altos/lisp: convert GC to non-recursive

Use a boolean array to note cons cells which would otherwise recurse,
then loop until that array is empty.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index 0d17994282cafc803743bb0ffda36b45b05def7f..17f1e0f55540dbc5e55db4cfaf35ca0d3d1474b4 100644 (file)
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -221,6 +221,10 @@ ao_lisp_mem_round(int size)
 
 #define AO_LISP_OTHER_POLY(other) ((ao_poly)(other) + AO_LISP_OTHER)
 
+static inline int ao_lisp_poly_base_type(ao_poly poly) {
+       return poly & AO_LISP_TYPE_MASK;
+}
+
 static inline int ao_lisp_poly_type(ao_poly poly) {
        int     type = poly & AO_LISP_TYPE_MASK;
        if (type == AO_LISP_OTHER)
@@ -384,11 +388,11 @@ void
 ao_lisp_poly_patom(ao_poly p);
 
 int
-ao_lisp_poly_mark(ao_poly p);
+ao_lisp_poly_mark(ao_poly p, uint8_t note_cons);
 
 /* returns 1 if the object has already been moved */
 int
-ao_lisp_poly_move(ao_poly *p);
+ao_lisp_poly_move(ao_poly *p, uint8_t note_cons);
 
 /* eval */
 

diff --git a/src/lisp/ao_lisp_atom.c b/src/lisp/ao_lisp_atom.c
index 5f1bcda02ac372b0bff2ba72c91d1bd9b7177de6..41ba97f5d7f5b674948d9da00324cdb0d97f5f10 100644 (file)
--- a/src/lisp/ao_lisp_atom.c
+++ b/src/lisp/ao_lisp_atom.c
@@ -48,7 +48,7 @@ static void atom_move(void *addr)
        struct ao_lisp_atom     *atom = addr;
 
        for (;;) {
-               if (ao_lisp_poly_move(&atom->next))
+               if (ao_lisp_poly_move(&atom->next, 0))
                        break;
                atom = ao_lisp_poly_atom(atom->next);
        }

diff --git a/src/lisp/ao_lisp_cons.c b/src/lisp/ao_lisp_cons.c
index 7d3ca68d6a7134914459791faaf283359264345a..855079b8b483022040a5124bef3b4ea0c77cf09e 100644 (file)
--- a/src/lisp/ao_lisp_cons.c
+++ b/src/lisp/ao_lisp_cons.c
@@ -21,7 +21,7 @@ static void cons_mark(void *addr)
        struct ao_lisp_cons     *cons = addr;
 
        for (;;) {
-               ao_lisp_poly_mark(cons->car);
+               ao_lisp_poly_mark(cons->car, 1);
                cons = ao_lisp_poly_cons(cons->cdr);
                if (!cons)
                        break;
@@ -44,10 +44,17 @@ static void cons_move(void *addr)
                return;
 
        for (;;) {
-               (void) ao_lisp_poly_move(&cons->car);
-               if (ao_lisp_poly_move(&cons->cdr))
+               struct ao_lisp_cons     *cdr;
+               int                     ret;
+
+               (void) ao_lisp_poly_move(&cons->car, 1);
+               cdr = ao_lisp_poly_cons(cons->cdr);
+               ret = ao_lisp_move_memory((void **) &cdr, sizeof (struct ao_lisp_cons));
+               if (cdr != ao_lisp_poly_cons(cons->cdr))
+                       cons->cdr = ao_lisp_cons_poly(cdr);
+               if (ret)
                        break;
-               cons = ao_lisp_poly_cons(cons->cdr);
+               cons = cdr;
        }
 }
 

diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index e3d653b99e1635e078967db28d84cf3a8ee26475..a5c742503f89452271a5dfb2c3124d63659ff212 100644 (file)
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -79,10 +79,10 @@ stack_mark(void *addr)
 {
        struct ao_lisp_stack    *stack = addr;
        for (;;) {
-               ao_lisp_poly_mark(stack->actuals);
-               ao_lisp_poly_mark(stack->formals);
+               ao_lisp_poly_mark(stack->actuals, 0);
+               ao_lisp_poly_mark(stack->formals, 0);
                /* no need to mark formals_tail */
-               ao_lisp_poly_mark(stack->frame);
+               ao_lisp_poly_mark(stack->frame, 0);
                stack = ao_lisp_poly_stack(stack->prev);
                if (ao_lisp_mark_memory(stack, sizeof (struct ao_lisp_stack)))
                        break;
@@ -122,10 +122,10 @@ stack_move(void *addr)
        while (stack) {
                void    *prev;
                int     ret;
-               (void) ao_lisp_poly_move(&stack->actuals);
-               (void) ao_lisp_poly_move(&stack->formals);
-               (void) ao_lisp_poly_move(&stack->formals_tail);
-               (void) ao_lisp_poly_move(&stack->frame);
+               (void) ao_lisp_poly_move(&stack->actuals, 0);
+               (void) ao_lisp_poly_move(&stack->formals, 0);
+               (void) ao_lisp_poly_move(&stack->formals_tail, 0);
+               (void) ao_lisp_poly_move(&stack->frame, 0);
                prev = ao_lisp_poly_stack(stack->prev);
                ret = ao_lisp_move(&ao_lisp_stack_type, &prev);
                if (prev != ao_lisp_poly_stack(stack->prev))

diff --git a/src/lisp/ao_lisp_frame.c b/src/lisp/ao_lisp_frame.c
index 8bf985710c73d7b94ae4b5be0046131604be9cb7..8791c4de8804780a03a5c1e744480e4b198e1244 100644 (file)
--- a/src/lisp/ao_lisp_frame.c
+++ b/src/lisp/ao_lisp_frame.c
@@ -48,7 +48,7 @@ frame_mark(void *addr)
                for (f = 0; f < frame->num; f++) {
                        struct ao_lisp_val      *v = &frame->vals[f];
 
-                       ao_lisp_poly_mark(v->val);
+                       ao_lisp_poly_mark(v->val, 0);
                        DBG ("\tframe mark atom %s %d val %d at %d\n",
                             ao_lisp_poly_atom(v->atom)->name,
                             OFFSET(v->atom), OFFSET(v->val), f);
@@ -69,19 +69,28 @@ frame_move(void *addr)
        int                     f;
 
        for (;;) {
+               struct ao_lisp_frame    *next;
+               int                     ret;
+
                DBG("frame move %p\n", frame);
                if (!AO_LISP_IS_POOL(frame))
                        break;
                for (f = 0; f < frame->num; f++) {
                        struct ao_lisp_val      *v = &frame->vals[f];
 
-                       ao_lisp_poly_move(&v->atom);
+                       ao_lisp_poly_move(&v->atom, 0);
                        DBG("moved atom %s\n", ao_lisp_poly_atom(v->atom)->name);
-                       ao_lisp_poly_move(&v->val);
+                       ao_lisp_poly_move(&v->val, 0);
                }
-               if (ao_lisp_poly_move(&frame->next))
+               next = ao_lisp_poly_frame(frame->next);
+               ret = 1;
+               if (next)
+                       ret = ao_lisp_move_memory((void **) &next, frame_size(next));
+               if (next != ao_lisp_poly_frame(frame->next))
+                       frame->next = ao_lisp_frame_poly(next);
+               if (ret)
                        break;
-               frame = ao_lisp_poly_frame(frame->next);
+               frame = next;
        }
 }
 

diff --git a/src/lisp/ao_lisp_mem.c b/src/lisp/ao_lisp_mem.c
index 6e656454b1c2fe22edb4857578a75dedb3904eff..c11ec25d96df982afa581549b5edc28d963b72b4 100644 (file)
--- a/src/lisp/ao_lisp_mem.c
+++ b/src/lisp/ao_lisp_mem.c
@@ -41,7 +41,7 @@ uint8_t       ao_lisp_pool[AO_LISP_POOL] __attribute__((aligned(4)));
 #define DBG_OFFSET(a)  ((int) ((uint8_t *) (a) - ao_lisp_pool))
 #define DBG(...) printf(__VA_ARGS__)
 #define DBG_DO(a)      a
-static int move_dump;
+static int move_dump = 1;
 static int move_depth;
 #define DBG_RESET() (move_depth = 0)
 #define DBG_MOVE(...) do { if(move_dump) { int d; for (d = 0; d < move_depth; d++) printf ("  "); printf(__VA_ARGS__); } } while (0)
@@ -68,8 +68,10 @@ struct ao_lisp_root {
 static struct ao_lisp_root     ao_lisp_root[AO_LISP_ROOT];
 
