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authorRubidium <rubidium@openttd.org>2021-04-15 19:44:43 +0200
committerCharles Pigott <charlespigott@googlemail.com>2021-04-17 19:18:51 +0100
commit44d1b964bf1c87324b82b1793218b5f79a9be9eb (patch)
tree548dc04ddc4516b2da417db26c5891852e77ff6b /src/3rdparty
parent47a99bb67632b6c05b70024f0639c767d057c6ae (diff)
downloadopenttd-44d1b964bf1c87324b82b1793218b5f79a9be9eb.tar.xz
Fix #7513: recursive array/class/table release caused stack overflow
Diffstat (limited to 'src/3rdparty')
-rw-r--r--src/3rdparty/squirrel/squirrel/sqarray.h12
-rw-r--r--src/3rdparty/squirrel/squirrel/sqclass.h16
-rw-r--r--src/3rdparty/squirrel/squirrel/sqobject.h22
-rw-r--r--src/3rdparty/squirrel/squirrel/sqstate.cpp29
-rw-r--r--src/3rdparty/squirrel/squirrel/sqstate.h5
-rw-r--r--src/3rdparty/squirrel/squirrel/sqtable.h10
6 files changed, 73 insertions, 21 deletions
diff --git a/src/3rdparty/squirrel/squirrel/sqarray.h b/src/3rdparty/squirrel/squirrel/sqarray.h
index 37d91bc4e..13ae11619 100644
--- a/src/3rdparty/squirrel/squirrel/sqarray.h
+++ b/src/3rdparty/squirrel/squirrel/sqarray.h
@@ -17,9 +17,9 @@ public:
return newarray;
}
#ifndef NO_GARBAGE_COLLECTOR
- void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue);
+ void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue) override;
#endif
- void Finalize(){
+ void Finalize() override {
_values.resize(0);
}
bool Get(const SQInteger nidx,SQObjectPtr &val)
@@ -78,9 +78,13 @@ public:
ShrinkIfNeeded();
return true;
}
- void Release()
+ void Release() override
{
- sq_delete(this,SQArray);
+ this->_sharedstate->DelayFinalFree(this);
+ }
+ void FinalFree() override
+ {
+ sq_delete(this, SQArray);
}
SQObjectPtrVec _values;
};
diff --git a/src/3rdparty/squirrel/squirrel/sqclass.h b/src/3rdparty/squirrel/squirrel/sqclass.h
index cb0973bbe..4fb6ecbd9 100644
--- a/src/3rdparty/squirrel/squirrel/sqclass.h
+++ b/src/3rdparty/squirrel/squirrel/sqclass.h
@@ -126,31 +126,33 @@ public:
}
return false;
}
- void Release() {
+ void Release() override {
_uiRef++;
try {
if (_hook) { _hook(_userpointer,0);}
} catch (...) {
_uiRef--;
if (_uiRef == 0) {
- SQInteger size = _memsize;
- this->~SQInstance();
- SQ_FREE(this, size);
+ this->_sharedstate->DelayFinalFree(this);
}
throw;
}
_uiRef--;
if(_uiRef > 0) return;
+ this->_sharedstate->DelayFinalFree(this);
+ }
+ void FinalFree() override
+ {
SQInteger size = _memsize;
this->~SQInstance();
SQ_FREE(this, size);
}
- void Finalize();
+ void Finalize() override;
#ifndef NO_GARBAGE_COLLECTOR
- void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue);
+ void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue) override;
#endif
bool InstanceOf(SQClass *trg);
- bool GetMetaMethod(SQVM *v,SQMetaMethod mm,SQObjectPtr &res);
+ bool GetMetaMethod(SQVM *v,SQMetaMethod mm,SQObjectPtr &res) override;
SQClass *_class;
SQUserPointer _userpointer;
diff --git a/src/3rdparty/squirrel/squirrel/sqobject.h b/src/3rdparty/squirrel/squirrel/sqobject.h
index ed4f31fcb..9212766ee 100644
--- a/src/3rdparty/squirrel/squirrel/sqobject.h
+++ b/src/3rdparty/squirrel/squirrel/sqobject.h
@@ -2,7 +2,7 @@
#ifndef _SQOBJECT_H_
#define _SQOBJECT_H_
-#include <forward_list>
+#include <vector>
#include "squtils.h"
#define SQ_CLOSURESTREAM_HEAD (('S'<<24)|('Q'<<16)|('I'<<8)|('R'))
@@ -350,6 +350,14 @@ struct SQCollectable : public SQRefCounted {
virtual void Finalize()=0;
static void AddToChain(SQCollectable **chain,SQCollectable *c);
static void RemoveFromChain(SQCollectable **chain,SQCollectable *c);
+
+ /**
+ * Helper to perform the final memory freeing of this instance. Since the destructor might
+ * release more objects, this can cause a very deep recursion. As such, the calls to this
+ * are to be done via _sharedstate->DelayFinalFree which ensures the calls to this method
+ * are done in an iterative instead of recursive approach.
+ */
+ virtual void FinalFree() {}
};
/**
@@ -357,19 +365,19 @@ struct SQCollectable : public SQRefCounted {
* The iterative approach provides effectively a depth first search approach.
*/
class SQGCMarkerQueue {
- std::forward_list<SQCollectable*> queue; ///< The queue of elements to still process.
