Rename fletch -> dartino

platforms/stm/disco_fletch/src/cmpctmalloc.c

Index: platforms/stm/disco_fletch/src/cmpctmalloc.c
diff --git a/platforms/stm/disco_fletch/src/cmpctmalloc.c b/platforms/stm/disco_fletch/src/cmpctmalloc.c
deleted file mode 100644
index 7df68e487fce88ef6d4ef18a6a8abc0efcd6e1fd..0000000000000000000000000000000000000000
--- a/platforms/stm/disco_fletch/src/cmpctmalloc.c
+++ /dev/null
@@ -1,902 +0,0 @@
-// Copyright (c) 2016, the Dartino project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE.md file.
-
-// This code is ported from the LK repository. To keep the code in
-// sync the define FLETCH_TARGET_OS_LK provides the code from the LK
-// repository. Without the define FLETCH_TARGET_OS_LK this code will
-// build and link for the disco_fletch project.
-#ifdef FLETCH_TARGET_OS_LK
-
-#include <debug.h>
-#include <trace.h>
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <kernel/thread.h>
-#include <kernel/mutex.h>
-#include <kernel/spinlock.h>
-#include <lib/cmpctmalloc.h>
-#include <lib/heap.h>
-#include <lib/page_alloc.h>
-
-#else  // FLETCH_TARGET_OS_LK
-
-#include "platforms/stm/disco_fletch/src/cmpctmalloc.h"
-
-#include <inttypes.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "platforms/stm/disco_fletch/src/globals.h"
-
-void* page_alloc(size_t pages);
-void page_free(void* start, size_t pages);
-
-typedef uintptr_t addr_t;
-typedef uintptr_t vaddr_t;
-
-#define LTRACEF(...)
-#define LTRACE_ENTRY
-#define DEBUG_ASSERT ASSERT
-#define ASSERT(condition)        \
-  while (false && (condition)) { \
-  }
-#define STATIC_ASSERT(condition)
-#define dprintf(...) fprintf(__VA_ARGS__)
-#define INFO stdout
-
-#endif  // FLETCH_TARGET_OS_LK
-
-// Malloc implementation tuned for space.
-//
-// Allocation strategy takes place with a global mutex.  Freelist entries are
-// kept in linked lists with 8 different sizes per binary order of magnitude
-// and the header size is two words with eager coalescing on free.
-
-#ifdef DEBUG
-#define CMPCT_DEBUG
-#endif
-
-#ifdef FLETCH_TARGET_OS_LK
-#define LOCAL_TRACE 0
-#endif
-
-#define ALLOC_FILL 0x99
-#define FREE_FILL 0x77
-#define PADDING_FILL 0x55
-
-#ifdef FLETCH_TARGET_OS_LK
-#if WITH_KERNEL_VM && !defined(HEAP_GROW_SIZE)
-#define HEAP_GROW_SIZE (1 * 1024 * 1024) /* Grow aggressively */
-#elif !defined(HEAP_GROW_SIZE)
-#define HEAP_GROW_SIZE (4 * 1024) /* Grow less aggressively */
-#endif
-#else
-#define HEAP_GROW_SIZE (4 * 1024) /* Grow less aggressively */
-#endif
-
-STATIC_ASSERT(IS_PAGE_ALIGNED(HEAP_GROW_SIZE));
-
-// Individual allocations above 4Mbytes are just fetched directly from the
-// block allocator.
-#define HEAP_ALLOC_VIRTUAL_BITS 22
-
-// When we grow the heap we have to have somewhere in the freelist to put the
-// resulting freelist entry, so the freelist has to have a certain number of
-// buckets.
-STATIC_ASSERT(HEAP_GROW_SIZE <= (1u << HEAP_ALLOC_VIRTUAL_BITS));
-
-// Buckets for allocations.  The smallest 15 buckets are 8, 16, 24, etc. up to
-// 120 bytes.  After that we round up to the nearest size that can be written
-// /^0*1...0*$/, giving 8 buckets per order of binary magnitude.  The freelist
-// entries in a given bucket have at least the given size, plus the header
-// size.  On 64 bit, the 8 byte bucket is useless, since the freelist header
-// is 16 bytes larger than the header, but we have it for simplicity.
-#define NUMBER_OF_BUCKETS (1 + 15 + (HEAP_ALLOC_VIRTUAL_BITS - 7) * 8)
-
-// All individual memory areas on the heap start with this.
-typedef struct header_struct {
-    struct header_struct *left;  // Pointer to the previous area in memory order.
