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// Object stacks, used in lieu of dynamically-sized frames.
#include <algorithm>
#include <cassert>
#include <cstdlib>
#include <iostream>
#include <new>
#include <stdint.h>
#include "rust_internal.h"
#include "rust_obstack.h"
#include "rust_shape.h"
#include "rust_task.h"
// ISAAC, let go of max()!
#ifdef max
#undef max
#endif
//const size_t DEFAULT_CHUNK_SIZE = 4096;
const size_t DEFAULT_CHUNK_SIZE = 500000;
const size_t DEFAULT_ALIGNMENT = 16;
// A single type-tagged allocation in a chunk.
struct rust_obstack_alloc {
size_t len;
const type_desc *tydesc;
uint8_t data[];
rust_obstack_alloc(size_t in_len, const type_desc *in_tydesc)
: len(in_len), tydesc(in_tydesc) {}
};
// A contiguous set of allocations.
struct rust_obstack_chunk {
rust_obstack_chunk *prev;
size_t size;
size_t alen;
size_t pad;
uint8_t data[];
rust_obstack_chunk(rust_obstack_chunk *in_prev, size_t in_size)
: prev(in_prev), size(in_size), alen(0) {}
void *alloc(size_t len, type_desc *tydesc);
bool free(void *ptr);
void *mark();
};
void *
rust_obstack_chunk::alloc(size_t len, type_desc *tydesc) {
alen = align_to(alen, DEFAULT_ALIGNMENT);
if (sizeof(rust_obstack_alloc) + len > size - alen) {
DPRINT("Not enough space, len=%lu!\n", len);
assert(0); // FIXME
return NULL; // Not enough space.
}
rust_obstack_alloc *a = new(data + alen) rust_obstack_alloc(len, tydesc);
alen += sizeof(*a) + len;
memset(a->data, '\0', len); // FIXME: For GC.
return &a->data;
}
bool
rust_obstack_chunk::free(void *ptr) {
uint8_t *p = (uint8_t *)ptr;
if (p < data || p > data + size)
return false;
assert(p <= data + alen);
alen = (size_t)(p - data);
return true;
}
void *
rust_obstack_chunk::mark() {
return data + alen;
}
// Allocates the given number of bytes in a new chunk.
void *
rust_obstack::alloc_new(size_t len, type_desc *tydesc) {
size_t chunk_size = std::max(sizeof(rust_obstack_alloc) + len,
DEFAULT_CHUNK_SIZE);
void *ptr = task->malloc(sizeof(chunk) + chunk_size, "obstack");
DPRINT("making new chunk at %p, len %lu\n", ptr, chunk_size);
chunk = new(ptr) rust_obstack_chunk(chunk, chunk_size);
return chunk->alloc(len, tydesc);
}
rust_obstack::~rust_obstack() {
while (chunk) {
rust_obstack_chunk *prev = chunk->prev;
task->free(chunk);
chunk = prev;
}
}
void *
rust_obstack::alloc(size_t len, type_desc *tydesc) {
if (!chunk)
return alloc_new(len, tydesc);
DPRINT("alloc sz %u", (uint32_t)len);
void *ptr = chunk->alloc(len, tydesc);
ptr = ptr ? ptr : alloc_new(len, tydesc);
return ptr;
}
void
rust_obstack::free(void *ptr) {
if (!ptr)
return;
DPRINT("free ptr %p\n", ptr);
assert(chunk);
while (!chunk->free(ptr)) {
DPRINT("deleting chunk at %p\n", chunk);
rust_obstack_chunk *prev = chunk->prev;
task->free(chunk);
chunk = prev;
assert(chunk);
}
}
void *
rust_obstack::mark() {
return chunk ? chunk->mark() : NULL;
}
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