+ std::vector<SQCollectable*> stack; ///< The elements to still process, with the most recent elements at the back.
public:
/** Whether there are any elements left to process. */
- bool IsEmpty() { return this->queue.empty(); }
+ bool IsEmpty() { return this->stack.empty(); }
/**
- * Remove the first element from the queue.
+ * Remove the most recently added element from the queue.
* Removal when the queue is empty results in undefined behaviour.
*/
SQCollectable *Pop()
{
- SQCollectable *collectable = this->queue.front();
- this->queue.pop_front();
+ SQCollectable *collectable = this->stack.back();
+ this->stack.pop_back();
return collectable;
}
@@ -382,7 +390,7 @@ public:
{
if ((collectable->_uiRef & MARK_FLAG) == 0) {
collectable->_uiRef |= MARK_FLAG;
- this->queue.push_front(collectable);
+ this->stack.push_back(collectable);
}
}
};
diff --git a/src/3rdparty/squirrel/squirrel/sqstate.cpp b/src/3rdparty/squirrel/squirrel/sqstate.cpp
index 9d91c7899..31345d664 100644
--- a/src/3rdparty/squirrel/squirrel/sqstate.cpp
+++ b/src/3rdparty/squirrel/squirrel/sqstate.cpp
@@ -99,6 +99,7 @@ SQSharedState::SQSharedState()
_notifyallexceptions = false;
_scratchpad=NULL;
_scratchpadsize=0;
+ _collectable_free_processing = false;
#ifndef NO_GARBAGE_COLLECTOR
_gc_chain=NULL;
#endif
@@ -226,6 +227,34 @@ SQInteger SQSharedState::GetMetaMethodIdxByName(const SQObjectPtr &name)
return -1;
}
+/**
+ * Helper function that is to be used instead of calling FinalFree directly on the instance,
+ * so the frees can happen iteratively. This as in the FinalFree the references to any other
+ * objects are released, which can cause those object to be freed yielding a potentially
+ * very deep stack in case of for example a link list.
+ *
+ * This is done internally by a vector onto which the to be freed instances are pushed. When
+ * this is called when not already processing, this method will actually call the FinalFree
+ * function which might cause more elements to end up in the queue which this method then
+ * picks up continueing until it has processed all instances in that queue.
+ * @param collectable The collectable to (eventually) free.
+ */
+void SQSharedState::DelayFinalFree(SQCollectable *collectable)
+{
+ this->_collectable_free_queue.push_back(collectable);
+
+ if (!this->_collectable_free_processing) {
+ this->_collectable_free_processing = true;
+ while (!this->_collectable_free_queue.empty()) {
+ SQCollectable *collectable = this->_collectable_free_queue.back();
+ this->_collectable_free_queue.pop_back();
+ collectable->FinalFree();
+ }
+ this->_collectable_free_processing = false;
+ }
+}
+
+
#ifndef NO_GARBAGE_COLLECTOR
void SQSharedState::EnqueueMarkObject(SQObjectPtr &o,SQGCMarkerQueue &queue)
diff --git a/src/3rdparty/squirrel/squirrel/sqstate.h b/src/3rdparty/squirrel/squirrel/sqstate.h
index d1a1f8dd6..547e6de47 100644
--- a/src/3rdparty/squirrel/squirrel/sqstate.h
+++ b/src/3rdparty/squirrel/squirrel/sqstate.h
@@ -61,6 +61,7 @@ struct SQSharedState
public:
SQChar* GetScratchPad(SQInteger size);
SQInteger GetMetaMethodIdxByName(const SQObjectPtr &name);
+ void DelayFinalFree(SQCollectable *collectable);
#ifndef NO_GARBAGE_COLLECTOR
SQInteger CollectGarbage(SQVM *vm);
static void EnqueueMarkObject(SQObjectPtr &o,SQGCMarkerQueue &queue);
@@ -74,6 +75,10 @@ public:
SQObjectPtr _registry;
SQObjectPtr _consts;
SQObjectPtr _constructoridx;
+ /** Queue to make freeing of collectables iterative. */
+ std::vector<SQCollectable *> _collectable_free_queue;
+ /** Whether someone is already processing the _collectable_free_queue. */
+ bool _collectable_free_processing;
#ifndef NO_GARBAGE_COLLECTOR
SQCollectable *_gc_chain;
#endif
diff --git a/src/3rdparty/squirrel/squirrel/sqtable.h b/src/3rdparty/squirrel/squirrel/sqtable.h
index 0083a90a9..fad2fdc60 100644
--- a/src/3rdparty/squirrel/squirrel/sqtable.h
+++ b/src/3rdparty/squirrel/squirrel/sqtable.h
@@ -50,7 +50,7 @@ public:
newtable->_delegate = NULL;
return newtable;
}
- void Finalize();
+ void Finalize() override;
SQTable *Clone();
~SQTable()
{
@@ -60,7 +60,7 @@ public:
SQ_FREE(_nodes, _numofnodes * sizeof(_HashNode));
}
#ifndef NO_GARBAGE_COLLECTOR
- void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue);
+ void EnqueueMarkObjectForChildren(SQGCMarkerQueue &queue) override;
#endif
inline _HashNode *_Get(const SQObjectPtr &key,SQHash hash)
{
@@ -81,7 +81,11 @@ public:
SQInteger CountUsed(){ return _usednodes;}
void Clear();
- void Release()
+ void Release() override
+ {
+ this->_sharedstate->DelayFinalFree(this);
+ }
+ void FinalFree() override
{
sq_delete(this, SQTable);
}