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Moving all GC code into runtime section
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@ckirsch
ckirsch committed Sep 5, 2023
1 parent 332ba5b commit 0ac253d
Showing 1 changed file with 174 additions and 174 deletions.
348 changes: 174 additions & 174 deletions selfie.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1547,180 +1547,6 @@ void init_memory(uint64_t megabytes) {
NUMBEROFLEAFPTES = PAGESIZE / sizeof(uint64_t*);
}

// -----------------------------------------------------------------
// ---------------------- GARBAGE COLLECTOR ------------------------
// -----------------------------------------------------------------

void reset_gc_counters();

// bootstrapped to actual functions during compilation ...
uint64_t fetch_stack_pointer() { return 0; } // indicate that gc is unavailable
uint64_t fetch_global_pointer() { return 0; }
uint64_t fetch_data_segment_size() { return 0; }

// ... here, not available on boot level 0 - only for compilation
void emit_fetch_stack_pointer();
void emit_fetch_global_pointer();
void emit_fetch_data_segment_size_interface();
void emit_fetch_data_segment_size_implementation(uint64_t fetch_dss_code_location);

void implement_gc_brk(uint64_t* context);

uint64_t is_gc_library(uint64_t* context);

// gc metadata entry
// +----+---------+
// | 0 | next | pointer to next entry
// | 1 | memory | pointer to allocated memory
// | 2 | size | size of allocated memory (in bytes!)
// | 3 | markbit | markbit indicating reachability of allocated memory
// +----+---------+

uint64_t* allocate_metadata(uint64_t* context);

uint64_t* get_metadata_next(uint64_t* entry) { return (uint64_t*) *entry; }
uint64_t* get_metadata_memory(uint64_t* entry) { return (uint64_t*) *(entry + 1); }
uint64_t get_metadata_size(uint64_t* entry) { return *(entry + 2); }
uint64_t get_metadata_markbit(uint64_t* entry) { return *(entry + 3); }

void set_metadata_next(uint64_t* entry, uint64_t* next) { *entry = (uint64_t) next; }
void set_metadata_memory(uint64_t* entry, uint64_t* memory) { *(entry + 1) = (uint64_t) memory; }
void set_metadata_size(uint64_t* entry, uint64_t size) { *(entry + 2) = size; }
void set_metadata_markbit(uint64_t* entry, uint64_t markbit) { *(entry + 3) = markbit; }

// getters and setters with different access in library/kernel

uint64_t get_stack_seg_start_gc(uint64_t* context);
uint64_t get_data_seg_start_gc(uint64_t* context);
uint64_t get_data_seg_end_gc(uint64_t* context);
uint64_t get_heap_seg_start_gc(uint64_t* context);
uint64_t get_heap_seg_end_gc(uint64_t* context);
uint64_t* get_used_list_head_gc(uint64_t* context);
uint64_t* get_free_list_head_gc(uint64_t* context);
uint64_t get_gcs_in_period_gc(uint64_t* context);
uint64_t get_gc_enabled_gc(uint64_t* context);

void set_data_and_heap_segments_gc(uint64_t* context);
void set_used_list_head_gc(uint64_t* context, uint64_t* used_list_head);
void set_free_list_head_gc(uint64_t* context, uint64_t* free_list_head);
void set_gcs_in_period_gc(uint64_t* context, uint64_t gcs);
void set_gc_enabled_gc(uint64_t* context);

uint64_t is_gc_enabled(uint64_t* context);

void gc_init_selfie(uint64_t* context);

// interface to initialize an external garbage collector (e.g. tools/boehm-gc.c)
void gc_init(uint64_t* context);

// this function performs first-fit retrieval of free memory in O(n) where n is memory size
// improvement: push O(n) down to O(1), e.g. using Boehm's chunk allocator, or even compact-fit
// see https://github.com/cksystemsgroup/compact-fit
uint64_t* retrieve_from_free_list(uint64_t* context, uint64_t size);

uint64_t gc_load_memory(uint64_t* context, uint64_t address);
void gc_store_memory(uint64_t* context, uint64_t address, uint64_t value);

void zero_object(uint64_t* context, uint64_t* metadata);

uint64_t* allocate_new_memory(uint64_t* context, uint64_t size);
uint64_t* reuse_memory(uint64_t* context, uint64_t size);
uint64_t* allocate_memory_selfie(uint64_t* context, uint64_t size);
uint64_t* gc_malloc_implementation(uint64_t* context, uint64_t size);