 static uint8_t ao_lisp_busy[AO_LISP_POOL / 32];
-
 static uint8_t ao_lisp_moving[AO_LISP_POOL / 32];
+static uint8_t ao_lisp_cons[AO_LISP_POOL / 32];
+static uint8_t ao_lisp_cons_last[AO_LISP_POOL / 32];
+static uint8_t ao_lisp_cons_noted;
 
 uint16_t       ao_lisp_top;
 
@@ -161,6 +163,17 @@ busy_object(uint8_t *tag, void *addr) {
        return 0;
 }
 
+static void
+note_cons(void *addr)
+{
+       DBG_MOVE("note cons %d\n", DBG_OFFSET(addr));
+       if (AO_LISP_IS_POOL(addr)) {
+               ao_lisp_cons_noted = 1;
+               mark(ao_lisp_cons, (uint8_t *) addr - ao_lisp_pool);
+       }
+}
+
+
 static void    *move_old, *move_new;
 static int     move_size;
 
@@ -173,11 +186,15 @@ move_object(void)
        DBG_MOVE("move %d -> %d\n", DBG_OFFSET(move_old), DBG_OFFSET(move_new));
        DBG_MOVE_IN();
        memset(ao_lisp_moving, '\0', sizeof (ao_lisp_moving));
+       memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+       ao_lisp_cons_noted = 0;
        for (i = 0; i < AO_LISP_ROOT; i++) {
                if (!ao_lisp_root[i].addr)
                        continue;
                if (ao_lisp_root[i].type) {
-                       DBG_DO(void *addr = *ao_lisp_root[i].addr);
+                       void *addr = *ao_lisp_root[i].addr;
+                       if (!addr)
+                               continue;
                        DBG_MOVE("root %d\n", DBG_OFFSET(addr));
                        if (!ao_lisp_move(ao_lisp_root[i].type,
                                          ao_lisp_root[i].addr)) {
@@ -186,13 +203,30 @@ move_object(void)
                                         *ao_lisp_root[i].addr);
                        }
                } else {
-                       DBG_DO(ao_poly p = *(ao_poly *) ao_lisp_root[i].addr);
-                       if (!ao_lisp_poly_move((ao_poly *) ao_lisp_root[i].addr)) {
+                       ao_poly p = *(ao_poly *) ao_lisp_root[i].addr;
+                       if (!p)
+                               continue;
+                       if (!ao_lisp_poly_move((ao_poly *) ao_lisp_root[i].addr, 0)) {
                                DBG_MOVE("root poly move from %04x to %04x\n",
                                         p, *(ao_poly *) ao_lisp_root[i].addr);
                        }
                }
        }
+       while (ao_lisp_cons_noted) {
+               memcpy(ao_lisp_cons_last, ao_lisp_cons, sizeof (ao_lisp_cons));
+               memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+               ao_lisp_cons_noted = 0;
+               for (i = 0; i < AO_LISP_POOL; i += 4) {
+                       if (busy(ao_lisp_cons_last, i)) {
+                               void *addr = ao_lisp_pool + i;
+                               DBG_MOVE("cons %d\n", DBG_OFFSET(addr));
+                               if (!ao_lisp_move(&ao_lisp_cons_type, &addr)) {
+                                       DBG_MOVE("cons moves from %p to %p\n",
+                                                ao_lisp_pool + i, addr);
+                               }
+                       }
+               }
+       }
        DBG_MOVE_OUT();
        DBG_MOVE("move done\n");
 }
@@ -220,25 +254,50 @@ dump_busy(void)
 #define DUMP_BUSY()
 #endif
 
