assert on duplicate listener in SfxListener
To enable finding the source of the duplicate calls, I add new SAL
API (only for internal use) to retrieve and symbolise stack
backtraces.
The theory is that it relatively cheap to just store a backtrace,
but quite expense to symbolise it to strings. Note that the
backtrace() library we use on Linux does not do a particularly
good job, but it gives enough information that developers can use
the addr2line tool to get more precise info.
Explanation of fixes in the code that triggered the assert:
In SwFrameHolder, we need to only call StartListening() if the
pFrame member is actually changing. We also need to call
EndListening() on the old values when pFrame changes.
In SwNavigationPI, there is already a StartListening() call in
the only place we assign to m_pCreateView.
In ImpEditEngine, we need to ignore duplicates, because it is
doing a ref-counting thing. By storing duplicates on the listener
list, it doesn't need to keep track of which stylesheets its
child nodes are using. Given that it therefore will see
duplicate events, there is probably some performance optimisation
opportunities here.
In MasterPageObserver::Implementation::RegisterDocument, we
seem to be getting called multiple times with the same
SdDrawDocument, so just check if we've been registered already
before calling StartListening()
In SvxShape::impl_initFromSdrObject, do the same thing we do
elsewhere in this class, i.e. only call StartListening()
if the model has changed.
Change-Id: I7eae5c774e1e8d56f0ad7bec80e4df0017b287ac
Reviewed-on: https://gerrit.libreoffice.org/41045
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
diff --git a/editeng/source/editeng/impedit5.cxx b/editeng/source/editeng/impedit5.cxx
index 5ec8e65..5ba3549 100644
--- a/editeng/source/editeng/impedit5.cxx
+++ b/editeng/source/editeng/impedit5.cxx
@@ -92,7 +92,7 @@ void ImpEditEngine::SetStyleSheet( sal_Int32 nPara, SfxStyleSheet* pStyle )
EndListening( *pCurStyle );
pNode->SetStyleSheet( pStyle, aStatus.UseCharAttribs() );
if ( pStyle )
StartListening( *pStyle );
StartListening( *pStyle, true );
ParaAttribsChanged( pNode );
}
FormatAndUpdate();
diff --git a/include/sal/backtrace.hxx b/include/sal/backtrace.hxx
new file mode 100644
index 0000000..2c854e1
--- /dev/null
+++ b/include/sal/backtrace.hxx
@@ -0,0 +1,44 @@
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#ifndef INCLUDED_SAL_BACKTRACE_HXX
#define INCLUDED_SAL_BACKTRACE_HXX
#include <sal/config.h>
#include <sal/saldllapi.h>
#include <sal/types.h>
#include <rtl/ustring.hxx>
#include <memory>
/// @cond INTERNAL
/**
Two stage API for recording and then later decoding stack backtraces.
Useful for debugging facilities where we are only interested in decoding
a small handful of recorded stack traces.
@param backtraceDepth value indicating the maximum backtrace depth; must be > 0
*/
#if defined LIBO_INTERNAL_ONLY
struct BacktraceState {
void** buffer;
int nDepth;
};
SAL_DLLPUBLIC std::unique_ptr<BacktraceState> SAL_CALL sal_backtrace_get(
sal_uInt32 backtraceDepth);
SAL_DLLPUBLIC OUString SAL_CALL sal_backtrace_to_string(
BacktraceState* backtraceState);
#endif