-    size_t size;
-} header_t;
-
-typedef struct free_struct {
-    header_t header;
-    struct free_struct *next;
-    struct free_struct *prev;
-} free_t;
-
-struct heap {
-    size_t size;
-    size_t remaining;
-#ifdef FLETCH_TARGET_OS_LK
-    mutex_t lock;
-#endif
-    free_t *free_lists[NUMBER_OF_BUCKETS];
-    // We have some 32 bit words that tell us whether there is an entry in the
-    // freelist.
-#define BUCKET_WORDS (((NUMBER_OF_BUCKETS) + 31) >> 5)
-    uint32_t free_list_bits[BUCKET_WORDS];
-};
-
-// Heap static vars.
-static struct heap theheap;
-
-static ssize_t heap_grow(size_t len, free_t **bucket);
-
-static void lock(void)
-{
-#ifdef FLETCH_TARGET_OS_LK
-    mutex_acquire(&theheap.lock);
-#endif
-}
-
-static void unlock(void)
-{
-#ifdef FLETCH_TARGET_OS_LK
-    mutex_release(&theheap.lock);
-#endif
-}
-
-static void dump_free(header_t *header)
-{
-    dprintf(INFO, "\t\tbase %p, end 0x%lx, len 0x%zx\n", header, (vaddr_t)header + header->size, header->size);
-}
-
-void cmpct_dump(void)
-{
-    lock();
-    dprintf(INFO, "Heap dump (using cmpctmalloc):\n");
-    dprintf(INFO, "\tsize %lu, remaining %lu\n",
-            (unsigned long)theheap.size,
-            (unsigned long)theheap.remaining);
-
-    dprintf(INFO, "\tfree list:\n");
-    for (int i = 0; i < NUMBER_OF_BUCKETS; i++) {
-        bool header_printed = false;
-        free_t *free_area = theheap.free_lists[i];
-        for (; free_area != NULL; free_area = free_area->next) {
-            ASSERT(free_area != free_area->next);
-            if (!header_printed) {
-                dprintf(INFO, "\tbucket %d\n", i);
-                header_printed = true;
-            }
-            dump_free(&free_area->header);
-        }
-    }
-    unlock();
-}
-
-// Operates in sizes that don't include the allocation header.
-static int size_to_index_helper(
-    size_t size, size_t *rounded_up_out, int adjust, int increment)
-{
-    // First buckets are simply 8-spaced up to 128.
-    if (size <= 128) {
-        if (sizeof(size_t) == 8u && size <= sizeof(free_t) - sizeof(header_t)) {
-            *rounded_up_out = sizeof(free_t) - sizeof(header_t);
-        } else {
-            *rounded_up_out = size;
-        }
-        // No allocation is smaller than 8 bytes, so the first bucket is for 8
-        // byte spaces (not including the header).  For 64 bit, the free list
-        // struct is 16 bytes larger than the header, so no allocation can be
-        // smaller than that (otherwise how to free it), but we have empty 8
-        // and 16 byte buckets for simplicity.
-        return (size >> 3) - 1;
-    }
-
-    // We are going to go up to the next size to round up, but if we hit a
-    // bucket size exactly we don't want to go up. By subtracting 8 here, we
-    // will do the right thing (the carry propagates up for the round numbers
-    // we are interested in).
-    size += adjust;
-    // After 128 the buckets are logarithmically spaced, every 16 up to 256,
-    // every 32 up to 512 etc.  This can be thought of as rows of 8 buckets.
-    // GCC intrinsic count-leading-zeros.
-    // Eg. 128-255 has 24 leading zeros and we want row to be 4.
-    unsigned row = sizeof(size_t) * 8 - 4 - __builtin_clzl(size);
-    // For row 4 we want to shift down 4 bits.
-    unsigned column = (size >> row) & 7;
-    int row_column = (row << 3) | column;
-    row_column += increment;
-    size = (8 + (row_column & 7)) << (row_column >> 3);
-    *rounded_up_out = size;
-    // We start with 15 buckets, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96,
-    // 104, 112, 120.  Then we have row 4, sizes 128 and up, with the
-    // row-column 8 and up.
-    int answer = row_column + 15 - 32;
-    DEBUG_ASSERT(answer < NUMBER_OF_BUCKETS);
-    return answer;
-}
-
-// Round up size to next bucket when allocating.
-static int size_to_index_allocating(size_t size, size_t *rounded_up_out)
-{
-    size_t rounded = ROUNDUP(size, 8);
-    return size_to_index_helper(rounded, rounded_up_out, -8, 1);
-}
-
-// Round down size to next bucket when freeing.
