rt: Remove the cycle collector

1 files changed, 0 insertions, 572 deletions

diff --git a/src/rt/rust_cc.cpp b/src/rt/rust_cc.cpp
deleted file mode 100644
index 0106b468c90..00000000000
--- a/src/rt/rust_cc.cpp
+++ /dev/null
@@ -1,572 +0,0 @@
-// Rust cycle collector. Temporary, but will probably stick around for some
-// time until LLVM's GC infrastructure is more mature.
-
-#include <map>
-#include <set>
-#include <vector>
-#include <ios>
-
-#include "rust_globals.h"
-#include "rust_cc.h"
-#include "rust_debug.h"
-#include "rust_shape.h"
-#include "rust_task.h"
-
-// The number of allocations Rust code performs before performing cycle
-// collection.
-#define RUST_CC_FREQUENCY   5000
-
-using namespace std;
-
-void
-annihilate_box(rust_task *task, rust_opaque_box *box);
-
-namespace cc {
-
-// Internal reference count computation
-
-typedef std::map<rust_opaque_box*,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.tables, in_dp),
-      ircs(other.ircs) {}
-
-    irc(const irc &other,
-        const uint8_t *in_sp,
-        const rust_shape_tables *in_tables = NULL)
-    : shape::data<irc,shape::ptr>(other.task,
-                                  other.align,
-                                  in_sp,
-                                  in_tables ? in_tables : other.tables,
-                                  other.dp),
-      ircs(other.ircs) {}
-
-    irc(const irc &other,
-        const uint8_t *in_sp,
-        const rust_shape_tables *in_tables,
-        shape::ptr in_dp)
-    : shape::data<irc,shape::ptr>(other.task,
-                                  other.align,
-                                  in_sp,
-                                  in_tables,
-                                  in_dp),
-      ircs(other.ircs) {}
-
-    irc(rust_task *in_task,
-        bool in_align,
-        const uint8_t *in_sp,
-        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_tables, shape::ptr(in_data)),
-          ircs(in_ircs) {}
-
-
-    void walk_vec2(bool is_pod, std::pair<uint8_t *,uint8_t *> data_range) {
-
-        // There can't be any outbound pointers from pod.
-        if (is_pod)
-            return;
-
-        irc sub(*this, shape::ptr(data_range.first));
-        shape::ptr data_end = sub.end_dp = shape::ptr(data_range.second);
-        while (sub.dp < data_end) {
-            sub.walk_reset();
-            // FIXME (#2669): shouldn't this be 'sub.align = true;'?
-            align = true;
-        }
-    }
-
-    void walk_vec2(bool is_pod) {
-        if (shape::get_dp<void *>(dp) == NULL)
-            return;
-
-        walk_vec2(is_pod, get_vec_data_range(dp));
-    }
-
-    void walk_unboxed_vec2(bool is_pod) {
-        walk_vec2(is_pod, get_unboxed_vec_data_range(dp));
-    }
-
-    void walk_slice2(bool is_pod, bool is_str) {
-        walk_vec2(is_pod, get_slice_data_range(is_str, dp));
-    }
-
-    void walk_fixedvec2(uint16_t n_elts, size_t elt_sz, bool is_pod) {
-        walk_vec2(is_pod, get_fixedvec_data_range(n_elts, elt_sz, dp));
-    }
-
-    void walk_tag2(shape::tag_info &tinfo, uint32_t tag_variant) {
-        shape::data<irc,shape::ptr>::walk_variant1(tinfo, tag_variant);
-    }
-
-    void walk_box2() {
-        // the box ptr can be NULL for env ptrs in closures and data
-        // not fully initialized
-        rust_opaque_box *box = *(rust_opaque_box**)dp;
-        if (box)
-            shape::data<irc,shape::ptr>::walk_box_contents1();
-    }
-
-    void walk_uniq2() {
-        rust_opaque_box *box = *(rust_opaque_box**)dp;
-        if (box)
-            shape::data<irc,shape::ptr>::walk_uniq_contents1();
-    }
-
-    void walk_rptr2() {
-        shape::data<irc,shape::ptr>::walk_rptr_contents1();
-    }
-
-    void walk_fn2(char code) {
-        switch (code) {
-          case shape::SHAPE_BOX_FN: {
-              shape::bump_dp<void*>(dp); // skip over the code ptr
-              walk_box2();               // walk over the environment ptr
-              break;
-          }
-          case shape::SHAPE_BARE_FN:        // Does not close over data.