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/svl/lstner.hxx b/include/svl/lstner.hxx
index 527a13b..ad79698 100644
--- a/include/svl/lstner.hxx
+++ b/include/svl/lstner.hxx
@@ -39,8 +39,8 @@ public:
SfxListener( const SfxListener &rCopy );
virtual ~SfxListener() COVERITY_NOEXCEPT_FALSE;
void StartListening( SfxBroadcaster& rBroadcaster, bool bPreventDups = false );
void EndListening( SfxBroadcaster& rBroadcaster, bool bAllDups = false );
void StartListening( SfxBroadcaster& rBroadcaster, bool bPreventDuplicates = false );
void EndListening( SfxBroadcaster& rBroadcaster, bool bRemoveAllDuplicates = false );
void EndListeningAll();
bool IsListening( SfxBroadcaster& rBroadcaster ) const;
diff --git a/sal/osl/unx/backtraceapi.cxx b/sal/osl/unx/backtraceapi.cxx
index 91be8d5..4838474 100644
--- a/sal/osl/unx/backtraceapi.cxx
+++ b/sal/osl/unx/backtraceapi.cxx
@@ -18,6 +18,7 @@
#include <rtl/ustrbuf.hxx>
#include <rtl/ustring.hxx>
#include <sal/types.h>
#include <sal/backtrace.hxx>
#include "backtrace.h"
#include "backtraceasstring.hxx"
@@ -58,4 +59,33 @@ OUString osl::detail::backtraceAsString(sal_uInt32 maxDepth) {
return b3.makeStringAndClear();
}
std::unique_ptr<BacktraceState> sal_backtrace_get(sal_uInt32 maxDepth)
{
assert(maxDepth != 0);
auto const maxInt = static_cast<unsigned int>(
std::numeric_limits<int>::max());
if (maxDepth > maxInt) {
maxDepth = static_cast<sal_uInt32>(maxInt);
}
auto b1 = new void *[maxDepth];
int n = backtrace(b1, static_cast<int>(maxDepth));
return std::unique_ptr<BacktraceState>(new BacktraceState{ b1, n });
}
OUString sal_backtrace_to_string(BacktraceState* backtraceState)
{
FreeGuard b2(backtrace_symbols(backtraceState->buffer, backtraceState->nDepth));
if (b2.buffer == nullptr) {
return OUString();
}
OUStringBuffer b3;
for (int i = 0; i != backtraceState->nDepth; ++i) {
if (i != 0) {
b3.append("\n");
}
b3.append(o3tl::runtimeToOUString(b2.buffer[i]));
}
return b3.makeStringAndClear();
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sal/osl/w32/backtrace.cxx b/sal/osl/w32/backtrace.cxx
index a8a4cf4..230adca 100644
--- a/sal/osl/w32/backtrace.cxx
+++ b/sal/osl/w32/backtrace.cxx
@@ -19,6 +19,7 @@
#include <DbgHelp.h>
#include <rtl/ustrbuf.hxx>
#include <sal/backtrace.hxx>
#include "backtraceasstring.hxx"
@@ -64,4 +65,54 @@ OUString osl::detail::backtraceAsString(sal_uInt32 maxDepth)
return aBuf.makeStringAndClear();
}
std::unique_ptr<BacktraceState> sal_backtrace_get(sal_uInt32 maxDepth)
{
assert(maxDepth != 0);
auto const maxUlong = std::numeric_limits<ULONG>::max();
if (maxDepth > maxUlong) {
maxDepth = static_cast<sal_uInt32>(maxUlong);
}
HANDLE hProcess = GetCurrentProcess();
SymInitialize( hProcess, nullptr, true );
auto pStack = new void *[maxDepth];
// https://msdn.microsoft.com/en-us/library/windows/desktop/bb204633.aspx
// "CaptureStackBackTrace function" claims that you "can capture up to
// MAXUSHORT frames", and on Windows Server 2003 and Windows XP it even
// "must be less than 63", but assume that a too large input value is
// clamped internally, instead of resulting in an error:
int nFrames = CaptureStackBackTrace( 0, static_cast<ULONG>(maxDepth), pStack, nullptr );