+static const struct ao_lisp_type const *ao_lisp_types[AO_LISP_NUM_TYPE] = {
+       [AO_LISP_CONS] = &ao_lisp_cons_type,
+       [AO_LISP_INT] = NULL,
+       [AO_LISP_STRING] = &ao_lisp_string_type,
+       [AO_LISP_OTHER] = (void *) 0x1,
+       [AO_LISP_ATOM] = &ao_lisp_atom_type,
+       [AO_LISP_BUILTIN] = &ao_lisp_builtin_type,
+       [AO_LISP_FRAME] = &ao_lisp_frame_type,
+};
+
+
 static void
 ao_lisp_mark_busy(void)
 {
        int i;
 
        memset(ao_lisp_busy, '\0', sizeof (ao_lisp_busy));
+       memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+       ao_lisp_cons_noted = 0;
        DBG("mark\n");
        for (i = 0; i < AO_LISP_ROOT; i++) {
                if (ao_lisp_root[i].type) {
                        void **a = ao_lisp_root[i].addr, *v;
                        if (a && (v = *a)) {
-                               DBG("root %p\n", v);
+                               DBG("root %d\n", DBG_OFFSET(v));
                                ao_lisp_mark(ao_lisp_root[i].type, v);
                        }
                } else {
                        ao_poly *a = (ao_poly *) ao_lisp_root[i].addr, p;
                        if (a && (p = *a)) {
-                               DBG("root %04x\n", p);
-                               ao_lisp_poly_mark(p);
+                               DBG("root 0x%04x\n", p);
+                               ao_lisp_poly_mark(p, 0);
+                       }
+               }
+       }
+       while (ao_lisp_cons_noted) {
+               memcpy(ao_lisp_cons_last, ao_lisp_cons, sizeof (ao_lisp_cons));
+               memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+               ao_lisp_cons_noted = 0;
+               for (i = 0; i < AO_LISP_POOL; i += 4) {
+                       if (busy(ao_lisp_cons_last, i)) {
+                               void *v = ao_lisp_pool + i;
+                               DBG("cons %d\n", DBG_OFFSET(v));
+                               ao_lisp_mark(&ao_lisp_cons_type, v);
                        }
                }
        }
@@ -274,6 +333,10 @@ ao_lisp_collect(void)
                                abort();
                        clear_object(ao_lisp_busy, move_old, move_size);
                        mark_object(ao_lisp_busy, move_new, move_size);
+                       if (busy_object(ao_lisp_cons, move_old)) {
+                               clear_object(ao_lisp_cons, move_old, move_size);
+                               mark_object(ao_lisp_cons, move_new, move_size);
+                       }
                        i += move_size;
                        top += move_size;
                        DUMP_BUSY();
@@ -296,6 +359,24 @@ ao_lisp_mark(const struct ao_lisp_type *type, void *addr)
        return 0;
 }
 
+int
+ao_lisp_poly_mark(ao_poly p, uint8_t do_note_cons)
+{
+       uint8_t type = ao_lisp_poly_type(p);
+
+       if (!p)
+               return 1;
+       if (type == AO_LISP_CONS && do_note_cons) {
+               note_cons(ao_lisp_ref(p));
+               return 0;
+       } else {
+               const struct ao_lisp_type *lisp_type = ao_lisp_types[ao_lisp_poly_type(p)];
+               if (lisp_type)
+                       return ao_lisp_mark(lisp_type, ao_lisp_ref(p));
+               return 1;
+       }
+}
+
 int
 ao_lisp_mark_memory(void *addr, int size)
 {
@@ -348,7 +429,7 @@ ao_lisp_move(const struct ao_lisp_type *type, void **ref)
                return 1;
 #endif
        DBG_MOVE("object %d\n", DBG_OFFSET(addr));
-       if (a < ao_lisp_pool || ao_lisp_pool + AO_LISP_POOL <= a)
+       if (!AO_LISP_IS_POOL(a))
                abort();
        DBG_MOVE_IN();
        addr = check_move(addr, size);
@@ -389,6 +470,47 @@ ao_lisp_move_memory(void **ref, int size)
        return 0;
 }
 
