Files
Nasal-Interpreter/version2.0/nasal_gc.h
T
Valk Richard Li 6d22d054ed update
2020-05-26 07:22:27 -07:00

729 lines
19 KiB
C++

#ifndef __NASAL_GC_H__
#define __NASAL_GC_H__
// all identifiers in nasal points to a memory space in nasal_gc.
// memory space uses std::vector<gc_unit>.
// gc_unit is a struct which has nasal_scalar and refcnt in it.(more details please see the definition of gc_unit bellow)
// when an identifier needs to be assigned,but the type of value is not the same as the identifier's value
// the identifier will get a new memory space in nasal_gc and do deep_copy()
// and the memory space that is not used ,its ref_cnt-=1.
class nasal_closure
{
private:
std::list<std::map<std::string,int> > closure;
public:
void set_clear();
void set_local_scope(std::list<std::map<std::string,int> >&);
std::list<std::map<std::string,int> >& get_local_scope();
void print_closure_ids();
};
class nasal_function
{
private:
// closure_updated flag is used to mark if this function's closure is updated.
// to avoid some unexpected errors,closure of each function must be updated before blocks popping back the last scope
bool closure_updated;
int closure_addr;
abstract_syntax_tree parameter_list;
abstract_syntax_tree function_root;
public:
nasal_function();
void set_clear();
void set_local_scope(int);
bool get_closure_update_state();
void set_closure_update_state(bool);
void set_paramemter_list(abstract_syntax_tree&);
void set_statement_block(abstract_syntax_tree&);
int get_local_scope();
abstract_syntax_tree& get_parameter_list();
abstract_syntax_tree& get_statement_block();
void deep_copy(nasal_function&);
};
class nasal_number
{
private:
double nas_number;
public:
void set_clear();
void set_number(double);
double get_number();
void deep_copy(nasal_number&);
};
class nasal_string
{
private:
std::string nas_string;
public:
void set_clear();
void set_string(std::string);
std::string get_string();
void deep_copy(nasal_string&);
};
class nasal_vector
{
private:
std::vector<int> nas_array;
public:
void set_clear();
void vec_push(int);
int* get_elem_addr(int);
int get_elem(int);
int vec_pop();
int get_size();
int* get_parent_hash_member_addr(std::string);
int get_parent_hash_member(std::string);
void generate_new_hash();
void deep_copy(nasal_vector&);
};
class nasal_hash
{
private:
std::map<std::string,int> nas_hash;
public:
void set_clear();
int* get_hash_member_addr(std::string);
int get_hash_member(std::string);
std::vector<int> get_elem();
void hash_push(std::string,int);
void hash_pop(std::string);
void deep_copy(nasal_hash&);
};
class nasal_scalar
{
private:
int type;
nasal_string var_string;
nasal_number var_number;
nasal_vector var_vector;
nasal_hash var_hash;
nasal_function var_func;
nasal_closure var_cls;
public:
nasal_scalar();
void set_type(int);
int get_type();
nasal_number& get_number();
nasal_string& get_string();
nasal_vector& get_vector();
nasal_hash& get_hash();
nasal_function& get_function();
nasal_closure& get_closure();
};
struct gc_unit
{
// collected: If gc collected this item,it'll be set to true.Otherwise it is false.
// elem: Item that this unit stores
// refcnt: Reference counter
bool collected;
bool is_const;
nasal_scalar elem;
int refcnt;
gc_unit()
{
collected=true;
refcnt=0;
return;
}
};
#ifndef NAS_POOL_SIZE
#define NAS_POOL_SIZE 128
struct memory_block
{
gc_unit space[NAS_POOL_SIZE];
};
class memory_block_base
{
private:
std::vector<memory_block*> mem_page;
int mem_size;
public:
memory_block_base()
{
mem_size=0;
memory_block* tmp=new memory_block;
mem_page.push_back(tmp);
return;
}
~memory_block_base()
{
mem_size=0;
int page_size=mem_page.size();
for(int i=0;i<page_size;++i)
delete mem_page[i];
return;
}
void clear()
{
int page_size=mem_page.size();
for(int i=0;i<page_size;++i)
delete mem_page[i];
mem_page.clear();
mem_size=0;
memory_block* tmp=new memory_block;
mem_page.push_back(tmp);
return;
}
gc_unit& operator[](int address)
{
int page_num=address/NAS_POOL_SIZE;
int block_plc=address%NAS_POOL_SIZE;
return mem_page[page_num]->space[block_plc];
}
void push_back()
{
++mem_size;
if(mem_size>mem_page.size()*NAS_POOL_SIZE)
{
memory_block* tmp=new memory_block;
mem_page.push_back(tmp);
}
return;
}
int size()
{
return mem_size;
}
int capacity()
{
return NAS_POOL_SIZE*mem_page.size();
}
};
#endif
class gc_manager
{
private:
// free_space list is used to store space that is not in use.