// interface to allocate an object using an external collector (e.g. tools/boehm-gc.c)
uint64_t* allocate_memory(uint64_t* context, uint64_t size);

// this function performs an O(n) list search where n is memory size
// improvement: push O(n) down to O(1), e.g. using Boehm's chunk allocator
uint64_t* get_metadata_if_address_is_valid(uint64_t* context, uint64_t address);

// interface to marking an object using an external collector (e.g. tools/boehm-gc.c)
void mark_object(uint64_t* context, uint64_t address);

void mark_object_selfie(uint64_t* context, uint64_t gc_address);
void mark_segment(uint64_t* context, uint64_t segment_start, uint64_t segment_end);

// this function scans the heap from two roots (data segment and stack) in O(n^2)
// where n is memory size; checking if a value is a pointer takes O(n), see above
// improvement: push O(n^2) down to O(n)
void mark(uint64_t* context);

void free_object(uint64_t* context, uint64_t* metadata, uint64_t* prev_metadata);

// interface to sweep marked objects using an external collector (e.g. tools/boehm-gc.c)
void sweep(uint64_t* context);

void sweep_selfie(uint64_t* context);

void gc_collect(uint64_t* context);

void print_gc_profile(uint64_t is_gc_kernel);

// ----------------------- LIBRARY FUNCTIONS -----------------------

uint64_t* gc_malloc(uint64_t size) {
return gc_malloc_implementation((uint64_t*) 0, size);
}

// ------------------------ GLOBAL CONSTANTS -----------------------

uint64_t GC_DISABLED = 0;
uint64_t GC_ENABLED = 1;

uint64_t GC_ON = 0; // turn on kernel variant of gc, generate gc library code

uint64_t USE_GC_LIBRARY = 0; // use library variant of gc or not

uint64_t GC_PERIOD = 1000; // gc every so often

uint64_t GC_REUSE = 1; // reuse memory with freelist by default

uint64_t GC_METADATA_SIZE = 32; // 2 * sizeof(uint64_t) + 2 * sizeof(uint64_t*)

uint64_t GC_WORDSIZE = 8; // sizeof(uint64_t) for library variant, otherwise WORDSIZE

uint64_t GC_MARKBIT_UNREACHABLE = 0; // indicating that an object is not reachable
uint64_t GC_MARKBIT_REACHABLE = 1; // indicating that an object is reachable by root or other reachable object

// ------------------------ GLOBAL VARIABLES -----------------------

uint64_t gc_data_seg_start = 0;
uint64_t gc_data_seg_end = 0;
uint64_t gc_heap_seg_start = 0;
uint64_t gc_heap_seg_end = 0;

uint64_t* gc_used_list = (uint64_t*) 0; // pointer to used-list head
uint64_t* gc_free_list = (uint64_t*) 0; // pointer to free-list head

uint64_t gc_num_gcs_in_period = 0;

uint64_t gc_num_mallocated = 0;
uint64_t gc_num_gced_mallocs = 0;
uint64_t gc_num_ungced_mallocs = 0;
uint64_t gc_num_reused_mallocs = 0;
uint64_t gc_num_collects = 0;
uint64_t gc_mem_mallocated = 0;
uint64_t gc_mem_objects = 0;
uint64_t gc_mem_metadata = 0;
uint64_t gc_mem_reused = 0;
uint64_t gc_mem_collected = 0;

// ------------------------- INITIALIZATION ------------------------

void reset_gc_counters() {
gc_num_mallocated = 0;
gc_num_gced_mallocs = 0;
gc_num_ungced_mallocs = 0;
gc_num_reused_mallocs = 0;
gc_num_collects = 0;
gc_mem_mallocated = 0;
gc_mem_objects = 0;
gc_mem_metadata = 0;
gc_mem_reused = 0;
gc_mem_collected = 0;
}