-static int size_to_index_freeing(size_t size)
-{
-    size_t dummy;
-    return size_to_index_helper(size, &dummy, 0, 0);
-}
-
-inline header_t *tag_as_free(void *left)
-{
-    return (header_t *)((uintptr_t)left | 1);
-}
-
-inline bool is_tagged_as_free(header_t *header)
-{
-    return ((uintptr_t)(header->left) & 1) != 0;
-}
-
-inline header_t *untag(void *left)
-{
-    return (header_t *)((uintptr_t)left & ~1);
-}
-
-inline header_t *right_header(header_t *header)
-{
-    return (header_t *)((char *)header + header->size);
-}
-
-inline static void set_free_list_bit(int index)
-{
-    theheap.free_list_bits[index >> 5] |= (1u << (31 - (index & 0x1f)));
-}
-
-inline static void clear_free_list_bit(int index)
-{
-    theheap.free_list_bits[index >> 5] &= ~(1u << (31 - (index & 0x1f)));
-}
-
-static int find_nonempty_bucket(int index)
-{
-    uint32_t mask = (1u << (31 - (index & 0x1f))) - 1;
-    mask = mask * 2 + 1;
-    mask &= theheap.free_list_bits[index >> 5];
-    if (mask != 0) return (index & ~0x1f) + __builtin_clz(mask);
-    for (index = ROUNDUP(index + 1, 32); index <= NUMBER_OF_BUCKETS; index += 32) {
-        mask = theheap.free_list_bits[index >> 5];
-        if (mask != 0u) return index + __builtin_clz(mask);
-    }
-    return -1;
-}
-
-static bool is_start_of_os_allocation(header_t *header)
-{
-    return header->left == untag(NULL);
-}
-
-static void create_free_area(void *address, void *left, size_t size, free_t **bucket)
-{
-    free_t *free_area = (free_t *)address;
-    free_area->header.size = size;
-    free_area->header.left = tag_as_free(left);
-    if (bucket == NULL) {
-        int index = size_to_index_freeing(size - sizeof(header_t));
-        set_free_list_bit(index);
-        bucket = &theheap.free_lists[index];
-    }
-    free_t *old_head = *bucket;
-    if (old_head != NULL) old_head->prev = free_area;
-    free_area->next = old_head;
-    free_area->prev = NULL;
-    *bucket = free_area;
-    theheap.remaining += size;
-#ifdef CMPCT_DEBUG
-    memset(free_area + 1, FREE_FILL, size - sizeof(free_t));
-#endif
-}
-
-static bool is_end_of_os_allocation(char *address)
-{
-    return ((header_t *)address)->size == 0;
-}
-
-static void free_to_os(header_t *header, size_t size)
-{
-    DEBUG_ASSERT(IS_PAGE_ALIGNED(size));
-    page_free(header, size >> PAGE_SIZE_SHIFT);
-    theheap.size -= size;
-}
-
-static void free_memory(void *address, void *left, size_t size)
-{
-    left = untag(left);
-    if (IS_PAGE_ALIGNED(left) &&
-            is_start_of_os_allocation(left) &&
-            is_end_of_os_allocation((char *)address + size)) {
-        free_to_os(left, size + ((header_t *)left)->size + sizeof(header_t));
-    } else {
-        create_free_area(address, left, size, NULL);
-    }
-}
-
-static void unlink_free(free_t *free_area, int bucket)
-{
-    theheap.remaining -= free_area->header.size;
-    ASSERT(theheap.remaining < 4000000000u);
-    free_t *next = free_area->next;
-    free_t *prev = free_area->prev;
-    if (theheap.free_lists[bucket] == free_area) {
-        theheap.free_lists[bucket] = next;
-        if (next == NULL) clear_free_list_bit(bucket);
-    }
-    if (prev != NULL) prev->next = next;
-    if (next != NULL) next->prev = prev;
-}
-
-static void unlink_free_unknown_bucket(free_t *free_area)
-{
-    return unlink_free(free_area, size_to_index_freeing(free_area->header.size - sizeof(header_t)));
-}
-
-static void *create_allocation_header(
-    void *address, size_t offset, size_t size, void *left)
-{
-    header_t *standalone = (header_t *)((char *)address + offset);
-    standalone->left = untag(left);
-    standalone->size = size;
-    return standalone + 1;
-}
-
-static void FixLeftPointer(header_t *right, header_t *new_left)
-{
-    int tag = (uintptr_t)right->left & 1;
-    right->left = (header_t *)(((uintptr_t)new_left & ~1) | tag);
-}
-
-static void WasteFreeMemory(void)
-{
-    while (theheap.remaining != 0) cmpct_alloc(1);
-}
-
-// If we just make a big allocation it gets rounded off.  If we actually
-// want to use a reasonably accurate amount of memory for test purposes, we
-// have to do many small allocations.