-          case shape::SHAPE_STACK_FN:       // Not reachable from heap.
-          case shape::SHAPE_UNIQ_FN: break; /* Can only close over sendable
-                                             * (and hence acyclic) data */
-          default: abort();
-        }
-    }
-
-    void walk_trait2() {
-        walk_box2();
-    }
-
-    void walk_tydesc2(char) {
-    }
-
-    void walk_res2(const shape::rust_fn *dtor, const uint8_t *end_sp) {
-        while (this->sp != end_sp) {
-            this->walk();
-            align = true;
-        }
-    }
-
-    void walk_subcontext2(irc &sub) { sub.walk(); }
-
-    void walk_uniq_contents2(irc &sub) { sub.walk(); }
-
-    void walk_rptr_contents2(irc &sub) { sub.walk(); }
-
-    void walk_box_contents2(irc &sub) {
-        maybe_record_irc();
-
-        // 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 maybe_record_irc() {
-        rust_opaque_box *box_ptr = *(rust_opaque_box **) dp;
-
-        if (!box_ptr)
-            return;
-
-        // Bump the internal reference count of the box.
-        if (ircs.find(box_ptr) == ircs.end()) {
-          LOG(task, gc,
-              "setting internal reference count for %p to 1",
-              box_ptr);
-          ircs[box_ptr] = 1;
-        } else {
-          uintptr_t newcount = ircs[box_ptr] + 1;
-          LOG(task, gc,
-              "bumping internal reference count for %p to %lu",
-              box_ptr, newcount);
-          ircs[box_ptr] = newcount;
-        }
-    }
-
-    void walk_struct2(const uint8_t *end_sp) {
-        while (this->sp != end_sp) {
-            this->walk();
-            align = true;
-        }
-    }
-
-    void walk_variant2(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_number2() { /* no-op */ }
-
-public:
-    static void compute_ircs(rust_task *task, irc_map &ircs);
-};
-
-void
-irc::walk_variant2(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);
-
-    assert(variant_id < 256);   // FIXME (#2666): 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) {
-    boxed_region *boxed = &task->boxed;
-    for (rust_opaque_box *box = boxed->first_live_alloc();
-         box != NULL;
-         box = box->next) {
-        type_desc *tydesc = box->td;
-        uint8_t *body = (uint8_t*) box_body(box);
-
-        LOG(task, gc,
-            "determining internal ref counts: "
-            "box=%p tydesc=%p body=%p",
-            box, tydesc, body);
-
-        shape::arena arena;
-
-        irc irc(task, true, tydesc->shape, tydesc->shape_tables,
-                body, ircs);
-        irc.walk();
-    }
-}
-
-
-// Root finding
-
-void
-find_roots(rust_task *task, irc_map &ircs,
-           std::vector<rust_opaque_box *> &roots) {
-    boxed_region *boxed = &task->boxed;
-    for (rust_opaque_box *box = boxed->first_live_alloc();
-         box != NULL;
-         box = box->next) {
-        uintptr_t ref_count = box->ref_count;
-
-        uintptr_t irc;
-        if (ircs.find(box) != ircs.end())
-            irc = ircs[box];
-        else
-            irc = 0;
-
-        if (irc < ref_count) {
-            // This allocation must be a root, because the internal reference
-            // count is smaller than the total reference count.
