Code cleanup

This commit is contained in:
Victor Olin 2023-03-08 16:47:34 +01:00
parent 7bb64c0489
commit cdc802476d
6 changed files with 503 additions and 459 deletions

View file

@ -2,14 +2,14 @@
#include <stdlib.h> #include <stdlib.h>
#define CHUNK_LIST_CAP 1024 namespace GC
{
namespace GC { struct Chunk
{
struct Chunk { bool marked;
bool marked; uintptr_t *start;
uintptr_t *start; size_t size;
size_t size; };
};
} }

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@ -6,11 +6,11 @@
#include "chunk.hpp" #include "chunk.hpp"
using namespace std; namespace GC
{
namespace GC { enum GCEventType
{
enum GCEventType {
CollectStart, CollectStart,
MarkStart, MarkStart,
ChunkMarked, ChunkMarked,
@ -20,23 +20,27 @@ namespace GC {
ReusedChunk ReusedChunk
}; };
using TimeStamp = chrono::_V2::system_clock::time_point; using TimeStamp = std::chrono::_V2::system_clock::time_point;
class GCEvent { class GCEvent
{
private: private:
// make const // make const
GCEventType m_type; GCEventType m_type;
TimeStamp m_timestamp; TimeStamp m_timestamp;
Chunk *m_chunk; Chunk *m_chunk;
public: public:
GCEvent(GCEventType type) { GCEvent(GCEventType type)
{
m_type = type; m_type = type;
m_timestamp = chrono::system_clock::now(); m_timestamp = std::chrono::system_clock::now();
} }
GCEvent(GCEventType type, Chunk *chunk) { GCEvent(GCEventType type, Chunk *chunk)
{
m_type = type; m_type = type;
m_timestamp = chrono::system_clock::now(); m_timestamp = std::chrono::system_clock::now();
m_chunk = chunk; m_chunk = chunk;
} }

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@ -8,91 +8,96 @@
#include "chunk.hpp" #include "chunk.hpp"
#define HEAP_SIZE 65536 #define HEAP_SIZE 65536
#define MARK (uint) 0x1 #define MARK (uint)0x1
#define SWEEP (uint) 0x2 #define SWEEP (uint)0x2
#define FREE (uint) 0x4 #define FREE (uint)0x4
#define COLLECT_ALL (uint) 0x7 #define COLLECT_ALL (uint)0x7
#define FREE_THRESH (uint) 20 #define FREE_THRESH (uint)20
namespace GC { namespace GC
{
class Heap { class Heap
{
private: private:
// Private constructor according to the singleton pattern
Heap()
{
m_heap = static_cast<char *>(malloc(HEAP_SIZE));
m_size = 0;
m_allocated_size = 0;
}
//Private constructor according to the singleton pattern // BEWARE only for testing, this should be adressed
Heap() { ~Heap()
m_heap = reinterpret_cast<char *>(malloc(HEAP_SIZE)); {
m_size = 0; std::free((char *)m_heap);
m_allocated_size = 0; }
}
// BEWARE only for testing, this should be adressed inline static Heap *the()
~Heap() { { // TODO: make private
std::free((char *)m_heap); if (m_instance) // if m_instance is not a nullptr
} return m_instance;
m_instance = new Heap();
return m_instance;
}
inline static Heap *the() { // TODO: make private inline static Chunk *getAt(std::vector<Chunk *> &list, size_t n)
if (m_instance) // if m_instance is not a nullptr {
return m_instance; auto iter = list.begin();
m_instance = new Heap(); if (!n)
return m_instance; return *iter;
} std::advance(iter, n);
return *iter;
}
inline static Chunk *getAt(std::vector<Chunk *> list, size_t n) { void collect();
auto iter = list.begin(); void sweep(Heap *heap);
if (!n) uintptr_t *try_recycle_chunks(size_t size);
return *iter; void free(Heap *heap);
std::advance(iter, n); void free_overlap(Heap *heap);
return *iter; void mark(uintptr_t *start, const uintptr_t *end, std::vector<Chunk *> &worklist);
} void print_line(Chunk *chunk);
void print_worklist(std::vector<Chunk *> &list);
void collect(); inline static Heap *m_instance = nullptr;
void sweep(Heap *heap); const char *m_heap;
uintptr_t *try_recycle_chunks(size_t size); size_t m_size;
void free(Heap* heap); size_t m_allocated_size;
void free_overlap(Heap *heap); uintptr_t *m_stack_top = nullptr;
void mark(uintptr_t *start, const uintptr_t *end, std::vector<Chunk *> worklist); bool m_profiler_enable = false;
void print_line(Chunk *chunk);
void print_worklist(std::vector<Chunk *> list);
inline static Heap *m_instance = nullptr; // maybe change to std::list
const char *m_heap; std::vector<Chunk *> m_allocated_chunks;
size_t m_size; std::vector<Chunk *> m_freed_chunks;
size_t m_allocated_size;
uintptr_t *m_stack_top = nullptr;
bool m_profiler_enable = false;
// maybe change to std::list public:
std::vector<Chunk *> m_allocated_chunks; /**
std::vector<Chunk *> m_freed_chunks; * These are the only two functions which are exposed
* as the API for LLVM. At the absolute start of the
* program the developer has to call init() to ensure
* that the address of the topmost stack frame is
* saved as the limit for scanning the stack in collect.