-static void *TestTrimHelper(ssize_t target)
-{
-   char *answer = NULL;
-   size_t remaining = theheap.remaining;
-   while (theheap.remaining - target > 512) {
-       char *next_block = cmpct_alloc(8 + ((theheap.remaining - target) >> 2));
-       *(char**)next_block = answer;
-       answer = next_block;
-       if (theheap.remaining > remaining) return answer;
-       // Abandon attemt to hit particular freelist entry size if we accidentally got more memory
-       // from the OS.
-       remaining = theheap.remaining;
-   }
-   return answer;
-}
-
-static void TestTrimFreeHelper(char *block)
-{
-    while (block) {
-        char *next_block = *(char **)block;
-        cmpct_free(block);
-        block = next_block;
-    }
-}
-
-#ifdef FLETCH_TARGET_OS_LK
-static void cmpct_test_trim(void)
-#else
-void cmpct_test_trim(void)
-#endif
-{
-    WasteFreeMemory();
-
-    size_t test_sizes[200];
-    int sizes = 0;
-
-    for (size_t s = 1; s < PAGE_SIZE * 4; s = (s + 1) * 1.1) {
-        test_sizes[sizes++] = s;
-        ASSERT(sizes < 200);
-    }
-    for (ssize_t s = -32; s <= 32; s += 8) {
-        test_sizes[sizes++] = PAGE_SIZE + s;
-        ASSERT(sizes < 200);
-    }
-
-    // Test allocations at the start of an OS allocation.
-    for (int with_second_alloc = 0; with_second_alloc < 2; with_second_alloc++) {
-        for (int i = 0; i < sizes; i++) {
-            size_t s = test_sizes[i];
-
-            char *a, *a2 = NULL;
-            a = cmpct_alloc(s);
-            if (with_second_alloc) {
-                a2 = cmpct_alloc(1);
-                if (s < PAGE_SIZE >> 1) {
-                    // It is the intention of the test that a is at the start of an OS allocation
-                    // and that a2 is "right after" it.  Otherwise we are not testing what I
-                    // thought.  OS allocations are certainly not smaller than a page, so check in
-                    // that case.
-                    ASSERT((uintptr_t)(a2 - a) < s * 1.13 + 48);
-                }
-            }
-            cmpct_trim();
-            size_t remaining = theheap.remaining;
-            // We should have < 1 page on either side of the a allocation.
-            ASSERT(remaining < PAGE_SIZE * 2);
-            cmpct_free(a);
-            if (with_second_alloc) {
-                // Now only a2 is holding onto the OS allocation.
-                ASSERT(theheap.remaining > remaining);
-            } else {
-                ASSERT(theheap.remaining == 0);
-            }
-            remaining = theheap.remaining;
-            cmpct_trim();
-            ASSERT(theheap.remaining <= remaining);
-            // If a was at least one page then the trim should have freed up that page.
-            if (s >= PAGE_SIZE && with_second_alloc) ASSERT(theheap.remaining < remaining);
-            if (with_second_alloc) cmpct_free(a2);
-        }
-        ASSERT(theheap.remaining == 0);
-    }
-
-    ASSERT(theheap.remaining == 0);
-
-    // Now test allocations near the end of an OS allocation.
-    for (ssize_t wobble = -64; wobble <= 64; wobble += 8) {
-        for (int i = 0; i < sizes; i++) {
-            size_t s = test_sizes[i];
-
-            if ((ssize_t)s + wobble < 0) continue;
-
-            char *start_of_os_alloc = cmpct_alloc(1);
-
-            // If the OS allocations are very small this test does not make sense.
-            if (theheap.remaining <= s + wobble) {
-                cmpct_free(start_of_os_alloc);
-                continue;
-            }
-
-            char *big_bit_in_the_middle = TestTrimHelper(s + wobble);
-            size_t remaining = theheap.remaining;
-
-            // If the remaining is big we started a new OS allocation and the test
-            // makes no sense.
