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// Rust cycle collector. Temporary, but will probably stick around for some
// time until LLVM's GC infrastructure is more mature.
#include "rust_gc.h"
#include "rust_internal.h"
#include "rust_shape.h"
#include "rust_task.h"
#include <cstdio>
#include <cstdlib>
#include <map>
#include <vector>
#include <stdint.h>
#undef DPRINT
#define DPRINT(fmt,...) fprintf(stderr, fmt, ##__VA_ARGS__)
namespace cc {
// Internal reference count computation
typedef std::map<void *,uintptr_t> irc_map;
class irc : public shape::data<irc,shape::ptr> {
friend class shape::data<irc,shape::ptr>;
irc_map ircs;
irc(const irc &other, const shape::ptr &in_dp)
: shape::data<irc,shape::ptr>(other.task, other.align, other.sp,
other.params, other.tables, in_dp),
ircs(other.ircs) {}
irc(const irc &other,
const uint8_t *in_sp,
const shape::type_param *in_params,
const rust_shape_tables *in_tables = NULL)
: shape::data<irc,shape::ptr>(other.task,
other.align,
in_sp,
in_params,
in_tables ? in_tables : other.tables,
other.dp),
ircs(other.ircs) {}
irc(const irc &other,
const uint8_t *in_sp,
const shape::type_param *in_params,
const rust_shape_tables *in_tables,
shape::ptr in_dp)
: shape::data<irc,shape::ptr>(other.task,
other.align,
in_sp,
in_params,
in_tables,
in_dp),
ircs(other.ircs) {}
irc(rust_task *in_task,
bool in_align,
const uint8_t *in_sp,
const shape::type_param *in_params,
const rust_shape_tables *in_tables,
uint8_t *in_data,
irc_map &in_ircs)
: shape::data<irc,shape::ptr>(in_task, in_align, in_sp, in_params,
in_tables, in_data),
ircs(in_ircs) {}
void walk_vec(bool is_pod, uint16_t sp_size) {
if (is_pod || shape::get_dp<void *>(dp) == NULL)
return; // There can't be any outbound pointers from this.
std::pair<uint8_t *,uint8_t *> data_range(get_vec_data_range(dp));
if (data_range.second - data_range.first > 100000)
abort(); // FIXME: Temporary sanity check.
irc sub(*this, data_range.first);
shape::ptr data_end = sub.end_dp = data_range.second;
while (sub.dp < data_end) {
sub.walk_reset();
align = true;
}
}
void walk_tag(shape::tag_info &tinfo, uint32_t tag_variant) {
shape::data<irc,shape::ptr>::walk_variant(tinfo, tag_variant);
}
void walk_box() {
shape::data<irc,shape::ptr>::walk_box_contents();
}
void walk_fn() {
shape::data<irc,shape::ptr>::walk_fn_contents(dp);
}
void walk_obj() {
shape::data<irc,shape::ptr>::walk_obj_contents(dp);
}
void walk_res(const shape::rust_fn *dtor, unsigned n_params,
const shape::type_param *params, const uint8_t *end_sp,
bool live) {
while (this->sp != end_sp) {
this->walk();
align = true;
}
}
void walk_subcontext(irc &sub) { sub.walk(); }
void walk_box_contents(irc &sub, shape::ptr &ref_count_dp) {
if (!ref_count_dp)
return;
// Bump the internal reference count of the box.
if (ircs.find((void *)dp) == ircs.end())
ircs[(void *)dp] = 1;
else
++ircs[(void *)dp];
// Do not traverse the contents of this box; it's in the allocation
// somewhere, so we're guaranteed to come back to it (if we haven't
// traversed it already).
}
void walk_struct(const uint8_t *end_sp) {
while (this->sp != end_sp) {
this->walk();
align = true;
}
}
void walk_variant(shape::tag_info &tinfo, uint32_t variant_id,
const std::pair<const uint8_t *,const uint8_t *>
variant_ptr_and_end);
template<typename T>
inline void walk_number() { /* no-op */ }
public:
static void compute_ircs(rust_task *task, irc_map &ircs);
};
void
irc::walk_variant(shape::tag_info &tinfo, uint32_t variant_id,
const std::pair<const uint8_t *,const uint8_t *>
variant_ptr_and_end) {
irc sub(*this, variant_ptr_and_end.first, tinfo.params);
assert(variant_id < 256); // FIXME: Temporary sanity check.
const uint8_t *variant_end = variant_ptr_and_end.second;
while (sub.sp < variant_end) {
sub.walk();
align = true;
}
}
void
irc::compute_ircs(rust_task *task, irc_map &ircs) {
std::map<void *,type_desc *>::iterator begin(task->local_allocs.begin()),
end(task->local_allocs.end());
while (begin != end) {
uint8_t *p = reinterpret_cast<uint8_t *>(begin->first);
type_desc *tydesc = begin->second;
DPRINT("determining internal ref counts: %p, tydesc=%p\n", p, tydesc);
// Prevents warnings for now
shape::arena arena;
shape::type_param *params =
shape::type_param::from_tydesc(tydesc, arena);
irc irc(task, true, tydesc->shape, params, tydesc->shape_tables, p,
ircs);
irc.walk();
++begin;
}
}
void
do_cc(rust_task *task) {
irc_map ircs;
irc::compute_ircs(task, ircs);
}
void
maybe_cc(rust_task *task) {
// FIXME: We ought to lock this.
static int zeal = -1;
if (zeal == -1) {
char *ev = getenv("RUST_CC_ZEAL");
zeal = ev && ev[0] != '\0' && ev[0] != '0';
}
if (zeal)
do_cc(task);
}
} // end namespace cc
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