*/
static void init();
static void dispose();
static void *alloc(size_t size);
public: // DEBUG ONLY
static inline Heap *debug_the()
/** { // TODO: make private
* These are the only two functions which are exposed if (m_instance) // if m_instance is not a nullptr
* as the API for LLVM. At the absolute start of the return m_instance;
* program the developer has to call init() to ensure m_instance = new Heap();
* that the address of the topmost stack frame is return m_instance;
* saved as the limit for scanning the stack in collect. }
*/ void collect(uint flags); // conditional collection
static void init(); void check_init(); // print dummy things
static void dispose(); void print_contents(); // print dummy things
static void *alloc(size_t size); void set_profiler(bool mode);
};
// DEBUG ONLY
static inline Heap *debug_the() { // TODO: make private
if (m_instance) // if m_instance is not a nullptr
return m_instance;
m_instance = new Heap();
return m_instance;
}
void collect(uint flags); // conditional collection
void check_init(); // print dummy things
void print_contents(); // print dummy things
void set_profiler(bool mode);
};
} }

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@ -6,8 +6,6 @@
#include "event.hpp" #include "event.hpp"
#include "heap.hpp" #include "heap.hpp"
using namespace std;
namespace GC { namespace GC {
class Profiler { class Profiler {
@ -23,7 +21,7 @@ namespace GC {
} }
inline static Profiler *m_instance = nullptr; inline static Profiler *m_instance = nullptr;
vector<GCEvent *> m_events; std::vector<GCEvent *> m_events;
public: public:
static void record(GCEventType type); static void record(GCEventType type);

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@ -6,8 +6,6 @@
#include "event.hpp" #include "event.hpp"
#include "heap.hpp" #include "heap.hpp"
// using namespace std;
namespace GC { namespace GC {
GCEventType GCEvent::getType() { GCEventType GCEvent::getType() {

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@ -8,405 +8,444 @@
#include <vector> #include <vector>
#include "../include/heap.hpp" #include "../include/heap.hpp"
using namespace std;
namespace GC { using std::cout, std::endl, std::vector, std::hex, std::dec;
/** namespace GC
* Initialises the heap singleton and saves the address {
* of the calling stack frame as the stack_top. Presumeably
* this address points to the stack frame of the compiled
* LLVM executable after linking.
*/
void Heap::init() {
Heap *heap = Heap::the();
heap->m_stack_top = reinterpret_cast<uintptr_t *>(__builtin_frame_address(1));
}
/** /**
* Disposes the heap at program exit. * Initialises the heap singleton and saves the address
*/ * of the calling stack frame as the stack_top. Presumeably
void Heap::dispose() { * this address points to the stack frame of the compiled
Heap *heap = Heap::the(); * LLVM executable after linking.
delete heap; */
} void Heap::init()
{
Heap *heap = Heap::the();
heap->m_stack_top = static_cast<uintptr_t *>(__builtin_frame_address(1));
}
/** /**
* Allocates a given amount of bytes on the heap. * Disposes the heap at program exit.
* */
* @param size The amount of bytes to be allocated. void Heap::dispose()
* {
* @return A pointer to the address where the memory Heap *heap = Heap::the();
* has been allocated. This pointer is supposed delete heap;
* to be casted to and object pointer. }
*/
void *Heap::alloc(size_t size) {
// Singleton /**
Heap *heap = Heap::the(); * Allocates a given amount of bytes on the heap.