return std::unique_ptr<BacktraceState>(new BacktraceState{ pStack, nFrames });
}
OUString sal_backtrace_to_string(BacktraceState* backtraceState)
{
OUStringBuffer aBuf;
SYMBOL_INFO * pSymbol;
pSymbol = static_cast<SYMBOL_INFO *>(calloc( sizeof( SYMBOL_INFO ) + 1024 * sizeof( char ), 1 ));
pSymbol->MaxNameLen = 1024 - 1;
pSymbol->SizeOfStruct = sizeof( SYMBOL_INFO );
HANDLE hProcess = GetCurrentProcess();
auto nFrames = backtraceState->nDepth;
for( int i = 0; i < nFrames; i++ )
{
SymFromAddr( hProcess, reinterpret_cast<DWORD64>(backtraceState->buffer[ i ]), nullptr, pSymbol );
aBuf.append( (sal_Int32)(nFrames - i - 1) );
aBuf.append( ": " );
aBuf.appendAscii( pSymbol->Name );
aBuf.append( " - 0x" );
aBuf.append( (sal_Int64)pSymbol->Address, 16 );
aBuf.append( "\n" );
}
free( pSymbol );
return aBuf.makeStringAndClear();
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sal/util/sal.map b/sal/util/sal.map
index b04487e..e9195a1 100644
--- a/sal/util/sal.map
+++ b/sal/util/sal.map
@@ -733,6 +733,12 @@ PRIVATE_1.3 { # LibreOffice 5.4
sal_detail_log_report;
} PRIVATE_1.2;
PRIVATE_1.4 { # LibreOffice 6.0
global:
_Z17sal_backtrace_getj;
_Z23sal_backtrace_to_stringP14BacktraceState;
} PRIVATE_1.3;
PRIVATE_textenc.1 { # LibreOffice 3.6
global:
_ZN3sal6detail7textenc20convertCharToUnicode*;
diff --git a/sd/source/ui/sidebar/MasterPageObserver.cxx b/sd/source/ui/sidebar/MasterPageObserver.cxx
index 86a9c15..57ea45fd 100644
--- a/sd/source/ui/sidebar/MasterPageObserver.cxx
+++ b/sd/source/ui/sidebar/MasterPageObserver.cxx
@@ -162,9 +162,11 @@ void MasterPageObserver::Implementation::RegisterDocument (
aMasterPageSet.insert (pMasterPage->GetName());
}
bool bAlreadyExists = maUsedMasterPages.find(&rDocument) != maUsedMasterPages.end();
maUsedMasterPages[&rDocument] = aMasterPageSet;
StartListening (rDocument);
if (!bAlreadyExists)
StartListening (rDocument);
}
void MasterPageObserver::Implementation::UnregisterDocument (
diff --git a/svl/source/notify/lstner.cxx b/svl/source/notify/lstner.cxx
index 4279e12..0b3d2e9 100644
--- a/svl/source/notify/lstner.cxx
+++ b/svl/source/notify/lstner.cxx
@@ -21,17 +21,22 @@
#include <svl/hint.hxx>
#include <svl/SfxBroadcaster.hxx>
#include <sal/backtrace.hxx>
#include <algorithm>
#include <cassert>
#include <deque>
#include <memory>
#include <map>
typedef std::deque<SfxBroadcaster*> SfxBroadcasterArr_Impl;
struct SfxListener::Impl
{
SfxBroadcasterArr_Impl maBCs;
#ifdef DBG_UTIL
std::map<SfxBroadcaster*, std::unique_ptr<BacktraceState>> maCallStacks;
#endif
};
// simple ctor of class SfxListener
@@ -68,27 +73,47 @@ void SfxListener::RemoveBroadcaster_Impl( SfxBroadcaster& rBroadcaster )
auto it = std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
if (it != mpImpl->maBCs.end()) {
mpImpl->maBCs.erase( it );
#ifdef DBG_UTIL
mpImpl->maCallStacks.erase( &rBroadcaster );
#endif
}
}
// registers a specific SfxBroadcaster
void SfxListener::StartListening( SfxBroadcaster& rBroadcaster, bool bPreventDups )
/**
Registers a specific SfxBroadcaster.
Some code uses duplicates as a kind of ref-counting thing i.e. they add and remove listeners
on different code paths, and they only really stop listening when the last EndListening() is called.
