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--- /dev/null
+++ libmalloc/libmalloc-116.30.3/src/magazine_tiny.c
@@ -0,0 +1,2158 @@
+/*
+ * Copyright (c) 2015 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include "internal.h"
+
+/*
+ * Get the size of the previous free block, which is stored in the last two
+ * bytes of the block. If the previous block is not free, then the result is
+ * undefined.
+ */
+static msize_t
+get_tiny_previous_free_msize(const void *ptr)
+{
+ // check whether the previous block is in the tiny region and a block header
+ // if so, then the size of the previous block is one, and there is no stored
+ // size.
+ if (ptr != TINY_REGION_FOR_PTR(ptr)) {
+ void *prev_block = (void *)((uintptr_t)ptr - TINY_QUANTUM);
+ uint32_t *prev_header = TINY_BLOCK_HEADER_FOR_PTR(prev_block);
+ msize_t prev_index = TINY_INDEX_FOR_PTR(prev_block);
+ if (BITARRAY_BIT(prev_header, prev_index)) {
+ return 1;
+ }
+ return TINY_PREVIOUS_MSIZE(ptr);
+ }
+ // don't read possibly unmapped memory before the beginning of the region
+ return 0;
+}
+
+static MALLOC_INLINE void
+set_tiny_meta_header_in_use(const void *ptr, msize_t msize)
+{
+ uint32_t *block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ msize_t index = TINY_INDEX_FOR_PTR(ptr);
+ msize_t clr_msize = msize - 1;
+ msize_t midx = (index >> 5) << 1;
+ uint32_t val = (1 << (index & 31));
+
+#if DEBUG_MALLOC
+ if (msize >= NUM_TINY_SLOTS) {
+ malloc_printf("set_tiny_meta_header_in_use() invariant broken %p %d\n", ptr, msize);
+ }
+ if ((unsigned)index + (unsigned)msize > 0x10000) {
+ malloc_printf("set_tiny_meta_header_in_use() invariant broken (2) %p %d\n", ptr, msize);
+ }
+#endif
+
+ block_header[midx] |= val; // BITARRAY_SET(block_header, index);
+ block_header[midx + 1] |= val; // BITARRAY_SET(in_use, index);
+
+ // bitarray_mclr(block_header, index, end_bit);
+ // bitarray_mclr(in_use, index, end_bit);
+
+ index++;
+ midx = (index >> 5) << 1;
+
+ unsigned start = index & 31;
+ unsigned end = start + clr_msize;
+
+#if defined(__LP64__)
+ if (end > 63) {
+ unsigned mask0 = (0xFFFFFFFFU >> (31 - start)) >> 1;
+ unsigned mask1 = (0xFFFFFFFFU << (end - 64));
+ block_header[midx + 0] &= mask0; // clear header
+ block_header[midx + 1] &= mask0; // clear in_use
+ block_header[midx + 2] = 0; // clear header
+ block_header[midx + 3] = 0; // clear in_use
+ block_header[midx + 4] &= mask1; // clear header
+ block_header[midx + 5] &= mask1; // clear in_use
+ } else
+#endif
+ if (end > 31) {
+ unsigned mask0 = (0xFFFFFFFFU >> (31 - start)) >> 1;
+ unsigned mask1 = (0xFFFFFFFFU << (end - 32));
+ block_header[midx + 0] &= mask0;
+ block_header[midx + 1] &= mask0;
+ block_header[midx + 2] &= mask1;
+ block_header[midx + 3] &= mask1;
+ } else {
+ unsigned mask = (0xFFFFFFFFU >> (31 - start)) >> 1;
+ mask |= (0xFFFFFFFFU << end);
+ block_header[midx + 0] &= mask;
+ block_header[midx + 1] &= mask;
+ }
+
+ // we set the block_header bit for the following block to reaffirm next block is a block
+ index += clr_msize;
+ midx = (index >> 5) << 1;
+ val = (1 << (index & 31));
+ block_header[midx] |= val; // BITARRAY_SET(block_header, (index+clr_msize));
+#if DEBUG_MALLOC
+ {
+ boolean_t ff;
+ msize_t mf;
+
+ mf = get_tiny_meta_header(ptr, &ff);
+ if (msize != mf) {
+ malloc_printf("setting header for tiny in_use %p : %d\n", ptr, msize);
+ malloc_printf("reading header for tiny %p : %d %d\n", ptr, mf, ff);
+ }
+ }
+#endif
+}
+
+static MALLOC_INLINE void set_tiny_meta_header_in_use_1(const void *ptr) // As above with msize == 1
+{
+ uint32_t *block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ msize_t index = TINY_INDEX_FOR_PTR(ptr);