*
* @param size The amount of bytes to be allocated.
*
* @return A pointer to the address where the memory
* has been allocated. This pointer is supposed
* to be casted to and object pointer.
*/
void *Heap::alloc(size_t size)
{
if (size < 0) { // Singleton
cout << "Heap: Cannot alloc less than 0B. No bytes allocated." << endl; Heap *heap = Heap::the();
return nullptr;
}
if (heap->m_size + size > HEAP_SIZE) { if (size < 0)
heap->collect(); {
// If collect failed, crash with OOM error cout << "Heap: Cannot alloc less than 0B. No bytes allocated." << endl;
assert(heap->m_size + size <= HEAP_SIZE && "Heap: Out Of Memory"); return nullptr;
} }
// If a chunk was recycled, return the old chunk address if (heap->m_size + size > HEAP_SIZE)
uintptr_t *reused_chunk = heap->try_recycle_chunks(size); {
if (reused_chunk != nullptr) { heap->collect();
return (void *)reused_chunk; // If collect failed, crash with OOM error
} assert(heap->m_size + size <= HEAP_SIZE && "Heap: Out Of Memory");
}
// If no free chunks was found (reused_chunk is a nullptr), // If a chunk was recycled, return the old chunk address
// then create a new chunk uintptr_t *reused_chunk = heap->try_recycle_chunks(size);
auto new_chunk = new Chunk; if (reused_chunk != nullptr)
new_chunk->size = size; {
new_chunk->start = (uintptr_t *)(heap->m_heap + heap->m_size); return static_cast<void *>(reused_chunk);
}
heap->m_size += size; // If no free chunks was found (reused_chunk is a nullptr),
// then create a new chunk
auto new_chunk = new Chunk;
new_chunk->size = size;
new_chunk->start = (uintptr_t *)(heap->m_heap + heap->m_size);
heap->m_allocated_chunks.push_back(new_chunk); heap->m_size += size;
// new_chunk should probably be a unique pointer, if that isn't implicit already heap->m_allocated_chunks.push_back(new_chunk);
return new_chunk->start;
}
/** // new_chunk should probably be a unique pointer, if that isn't implicit already
* Tries to recycle used and freed chunks that are return new_chunk->start;
* already allocated objects by the OS but freed }
* from our Heap. This reduces the amount of GC
* objects slightly which saves time from malloc'ing
* memory from the OS.
*
* @param size Amount of bytes needed for the object
* which is about to be allocated.
*
* @returns If a chunk is found and recycled, a
* pointer to the allocated memory for
* the object is returned. If not, a
* nullptr is returned to signify no
* chunks were found.
*/
uintptr_t *Heap::try_recycle_chunks(size_t size) {
auto heap = Heap::the();
// Check if there are any freed chunks large enough for current request
for (size_t i = 0; i < heap->m_freed_chunks.size(); i++) {
// auto cp = heap->m_freed_chunks.at(i);
auto cp = getAt(heap->m_freed_chunks, i);
auto iter = heap->m_freed_chunks.begin();
advance(iter, i);
if (cp->size > size)
{
// Split the chunk, use one part and add the remaining part to
// the list of freed chunks
size_t diff = cp->size - size;
auto chunk_complement = new Chunk; /**
chunk_complement->size = diff; * Tries to recycle used and freed chunks that are
chunk_complement->start = cp->start + cp->size; * already allocated objects by the OS but freed
* from our Heap. This reduces the amount of GC
* objects slightly which saves time from malloc'ing
* memory from the OS.
*
* @param size Amount of bytes needed for the object
* which is about to be allocated.
*
* @returns If a chunk is found and recycled, a
* pointer to the allocated memory for
* the object is returned. If not, a
* nullptr is returned to signify no
* chunks were found.