-            if (remaining > 128 + s * 1.13 + wobble) {
-                cmpct_free(start_of_os_alloc);
-                TestTrimFreeHelper(big_bit_in_the_middle);
-                continue;
-            }
-
-            cmpct_free(start_of_os_alloc);
-            remaining = theheap.remaining;
-
-            // This trim should sometimes trim a page off the end of the OS allocation.
-            cmpct_trim();
-            ASSERT(theheap.remaining <= remaining);
-            remaining = theheap.remaining;
-
-            // We should have < 1 page on either side of the big allocation.
-            ASSERT(remaining < PAGE_SIZE * 2);
-
-            TestTrimFreeHelper(big_bit_in_the_middle);
-        }
-    }
-}
-
-
-#ifdef FLETCH_TARGET_OS_LK
-static void cmpct_test_buckets(void)
-#else
-void cmpct_test_buckets(void)
-#endif
-{
-    size_t rounded;
-    unsigned bucket;
-    // Check for the 8-spaced buckets up to 128.
-    for (unsigned i = 1; i <= 128; i++) {
-        // Round up when allocating.
-        bucket = size_to_index_allocating(i, &rounded);
-        unsigned expected = (ROUNDUP(i, 8) >> 3) - 1;
-        ASSERT(bucket == expected);
-        ASSERT(IS_ALIGNED(rounded, 8));
-        ASSERT(rounded >= i);
-        if (i >= sizeof(free_t) - sizeof(header_t)) {
-            // Once we get above the size of the free area struct (4 words), we
-            // won't round up much for these small size.
-            ASSERT(rounded - i < 8);
-        }
-        // Only rounded sizes are freed.
-        if ((i & 7) == 0) {
-            // Up to size 128 we have exact buckets for each multiple of 8.
-            ASSERT(bucket == (unsigned)size_to_index_freeing(i));
-        }
-    }
-    int bucket_base = 7;
-    for (unsigned j = 16; j < 1024; j *= 2, bucket_base += 8) {
-        // Note the "<=", which ensures that we test the powers of 2 twice to ensure
-        // that both ways of calculating the bucket number match.
-        for (unsigned i = j * 8; i <= j * 16; i++) {
-            // Round up to j multiple in this range when allocating.
-            bucket = size_to_index_allocating(i, &rounded);
-            unsigned expected = bucket_base + ROUNDUP(i, j) / j;
-            ASSERT(bucket == expected);
-            ASSERT(IS_ALIGNED(rounded, j));
-            ASSERT(rounded >= i);
-            ASSERT(rounded - i < j);
-            // Only 8-rounded sizes are freed or chopped off the end of a free area
-            // when allocating.
-            if ((i & 7) == 0) {
-                // When freeing, if we don't hit the size of the bucket precisely,
-                // we have to put the free space into a smaller bucket, because
-                // the buckets have entries that will always be big enough for
-                // the corresponding allocation size (so we don't have to
-                // traverse the free chains to find a big enough one).
-                if ((i % j) == 0) {
-                    ASSERT((int)bucket == size_to_index_freeing(i));
-                } else {
-                    ASSERT((int)bucket - 1 == size_to_index_freeing(i));
-                }
-            }
-        }
-    }
-}
-
-static void cmpct_test_get_back_newly_freed_helper(size_t size)
-{
-    void *allocated = cmpct_alloc(size);
-    if (allocated == NULL) return;
-    char *allocated2 = cmpct_alloc(8);
-    char *expected_position = (char *)allocated + size;
-    if (allocated2 < expected_position || allocated2 > expected_position + 128) {
-        // If the allocated2 allocation is not in the same OS allocation as the
-        // first allocation then the test may not work as expected (the memory
-        // may be returned to the OS when we free the first allocation, and we
-        // might not get it back).
-        cmpct_free(allocated);
-        cmpct_free(allocated2);
-        return;
-    }
-
-    cmpct_free(allocated);
-    void *allocated3 = cmpct_alloc(size);
-    // To avoid churn and fragmentation we would want to get the newly freed
-    // memory back again when we allocate the same size shortly after.