+ msize_t midx = (index >> 5) << 1;
+ uint32_t val = (1 << (index & 31));
+
+ block_header[midx] |= val; // BITARRAY_SET(block_header, index);
+ block_header[midx + 1] |= val; // BITARRAY_SET(in_use, index);
+
+ index++;
+ midx = (index >> 5) << 1;
+ val = (1 << (index & 31));
+
+ block_header[midx] |= val; // BITARRAY_SET(block_header, (index+clr_msize))
+}
+
+static MALLOC_INLINE void
+set_tiny_meta_header_middle(const void *ptr)
+{
+ // indicates this block is in the middle of an in use block
+ uint32_t *block_header;
+ uint32_t *in_use;
+ msize_t index;
+
+ block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ in_use = TINY_INUSE_FOR_HEADER(block_header);
+ index = TINY_INDEX_FOR_PTR(ptr);
+
+ BITARRAY_CLR(block_header, index);
+ BITARRAY_CLR(in_use, index);
+}
+
+static MALLOC_INLINE void
+set_tiny_meta_header_free(const void *ptr, msize_t msize)
+{
+ // !msize is acceptable and means 65536
+ uint32_t *block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ msize_t index = TINY_INDEX_FOR_PTR(ptr);
+ msize_t midx = (index >> 5) << 1;
+ uint32_t val = (1 << (index & 31));
+
+#if DEBUG_MALLOC
+ if ((unsigned)index + (unsigned)msize > 0x10000) {
+ malloc_printf("setting header for tiny free %p msize too large: %d\n", ptr, msize);
+ }
+#endif
+
+ block_header[midx] |= val; // BITARRAY_SET(block_header, index);
+ block_header[midx + 1] &= ~val; // BITARRAY_CLR(in_use, index);
+
+ // mark the end of this block if msize is > 1. For msize == 0, the whole
+ // region is free, so there is no following block. For msize == 1, there is
+ // no space to write the size on 64 bit systems. The size for 1 quantum
+ // blocks is computed from the metadata bitmaps.
+ if (msize > 1) {
+ void *follower = FOLLOWING_TINY_PTR(ptr, msize);
+ TINY_PREVIOUS_MSIZE(follower) = msize;
+ TINY_FREE_SIZE(ptr) = msize;
+ }
+ if (msize == 0) {
+ TINY_FREE_SIZE(ptr) = msize;
+ }
+#if DEBUG_MALLOC
+ boolean_t ff;
+ msize_t mf = get_tiny_meta_header(ptr, &ff);
+ if ((msize != mf) || !ff) {
+ malloc_printf("setting header for tiny free %p : %u\n", ptr, msize);
+ malloc_printf("reading header for tiny %p : %u %u\n", ptr, mf, ff);
+ }
+#endif
+}
+
+static MALLOC_INLINE boolean_t
+tiny_meta_header_is_free(const void *ptr)
+{
+ uint32_t *block_header;
+ uint32_t *in_use;
+ msize_t index;
+
+ block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ in_use = TINY_INUSE_FOR_HEADER(block_header);
+ index = TINY_INDEX_FOR_PTR(ptr);
+ if (!BITARRAY_BIT(block_header, index)) {
+ return 0;
+ }
+ return !BITARRAY_BIT(in_use, index);
+}
+
+static MALLOC_INLINE void *
+tiny_previous_preceding_free(void *ptr, msize_t *prev_msize)
+{
+ // returns the previous block, assuming and verifying it's free
+ uint32_t *block_header;
+ uint32_t *in_use;
+ msize_t index;
+ msize_t previous_msize;
+ msize_t previous_index;
+ void *previous_ptr;
+
+ block_header = TINY_BLOCK_HEADER_FOR_PTR(ptr);
+ in_use = TINY_INUSE_FOR_HEADER(block_header);
+ index = TINY_INDEX_FOR_PTR(ptr);
+
+ if (!index) {
+ return NULL;
+ }
+ if ((previous_msize = get_tiny_previous_free_msize(ptr)) > index) {
+ return NULL;
+ }
+
+ previous_index = index - previous_msize;
+ previous_ptr = (void *)((uintptr_t)TINY_REGION_FOR_PTR(ptr) + TINY_BYTES_FOR_MSIZE(previous_index));
+ if (!BITARRAY_BIT(block_header, previous_index)) {
+ return NULL;
+ }
+ if (BITARRAY_BIT(in_use, previous_index)) {
+ return NULL;
+ }
+ if (get_tiny_free_size(previous_ptr) != previous_msize) {
+ return NULL;
+ }
+
+ // conservative check did match true check
+ *prev_msize = previous_msize;
+ return previous_ptr;
+}
+
+/*
+ * Adds an item to the proper free list, and also marks the meta-header of the
+ * block properly.
