altos/lisp: bounds check in move_map plus binary search

This makes move_map faster by skipping all addresses which aren't
changing.

Also changed the interface from address to offset to avoid computing
the offset multiple times.

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

diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index e238d4fed8507af928939192f0be1527751ec4d9..af6ff8bbc149c37c95b6af45de11234e99fb722b 100644 (file)
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -128,6 +128,7 @@ ao_lisp_is_const(ao_poly poly) {
 
 #define AO_LISP_IS_CONST(a)    (ao_lisp_const <= ((uint8_t *) (a)) && ((uint8_t *) (a)) < ao_lisp_const + AO_LISP_POOL_CONST)
 #define AO_LISP_IS_POOL(a)     (ao_lisp_pool <= ((uint8_t *) (a)) && ((uint8_t *) (a)) < ao_lisp_pool + AO_LISP_POOL)
+#define AO_LISP_IS_INT(p)      (ao_lisp_base_type(p) == AO_LISP_INT);
 
 void *
 ao_lisp_ref(ao_poly poly);

diff --git a/src/lisp/ao_lisp_mem.c b/src/lisp/ao_lisp_mem.c
index 2599f719f21ad48ab8af6c078c3447261295a49d..e8907cf622ef0b7ca20805d1d67bcae4c1618f58 100644 (file)
--- a/src/lisp/ao_lisp_mem.c
+++ b/src/lisp/ao_lisp_mem.c
@@ -236,10 +236,10 @@ static uint8_t    ao_lisp_cons_noted;
 uint16_t       ao_lisp_top;
 
 struct ao_lisp_chunk {
-       uint16_t                old_addr;
+       uint16_t                old_offset;
        union {
                uint16_t        size;
-               uint16_t        new_addr;
+               uint16_t        new_offset;
        };
 };
 
@@ -284,14 +284,11 @@ static inline int limit(int offset) {
 static int total_marked;
 
 static void
-note_cons(void *addr)
+note_cons(uint16_t offset)
 {
-       if (AO_LISP_IS_POOL(addr)) {
-               int     offset = pool_offset(addr);
-               MDBG_MOVE("note cons %d\n", MDBG_OFFSET(addr));
-               ao_lisp_cons_noted = 1;
-               mark(ao_lisp_cons_note, offset);
-       }
+       MDBG_MOVE("note cons %d\n", offset);
+       ao_lisp_cons_noted = 1;
+       mark(ao_lisp_cons_note, offset);
 }
 
 static uint16_t        chunk_low, chunk_high;
@@ -299,11 +296,11 @@ static uint16_t   chunk_first, chunk_last;
 static int chunk_busy;
 
 static void
-note_chunk(uint16_t addr, uint16_t size)
+note_chunk(uint16_t offset, uint16_t size)
 {
        int l, r;
 
-       if (addr < chunk_low || chunk_high <= addr)
+       if (offset < chunk_low || chunk_high <= offset)
                return;
 
        /* Binary search for the location */
@@ -311,7 +308,7 @@ note_chunk(uint16_t addr, uint16_t size)
        r = chunk_busy - 1;
        while (l <= r) {
                int m = (l + r) >> 1;
-               if (ao_lisp_chunk[m].old_addr < addr)
+               if (ao_lisp_chunk[m].old_offset < offset)
                        l = m + 1;
                else
                        r = m - 1;
@@ -327,7 +324,7 @@ note_chunk(uint16_t addr, uint16_t size)
                ao_lisp_abort();
 
        /* Off the left side */
-       if (l == 0 && chunk_busy && addr > ao_lisp_chunk[0].old_addr)
+       if (l == 0 && chunk_busy && offset > ao_lisp_chunk[0].old_offset)
                ao_lisp_abort();
 #endif
 
@@ -339,7 +336,7 @@ note_chunk(uint16_t addr, uint16_t size)
                (end - (l+1)) * sizeof (struct ao_lisp_chunk));
 