// -----------------------------------------------------------------
// ------------------------- INSTRUCTIONS --------------------------
// -----------------------------------------------------------------
Expand Down Expand Up @@ -2337,6 +2163,180 @@ uint64_t is_heap_address(uint64_t* context, uint64_t vaddr);
uint64_t is_address_between_stack_and_heap(uint64_t* context, uint64_t vaddr);
uint64_t is_data_stack_heap_address(uint64_t* context, uint64_t vaddr);

// -----------------------------------------------------------------
// ---------------------- GARBAGE COLLECTOR ------------------------
// -----------------------------------------------------------------

void reset_gc_counters();

// bootstrapped to actual functions during compilation ...
uint64_t fetch_stack_pointer() { return 0; } // indicate that gc is unavailable
uint64_t fetch_global_pointer() { return 0; }
uint64_t fetch_data_segment_size() { return 0; }

// ... here, not available on boot level 0 - only for compilation
void emit_fetch_stack_pointer();
void emit_fetch_global_pointer();
void emit_fetch_data_segment_size_interface();
void emit_fetch_data_segment_size_implementation(uint64_t fetch_dss_code_location);

void implement_gc_brk(uint64_t* context);

uint64_t is_gc_library(uint64_t* context);

// gc metadata entry
// +----+---------+
// | 0 | next | pointer to next entry
// | 1 | memory | pointer to allocated memory
// | 2 | size | size of allocated memory (in bytes!)
// | 3 | markbit | markbit indicating reachability of allocated memory
// +----+---------+

uint64_t* allocate_metadata(uint64_t* context);

uint64_t* get_metadata_next(uint64_t* entry) { return (uint64_t*) *entry; }
uint64_t* get_metadata_memory(uint64_t* entry) { return (uint64_t*) *(entry + 1); }
uint64_t get_metadata_size(uint64_t* entry) { return *(entry + 2); }
uint64_t get_metadata_markbit(uint64_t* entry) { return *(entry + 3); }

void set_metadata_next(uint64_t* entry, uint64_t* next) { *entry = (uint64_t) next; }
void set_metadata_memory(uint64_t* entry, uint64_t* memory) { *(entry + 1) = (uint64_t) memory; }
void set_metadata_size(uint64_t* entry, uint64_t size) { *(entry + 2) = size; }
void set_metadata_markbit(uint64_t* entry, uint64_t markbit) { *(entry + 3) = markbit; }

// getters and setters with different access in library/kernel

uint64_t get_stack_seg_start_gc(uint64_t* context);
uint64_t get_data_seg_start_gc(uint64_t* context);
uint64_t get_data_seg_end_gc(uint64_t* context);
uint64_t get_heap_seg_start_gc(uint64_t* context);
uint64_t get_heap_seg_end_gc(uint64_t* context);
uint64_t* get_used_list_head_gc(uint64_t* context);
uint64_t* get_free_list_head_gc(uint64_t* context);
uint64_t get_gcs_in_period_gc(uint64_t* context);
uint64_t get_gc_enabled_gc(uint64_t* context);

void set_data_and_heap_segments_gc(uint64_t* context);
void set_used_list_head_gc(uint64_t* context, uint64_t* used_list_head);
void set_free_list_head_gc(uint64_t* context, uint64_t* free_list_head);
void set_gcs_in_period_gc(uint64_t* context, uint64_t gcs);
void set_gc_enabled_gc(uint64_t* context);

uint64_t is_gc_enabled(uint64_t* context);

void gc_init_selfie(uint64_t* context);

// interface to initialize an external garbage collector (e.g. tools/boehm-gc.c)
void gc_init(uint64_t* context);

// this function performs first-fit retrieval of free memory in O(n) where n is memory size
// improvement: push O(n) down to O(1), e.g. using Boehm's chunk allocator, or even compact-fit
// see https://github.com/cksystemsgroup/compact-fit
uint64_t* retrieve_from_free_list(uint64_t* context, uint64_t size);

uint64_t gc_load_memory(uint64_t* context, uint64_t address);
void gc_store_memory(uint64_t* context, uint64_t address, uint64_t value);

void zero_object(uint64_t* context, uint64_t* metadata);

uint64_t* allocate_new_memory(uint64_t* context, uint64_t size);
uint64_t* reuse_memory(uint64_t* context, uint64_t size);
uint64_t* allocate_memory_selfie(uint64_t* context, uint64_t size);
uint64_t* gc_malloc_implementation(uint64_t* context, uint64_t size);