+ * Assumes szone has been locked
+ */
+static void
+tiny_free_list_add_ptr(szone_t *szone, magazine_t *tiny_mag_ptr, void *ptr, msize_t msize)
+{
+ grain_t slot = (!msize || (msize >= NUM_TINY_SLOTS)) ? NUM_TINY_SLOTS - 1 : msize - 1;
+ tiny_free_list_t *free_ptr = ptr;
+ tiny_free_list_t *free_head = tiny_mag_ptr->mag_free_list[slot].p;
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in %s, ptr=%p, msize=%d\n", __FUNCTION__, ptr, msize);
+ }
+ if (((uintptr_t)ptr) & (TINY_QUANTUM - 1)) {
+ szone_error(szone, 1, "tiny_free_list_add_ptr: Unaligned ptr", ptr, NULL);
+ }
+#endif
+ set_tiny_meta_header_free(ptr, msize);
+ if (free_head) {
+#if DEBUG_MALLOC
+ if (free_list_unchecksum_ptr(szone, &free_head->previous)) {
+ szone_error(szone, 1, "tiny_free_list_add_ptr: Internal invariant broken (free_head->previous)", ptr,
+ "ptr=%p slot=%d free_head=%p previous=%p\n", ptr, slot, (void *)free_head, free_head->previous.p);
+ }
+ if (!tiny_meta_header_is_free(free_head)) {
+ szone_error(szone, 1, "tiny_free_list_add_ptr: Internal invariant broken (free_head is not a free pointer)", ptr,
+ "ptr=%p slot=%d free_head=%p\n", ptr, slot, (void *)free_head);
+ }
+#endif
+ free_head->previous.u = free_list_checksum_ptr(szone, free_ptr);
+ } else {
+ BITMAPV_SET(tiny_mag_ptr->mag_bitmap, slot);
+ }
+ free_ptr->previous.u = free_list_checksum_ptr(szone, NULL);
+ free_ptr->next.u = free_list_checksum_ptr(szone, free_head);
+
+ tiny_mag_ptr->mag_free_list[slot].p = free_ptr;
+}
+
+/*
+ * Removes the item pointed to by ptr in the proper free list.
+ * Assumes szone has been locked
+ */
+static void
+tiny_free_list_remove_ptr(szone_t *szone, magazine_t *tiny_mag_ptr, void *ptr, msize_t msize)
+{
+ grain_t slot = (!msize || (msize >= NUM_TINY_SLOTS)) ? NUM_TINY_SLOTS - 1 : msize - 1;
+ tiny_free_list_t *free_ptr = ptr, *next, *previous;
+
+ next = free_list_unchecksum_ptr(szone, &free_ptr->next);
+ previous = free_list_unchecksum_ptr(szone, &free_ptr->previous);
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("In %s, ptr=%p, msize=%d\n", __FUNCTION__, ptr, msize);
+ }
+#endif
+ if (!previous) {
+ // The block to remove is the head of the free list
+#if DEBUG_MALLOC
+ if (tiny_mag_ptr->mag_free_list[slot] != ptr) {
+ szone_error(szone, 1, "tiny_free_list_remove_ptr: Internal invariant broken (tiny_mag_ptr->mag_free_list[slot])", ptr,
+ "ptr=%p slot=%d msize=%d tiny_mag_ptr->mag_free_list[slot]=%p\n", ptr, slot, msize,
+ (void *)tiny_mag_ptr->mag_free_list[slot]);
+ return;
+ }
+#endif
+ tiny_mag_ptr->mag_free_list[slot].p = next;
+ if (!next) {
+ BITMAPV_CLR(tiny_mag_ptr->mag_bitmap, slot);
+ }
+ } else {
+ // We know free_ptr is already checksummed, so we don't need to do it
+ // again.
