[英]Why does memory allocation fail in this situation?
我已经调试该程序很长时间了,但是我仍然无法弄清为什么内存分配失败。因此,这是我的代码的一部分:
for(int k = 0; k < cur_Candidates.size(); k++)
{
bool flag = false;
QuickSI_SGI(cur_Candidates[k],flag, datacodes);
if( flag == true )
{
CurGlobalVariables.Answers.push_back(cur_Candidates[k]);
}
}
上面的代码是一个循环, QuickSI_SGI(cur_Candidates[k],flag, datacodes)
都调用函数QuickSI_SGI(cur_Candidates[k],flag, datacodes)
。
据我所知,当函数返回时,分配给该函数的空间将被释放。但是,当我调试程序时,我发现使用的内存随着循环的进行而增加。不幸的是,这是一个长循环!循环失败,程序失败并警告内存分配失败! 我对此很困惑。
很抱歉,我没有在函数QuickSI_SGI()
告知详细信息,该函数中没有“ new”或“ malloc”语句,并且我仅在函数中使用了vector,并且警告是为vector分配内存失败。 cur_Candidates
是包含整数cur_Candidates
的向量。 CurGlobalVariables.Answers
与cur_Candidates
相同。 我正在使用VS2010,CPU:Intel i5,内存:8GB。
这是函数:
Status PrefixQuickSI::QuickSI_SGI(int cur_graphid, bool &flag, QISequence datacodes[10000])
{
Status st;
int cur_size, query_size;
ECVector<char> cur_UsageTab;
cur_UsageTab.clear();
ECVector<SequenceIndex> cur_MappingTab;
cur_MappingTab.clear();
cur_size = CurGlobalVariables._sequence.size();
int graphsize = cur_size + datacodes[cur_graphid].numOfPrefixNode;
if((graphsize - 1) > m_QueryGraph->V())
{
flag = false;
return OK;
}
for(int i = 0; i < m_UsageTab.size(); i ++)
cur_UsageTab.push_back(m_UsageTab[i]);
for(int i = 0; i < m_MappingTab.size(); i ++)
{
if(i == cur_size)
cur_MappingTab.push_back(NO_SEQUENCE_INDEX);
cur_MappingTab.push_back(m_MappingTab[i]);
}
std::vector<_QISymbol> cur_sequence;
cur_sequence.clear();
for(int i = 0; i < CurGlobalVariables._sequence.size(); i ++)
cur_sequence.push_back(CurGlobalVariables._sequence[i]);
int depth = 0;
st = my_QucikSI(cur_sequence, datacodes[cur_graphid], depth, cur_size,cur_UsageTab,cur_MappingTab, flag);
if (flag==true)
{
return OK;
}
else
{
flag = false;
return OK;
}
return OK;
}
这是另一个功能:
Status PrefixQuickSI::my_QucikSI(std::vector<_QISymbol> &cur_sequence, QISequence &graphcode, int &depth, int feature_size, ECVector<char> cur_UsageTab, ECVector<SequenceIndex> cur_MappingTab, bool &flag)
{
Status st;
int vcnt = m_QueryGraph->V();
_QISymbol T;
if(depth == 0)
{
T.tSymbol = graphcode.sequence[depth]->tSymbol;
T.rSymbols.clear();
for(int i = 0; i < graphcode.sequence[depth]->numOfRSymbol; i++)
{
int v1,v2;
Label elabel;
v1 = graphcode.sequence[depth]->rSymbol[i].val;
v2 = graphcode.sequence[depth]->rSymbol[i+1].val;
elabel = graphcode.sequence[depth]->rSymbol[i].lable;
if(m_QueryGraph->getELabel(cur_MappingTab[v1],cur_MappingTab[v2]) != elabel)
{
flag = false;
return OK;
}
T.rSymbols.push_back(graphcode.sequence[depth]->rSymbol[i]);
T.rSymbols.push_back(graphcode.sequence[depth]->rSymbol[i+1]);
i++;
}
depth++;
cur_sequence.push_back(T);
if(depth == graphcode.numOfPrefixNode)
{
flag =true;
return OK;
}
else
{
st = my_QucikSI(cur_sequence, graphcode,depth, feature_size, cur_UsageTab, cur_MappingTab, flag);
if(flag == true)
{
return OK;
}
else
{
flag = false;
return OK;
}
}
}
else
{
T.tSymbol = graphcode.sequence[depth]->tSymbol;
for( int j = 0; j < graphcode.sequence[depth]->numOfRSymbol; ++j )
{
RSymbol rSymbol;
rSymbol = graphcode.sequence[depth]->rSymbol[j];
T.rSymbols.push_back(rSymbol);
}
int pV;
VertexIDSet Vcandiates;
for( int i = 0; i < vcnt; i++ )
{
pV = T.tSymbol.p;
if( cur_UsageTab[i] > 0 || m_QueryGraph->getLabel(i) != T.tSymbol.l || m_QueryGraph->getELabel(i, cur_MappingTab[pV]) != T.tSymbol.pl)
continue;
Vcandiates.insert(i);
}
if(Vcandiates.size() == 0)
{
flag = false;
return OK;
}
for( VertexIDSet::const_iterator v = Vcandiates.begin(); v != Vcandiates.end(); v++ )
{
bool mis_match = false;
for( std::vector<RSymbol>::const_iterator r = T.rSymbols.begin(); r != T.rSymbols.end(); r++ )
{
if( !MatchREntry(cur_sequence, *v, *r) )
{
mis_match = true;
break;
}
}
if( mis_match )
continue;
cur_MappingTab[feature_size + depth] = *v;
cur_UsageTab[*v] = 1;
depth++;
cur_sequence.push_back(T);
if(depth == graphcode.numOfPrefixNode)
{
flag = true;
return OK;
}
else
{
st = my_QucikSI(cur_sequence, graphcode,depth, feature_size, cur_UsageTab, cur_MappingTab,flag);
if(flag == true)
{
return OK;
}
else
{
cur_UsageTab[*v] = 0;
depth--;
cur_sequence.pop_back();
}
}
}
}
return OK;
}
在函数中,参数和局部变量分配在堆栈上。
这些变量的内存在函数返回时自动释放。
如果您的函数使用new
关键字分配内存,那么该内存将分配在堆上,您必须使用delete
关键字自己释放它。
例如:
void QuickSI_SGI(int value){ // 'value' will be destroyed on return
string text="Some text"; // 'text' will be destroyed on return
char* list=new char[10]; // This allocates 10 bytes on the heap
// and a pointer to them on the stack.
// The pointer will be destroyed like
// every other local variable, but
// those 10 bytes won't.
delete list; // So you need to manually free that
return; // memory before return
}
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