        /* Add new entry */
-       ao_lisp_chunk[l].old_addr = addr;
+       ao_lisp_chunk[l].old_offset = offset;
        ao_lisp_chunk[l].size = size;
 
        /* Increment the number of elements up to the size of the array */
@@ -348,7 +345,7 @@ note_chunk(uint16_t addr, uint16_t size)
 
        /* Set the top address if the array is full */
        if (chunk_busy == AO_LISP_NCHUNK)
-               chunk_high = ao_lisp_chunk[AO_LISP_NCHUNK-1].old_addr +
+               chunk_high = ao_lisp_chunk[AO_LISP_NCHUNK-1].old_offset +
                        ao_lisp_chunk[AO_LISP_NCHUNK-1].size;
 }
 
@@ -508,41 +505,53 @@ ao_lisp_collect(uint8_t style)
                DUMP_BUSY();
 
                /* Find the first moving object */
-               for (i = 0; i < AO_LISP_NCHUNK; i++) {
+               for (i = 0; i < chunk_busy; i++) {
                        uint16_t        size = ao_lisp_chunk[i].size;
 
+#if DBG_MEM
                        if (!size)
-                               break;
+                               ao_lisp_abort();
+#endif
 
-                       if (ao_lisp_chunk[i].old_addr > top)
+                       if (ao_lisp_chunk[i].old_offset > top)
                                break;
+
+                       MDBG_MOVE("chunk %d %d not moving\n",
+                                 ao_lisp_chunk[i].old_offset,
+                                 ao_lisp_chunk[i].size);
 #if DBG_MEM
-                       if (ao_lisp_chunk[i].old_addr != top)
+                       if (ao_lisp_chunk[i].old_offset != top)
                                ao_lisp_abort();
 #endif
-
                        top += size;
-                       MDBG_MOVE("chunk %d %d not moving\n",
-                                 ao_lisp_chunk[i].old_addr,
-                                 ao_lisp_chunk[i].size);
                }
 
+               /*
+                * Limit amount of chunk array used in mapping moves
+                * to the active region
+                */
                chunk_first = i;
+               chunk_low = ao_lisp_chunk[i].old_offset;
+
                /* Copy all of the objects */
-               for (; i < AO_LISP_NCHUNK; i++) {
+               for (; i < chunk_busy; i++) {
                        uint16_t        size = ao_lisp_chunk[i].size;
 
+#if DBG_MEM
                        if (!size)
-                               break;
+                               ao_lisp_abort();
+#endif
 
                        MDBG_MOVE("chunk %d %d -> %d\n",
-                                 ao_lisp_chunk[i].old_addr,
+                                 ao_lisp_chunk[i].old_offset,
                                  size,
                                  top);
-                       ao_lisp_chunk[i].new_addr = top;
+                       ao_lisp_chunk[i].new_offset = top;
+
                        memmove(&ao_lisp_pool[top],
-                               &ao_lisp_pool[ao_lisp_chunk[i].old_addr],
+                               &ao_lisp_pool[ao_lisp_chunk[i].old_offset],
                                size);
+
                        top += size;
                }
 
@@ -564,9 +573,13 @@ ao_lisp_collect(uint8_t style)
 #endif
                }
 
+               /* If we ran into the end of the heap, then
+                * there's no need to keep walking
+                */
                if (chunk_last != AO_LISP_NCHUNK)
                        break;
 
+               /* Next loop starts right above this loop */
                chunk_low = chunk_high;
        }
 
@@ -590,10 +603,11 @@ ao_lisp_collect(uint8_t style)
 
 /*
  * Mark interfaces for objects
- *
- * Note a reference to memory and
- * collect information about a few object sizes
- * at a time
+ */
+
+/*
+ * Note a reference to memory and collect information about a few
+ * object sizes at a time
  */
 
 int
@@ -614,6 +628,9 @@ ao_lisp_mark_memory(const struct ao_lisp_type *type, void *addr)
        return 0;
 }
 