+ previous->next = free_ptr->next;
+ }
+ if (next) {
+ // We know free_ptr is already checksummed, so we don't need to do it
+ // again.
+ next->previous = free_ptr->previous;
+ }
+}
+
+void
+tiny_finalize_region(szone_t *szone, magazine_t *tiny_mag_ptr)
+{
+ void *last_block, *previous_block;
+ uint32_t *last_header;
+ msize_t last_msize, previous_msize, last_index;
+
+ // It is possible that the block prior to the last block in the region has
+ // been free'd, but was not coalesced with the free bytes at the end of the
+ // block, since we treat the bytes at the end of the region as "in use" in
+ // the meta headers. Attempt to coalesce the last block with the previous
+ // block, so we don't violate the "no consecutive free blocks" invariant.
+ //
+ // FIXME: Need to investigate how much work would be required to increase
+ // 'mag_bytes_free_at_end' when freeing the preceding block, rather
+ // than performing this workaround.
+ //
+
+ if (tiny_mag_ptr->mag_bytes_free_at_end) {
+ last_block = (void *)((uintptr_t)TINY_REGION_END(tiny_mag_ptr->mag_last_region) - tiny_mag_ptr->mag_bytes_free_at_end);
+ last_msize = TINY_MSIZE_FOR_BYTES(tiny_mag_ptr->mag_bytes_free_at_end);
+ last_header = TINY_BLOCK_HEADER_FOR_PTR(last_block);
+ last_index = TINY_INDEX_FOR_PTR(last_block);
+
+ // Before anything we transform any remaining mag_bytes_free_at_end into a
+ // regular free block. We take special care here to update the bitfield
+ // information, since we are bypassing the normal free codepath. If there
+ // is more than one quanta worth of memory in mag_bytes_free_at_end, then
+ // there will be two block headers:
+ // 1) header for the free space at end, msize = 1
+ // 2) header inserted by set_tiny_meta_header_in_use after block
+ // We must clear the second one so that when the free block's size is
+ // queried, we do not think the block is only 1 quantum in size because
+ // of the second set header bit.
+ if (last_index != (NUM_TINY_BLOCKS - 1)) {
+ BITARRAY_CLR(last_header, (last_index + 1));
+ }
+
+ previous_block = tiny_previous_preceding_free(last_block, &previous_msize);
+ if (previous_block) {
+ set_tiny_meta_header_middle(last_block);
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, previous_block, previous_msize);
+ last_block = previous_block;
+ last_msize += previous_msize;
+ }
+
+ // splice last_block into the free list
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, last_block, last_msize);
+ tiny_mag_ptr->mag_bytes_free_at_end = 0;
+ }
+
+#if CONFIG_ASLR_INTERNAL
+ // Coalesce the big free block at start with any following free blocks
+ if (tiny_mag_ptr->mag_bytes_free_at_start) {
+ last_block = TINY_REGION_ADDRESS(tiny_mag_ptr->mag_last_region);
+ last_msize = TINY_MSIZE_FOR_BYTES(tiny_mag_ptr->mag_bytes_free_at_start);
+
+ void *next_block = (void *)((uintptr_t)last_block + tiny_mag_ptr->mag_bytes_free_at_start);
+
+ // clear the in use bit we were using to mark the end of the big start block
+ set_tiny_meta_header_middle((void *)((uintptr_t)next_block - TINY_QUANTUM));
+
+ // Coalesce the big start block with any following free blocks
+ if (tiny_meta_header_is_free(next_block)) {
+ msize_t next_msize = get_tiny_free_size(next_block);
+ set_tiny_meta_header_middle(next_block);
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, next_block, next_msize);
+ last_msize += next_msize;
+ }
+
+ // splice last_block into the free list
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, last_block, last_msize);
+ tiny_mag_ptr->mag_bytes_free_at_start = 0;
+ }
+#endif
+
+ tiny_mag_ptr->mag_last_region = NULL;
+}
+
+int
+tiny_free_detach_region(szone_t *szone, magazine_t *tiny_mag_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)TINY_REGION_ADDRESS(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)TINY_REGION_END(r);
+ boolean_t is_free;
+ msize_t msize;