std::list<int> free_space;
/*
cannot use std::vector to simulate memory
because if vector memory is not enough,vector will use another larger memory as it's main memory
then all the things will be moved to a new space,
at this time if you reference a member in it,this will cause segmentation error.
*/
memory_block_base memory;
bool error_occurred;
public:
void gc_init()
{
// this function must be called in class nasal_runtime before running any codes
memory.clear();
free_space.clear();
error_occurred=false;
return;
}
int gc_alloc()
{
// add a new space for a new value
// if list free_space is not empty,it will get the address at the front and give it to the new value
// if list free_space is empty,it will add new space in memory vector and give it to the new value
// by this way it can manage memory efficiently.
if(free_space.empty())
{
memory.push_back();
free_space.push_back(memory.size()-1);
}
int alloc_plc=free_space.front();
free_space.pop_front();
memory[alloc_plc].collected=false;
memory[alloc_plc].refcnt=1;
return alloc_plc;
}
int get_reference(int addr)
{
// get the reference counts of the scalar
if(addr>=memory.size())
return -1;
return memory[addr].refcnt;
}
nasal_scalar& get_scalar(int addr)
{
// get the reference of the scalar
return memory[addr].elem;
}
bool place_check(const int addr)
{
// check if this place is in memory
// and this place is uncollected
// this function is often used when an identifier is calling a space in memory
return (0<=addr) && (addr<memory.size()) && (!memory[addr].collected);
}
bool reference_add(const int addr)
{
if((0<=addr) && (addr<memory.size()) && (!memory[addr].collected))
++memory[addr].refcnt;
else
{
std::cout<<">> [Gc] fatal error: reference unexpected memory place ";
prt_hex(addr);
std::cout<<" ."<<std::endl;
return false;
}
return true;
}
bool reference_delete(const int addr)
{
if((0<=addr) && (addr<memory.size()) && (!memory[addr].collected))
{
--memory[addr].refcnt;
if(!memory[addr].refcnt)
{
// if refcnt is 0,then starting the destructor
// std::cout<<">> [Gc] collected ";prt_hex(addr);std::cout<<std::endl;
memory[addr].collected=true;
switch(memory[addr].elem.get_type())
{
case scalar_number: memory[addr].elem.get_number().set_clear(); break;
case scalar_string: memory[addr].elem.get_string().set_clear(); break;
case scalar_vector: memory[addr].elem.get_vector().set_clear(); break;
case scalar_hash: memory[addr].elem.get_hash().set_clear(); break;
case scalar_function:memory[addr].elem.get_function().set_clear();break;
case scalar_closure: memory[addr].elem.get_closure().set_clear(); break;
default:break;
}
memory[addr].elem.set_type(scalar_nil);
free_space.push_back(addr);
}
}
else
{
std::cout<<">> [Gc] fatal error: delete unexpected memory address: ";
prt_hex(addr);
std::cout<<" ."<<std::endl;
return false;
}
return true;
}
void info_print()
{
std::cout<<">> [Gc] memory size:"<<memory.size()*sizeof(gc_unit)<<" byte."<<std::endl;
std::cout<<">> [Gc] memory capacity:"<<memory.capacity()*sizeof(gc_unit)<<" byte."<<std::endl;
std::cout<<">> [Gc] memory usage: "<<std::endl;
int cnt=0;
for(int i=0;i<memory.size();++i)
if(!memory[i].collected)
{
prt_hex(i);
std::cout<<"["<<memory[i].refcnt<<"]";
// cnt is used to check if it is the right time to output in the next line
++cnt;
if(!(cnt%8))
std::cout<<std::endl;
else
std::cout<<" ";
}
if(cnt%8)
std::cout<<std::endl;
return;
}
bool check_error()
{
