Made exposed endpoints static

This commit is contained in:
Victor Olin 2023-02-24 12:01:37 +01:00
parent bbd2650445
commit a684fe1ea0
6 changed files with 121 additions and 62 deletions

View file

@ -23,6 +23,14 @@ namespace GC {
heap->m_stack_end = reinterpret_cast<uintptr_t *>(__builtin_frame_address(1));
}
/**
* Disposes the heap at program exit.
*/
void Heap::dispose() {
Heap *heap = Heap::the();
delete heap;
}
/**
* Allocates a given amount of bytes on the heap.
*
@ -43,13 +51,13 @@ namespace GC {
}
if (heap->m_size + size > HEAP_SIZE) {
collect(heap);
heap->collect();
// If collect failed, crash with OOM error
assert(heap->m_size + size <= HEAP_SIZE && "Heap: Out Of Memory");
}
// If a chunk was recycled, return the old chunk address
uintptr_t *reused_chunk = try_recycle_chunks(heap, size);
uintptr_t *reused_chunk = heap->try_recycle_chunks(size);
if (reused_chunk != nullptr) {
return (void *)reused_chunk;
}
@ -58,7 +66,7 @@ namespace GC {
// then create a new chunk
auto new_chunk = new Chunk;
new_chunk->size = size;
new_chunk->start = (uintptr_t *)(heap->m_heap + m_size);
new_chunk->start = (uintptr_t *)(heap->m_heap + heap->m_size);
heap->m_size += size;
@ -75,8 +83,6 @@ namespace GC {
* objects slightly which saves time from malloc'ing
* memory from the OS.
*
* @param heap Pointer to the singleton Heap instance
*
* @param size Amount of bytes needed for the object
* which is about to be allocated.
*
@ -86,10 +92,14 @@ namespace GC {
* nullptr is returned to signify no
* chunks were found.
*/
uintptr_t *Heap::try_recycle_chunks(Heap *heap, size_t size) {
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 = 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
@ -100,7 +110,7 @@ namespace GC {
chunk_complement->size = diff;
chunk_complement->start = cp->start + cp->size;
heap->m_freed_chunks.erase(m_freed_chunks.begin() + i);
heap->m_freed_chunks.erase(iter);
heap->m_freed_chunks.push_back(chunk_complement);
heap->m_allocated_chunks.push_back(cp);
@ -109,7 +119,7 @@ namespace GC {
else if (cp->size == size)
{
// Reuse the whole chunk
heap->m_freed_chunks.erase(m_freed_chunks.begin() + i);
heap->m_freed_chunks.erase(iter);
heap->m_allocated_chunks.push_back(cp);
return cp->start;
}
@ -123,11 +133,10 @@ namespace GC {
* left on the heap, a collection is triggered. This
* function is private so that the user cannot trigger
* a collection unneccessarily.
*
* @param heap Heap singleton instance, only for avoiding
* redundant calls to the singleton get
*/
void Heap::collect(Heap *heap) {
void Heap::collect() {
// Get instance
auto heap = Heap::the();
// get current stack
auto stack_start = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
@ -148,24 +157,26 @@ namespace GC {
}
/**
* Iterates through the stack, if an element on the stack points to a chunk
* that chunk is marked (i.e. reachable). It only marks element which are directly
* reachable from the chunk, so no chain of pointers from the stack are detected.
* 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.
* @param worklist The currently allocated chunks, which haven't been marked.
*/
void Heap::mark(uintptr_t *start, const uintptr_t *end, vector<Chunk*> worklist) {
void Heap::mark(uintptr_t *start, const uintptr_t *end, list<Chunk*> worklist) {
int counter = 0;
// To find adresses thats in the worklist
for (; start < end; start++) {
counter++;
// all pointers must be aligned as double words
for (auto it = worklist.begin(); it != worklist.end();) {
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);
@ -181,7 +192,9 @@ namespace GC {
if (!chunk->marked) {
chunk->marked = true;
// 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 {
@ -203,19 +216,22 @@ namespace GC {
* @param heap Pointer to the heap to oporate on.
*/
void Heap::sweep(Heap *heap) {
for (auto it = heap->m_allocated_chunks.begin(); it != heap->m_allocated_chunks.end();) {
Chunk *chunk = *it;
auto iter = heap->m_allocated_chunks.begin();
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.
if (chunk->marked) {
chunk->marked = false;
++it;
++iter;
}
else {
// Add the unmarked chunks to freed chunks and remove from
// the list of allocated chunks
heap->m_freed_chunks.push_back(chunk);
it = heap->m_allocated_chunks.erase(it);
iter = heap->m_allocated_chunks.erase(iter);
}
}
}
@ -257,13 +273,15 @@ namespace GC {
* larger chunks.
*/
void Heap::free_overlap(Heap *heap) {
std::vector<Chunk *> filtered;
std::list<Chunk *> filtered;
size_t i = 0;
filtered.push_back(heap->m_freed_chunks.at(i++));
// 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 = 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);
@ -366,7 +384,7 @@ namespace GC {
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::list<Chunk *> list) {
for (auto cp : list) {
cout << "Chunk at:\t" << cp->start << "\nSize:\t\t" << cp->size << endl;
}