*/
uintptr_t *Heap::try_recycle_chunks(size_t size)
{
auto heap = Heap::the();
// Check if there are any freed chunks large enough for current request
for (size_t i = 0; i < heap->m_freed_chunks.size(); i++)
{
auto chunk = getAt(heap->m_freed_chunks, i);
auto iter = heap->m_freed_chunks.begin();
advance(iter, i);
if (chunk->size > size)
{
// Split the chunk, use one part and add the remaining part to
// the list of freed chunks
size_t diff = chunk->size - size;
heap->m_freed_chunks.erase(iter); auto chunk_complement = new Chunk;
heap->m_freed_chunks.push_back(chunk_complement); chunk_complement->size = diff;
heap->m_allocated_chunks.push_back(cp); chunk_complement->start = chunk->start + chunk->size;
return cp->start; heap->m_freed_chunks.erase(iter);
} heap->m_freed_chunks.push_back(chunk_complement);
else if (cp->size == size) heap->m_allocated_chunks.push_back(chunk);
{
// Reuse the whole chunk
heap->m_freed_chunks.erase(iter);
heap->m_allocated_chunks.push_back(cp);
return cp->start;
}
}
return nullptr;
}
/** return chunk->start;
* Collection phase of the garbage collector. When }
* an allocation is requested and there is no space else if (chunk->size == size)
* left on the heap, a collection is triggered. This {
* function is private so that the user cannot trigger // Reuse the whole chunk
* a collection unneccessarily. heap->m_freed_chunks.erase(iter);
*/ heap->m_allocated_chunks.push_back(chunk);
void Heap::collect() { return chunk->start;
// Get instance }
auto heap = Heap::the(); }
return nullptr;
}
// get current stack /**
auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0)); * Collection phase of the garbage collector. When
* an allocation is requested and there is no space
* left on the heap, a collection is triggered. This
* function is private so that the user cannot trigger
* a collection unneccessarily.
*/
void Heap::collect()
{
// Get instance
auto heap = Heap::the();
uintptr_t *stack_top = heap->m_stack_top != nullptr ? heap->m_stack_top : (uintptr_t *)0; // get current stack
auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
auto work_list = heap->m_allocated_chunks; uintptr_t *stack_top = heap->m_stack_top != nullptr ? heap->m_stack_top : (uintptr_t *)0;
mark(stack_bottom, stack_top, work_list);
sweep(heap); auto work_list = heap->m_allocated_chunks;
mark(stack_bottom, stack_top, work_list);
free(heap); sweep(heap);
}
/** free(heap);
* Iterates through the stack, if an element on the stack points to a chunk, }
* called a root chunk, that chunk is marked (i.e. reachable).
* Then it recursively follows all chunks which are possibly reachable from
* the root chunk and mark those chunks.
* If a chunk is marked it is removed from the worklist, since it's no longer of
* concern for this method.
*
* @param start Pointer to the start of the stack frame.
* @param end Pointer to the end of the stack frame.
* @param worklist The currently allocated chunks, which haven't been marked.
*/
void Heap::mark(uintptr_t *start, const uintptr_t *end, vector<Chunk*> worklist) {
int counter = 0;
// To find adresses thats in the worklist
for (; start < end; start++) {
counter++;
auto it = worklist.begin();
auto stop = worklist.end();
// for (auto it = worklist.begin(); it != worklist.end();) {
while (it != stop) {
Chunk *chunk = *it;
auto c_start = reinterpret_cast<uintptr_t>(chunk->start); /**
auto c_size = reinterpret_cast<uintptr_t>(chunk->size); * Iterates through the stack, if an element on the stack points to a chunk,
auto c_end = reinterpret_cast<uintptr_t>(c_start + c_size); * called a root chunk, that chunk is marked (i.e. reachable).
* Then it recursively follows all chunks which are possibly reachable from
* the root chunk and mark those chunks.
* If a chunk is marked it is removed from the worklist, since it's no longer of
* concern for this method.
*
* @param start Pointer to the start of the stack frame.
* @param end Pointer to the end of the stack frame.
* @param worklist The currently allocated chunks, which haven't been marked.