return error_occurred;
}
};
gc_manager nasal_gc;
// this object is used in "nasal_runtime.h"
// because there must be only one gc when running a program(one process)
void nasal_closure::set_clear()
{
if(!closure.size())
return;
for(std::list<std::map<std::string,int> >::iterator iter=closure.begin();iter!=closure.end();++iter)
for(std::map<std::string,int>::iterator i=iter->begin();i!=iter->end();++i)
nasal_gc.reference_delete(i->second);
closure.clear();
return;
}
void nasal_closure::set_local_scope(std::list<std::map<std::string,int> >& tmp_scope)
{
if(closure.size())
for(std::list<std::map<std::string,int> >::iterator iter=closure.begin();iter!=closure.end();++iter)
for(std::map<std::string,int>::iterator i=iter->begin();i!=iter->end();++i)
nasal_gc.reference_delete(i->second);
closure.clear();
closure=tmp_scope;
for(std::list<std::map<std::string,int> >::iterator iter=closure.begin();iter!=closure.end();++iter)
for(std::map<std::string,int>::iterator i=iter->begin();i!=iter->end();++i)
nasal_gc.reference_add(i->second);
return;
}
std::list<std::map<std::string,int> >& nasal_closure::get_local_scope()
{
return closure;
}
void nasal_closure::print_closure_ids()
{
for(std::list<std::map<std::string,int> >::iterator iter=closure.begin();iter!=closure.end();++iter)
for(std::map<std::string,int>::iterator i=iter->begin();i!=iter->end();++i)
{
std::cout<<i->first<<": ";
prt_hex(i->second);
std::cout<<std::endl;
}
return;
}
nasal_function::nasal_function()
{
closure_updated=false;
closure_addr=-1;
return;
}
void nasal_function::set_clear()
{
closure_updated=false;
if(closure_addr>=0)
nasal_gc.reference_delete(closure_addr);
closure_addr=-1;
function_root.set_clear();
return;
}
void nasal_function::set_local_scope(int tmp_addr)
{
if(closure_addr>=0)
nasal_gc.reference_delete(closure_addr);
closure_addr=tmp_addr;
return;
}
bool nasal_function::get_closure_update_state()
{
return closure_updated;
}
void nasal_function::set_closure_update_state(bool _state)
{
closure_updated=_state;
return;
}
void nasal_function::set_paramemter_list(abstract_syntax_tree& para_list)
{
parameter_list=para_list;
return;
}
void nasal_function::set_statement_block(abstract_syntax_tree& func_block)
{
function_root=func_block;
return;
}
int nasal_function::get_local_scope()
{
return closure_addr;
}
abstract_syntax_tree& nasal_function::get_parameter_list()
{
return parameter_list;
}
abstract_syntax_tree& nasal_function::get_statement_block()
{
return function_root;
}
void nasal_function::deep_copy(nasal_function& tmp)
{
if(closure_addr>=0)
nasal_gc.reference_delete(closure_addr);
closure_addr=tmp.closure_addr;
nasal_gc.reference_add(closure_addr);
// copy abstract_syntax_tree
parameter_list=tmp.parameter_list;
function_root=tmp.function_root;
return;
}
void nasal_number::set_clear()
{
nas_number=0;
return;
}
void nasal_number::set_number(double num)
{
nas_number=num;
return;
}
double nasal_number::get_number()
{
return nas_number;
}
void nasal_number::deep_copy(nasal_number& tmp)
{
nas_number=tmp.nas_number;
return;
}
void nasal_string::set_clear()
{
nas_string="";
return;
}
void nasal_string::set_string(std::string str)
{
nas_string=str;
return;
}
std::string nasal_string::get_string()
{
return nas_string;
}
void nasal_string::deep_copy(nasal_string& tmp)
{
nas_string=tmp.nas_string;
return;
}
void nasal_vector::set_clear()
{
for(int i=0;i<nas_array.size();++i)
nasal_gc.reference_delete(nas_array[i]);