+ int total_alloc = 0;
+
+ while (current < limit) {
+ msize = get_tiny_meta_header((void *)current, &is_free);
+ if (is_free && !msize && (current == start)) {
+ // first block is all free
+ break;
+ }
+ if (!msize) {
+#if DEBUG_MALLOC
+ malloc_printf("*** tiny_free_detach_region error with %p: msize=%d is_free =%d\n", (void *)current, msize, is_free);
+#endif
+ break;
+ }
+ if (is_free) {
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, (void *)current, msize);
+ } else {
+ total_alloc++;
+ }
+ current += TINY_BYTES_FOR_MSIZE(msize);
+ }
+ return total_alloc;
+}
+
+size_t
+tiny_free_reattach_region(szone_t *szone, magazine_t *tiny_mag_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)TINY_REGION_ADDRESS(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)TINY_REGION_END(r);
+ boolean_t is_free;
+ msize_t msize;
+ size_t total_alloc = 0;
+
+ while (current < limit) {
+ msize = get_tiny_meta_header((void *)current, &is_free);
+ if (is_free && !msize && (current == start)) {
+ // first block is all free
+ break;
+ }
+ if (!msize) {
+#if DEBUG_MALLOC
+ malloc_printf("*** tiny_free_reattach_region error with %p: msize=%d is_free =%d\n", (void *)current, msize, is_free);
+#endif
+ break;
+ }
+ if (is_free) {
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, (void *)current, msize);
+ } else {
+ total_alloc += TINY_BYTES_FOR_MSIZE(msize);
+ }
+ current += TINY_BYTES_FOR_MSIZE(msize);
+ }
+ return total_alloc;
+}
+
+typedef struct {
+ uint8_t pnum, size;
+} tiny_pg_pair_t;
+
+void
+tiny_free_scan_madvise_free(szone_t *szone, magazine_t *depot_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)TINY_REGION_ADDRESS(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)TINY_REGION_END(r);
+ boolean_t is_free;
+ msize_t msize;
+ tiny_pg_pair_t advisory[((TINY_REGION_PAYLOAD_BYTES + vm_page_quanta_size - 1) >> vm_page_quanta_shift) >>
+ 1]; // 256bytes stack allocated
+ int advisories = 0;
+
+ // Scan the metadata identifying blocks which span one or more pages. Mark the pages MADV_FREE taking care to preserve free list
+ // management data.
+ while (current < limit) {
+ msize = get_tiny_meta_header((void *)current, &is_free);
+ if (is_free && !msize && (current == start)) {
+ // first block is all free
+#if DEBUG_MALLOC
+ malloc_printf("*** tiny_free_scan_madvise_free first block is all free! %p: msize=%d is_free =%d\n", (void *)current,
+ msize, is_free);
+#endif
+ uintptr_t pgLo = round_page_kernel(start + sizeof(tiny_free_list_t) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_kernel(start + TINY_REGION_SIZE - sizeof(msize_t));
+
+ if (pgLo < pgHi) {
+ advisory[advisories].pnum = (pgLo - start) >> vm_kernel_page_shift;
+ advisory[advisories].size = (pgHi - pgLo) >> vm_kernel_page_shift;
+ advisories++;
+ }
+ break;
+ }
+ if (!msize) {
+#if DEBUG_MALLOC
+ malloc_printf("*** tiny_free_scan_madvise_free error with %p: msize=%d is_free =%d\n", (void *)current, msize, is_free);
+#endif
+ break;
+ }
+ if (is_free) {
+ uintptr_t pgLo = round_page_kernel(current + sizeof(tiny_free_list_t) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_kernel(current + TINY_BYTES_FOR_MSIZE(msize) - sizeof(msize_t));
+
+ if (pgLo < pgHi) {
+ advisory[advisories].pnum = (pgLo - start) >> vm_kernel_page_shift;
+ advisory[advisories].size = (pgHi - pgLo) >> vm_kernel_page_shift;
+ advisories++;
+ }
+ }
+ current += TINY_BYTES_FOR_MSIZE(msize);
+ }
+
+ if (advisories > 0) {
+ int i;
+
+ // So long as the following hold for this region:
+ // (1) No malloc()'s are ever performed from the depot (hence free pages remain free,)
+ // (2) The region is not handed over to a per-CPU magazine (where malloc()'s could be performed),
+ // (3) The entire region is not mumap()'d (so the madvise's are applied to the intended addresses),
+ // then the madvise opportunities collected just above can be applied outside all locks.