*/
void Heap::mark(uintptr_t *start, const uintptr_t *end, vector<Chunk *> &worklist)
{
int counter = 0;
// To find adresses thats in the worklist
for (; start < end; start++)
{
counter++;
auto it = worklist.begin();
auto stop = worklist.end();
// for (auto it = worklist.begin(); it != worklist.end();) {
while (it != stop)
{
Chunk *chunk = *it;
cout << "Start points to:\t" << hex << *start << endl; auto c_start = reinterpret_cast<uintptr_t>(chunk->start);
cout << "Chunk start:\t\t" << hex << c_start << endl; auto c_size = reinterpret_cast<uintptr_t>(chunk->size);
cout << "Chunk end:\t\t" << hex << c_end << "\n" << endl; auto c_end = reinterpret_cast<uintptr_t>(c_start + c_size);
// Check if the stack pointer aligns with the chunk cout << "Start points to:\t" << hex << *start << endl;
if (c_start <= *start && *start < c_end) { cout << "Chunk start:\t\t" << hex << c_start << endl;
cout << "Chunk end:\t\t" << hex << c_end << "\n"
<< endl;
if (!chunk->marked) { // Check if the stack pointer aligns with the chunk
chunk->marked = true; if (c_start <= *start && *start < c_end)
// Remove the marked chunk from the worklist {
it = worklist.erase(it);
// Recursively call mark, to see if the reachable chunk further points to another chunk
mark((uintptr_t*) c_start, (uintptr_t*) c_end, worklist);
}
else {
++it;
}
}
else {
++it;
}
}
}
cout << "Counter: " << counter << endl;
}
/** if (!chunk->marked)
* Sweeps the heap, unmarks the marked chunks for the next cycle, {
* adds the unmarked nodes to the list of freed chunks; to be freed. chunk->marked = true;
* // Remove the marked chunk from the worklist
* @param heap Pointer to the heap singleton instance. it = worklist.erase(it);
*/ // Recursively call mark, to see if the reachable chunk further points to another chunk
void Heap::sweep(Heap *heap) { mark((uintptr_t *)c_start, (uintptr_t *)c_end, worklist);
auto iter = heap->m_allocated_chunks.begin(); }
auto stop = heap->m_allocated_chunks.end(); else
// for (auto it = heap->m_allocated_chunks.begin(); it != heap->m_allocated_chunks.end();) { {
while (iter != stop) { ++it;
Chunk *chunk = *iter; }
}
else
{
++it;
}
}
}
cout << "Counter: " << counter << endl;
}
// Unmark the marked chunks for the next iteration. /**
if (chunk->marked) { * Sweeps the heap, unmarks the marked chunks for the next cycle,
chunk->marked = false; * adds the unmarked nodes to the list of freed chunks; to be freed.
++iter; *
} * @param heap Pointer to the heap singleton instance.
else { */
// Add the unmarked chunks to freed chunks and remove from void Heap::sweep(Heap *heap)
// the list of allocated chunks {
heap->m_freed_chunks.push_back(chunk); auto iter = heap->m_allocated_chunks.begin();
iter = heap->m_allocated_chunks.erase(iter); auto stop = heap->m_allocated_chunks.end();
} // for (auto it = heap->m_allocated_chunks.begin(); it != heap->m_allocated_chunks.end();) {
} while (iter != stop)
} {
Chunk *chunk = *iter;
/** // Unmark the marked chunks for the next iteration.
* Frees chunks that was moved to the list m_freed_chunks if (chunk->marked)
* by the sweep phase. If there are more than a certain {
* amount of free chunks, delete the free chunks to chunk->marked = false;
* avoid cluttering. ++iter;
* }
* @param heap Heap singleton instance, only for avoiding else
* redundant calls to the singleton get {
*/ // Add the unmarked chunks to freed chunks and remove from
void Heap::free(Heap *heap) { // the list of allocated chunks
if (heap->m_freed_chunks.size() > FREE_THRESH) { heap->m_freed_chunks.push_back(chunk);
while (heap->m_freed_chunks.size()) { iter = heap->m_allocated_chunks.erase(iter);
auto chunk = heap->m_freed_chunks.back(); }
heap->m_freed_chunks.pop_back(); }
delete chunk; }
}
}
// if there are chunks but not more than FREE_THRESH
else if (heap->m_freed_chunks.size()) {
// essentially, always check for overlap between
// chunks before finishing the allocation
free_overlap(heap);
}
}
/** /**
* Checks for overlaps between freed chunks of memory * Frees chunks that was moved to the list m_freed_chunks
* and removes overlapping chunks while prioritizing * by the sweep phase. If there are more than a certain
* the chunks at lower addresses. * amount of free chunks, delete the free chunks to
* * avoid cluttering.