std::vector<int> vec_for_swap;
nas_array.swap(vec_for_swap);
return;
}
void nasal_vector::vec_push(int addr)
{
nas_array.push_back(addr);
return;
}
int* nasal_vector::get_elem_addr(int addr)
{
// 0 ~ size-1 -size ~ -1
int bound=nas_array.size();
if(-bound<=addr && addr<0)
return &nas_array[bound+addr];
else if(0<=addr && addr<bound)
return &nas_array[addr];
return NULL;
}
int nasal_vector::get_elem(int addr)
{
// 0 ~ size-1 -size ~ -1
int bound=nas_array.size();
if(-bound<=addr && addr<0)
return nas_array[bound+addr];
else if(0<=addr && addr<bound)
return nas_array[addr];
return -1;
}
int nasal_vector::vec_pop()
{
int ret=nas_array.back();
nas_array.pop_back();
return ret;
}
int nasal_vector::get_size()
{
return nas_array.size();
}
int* nasal_vector::get_parent_hash_member_addr(std::string member_name)
{
int* ret_addr=NULL;
for(int i=0;i<nas_array.size();++i)
if(nasal_gc.get_scalar(nas_array[i]).get_type()==scalar_hash)
{
ret_addr=nasal_gc.get_scalar(nas_array[i]).get_hash().get_hash_member_addr(member_name);
if(ret_addr)
break;
}
return ret_addr;
}
int nasal_vector::get_parent_hash_member(std::string member_name)
{
int ret_addr=-1;
for(int i=0;i<nas_array.size();++i)
if(nasal_gc.get_scalar(nas_array[i]).get_type()==scalar_hash)
{
ret_addr=nasal_gc.get_scalar(nas_array[i]).get_hash().get_hash_member(member_name);
if(ret_addr>=0)
break;
}
return ret_addr;
}
void nasal_vector::generate_new_hash()
{
for(int i=0;i<nas_array.size();++i)
if(nas_array[i]>=0 && nasal_gc.get_scalar(nas_array[i]).get_type()==scalar_hash)
{
int tmp_addr=nas_array[i];
nas_array[i]=nasal_gc.gc_alloc();
nasal_gc.get_scalar(nas_array[i]).set_type(scalar_hash);
nasal_gc.get_scalar(nas_array[i]).get_hash().deep_copy(nasal_gc.get_scalar(tmp_addr).get_hash());
nasal_gc.reference_delete(tmp_addr);;
}
return;
}
void nasal_vector::deep_copy(nasal_vector& tmp)
{
// before deep copy,nasal_vector needs to delete all values in it.
for(int i=0;i<nas_array.size();++i)
nasal_gc.reference_delete(nas_array[i]);
// copy process
for(int i=0;i<tmp.nas_array.size();++i)
{
int tmp_type=nasal_gc.get_scalar(tmp.nas_array[i]).get_type();
int new_addr=nasal_gc.gc_alloc();
nasal_gc.get_scalar(new_addr).set_type(tmp_type);
if(tmp_type==scalar_nil)
;
else if(tmp_type==scalar_number)
nasal_gc.get_scalar(new_addr).get_number().deep_copy(nasal_gc.get_scalar(tmp.nas_array[i]).get_number());
else if(tmp_type==scalar_string)
nasal_gc.get_scalar(new_addr).get_string().deep_copy(nasal_gc.get_scalar(tmp.nas_array[i]).get_string());
else if(tmp_type==scalar_vector)
nasal_gc.get_scalar(new_addr).get_vector().deep_copy(nasal_gc.get_scalar(tmp.nas_array[i]).get_vector());
else if(tmp_type==scalar_hash)
nasal_gc.get_scalar(new_addr).get_hash().deep_copy(nasal_gc.get_scalar(tmp.nas_array[i]).get_hash());
else if(tmp_type==scalar_function)
nasal_gc.get_scalar(new_addr).get_function().deep_copy(nasal_gc.get_scalar(tmp.nas_array[i]).get_function());
nas_array.push_back(new_addr);
}
return;
}
void nasal_hash::set_clear()
{
for(std::map<std::string,int>::iterator i=nas_hash.begin();i!=nas_hash.end();++i)
nasal_gc.reference_delete(i->second);
return;
}
int* nasal_hash::get_hash_member_addr(std::string member_name)
{
if(nas_hash.find(member_name)!=nas_hash.end())
return &nas_hash[member_name];
else if(nas_hash.find("parents")!=nas_hash.end())
return nasal_gc.get_scalar(nas_hash["parents"]).get_vector().get_parent_hash_member_addr(member_name);