-    ASSERT(allocated3 == allocated);
-    cmpct_free(allocated2);
-    cmpct_free(allocated3);
-}
-
-#ifdef FLETCH_TARGET_OS_LK
-static void cmpct_test_get_back_newly_freed(void)
-#else
-void cmpct_test_get_back_newly_freed(void)
-#endif
-{
-    size_t increment = 16;
-    for (size_t i = 128; i <= 0x8000000; i *= 2, increment *= 2) {
-        for (size_t j = i; j < i * 2; j += increment) {
-            cmpct_test_get_back_newly_freed_helper(i - 8);
-            cmpct_test_get_back_newly_freed_helper(i);
-            cmpct_test_get_back_newly_freed_helper(i + 1);
-        }
-    }
-    for (size_t i = 1024; i <= 2048; i++) {
-        cmpct_test_get_back_newly_freed_helper(i);
-    }
-}
-
-#ifdef FLETCH_TARGET_OS_LK
-static void cmpct_test_return_to_os(void)
-#else
-void cmpct_test_return_to_os(void)
-#endif
-{
-    cmpct_trim();
-    size_t remaining = theheap.remaining;
-    // This goes in a new OS allocation since the trim above removed any free
-    // area big enough to contain it.
-    void *a = cmpct_alloc(5000);
-    void *b = cmpct_alloc(2500);
-    cmpct_free(a);
-    cmpct_free(b);
-    // If things work as expected the new allocation is at the start of an OS
-    // allocation.  There's just one sentinel and one header to the left of it.
-    // It that's not the case then the allocation was met from some space in
-    // the middle of an OS allocation, and our test won't work as expected, so
-    // bail out.
-    if (((uintptr_t)a & (PAGE_SIZE - 1)) != sizeof(header_t) * 2) return;
-    // No trim needed when the entire OS allocation is free.
-    ASSERT(remaining == theheap.remaining);
-}
-
-static void *large_alloc(size_t size)
-{
-#ifdef CMPCT_DEBUG
-    size_t requested_size = size;
-#endif
-    size = ROUNDUP(size, 8);
-    free_t *free_area = NULL;
-    lock();
-    heap_grow(size, &free_area);
-    void *result =
-        create_allocation_header(free_area, 0, free_area->header.size, free_area->header.left);
-    // Normally the 'remaining free space' counter would be decremented when we
-    // unlink the free area from its bucket.  However in this case the free
-    // area was too big to go in any bucket and we had it in our own
-    // "free_area" variable so there is no unlinking and we have to adjust the
-    // counter here.
-    theheap.remaining -= free_area->header.size;
-    unlock();
-#ifdef CMPCT_DEBUG
-    memset(result, ALLOC_FILL, requested_size);
-    memset((char *)result + requested_size, PADDING_FILL, free_area->header.size - requested_size);
-#endif
-    return result;
-}
-
-void cmpct_trim(void)
-{
-    // Look at free list entries that are at least as large as one page plus a
-    // header. They might be at the start or the end of a block, so we can trim
-    // them and free the page(s).
-    lock();
-    for (int bucket = size_to_index_freeing(PAGE_SIZE);
-            bucket < NUMBER_OF_BUCKETS;
-            bucket++) {
-        free_t * next;
-        for (free_t *free_area = theheap.free_lists[bucket];
-                free_area != NULL;
-                free_area = next) {
-            DEBUG_ASSERT(free_area->header.size >= PAGE_SIZE + sizeof(header_t));
-            next = free_area->next;
-            header_t *right = right_header(&free_area->header);
-            if (is_end_of_os_allocation((char *)right)) {
-                char *old_os_allocation_end = (char *)ROUNDUP((uintptr_t)right, PAGE_SIZE);
-                // The page will end with a smaller free list entry and a header-sized sentinel.
-                char *new_os_allocation_end = (char *)
-                    ROUNDUP((uintptr_t)free_area + sizeof(header_t) + sizeof(free_t), PAGE_SIZE);
-                size_t freed_up = old_os_allocation_end - new_os_allocation_end;
-                DEBUG_ASSERT(IS_PAGE_ALIGNED(freed_up));
-                // Rare, because we only look at large freelist entries, but unlucky rounding
-                // could mean we can't actually free anything here.
-                if (freed_up == 0) continue;
-                unlink_free(free_area, bucket);
-                size_t new_free_size = free_area->header.size - freed_up;
-                DEBUG_ASSERT(new_free_size >= sizeof(free_t));
-                // Right sentinel, not free, stops attempts to coalesce right.
-                create_allocation_header(free_area, new_free_size, 0, free_area);
-                // Also puts it in the correct bucket.
-                create_free_area(free_area, untag(free_area->header.left), new_free_size, NULL);
-                page_free(new_os_allocation_end, freed_up >> PAGE_SIZE_SHIFT);
-                theheap.size -= freed_up;
-            } else if (is_start_of_os_allocation(untag(free_area->header.left))) {
-                char *old_os_allocation_start =
-                    (char *)ROUNDDOWN((uintptr_t)free_area, PAGE_SIZE);
-                // For the sentinel, we need at least one header-size of space between the page
-                // edge and the first allocation to the right of the free area.
