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[libcalamares] Fix memory ownership of KPMManager

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- The InternalManager object should have at most one living
   instance at a time.
 - getInternal() hands out shared_ptr<>s to the one living instance,
   or creates a new one.
 - The creation of a new InternalManager shouldn't count as a reference
   to it, and it mustn't be deleted after the shared_ptr<>s have done
   their work.
 - So static shared_ptr<InternalManager> was the wrong choice,
   since that leads to double deletes.
 - While here, be a little more chatty when loading KPMCore.
This commit is contained in:
Adriaan de Groot 2019-06-13 22:30:21 +02:00
parent 1674c81e9c
commit a01539b664
2 changed files with 22 additions and 12 deletions
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33
src/libcalamares/partition/KPMManager.cpp
View File

@ -20,6 +20,7 @@
#include "utils/Logger.h"
#include <kpmcore/backend/corebackend.h>
#include <kpmcore/backend/corebackendmanager.h>
#if defined( WITH_KPMCORE4API )
#include <kpmcore/util/externalcommand.h>
@ -41,16 +42,23 @@ public:
};
static bool s_kpm_loaded = false;
static bool s_loaded = false;
static std::shared_ptr< InternalManager > s_backend;
/*
* We have one living InternalManager object at a time.
* It is managed by shared_ptr<>s help by KPMManager
* objects, but since we can create KPMManager objects
* independent of each other, all of which share ownership
* of the same InternalManager, hang on to one extra reference
* to the InternalManager so we can hand it out in getInternal().
*/
static std::weak_ptr< InternalManager > s_backend;
InternalManager::InternalManager()
{
Q_ASSERT( !s_loaded );
s_loaded = true;
s_backend.reset( this );
cDebug() << "KPMCore backend starting ..";
Q_ASSERT( s_backend.expired() );
if ( !s_kpm_loaded )
{
QByteArray backendName = qgetenv( "KPMCORE_BACKEND" );
@ -61,6 +69,8 @@ InternalManager::InternalManager()
}
else
{
auto* backend_p = CoreBackendManager::self()->backend();
cDebug() << Logger::SubEntry << "Backend @" << (void *)backend_p << backend_p->id() << backend_p->version();
s_kpm_loaded = true;
}
}
@ -70,8 +80,6 @@ InternalManager::~InternalManager()
{
cDebug() << "Cleaning up KPMCore backend ..";
s_loaded = false;
#if defined( WITH_KPMCORE4API )
auto backend_p = CoreBackendManager::self()->backend();
if ( backend_p )
@ -84,12 +92,15 @@ InternalManager::~InternalManager()
std::shared_ptr< InternalManager >
getInternal()
{
cDebug() << "KPMCore internal" << s_backend.use_count();
if ( !s_loaded )
if ( s_backend.expired() )
{
return std::make_shared< InternalManager >();
auto p = std::make_shared< InternalManager >();
s_backend = p;
return p;
}
return s_backend;
return s_backend.lock();
}
KPMManager::KPMManager()

1
src/libcalamares/partition/KPMManager.h
View File

@ -52,7 +52,6 @@ public:
operator bool() const;
private:
std::shared_ptr< InternalManager > m_d;
};
} // namespace Partition