+/*
+ * Mark an object and all that it refereces
+ */
 int
 ao_lisp_mark(const struct ao_lisp_type *type, void *addr)
 {
@@ -629,64 +646,82 @@ ao_lisp_mark(const struct ao_lisp_type *type, void *addr)
        return ret;
 }
 
+/*
+ * Mark an object, unless it is a cons cell and
+ * do_note_cons is set. In that case, just
+ * set a bit in the cons note array; those
+ * will be marked in a separate pass to avoid
+ * deep recursion in the collector
+ */
 int
 ao_lisp_poly_mark(ao_poly p, uint8_t do_note_cons)
 {
        uint8_t type;
        void    *addr;
 
-       if (!p)
+       type = ao_lisp_poly_base_type(p);
+
+       if (type == AO_LISP_INT)
                return 1;
 
-       type = ao_lisp_poly_base_type(p);
        addr = ao_lisp_ref(p);
-
        if (!AO_LISP_IS_POOL(addr))
                return 1;
 
        if (type == AO_LISP_CONS && do_note_cons) {
-               note_cons(ao_lisp_ref(p));
+               note_cons(pool_offset(addr));
                return 1;
        } else {
-               const struct ao_lisp_type       *lisp_type;
+               if (type == AO_LISP_OTHER)
+                       type = ao_lisp_other_type(addr);
 
-               if (type == AO_LISP_OTHER) {
-                       type = ao_lisp_other_type(ao_lisp_poly_other(p));
+               const struct ao_lisp_type *lisp_type = ao_lisp_types[type];
 #if DBG_MEM
-                       if (type <= AO_LISP_OTHER || AO_LISP_NUM_TYPE <= type)
-                               ao_lisp_abort();
+               if (!lisp_type)
+                       ao_lisp_abort();
 #endif
-               }
 
-               lisp_type = ao_lisp_types[ao_lisp_poly_type(p)];
-               if (!lisp_type)
-                       return 1;
-               return ao_lisp_mark(lisp_type, ao_lisp_ref(p));
+               return ao_lisp_mark(lisp_type, addr);
        }
 }
 
-static void *
-move_map(void *addr)
+/*
+ * Find the current location of an object
+ * based on the original location. For unmoved
+ * objects, this is simple. For moved objects,
+ * go search for it
+ */
+
+static uint16_t
+move_map(uint16_t offset)
 {
-       uint16_t        offset = pool_offset(addr);
-       int             i;
-
-       for (i = chunk_first; i < chunk_last; i++) {
-               if (ao_lisp_chunk[i].old_addr == offset) {
-                       MDBG_MOVE("move %d -> %d\n",
-                                 ao_lisp_chunk[i].old_addr,
-                                 ao_lisp_chunk[i].new_addr);
-                       return ao_lisp_pool + ao_lisp_chunk[i].new_addr;
-               }
+       int             l, r;
+
+       if (offset < chunk_low || chunk_high <= offset)
+               return offset;
+
+       /* Binary search for the location */
+       l = chunk_first;
+       r = chunk_busy - 1;
+       while (l <= r) {
+               int m = (l + r) >> 1;
+               if (ao_lisp_chunk[m].old_offset < offset)
+                       l = m + 1;
+               else
+                       r = m - 1;
        }
-       return addr;
+#if DBG_MEM
+       if (ao_lisp_chunk[l].old_offset != offset)
+               ao_lisp_abort();
+#endif
+       return ao_lisp_chunk[l].new_offset;
 }
 
 int
 ao_lisp_move_memory(const struct ao_lisp_type *type, void **ref)
 {
        void            *addr = *ref;
-       int             offset;
+       uint16_t        offset, orig_offset;
 
        if (!AO_LISP_IS_POOL(addr))
                return 1;
@@ -694,14 +729,14 @@ ao_lisp_move_memory(const struct ao_lisp_type *type, void **ref)
        (void) type;
 