+int
+ao_lisp_poly_move(ao_poly *ref, uint8_t do_note_cons)
+{
+       uint8_t                         type;
+       ao_poly                         p = *ref;
+       const struct ao_lisp_type       *lisp_type;
+       int                             ret;
+       void                            *addr;
+
+       if (!p)
+               return 1;
+
+       type = ao_lisp_poly_base_type(p);
+       addr = ao_lisp_ref(p);
+       if (type == AO_LISP_CONS && do_note_cons) {
+               note_cons(addr);
+               addr = check_move(addr, sizeof (struct ao_lisp_cons));
+               ret = 1;
+       } else {
+
+               if (type == AO_LISP_OTHER)
+                       type = ao_lisp_other_type(ao_lisp_move_map(ao_lisp_poly_other(p)));
+
+               if (type >= AO_LISP_NUM_TYPE)
+                       abort();
+
+               lisp_type = ao_lisp_types[type];
+               if (!lisp_type)
+                       return 1;
+               ret = ao_lisp_move(lisp_type, &addr);
+       }
+
+       if (addr != ao_lisp_ref(p)) {
+               ao_poly np = ao_lisp_poly(addr, p & AO_LISP_TYPE_MASK);
+               DBG("poly %d moved %04x -> %04x\n",
+                   type, p, np);
+               *ref = np;
+       }
+       return ret;
+}
+
 #ifdef DBG_POOL
 static int AO_LISP_POOL_CUR = AO_LISP_POOL / 8;
 

diff --git a/src/lisp/ao_lisp_prim.c b/src/lisp/ao_lisp_prim.c
index 82386a83ca2e05b5e82762bf12060b863989c660..3c081ee89fbeab3be336fe4f298dc824fb926b9e 100644 (file)
--- a/src/lisp/ao_lisp_prim.c
+++ b/src/lisp/ao_lisp_prim.c
@@ -76,54 +76,3 @@ ao_lisp_poly_patom(ao_poly p)
                f->patom(p);
 }
 
-static const struct ao_lisp_type const *ao_lisp_types[AO_LISP_NUM_TYPE] = {
-       [AO_LISP_CONS] = &ao_lisp_cons_type,
-       [AO_LISP_INT] = NULL,
-       [AO_LISP_STRING] = &ao_lisp_string_type,
-       [AO_LISP_OTHER] = (void *) 0x1,
-       [AO_LISP_ATOM] = &ao_lisp_atom_type,
-       [AO_LISP_BUILTIN] = &ao_lisp_builtin_type,
-       [AO_LISP_FRAME] = &ao_lisp_frame_type,
-};
-
-int
-ao_lisp_poly_mark(ao_poly p)
-{
-       const struct ao_lisp_type *lisp_type = ao_lisp_types[ao_lisp_poly_type(p)];
-       if (lisp_type)
-               return ao_lisp_mark(lisp_type, ao_lisp_ref(p));
-       return 1;
-}
-
-int
-ao_lisp_poly_move(ao_poly *ref)
-{
-       uint8_t                         type;
-       ao_poly                         p = *ref;
-       const struct ao_lisp_type       *lisp_type;
-       int                             ret;
-       void                            *addr;
-
-       if (!p)
-               return 1;
-
-       type = p & AO_LISP_TYPE_MASK;
-       if (type == AO_LISP_OTHER)
-               type = ao_lisp_other_type(ao_lisp_move_map(ao_lisp_poly_other(p)));
-
-       if (type >= AO_LISP_NUM_TYPE)
-               abort();
-
-       lisp_type = ao_lisp_types[type];
-       if (!lisp_type)
-               return 1;
-       addr = ao_lisp_ref(p);
-       ret = ao_lisp_move(lisp_type, &addr);
-       if (addr != ao_lisp_ref(p)) {
-               ao_poly np = ao_lisp_poly(addr, p & AO_LISP_TYPE_MASK);
-               DBG("poly %d moved %04x -> %04x\n",
-                   type, p, np);
-               *ref = np;
-       }
-       return ret;
-}