-            LOG(task, gc,"root found: %p, irc %lu, ref count %lu",
-                box, irc, ref_count);
-            roots.push_back(box);
-        } else {
-            LOG(task, gc, "nonroot found: %p, irc %lu, ref count %lu",
-                box, irc, ref_count);
-            assert(irc == ref_count && "Internal reference count must be "
-                   "less than or equal to the total reference count!");
-        }
-    }
-}
-
-
-// Marking
-
-class mark : public shape::data<mark,shape::ptr> {
-    friend class shape::data<mark,shape::ptr>;
-
-    std::set<rust_opaque_box *> &marked;
-
-    mark(const mark &other, const shape::ptr &in_dp)
-    : shape::data<mark,shape::ptr>(other.task, other.align, other.sp,
-                                    other.tables, in_dp),
-      marked(other.marked) {}
-
-    mark(const mark &other,
-         const uint8_t *in_sp,
-         const rust_shape_tables *in_tables = NULL)
-    : shape::data<mark,shape::ptr>(other.task,
-                                   other.align,
-                                   in_sp,
-                                   in_tables ? in_tables : other.tables,
-                                   other.dp),
-      marked(other.marked) {}
-
-    mark(const mark &other,
-         const uint8_t *in_sp,
-         const rust_shape_tables *in_tables,
-         shape::ptr in_dp)
-    : shape::data<mark,shape::ptr>(other.task,
-                                   other.align,
-                                   in_sp,
-                                   in_tables,
-                                   in_dp),
-      marked(other.marked) {}
-
-    mark(rust_task *in_task,
-         bool in_align,
-         const uint8_t *in_sp,
-         const rust_shape_tables *in_tables,
-         uint8_t *in_data,
-         std::set<rust_opaque_box*> &in_marked)
-        : shape::data<mark,shape::ptr>(in_task, in_align, in_sp,
-                                       in_tables, shape::ptr(in_data)),
-      marked(in_marked) {}
-
-    void walk_vec2(bool is_pod, std::pair<uint8_t *,uint8_t *> data_range) {
-
-        // There can't be any outbound pointers from pod.
-        if (is_pod)
-            return;
-
-        if (data_range.second - data_range.first > 100000)
-            abort();    // FIXME (#2666): Temporary sanity check.
-
-        mark sub(*this, shape::ptr(data_range.first));
-        shape::ptr data_end = sub.end_dp = shape::ptr(data_range.second);
-        while (sub.dp < data_end) {
-            sub.walk_reset();
-            align = true;
-        }
-    }
-
-    void walk_vec2(bool is_pod) {
-        if (shape::get_dp<void *>(dp) == NULL)
-            return;
-        walk_vec2(is_pod, get_vec_data_range(dp));
-    }
-
-    void walk_unboxed_vec2(bool is_pod) {
-        walk_vec2(is_pod, get_unboxed_vec_data_range(dp));
-    }
-
-    void walk_slice2(bool is_pod, bool is_str) {
-        walk_vec2(is_pod, get_slice_data_range(is_str, dp));
-    }
-
-    void walk_fixedvec2(uint16_t n_elts, size_t elt_sz, bool is_pod) {
-        walk_vec2(is_pod, get_fixedvec_data_range(n_elts, elt_sz, dp));
-    }
-
-    void walk_tag2(shape::tag_info &tinfo, uint32_t tag_variant) {
-        shape::data<mark,shape::ptr>::walk_variant1(tinfo, tag_variant);
-    }
-
-    void walk_box2() {
-        // the box ptr can be NULL for env ptrs in closures and data
-        // not fully initialized
-        rust_opaque_box *box = *(rust_opaque_box**)dp;
-        if (box)
-            shape::data<mark,shape::ptr>::walk_box_contents1();
-    }
-
-    void walk_uniq2() {
-        rust_opaque_box *box = *(rust_opaque_box**)dp;
-        if (box)
-            shape::data<mark,shape::ptr>::walk_uniq_contents1();
-    }
-
-    void walk_rptr2() {
-        shape::data<mark,shape::ptr>::walk_rptr_contents1();
-    }
-
-    void walk_fn2(char code) {
-        switch (code) {
-          case shape::SHAPE_BOX_FN: {
-              shape::bump_dp<void*>(dp); // skip over the code ptr
-              walk_box2();               // walk over the environment ptr
-              break;
-          }
-          case shape::SHAPE_BARE_FN:        // Does not close over data.
-          case shape::SHAPE_STACK_FN:       // Not reachable from heap.
-          case shape::SHAPE_UNIQ_FN: break; /* Can only close over sendable
-                                             * (and hence acyclic) data */
-          default: abort();
-        }
-    }
-
-    void walk_res2(const shape::rust_fn *dtor, const uint8_t *end_sp) {
-        while (this->sp != end_sp) {
-            this->walk();
-            align = true;
-        }
-    }
-
-    void walk_trait2() {
-        walk_box2();
-    }
-
-    void walk_tydesc2(char) {
-    }
-
-    void walk_subcontext2(mark &sub) { sub.walk(); }
-
-    void walk_uniq_contents2(mark &sub) { sub.walk(); }
-
-    void walk_rptr_contents2(mark &sub) { sub.walk(); }
-
-    void walk_box_contents2(mark &sub) {
-        rust_opaque_box *box_ptr = *(rust_opaque_box **) dp;
-
-        if (!box_ptr)
-            return;
-
-        if (marked.find(box_ptr) != marked.end())
-            return; // Skip to avoid chasing cycles.
