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the language's heap doesn't grow anymore during a collection. Instead the collection throws an error to the runtime

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This commit is contained in:
Francesco Cozzuto
2022-04-15 16:21:10 +02:00
parent f8fdf7d0df
commit 9f825673c3
4 changed files with 35 additions and 23 deletions
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src/objects/heap.c
+20 -12
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@@ -38,18 +38,20 @@
** | The collection algorithm is move-and-compact. The allocator is a |
** | bump-pointer allocator. When the base pool of memory is filled up, |
** | further allocations are forwarded to the stdlib's malloc, but are kept |
** | track of by putting them in a linked list. When the parent system decides|
** | to free up some memory, a new heap is allocated and the live objects are |
** | moved to it, then the old heap is freed. The references between live |
** | objects are updated when moving them.Some objects implement destructors |
** | that must be called when a new heap is allocated and they're not moved |
** | to it. An auxiliary list of allocated objects with destructors is stored |
** | alongside the heap. When the live objects are moved and the ones to be |
** | destroyed are left in the old one, the list of objects with destructors |
** | is iterated over and the objects in it that weren't moved are destroied |
** | and removed from the list. This approach becomes linearly slower with |
** | the number of allocated objects with destructors, but it's assumed that |
** | not many of them implement them. |
** | track of by putting them in a linked list. When the language's runtime |
** | system decides to free up some memory, a new heap is allocated and the |
** | live objects are moved to it, then the old heap is freed. The references |
** | between live objects are updated when moving them. Some objects implement|
** | destructors that must be called when a new heap is allocated and they're |
** | not moved to it. An auxiliary list of allocated objects with destructors |
** | is stored alongside the heap. When the live objects are moved and the |
** | ones to be destroyed are left in the old one, the list of objects with |
** | destructors is iterated over and the objects in it that weren't moved are|
** | destroied and removed from the list. This approach becomes linearly |
** | slower with the number of allocated objects with destructors, but it's |
** | assumed that not many of them implement them. |
** | If during a collection the new memory pool is filled up, then an error is|
** | thrown to the parent system. |
** | |
** | HOW ARE POINTERS UPDATED? |
** | Basically, when an object is moved from the old to the new heap, the |
@@ -291,6 +293,12 @@ void *Heap_RawMalloc(Heap *heap, int size, Error *err)
if(heap->used + size > heap->size)
{
if(heap->collecting)
{
Error_Report(err, 1, "Out of heap");
return NULL;
}
OflowAlloc *oflow = malloc(sizeof(OflowAlloc) + size);
if(oflow == 0)