-                char *new_os_allocation_start =
-                    (char *)ROUNDDOWN((uintptr_t)(right - 1), PAGE_SIZE);
-                size_t freed_up = new_os_allocation_start - old_os_allocation_start;
-                DEBUG_ASSERT(IS_PAGE_ALIGNED(freed_up));
-                // This should not happen because we only look at the large free list buckets.
-                if (freed_up == 0) continue;
-                unlink_free(free_area, bucket);
-                size_t sentinel_size = sizeof(header_t);
-                size_t new_free_size = free_area->header.size - freed_up;
-                if (new_free_size < sizeof(free_t)) {
-                    sentinel_size += new_free_size;
-                    new_free_size = 0;
-                }
-                // Left sentinel, not free, stops attempts to coalesce left.
-                create_allocation_header(new_os_allocation_start, 0, sentinel_size, NULL);
-                if (new_free_size == 0) {
-                    FixLeftPointer(right, (header_t *)new_os_allocation_start);
-                } else {
-                    DEBUG_ASSERT(new_free_size >= sizeof(free_t));
-                    char *new_free = new_os_allocation_start + sentinel_size;
-                    // Also puts it in the correct bucket.
-                    create_free_area(new_free, new_os_allocation_start, new_free_size, NULL);
-                    FixLeftPointer(right, (header_t *)new_free);
-                }
-                page_free(old_os_allocation_start, freed_up >> PAGE_SIZE_SHIFT);
-                theheap.size -= freed_up;
-            }
-        }
-    }
-    unlock();
-}
-
-void *cmpct_alloc(size_t size)
-{
-    if (size == 0u) return NULL;
-
-    if (size + sizeof(header_t) > (1u << HEAP_ALLOC_VIRTUAL_BITS)) return large_alloc(size);
-
-    size_t rounded_up;
-    int start_bucket = size_to_index_allocating(size, &rounded_up);
-
-    rounded_up += sizeof(header_t);
-
-    lock();
-    int bucket = find_nonempty_bucket(start_bucket);
-    if (bucket == -1) {
-        // Grow heap by at least 12% if we can.
-        size_t growby = MIN(1u << HEAP_ALLOC_VIRTUAL_BITS,
-                            MAX(theheap.size >> 3,
-                                MAX(HEAP_GROW_SIZE, rounded_up)));
-        while (heap_grow(growby, NULL) < 0) {
-            if (growby <= rounded_up) {
-                unlock();
-                return NULL;
-            }
-            growby = MAX(growby >> 1, rounded_up);
-        }
-        bucket = find_nonempty_bucket(start_bucket);
-    }
-    free_t *head = theheap.free_lists[bucket];
-    size_t left_over = head->header.size - rounded_up;
-    // We can't carve off the rest for a new free space if it's smaller than the
-    // free-list linked structure.  We also don't carve it off if it's less than
-    // 1.6% the size of the allocation.  This is to avoid small long-lived
-    // allocations being placed right next to large allocations, hindering
-    // coalescing and returning pages to the OS.
-    if (left_over >= sizeof(free_t) && left_over > (size >> 6)) {
-        header_t *right = right_header(&head->header);
-        unlink_free(head, bucket);
-        void *free = (char *)head + rounded_up;
-        create_free_area(free, head, left_over, NULL);
-        FixLeftPointer(right, (header_t *)free);
-        head->header.size -= left_over;
-    } else {
-        unlink_free(head, bucket);
-    }
-    void *result =
-        create_allocation_header(head, 0, head->header.size, head->header.left);
-#ifdef CMPCT_DEBUG
-    memset(result, ALLOC_FILL, size);
-    memset(((char *)result) + size, PADDING_FILL, rounded_up - size - sizeof(header_t));
-#endif
-    unlock();
-    return result;
-}
-
-void *cmpct_memalign(size_t size, size_t alignment)
-{
-    if (alignment < 8) return cmpct_alloc(size);
-    size_t padded_size =
-        size + alignment + sizeof(free_t) + sizeof(header_t);
-    char *unaligned = (char *)cmpct_alloc(padded_size);
-    lock();
-    size_t mask = alignment - 1;
-    uintptr_t payload_int = (uintptr_t)unaligned + sizeof(free_t) +
-                            sizeof(header_t) + mask;
-    char *payload = (char *)(payload_int & ~mask);
-    if (unaligned != payload) {
-        header_t *unaligned_header = (header_t *)unaligned - 1;
-        header_t *header = (header_t *)payload - 1;
-        size_t left_over = payload - unaligned;
-        create_allocation_header(
-            header, 0, unaligned_header->size - left_over, unaligned_header);
-        header_t *right = right_header(unaligned_header);
-        unaligned_header->size = left_over;
-        FixLeftPointer(right, header);
-        unlock();
-        cmpct_free(unaligned);
-    } else {
-        unlock();
-    }
-    // TODO: Free the part after the aligned allocation.