-
-        marked.insert(box_ptr);
-        sub.walk();
-    }
-
-    void walk_struct2(const uint8_t *end_sp) {
-        while (this->sp != end_sp) {
-            this->walk();
-            align = true;
-        }
-    }
-
-    void walk_variant2(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_number2() { /* no-op */ }
-
-public:
-    static void do_mark(rust_task *task,
-                        const std::vector<rust_opaque_box *> &roots,
-                        std::set<rust_opaque_box*> &marked);
-};
-
-void
-mark::walk_variant2(shape::tag_info &tinfo, uint32_t variant_id,
-                   const std::pair<const uint8_t *,const uint8_t *>
-                   variant_ptr_and_end) {
-    mark sub(*this, variant_ptr_and_end.first);
-
-    assert(variant_id < 256);   // FIXME (#2666): Temporary sanity check.
-
-    const uint8_t *variant_end = variant_ptr_and_end.second;
-    while (sub.sp < variant_end) {
-        sub.walk();
-        align = true;
-    }
-}
-
-void
-mark::do_mark(rust_task *task,
-              const std::vector<rust_opaque_box *> &roots,
-              std::set<rust_opaque_box *> &marked) {
-    std::vector<rust_opaque_box *>::const_iterator
-      begin(roots.begin()),
-      end(roots.end());
-    while (begin != end) {
-        rust_opaque_box *box = *begin;
-        if (marked.find(box) == marked.end()) {
-            marked.insert(box);
-
-            const type_desc *tydesc = box->td;
-
-            LOG(task, gc, "marking: %p, tydesc=%p", box, tydesc);
-
-            uint8_t *p = (uint8_t*) box_body(box);
-            shape::arena arena;
-
-            mark mark(task, true, tydesc->shape, tydesc->shape_tables,
-                      p, marked);
-            mark.walk();
-        }
-
-        ++begin;
-    }
-}
-
-void
-do_sweep(rust_task *task,
-         const std::set<rust_opaque_box*> &marked) {
-    boxed_region *boxed = &task->boxed;
-    rust_opaque_box *box = boxed->first_live_alloc();
-    while (box != NULL) {
-        // save next ptr as we may be freeing box
-        rust_opaque_box *box_next = box->next;
-        if (marked.find(box) == marked.end()) {
-            LOG(task, gc, "object is part of a cycle: %p", box);
-            annihilate_box(task, box);
-        }
-        box = box_next;
-    }
-}
-
-
-void
-do_cc(rust_task *task) {
-    LOG(task, gc, "cc");
-
-    irc_map ircs;
-    irc::compute_ircs(task, ircs);
-
-    std::vector<rust_opaque_box*> roots;
-    find_roots(task, ircs, roots);
-
-    std::set<rust_opaque_box*> marked;
-    mark::do_mark(task, roots, marked);
-
-    do_sweep(task, marked);
-}
-
-void
-do_final_cc(rust_task *task) {
-    do_cc(task);
-
-    boxed_region *boxed = &task->boxed;
-    for (rust_opaque_box *box = boxed->first_live_alloc();
-         box != NULL;
-         box = box->next) {
-        cerr << "Unreclaimed object found at " << (void*) box << ": ";
-        const type_desc *td = box->td;
-        shape::arena arena;
-        shape::log log(task, true, td->shape, td->shape_tables,
-                       (uint8_t*)box_body(box), cerr);
-        log.walk();
-        cerr << "\n";
-    }
-}
-
-void
-maybe_cc(rust_task *task) {
-    static debug::flag zeal("RUST_CC_ZEAL");
-    if (*zeal) {
-        do_cc(task);
-        return;
-    }
-
-    // FIXME (#1498): depressingly, due to alignment bugs the whole file is
-    // disabled presently unless you're doing testing. Remove the whole thing
-    // when we transition to using a visitor for GC/CC.
-#if 0
-    if (task->cc_counter++ > RUST_CC_FREQUENCY) {
-        task->cc_counter = 0;
-        do_cc(task);
-    }
-#endif
-}
-
-}   // end namespace cc
-
-//
-// Local Variables:
-// mode: C++
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// End:
-//