        MDBG_MOVE("move memory %d\n", MDBG_OFFSET(addr));
-       addr = move_map(addr);
-       if (addr != *ref) {
+       orig_offset = pool_offset(addr);
+       offset = move_map(orig_offset);
+       if (offset != orig_offset) {
                MDBG_MOVE("update ref %d %d -> %d\n",
                          AO_LISP_IS_POOL(ref) ? MDBG_OFFSET(ref) : -1,
-                         MDBG_OFFSET(*ref), MDBG_OFFSET(addr));
-               *ref = addr;
+                         orig_offset, offset);
+               *ref = ao_lisp_pool + offset;
        }
-       offset = pool_offset(addr);
        if (busy(ao_lisp_busy, offset)) {
                MDBG_MOVE("already moved\n");
                return 1;
@@ -729,47 +764,46 @@ ao_lisp_move(const struct ao_lisp_type *type, void **ref)
 int
 ao_lisp_poly_move(ao_poly *ref, uint8_t do_note_cons)
 {
-       uint8_t                         type;
-       ao_poly                         p = *ref;
-       int                             ret;
-       void                            *addr;
+       uint8_t         type;
+       ao_poly         p = *ref;
+       int             ret;
+       void            *addr;
+       uint16_t        offset, orig_offset;
+       uint8_t         base_type;
+
+       base_type = type = ao_lisp_poly_base_type(p);
 
-       if (!p)
+       if (type == AO_LISP_INT)
                return 1;
 
        addr = ao_lisp_ref(p);
-
        if (!AO_LISP_IS_POOL(addr))
                return 1;
 
-       type = ao_lisp_poly_base_type(p);
+       orig_offset = pool_offset(addr);
+       offset = move_map(orig_offset);
 
        if (type == AO_LISP_CONS && do_note_cons) {
-               note_cons(addr);
-               addr = move_map(addr);
+               note_cons(orig_offset);
                ret = 1;
        } else {
-               const struct ao_lisp_type       *lisp_type;
+               if (type == AO_LISP_OTHER)
+                       type = ao_lisp_other_type(ao_lisp_pool + offset);
 
-               if (type == AO_LISP_OTHER) {
-                       type = ao_lisp_other_type(move_map(ao_lisp_poly_other(p)));
+               const struct ao_lisp_type *lisp_type = ao_lisp_types[type];
 #if DBG_MEM
-                       if (type <= AO_LISP_OTHER || AO_LISP_NUM_TYPE <= type)
-                               ao_lisp_abort();
+               if (!lisp_type)
+                       ao_lisp_abort();
 #endif
-               }
 
-               lisp_type = ao_lisp_types[type];
-               if (!lisp_type)
-                       return 1;
                ret = ao_lisp_move(lisp_type, &addr);
        }
 
        /* Re-write the poly value */
-       if (addr != ao_lisp_ref(p)) {
-               ao_poly np = ao_lisp_poly(addr, p & AO_LISP_TYPE_MASK);
+       if (offset != orig_offset) {
+               ao_poly np = ao_lisp_poly(ao_lisp_pool + offset, base_type);
                MDBG_MOVE("poly %d moved %d -> %d\n",
-                         type, MDBG_OFFSET(ao_lisp_ref(p)), MDBG_OFFSET(ao_lisp_ref(np)));
+                         type, orig_offset, offset);
                *ref = np;
        }
        return ret;
@@ -797,8 +831,8 @@ ao_lisp_alloc(int size)
        MDBG_DO(if (dbg_validate) ao_lisp_validate());
        size = ao_lisp_size_round(size);
        if (ao_lisp_top + size > AO_LISP_POOL) {
-               if (!ao_lisp_collect(AO_LISP_COLLECT_INCREMENTAL) &&
-                   !ao_lisp_collect(AO_LISP_COLLECT_FULL))
+               if (ao_lisp_collect(AO_LISP_COLLECT_INCREMENTAL) < size &&
+                   ao_lisp_collect(AO_LISP_COLLECT_FULL) < size)
                {
                        ao_lisp_error(AO_LISP_OOM, "out of memory");
                        return NULL;