-    return payload;
-}
-
-void cmpct_free(void *payload)
-{
-    if (payload == NULL) return;
-    header_t *header = (header_t *)payload - 1;
-    DEBUG_ASSERT(!is_tagged_as_free(header));  // Double free!
-    size_t size = header->size;
-    lock();
-    header_t *left = header->left;
-    if (left != NULL && is_tagged_as_free(left)) {
-        // Coalesce with left free object.
-        unlink_free_unknown_bucket((free_t *)left);
-        header_t *right = right_header(header);
-        if (is_tagged_as_free(right)) {
-            // Coalesce both sides.
-            unlink_free_unknown_bucket((free_t *)right);
-            header_t *right_right = right_header(right);
-            FixLeftPointer(right_right, left);
-            free_memory(left, left->left, left->size + size + right->size);
-        } else {
-            // Coalesce only left.
-            FixLeftPointer(right, left);
-            free_memory(left, left->left, left->size + size);
-        }
-    } else {
-        header_t *right = right_header(header);
-        if (is_tagged_as_free(right)) {
-            // Coalesce only right.
-            header_t *right_right = right_header(right);
-            unlink_free_unknown_bucket((free_t *)right);
-            FixLeftPointer(right_right, header);
-            free_memory(header, left, size + right->size);
-        } else {
-            free_memory(header, left, size);
-        }
-    }
-    unlock();
-}
-
-void *cmpct_realloc(void *payload, size_t size)
-{
-    if (payload == NULL) return cmpct_alloc(size);
-    header_t *header = (header_t *)payload - 1;
-    size_t old_size = header->size - sizeof(header_t);
-    void *new_payload = cmpct_alloc(size);
-    memcpy(new_payload, payload, MIN(size, old_size));
-    cmpct_free(payload);
-    return new_payload;
-}
-
-static void add_to_heap(void *new_area, size_t size, free_t **bucket)
-{
-    void *top = (char *)new_area + size;
-    header_t *left_sentinel = (header_t *)new_area;
-    // Not free, stops attempts to coalesce left.
-    create_allocation_header(left_sentinel, 0, sizeof(header_t), NULL);
-    header_t *new_header = left_sentinel + 1;
-    size_t free_size = size - 2 * sizeof(header_t);
-    create_free_area(new_header, left_sentinel, free_size, bucket);
-    header_t *right_sentinel = (header_t *)(top - sizeof(header_t));
-    // Not free, stops attempts to coalesce right.
-    create_allocation_header(right_sentinel, 0, 0, new_header);
-}
-
-// Create a new free-list entry of at least size bytes (including the
-// allocation header).  Called with the lock, apart from during init.
-static ssize_t heap_grow(size_t size, free_t **bucket)
-{
-    // The new free list entry will have a header on each side (the
-    // sentinels) so we need to grow the gross heap size by this much more.
-    size += 2 * sizeof(header_t);
-    size = ROUNDUP(size, PAGE_SIZE);
-    void *ptr = page_alloc(size >> PAGE_SIZE_SHIFT);
-    theheap.size += size;
-    if (ptr == NULL) return -1;
-    LTRACEF("growing heap by 0x%zx bytes, new ptr %p\n", size, ptr);
-    add_to_heap(ptr, size, bucket);
-    return size;
-}
-
-void cmpct_init(void)
-{
-    LTRACE_ENTRY;
-
-    // Create a mutex.
-#ifdef FLETCH_TARGET_OS_LK
-    mutex_init(&theheap.lock);
-#endif
-
-    // Initialize the free list.
-    for (int i = 0; i < NUMBER_OF_BUCKETS; i++) {
-        theheap.free_lists[i] = NULL;
-    }
-    for (int i = 0; i < BUCKET_WORDS; i++) {
-        theheap.free_list_bits[i] = 0;
-    }
-
-    size_t initial_alloc = HEAP_GROW_SIZE - 2 * sizeof(header_t);
-
-    theheap.remaining = 0;
-
-    heap_grow(initial_alloc, NULL);
-}