* @param heap Heap singleton instance, only for avoiding *
* redundant calls to the singleton get * @param heap Heap singleton instance, only for avoiding
* * redundant calls to the singleton get
* @note Maybe this should be changed to prioritizing */
* larger chunks. void Heap::free(Heap *heap)
*/ {
void Heap::free_overlap(Heap *heap) { if (heap->m_freed_chunks.size() > FREE_THRESH)
std::vector<Chunk *> filtered; {
size_t i = 0; while (heap->m_freed_chunks.size())
// filtered.push_back(heap->m_freed_chunks.at(i++)); {
filtered.push_back(getAt(heap->m_freed_chunks, i++)); auto chunk = heap->m_freed_chunks.back();
cout << filtered.back()->start << endl; heap->m_freed_chunks.pop_back();
for (; i < heap->m_freed_chunks.size(); i++) { delete chunk;
auto prev = filtered.back(); }
// auto next = heap->m_freed_chunks.at(i); }
auto next = getAt(heap->m_freed_chunks, i); // if there are chunks but not more than FREE_THRESH
auto p_start = (uintptr_t)(prev->start); else if (heap->m_freed_chunks.size())
auto p_size = (uintptr_t)(prev->size); {
auto n_start = (uintptr_t)(next->start); // essentially, always check for overlap between
if (n_start >= (p_start + p_size)) { // chunks before finishing the allocation
filtered.push_back(next); free_overlap(heap);
} }
} }
heap->m_freed_chunks.swap(filtered);
}
// ----- ONLY DEBUGGING ----------------------------------------------------------------------- /**
* Checks for overlaps between freed chunks of memory
* and removes overlapping chunks while prioritizing
* the chunks at lower addresses.
*
* @param heap Heap singleton instance, only for avoiding
* redundant calls to the singleton get
*
* @note Maybe this should be changed to prioritizing
* larger chunks.
*/
void Heap::free_overlap(Heap *heap)
{
std::vector<Chunk *> filtered;
size_t i = 0;
// filtered.push_back(heap->m_freed_chunks.at(i++));
filtered.push_back(getAt(heap->m_freed_chunks, i++));
cout << filtered.back()->start << endl;
for (; i < heap->m_freed_chunks.size(); i++)
{
auto prev = filtered.back();
// auto next = heap->m_freed_chunks.at(i);
auto next = getAt(heap->m_freed_chunks, i);
auto p_start = (uintptr_t)(prev->start);
auto p_size = (uintptr_t)(prev->size);
auto n_start = (uintptr_t)(next->start);
if (n_start >= (p_start + p_size))
{
filtered.push_back(next);
}
}
heap->m_freed_chunks.swap(filtered);
}
/** // ----- ONLY DEBUGGING -----------------------------------------------------------------------
* Prints the result of Heap::init() and a dummy value
* for the current stack frame for reference.
*/
void Heap::check_init() {
auto heap = Heap::the();
cout << "Heap addr:\t" << heap << endl;
cout << "GC m_stack_top:\t" << heap->m_stack_top << endl;
auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
cout << "GC stack_bottom:\t" << stack_bottom << endl;
}
/** /**
* Conditional collection, only to be used in debugging * Prints the result of Heap::init() and a dummy value
* * for the current stack frame for reference.
* @param flags Bitmap of flags */
*/ void Heap::check_init()
void Heap::collect(uint flags) { {
auto heap = Heap::the();
cout << "Heap addr:\t" << heap << "\n";
cout << "GC m_stack_top:\t" << heap->m_stack_top << "\n";
auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
cout << "GC stack_bottom:\t" << stack_bottom << endl;
}
cout << "DEBUG COLLECT\nFLAGS: "; /**
if (flags & MARK) * Conditional collection, only to be used in debugging
cout << "\n - MARK"; *
if (flags & SWEEP) * @param flags Bitmap of flags
cout << "\n - SWEEP"; */
if (flags & FREE) void Heap::collect(uint flags)
cout << "\n - FREE"; {
cout << endl;
auto heap = Heap::the(); cout << "DEBUG COLLECT\nFLAGS: ";
if (flags & MARK)
cout << "\n - MARK";
if (flags & SWEEP)
cout << "\n - SWEEP";
if (flags & FREE)
cout << "\n - FREE";
cout << "\n";
// get the frame adress, whwere local variables and saved registers are located auto heap = Heap::the();
auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
cout << "Stack bottom in collect:\t" << stack_bottom << endl;
uintptr_t *stack_top;
if (heap->m_stack_top != nullptr) // get the frame adress, whwere local variables and saved registers are located
