1279

 #14 presumably server_mount_ready_cb of gtkplacesview.c should protect its gtk

     calls with gdk_threads_enter/gdk_threads_leave like enclosing_volume_mount_cb

     of gtkfilesystem.c does.

Seeing as gdk_threads_leave/gdk_threads_enter is gone in gtk4 I doubt

there's any point looking for a fix in gtk3 and we should just try and

survive the problem.

Change-Id: I007be4dee4f615d4431e27034dcf7f3d446c3e9a

Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116559

Tested-by: Jenkins

Reviewed-by: Caolán McNamara <caolanm@redhat.com>

(cherry picked from commit 08b7529f628eda1d209cf27f9bbe52ee336fef62)

---

 vcl/unx/gtk3/gtk3gtkinst.cxx | 30 ++++++++++++++++++++++--------

 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/vcl/unx/gtk3/gtk3gtkinst.cxx b/vcl/unx/gtk3/gtk3gtkinst.cxx

index 2d4dc36ce5fe..bba4e07f3003 100644

--- a/vcl/unx/gtk3/gtk3gtkinst.cxx

+++ b/vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -314,20 +314,34 @@ thread_local std::stack<sal_uInt32> GtkYieldMutex::yieldCounts;

 void GtkYieldMutex::ThreadsEnter()

 {

     acquire();

-    if (!yieldCounts.empty()) {

-        auto n = yieldCounts.top();

-        yieldCounts.pop();

-        assert(n > 0);

-        n--;

-        if (n > 0)

-            acquire(n);

+    if (yieldCounts.empty())

+        return;

+    auto n = yieldCounts.top();

+    yieldCounts.pop();

+

+    const bool bUndoingLeaveWithoutEnter = n == 0;

+    // if the ThreadsLeave bLeaveWithoutEnter of true condition occurred to

+    // create this entry then return early undoing the initial acquire of the

+    // function

+    if G_UNLIKELY(bUndoingLeaveWithoutEnter)

+    {

+        release();

+        return;

     }

+

+    assert(n > 0);

+    n--;

+    if (n > 0)

+        acquire(n);

 }

 void GtkYieldMutex::ThreadsLeave()

 {

-    assert(m_nCount != 0);

+    const bool bLeaveWithoutEnter = m_nCount == 0;

+    SAL_WARN_IF(bLeaveWithoutEnter, "vcl.gtk", "gdk_threads_leave without matching gdk_threads_enter");

     yieldCounts.push(m_nCount);

+    if G_UNLIKELY(bLeaveWithoutEnter) // this ideally shouldn't happen, but can due to the gtk3 file dialog

+        return;

     release(true);

 }

-- 

2.31.1