*/
void SfxListener::StartListening( SfxBroadcaster& rBroadcaster, bool bPreventDuplicates )
{
if ( !bPreventDups || !IsListening( rBroadcaster ) )
bool bListeningAlready = IsListening( rBroadcaster );
#ifdef DBG_UTIL
if (bListeningAlready && !bPreventDuplicates)
{
auto f = mpImpl->maCallStacks.find( &rBroadcaster );
SAL_INFO("svl", "previous StartListening call came from: " << sal_backtrace_to_string(f->second.get()));
}
#endif
assert(!(bListeningAlready && !bPreventDuplicates) && "duplicate listener, try building with DBG_UTIL to find the other insert site.");
if ( !bListeningAlready || !bPreventDuplicates )
{
rBroadcaster.AddListener(*this);
mpImpl->maBCs.push_back( &rBroadcaster );
#ifdef DBG_UTIL
mpImpl->maCallStacks.emplace( &rBroadcaster, sal_backtrace_get(10) );
#endif
assert(IsListening(rBroadcaster) && "StartListening failed");
}
}
// unregisters a specific SfxBroadcaster
void SfxListener::EndListening( SfxBroadcaster& rBroadcaster, bool bAllDups )
void SfxListener::EndListening( SfxBroadcaster& rBroadcaster, bool bRemoveAllDuplicates )
{
SfxBroadcasterArr_Impl::iterator beginIt = mpImpl->maBCs.begin();
do
@@ -100,8 +125,11 @@ void SfxListener::EndListening( SfxBroadcaster& rBroadcaster, bool bAllDups )
}
rBroadcaster.RemoveListener(*this);
beginIt = mpImpl->maBCs.erase( it );
#ifdef DBG_UTIL
mpImpl->maCallStacks.erase( &rBroadcaster );
#endif
}
while ( bAllDups );
while ( bRemoveAllDuplicates );
}
@@ -116,6 +144,9 @@ void SfxListener::EndListeningAll()
pBC->RemoveListener(*this);
mpImpl->maBCs.pop_front();
}
#ifdef DBG_UTIL
mpImpl->maCallStacks.clear();
#endif
}
diff --git a/svx/source/unodraw/unoshape.cxx b/svx/source/unodraw/unoshape.cxx
index 49dbba6..d0e59bc 100644
--- a/svx/source/unodraw/unoshape.cxx
+++ b/svx/source/unodraw/unoshape.cxx
@@ -353,15 +353,20 @@ void SvxShape::impl_initFromSdrObject()
}
osl_atomic_decrement( &m_refCount );
mpModel = mpObj->GetModel();
auto pNewModel = mpObj->GetModel();
if (pNewModel != mpModel)
{
if (mpModel)
EndListening( *mpModel );
if (pNewModel)
StartListening( *pNewModel );
mpModel = pNewModel;
}
// #i40944#
// Do not simply return when no model but do the type corrections
// following below.
if(mpModel)
{
StartListening( *mpModel );
}
const SdrInventor nInventor = mpObj->GetObjInventor();
diff --git a/sw/source/core/layout/frmtool.cxx b/sw/source/core/layout/frmtool.cxx
index f058859..5beb864 100644
--- a/sw/source/core/layout/frmtool.cxx
+++ b/sw/source/core/layout/frmtool.cxx
@@ -3181,8 +3181,13 @@ public:
void SwFrameHolder::SetFrame( SwFrame* pHold )
{
bSet = true;
pFrame = pHold;
StartListening(*pHold);
if (pFrame != pHold)
{
if (pFrame)
EndListening(*pFrame);
StartListening(*pHold);
pFrame = pHold;
}
}
void SwFrameHolder::Reset()
diff --git a/sw/source/uibase/utlui/navipi.cxx b/sw/source/uibase/utlui/navipi.cxx
index e580cef..9765031 100644
--- a/sw/source/uibase/utlui/navipi.cxx
+++ b/sw/source/uibase/utlui/navipi.cxx
@@ -718,8 +718,6 @@ SwNavigationPI::SwNavigationPI(SfxBindings* _pBindings,
m_aGlobalTree->SetFont(aFont);
StartListening(*SfxGetpApp());
if ( m_pCreateView )
StartListening(*m_pCreateView);
sal_uInt16 nNavId = m_aContentToolBox->GetItemId("navigation");
m_aContentToolBox->SetItemBits(nNavId, m_aContentToolBox->GetItemBits(nNavId) | ToolBoxItemBits::DROPDOWNONLY );
@@ -886,6 +884,7 @@ void SwNavigationPI::Notify( SfxBroadcaster& rBrdc, const SfxHint& rHint )
{
if (rHint.GetId() == SfxHintId::Dying)
{
EndListening(*m_pCreateView);
m_pCreateView = nullptr;
}
}