stack_top = heap->m_stack_top; auto stack_bottom = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
else cout << "Stack bottom in collect:\t" << stack_bottom << "\n";
stack_top = (uintptr_t *) stack_bottom + 80; // dummy value uintptr_t *stack_top = heap->m_stack_top;
cout << "Stack end in collect:\t " << stack_top << endl; cout << "Stack end in collect:\t " << stack_top << endl;
auto work_list = heap->m_allocated_chunks; auto work_list = heap->m_allocated_chunks;
if (flags & MARK) { if (flags & MARK)
mark(stack_bottom, stack_top, work_list); mark(stack_bottom, stack_top, work_list);
}
if (flags & SWEEP) { if (flags & SWEEP)
sweep(heap); sweep(heap);
}
if (flags & FREE) { if (flags & FREE)
free(heap); free(heap);
} }
}
// Mark child references from the root references // Mark child references from the root references
void mark_test(vector<Chunk *> worklist) { void mark_test(vector<Chunk *> &worklist)
while (worklist.size() > 0) { {
Chunk *ref = worklist.back(); while (worklist.size() > 0)
worklist.pop_back(); {
Chunk *child = (Chunk*) ref; // this is probably not correct Chunk *ref = worklist.back();
if (child != nullptr && !child->marked) { worklist.pop_back();
child->marked = true; Chunk *child = (Chunk *)ref; // this is probably not correct
worklist.push_back(child); if (child != nullptr && !child->marked)
mark_test(worklist); {
} child->marked = true;
} worklist.push_back(child);
} mark_test(worklist);
}
}
}
// Mark the root references and look for child references to them // Mark the root references and look for child references to them
void mark_from_roots(uintptr_t *start, const uintptr_t *end) { void mark_from_roots(uintptr_t *start, const uintptr_t *end)
vector<Chunk *> worklist; {
for (;start > end; start --) { vector<Chunk *> worklist;
if (*start % 8 == 0) { // all pointers must be aligned as double words for (; start > end; start--)
Chunk *ref = (Chunk*) *start; {
if (ref != nullptr && !ref->marked) { if (*start % 8 == 0)
ref->marked = true; { // all pointers must be aligned as double words
worklist.push_back(ref); Chunk *ref = (Chunk *)*start;
mark_test(worklist); if (ref != nullptr && !ref->marked)
} {
} ref->marked = true;
} worklist.push_back(ref);
} mark_test(worklist);
}
}
}
}
// For testing purposes // For testing purposes
void Heap::print_line(Chunk *chunk) { void Heap::print_line(Chunk *chunk)
cout << "Marked: " << chunk->marked << "\nStart adr: " << chunk->start << "\nSize: " << chunk->size << " B\n" << endl; {
} cout << "Marked: " << chunk->marked << "\nStart adr: " << chunk->start << "\nSize: " << chunk->size << " B\n"
<< endl;
}
void Heap::print_worklist(std::vector<Chunk *> list) { void Heap::print_worklist(std::vector<Chunk *> &list)
for (auto cp : list) { {
cout << "Chunk at:\t" << cp->start << "\nSize:\t\t" << cp->size << endl; for (auto cp : list)
} cout << "Chunk at:\t" << cp->start << "\nSize:\t\t" << cp->size << "\n";
} cout << endl;
}
void Heap::print_contents() { void Heap::print_contents()
auto heap = Heap::the(); {
if (heap->m_allocated_chunks.size()) { auto heap = Heap::the();
cout << "\nALLOCATED CHUNKS #" << dec << heap->m_allocated_chunks.size() << endl; if (heap->m_allocated_chunks.size())
for (auto chunk : heap->m_allocated_chunks) { {
print_line(chunk); cout << "\nALLOCATED CHUNKS #" << dec << heap->m_allocated_chunks.size() << endl;
} for (auto chunk : heap->m_allocated_chunks)
} else { print_line(chunk);
cout << "NO ALLOCATIONS\n" << endl; }
} else
if (heap->m_freed_chunks.size()) { {
cout << "\nFREED CHUNKS #" << dec << heap->m_freed_chunks.size() << endl; cout << "NO ALLOCATIONS\n" << endl;
for (auto fchunk : heap->m_freed_chunks) { }
print_line(fchunk); if (heap->m_freed_chunks.size())
} {
} else { cout << "\nFREED CHUNKS #" << dec << heap->m_freed_chunks.size() << endl;
cout << "NO FREED CHUNKS" << endl; for (auto fchunk : heap->m_freed_chunks)
} print_line(fchunk);
} }
else
{
cout << "NO FREED CHUNKS" << endl;
}
}
void Heap::set_profiler(bool mode) { void Heap::set_profiler(bool mode)
auto heap = Heap::the(); {
heap->m_profiler_enable = mode; auto heap = Heap::the();
} heap->m_profiler_enable = mode;
}
} }