return NULL;
}
int nasal_hash::get_hash_member(std::string member_name)
{
if(nas_hash.find(member_name)!=nas_hash.end())
return nas_hash[member_name];
else if(nas_hash.find("parents")!=nas_hash.end())
return nasal_gc.get_scalar(nas_hash["parents"]).get_vector().get_parent_hash_member(member_name);
return -1;
}
std::vector<int> nasal_hash::get_elem()
{
std::vector<int> vec;
for(std::map<std::string,int>::iterator i=nas_hash.begin();i!=nas_hash.end();++i)
vec.push_back(i->second);
return vec;
}
void nasal_hash::hash_push(std::string member_name,int addr)
{
nas_hash[member_name]=addr;
return;
}
void nasal_hash::hash_pop(std::string member_name)
{
if(nas_hash.find(member_name)!=nas_hash.end())
{
nasal_gc.reference_delete(nas_hash[member_name]);
nas_hash.erase(member_name);
}
return;
}
void nasal_hash::deep_copy(nasal_hash& tmp)
{
// defore deep copy,nasal_hash needs to delete all members in it
for(std::map<std::string,int>::iterator i=nas_hash.begin();i!=nas_hash.end();++i)
nasal_gc.reference_delete(i->second);
// copy process
for(std::map<std::string,int>::iterator i=tmp.nas_hash.begin();i!=tmp.nas_hash.end();++i)
{
int tmp_type=nasal_gc.get_scalar(i->second).get_type();
int new_addr=nasal_gc.gc_alloc();
nasal_gc.get_scalar(new_addr).set_type(tmp_type);
switch(tmp_type)
{
case scalar_nil :break;
case scalar_number :nasal_gc.get_scalar(new_addr).get_number().deep_copy(nasal_gc.get_scalar(i->second).get_number());break;
case scalar_string :nasal_gc.get_scalar(new_addr).get_string().deep_copy(nasal_gc.get_scalar(i->second).get_string());break;
case scalar_vector :nasal_gc.get_scalar(new_addr).get_vector().deep_copy(nasal_gc.get_scalar(i->second).get_vector());break;
case scalar_hash :nasal_gc.get_scalar(new_addr).get_hash().deep_copy(nasal_gc.get_scalar(i->second).get_hash());break;
case scalar_function:nasal_gc.get_scalar(new_addr).get_function().deep_copy(nasal_gc.get_scalar(i->second).get_function());break;
}
nas_hash[i->first]=new_addr;
}
return;
}
nasal_scalar::nasal_scalar()
{
type=scalar_nil;
return;
}
void nasal_scalar::set_type(int tmp_type)
{
// scalar_function is the last enum in enum::scalar_type
type=tmp_type>scalar_closure? scalar_nil:tmp_type;
return;
}
int nasal_scalar::get_type()
{
// get scalar type
return type;
}
nasal_number& nasal_scalar::get_number()
{
// get nasal_number
return var_number;
}
nasal_string& nasal_scalar::get_string()
{
// get nasal_string
return var_string;
}
nasal_vector& nasal_scalar::get_vector()
{
// get nasal_vector
return var_vector;
}
nasal_hash& nasal_scalar::get_hash()
{
// get nasal_hash
return var_hash;
}
nasal_function& nasal_scalar::get_function()
{
// get nasal_function
return var_func;
}
nasal_closure& nasal_scalar::get_closure()
{
// get nasal_closure
return var_cls;
}
#endif
/*
code: var i=1;
int addr=nasal_gc.gc_alloc();
nasal_gc.get_scalar(addr).set_type(scalar_number);
nasal_gc.get_scalar(addr).set_number(1);
code: var i='hello';
int addr=nasal_gc.gc_alloc();
nasal_gc.get_scalar(addr).set_type(scalar_string);
nasal_gc.get_scalar(addr).set_string("hello");
code: var i=[];
int addr=vector_generation();
nasal_gc.get_scalar(addr).set_type(scalar_vector);
code: var i={};
int addr=hash_generation();
nasal_gc.get_scalar(addr).set_type(scalar_hash);
nasal_gc.get_scalar(addr).get_hash().set_self_addr(addr);
code: var i=func{return 0;}
// copy local_scope if needed
// copy abstract_syntax_tree
*/