// interface to allocate an object using an external collector (e.g. tools/boehm-gc.c)
uint64_t* allocate_memory(uint64_t* context, uint64_t size);

// this function performs an O(n) list search where n is memory size
// improvement: push O(n) down to O(1), e.g. using Boehm's chunk allocator
uint64_t* get_metadata_if_address_is_valid(uint64_t* context, uint64_t address);

// interface to marking an object using an external collector (e.g. tools/boehm-gc.c)
void mark_object(uint64_t* context, uint64_t address);

void mark_object_selfie(uint64_t* context, uint64_t gc_address);
void mark_segment(uint64_t* context, uint64_t segment_start, uint64_t segment_end);

// this function scans the heap from two roots (data segment and stack) in O(n^2)
// where n is memory size; checking if a value is a pointer takes O(n), see above
// improvement: push O(n^2) down to O(n)
void mark(uint64_t* context);

void free_object(uint64_t* context, uint64_t* metadata, uint64_t* prev_metadata);

// interface to sweep marked objects using an external collector (e.g. tools/boehm-gc.c)
void sweep(uint64_t* context);

void sweep_selfie(uint64_t* context);

void gc_collect(uint64_t* context);

void print_gc_profile(uint64_t is_gc_kernel);

// ----------------------- LIBRARY FUNCTIONS -----------------------

uint64_t* gc_malloc(uint64_t size) {
return gc_malloc_implementation((uint64_t*) 0, size);
}

// ------------------------ GLOBAL CONSTANTS -----------------------

uint64_t GC_DISABLED = 0;
uint64_t GC_ENABLED = 1;

uint64_t GC_ON = 0; // turn on kernel variant of gc, generate gc library code

uint64_t USE_GC_LIBRARY = 0; // use library variant of gc or not

uint64_t GC_PERIOD = 1000; // gc every so often

uint64_t GC_REUSE = 1; // reuse memory with freelist by default

uint64_t GC_METADATA_SIZE = 32; // 2 * sizeof(uint64_t) + 2 * sizeof(uint64_t*)

uint64_t GC_WORDSIZE = 8; // sizeof(uint64_t) for library variant, otherwise WORDSIZE

uint64_t GC_MARKBIT_UNREACHABLE = 0; // indicating that an object is not reachable
uint64_t GC_MARKBIT_REACHABLE = 1; // indicating that an object is reachable by root or other reachable object

// ------------------------ GLOBAL VARIABLES -----------------------

uint64_t gc_data_seg_start = 0;
uint64_t gc_data_seg_end = 0;
uint64_t gc_heap_seg_start = 0;
uint64_t gc_heap_seg_end = 0;

uint64_t* gc_used_list = (uint64_t*) 0; // pointer to used-list head
uint64_t* gc_free_list = (uint64_t*) 0; // pointer to free-list head

uint64_t gc_num_gcs_in_period = 0;

uint64_t gc_num_mallocated = 0;
uint64_t gc_num_gced_mallocs = 0;
uint64_t gc_num_ungced_mallocs = 0;
uint64_t gc_num_reused_mallocs = 0;
uint64_t gc_num_collects = 0;
uint64_t gc_mem_mallocated = 0;
uint64_t gc_mem_objects = 0;
uint64_t gc_mem_metadata = 0;
uint64_t gc_mem_reused = 0;
uint64_t gc_mem_collected = 0;

// ------------------------- INITIALIZATION ------------------------

void reset_gc_counters() {
gc_num_mallocated = 0;
gc_num_gced_mallocs = 0;
gc_num_ungced_mallocs = 0;
gc_num_reused_mallocs = 0;
gc_num_collects = 0;
gc_mem_mallocated = 0;
gc_mem_objects = 0;
gc_mem_metadata = 0;
gc_mem_reused = 0;
gc_mem_collected = 0;
}

// -----------------------------------------------------------------
// -------------------------- MICROKERNEL --------------------------
// -----------------------------------------------------------------
Expand Down

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