+ // (1) is ensured by design, (2) and (3) are ensured by bumping the globally visible counter node->pinned_to_depot.
+
+ OSAtomicIncrement32Barrier(&(REGION_TRAILER_FOR_TINY_REGION(r)->pinned_to_depot));
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, depot_ptr);
+ for (i = 0; i < advisories; ++i) {
+ uintptr_t addr = (advisory[i].pnum << vm_kernel_page_shift) + start;
+ size_t size = advisory[i].size << vm_kernel_page_shift;
+
+ madvise_free_range(szone, r, addr, addr + size, NULL);
+ }
+ SZONE_MAGAZINE_PTR_LOCK(szone, depot_ptr);
+ OSAtomicDecrement32Barrier(&(REGION_TRAILER_FOR_TINY_REGION(r)->pinned_to_depot));
+ }
+}
+
+static region_t
+tiny_find_msize_region(szone_t *szone, magazine_t *tiny_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ tiny_free_list_t *ptr;
+ grain_t slot = msize - 1;
+ free_list_t *free_list = tiny_mag_ptr->mag_free_list;
+ free_list_t *the_slot = free_list + slot;
+ free_list_t *limit;
+#if defined(__LP64__)
+ uint64_t bitmap;
+#else
+ uint32_t bitmap;
+#endif
+ // Assumes we've locked the magazine
+ CHECK_MAGAZINE_PTR_LOCKED(szone, tiny_mag_ptr, __PRETTY_FUNCTION__);
+
+ // Look for an exact match by checking the freelist for this msize.
+ ptr = the_slot->p;
+ if (ptr) {
+ return TINY_REGION_FOR_PTR(ptr);
+ }
+
+ // Mask off the bits representing slots holding free blocks smaller than the
+ // size we need. If there are no larger free blocks, try allocating from
+ // the free space at the end of the tiny region.
+#if defined(__LP64__)
+ bitmap = ((uint64_t *)(tiny_mag_ptr->mag_bitmap))[0] & ~((1ULL << slot) - 1);
+#else
+ bitmap = tiny_mag_ptr->mag_bitmap[0] & ~((1 << slot) - 1);
+#endif
+ if (!bitmap) {
+ return NULL;
+ }
+
+ slot = BITMAPV_CTZ(bitmap);
+ limit = free_list + NUM_TINY_SLOTS - 1;
+ free_list += slot;
+
+ if (free_list < limit) {
+ ptr = free_list->p;
+ if (ptr) {
+ return TINY_REGION_FOR_PTR(ptr);
+ } else {
+ /* Shouldn't happen. Fall through to look at last slot. */
+#if DEBUG_MALLOC
+ malloc_printf("in tiny_find_msize_region(), mag_bitmap out of sync, slot=%d\n", slot);
+#endif
+ }
+ }
+
+ // We are now looking at the last slot, which contains blocks equal to, or
+ // due to coalescing of free blocks, larger than (NUM_TINY_SLOTS - 1) * tiny quantum size.
+ ptr = limit->p;
+ if (ptr) {
+ return TINY_REGION_FOR_PTR(ptr);
+ }
+
+ return NULL;
+}
+
+static MALLOC_INLINE void
+tiny_madvise_free_range_no_lock(szone_t *szone,
+ magazine_t *tiny_mag_ptr,
+ region_t region,
+ void *headptr,
+ size_t headsize,
+ void *ptr,
+ msize_t msize)
+{
+ region_trailer_t *node = REGION_TRAILER_FOR_TINY_REGION(region);
+
+ // Lock on tiny_magazines[mag_index] is already held here
+ // Calculate the first page in the coalesced block that would be safe to mark MADV_FREE
+ size_t free_header_size = sizeof(tiny_free_list_t) + sizeof(msize_t);
+ uintptr_t safe_ptr = (uintptr_t)ptr + free_header_size;
+ uintptr_t round_safe = round_page_kernel(safe_ptr);
+
+ // Calculate the last page in the coalesced block that would be safe to mark MADV_FREE
+ size_t free_tail_size = sizeof(msize_t);
+ uintptr_t safe_extent = (uintptr_t)ptr + TINY_BYTES_FOR_MSIZE(msize) - free_tail_size;
+ uintptr_t trunc_extent = trunc_page_kernel(safe_extent);
+
+ // The newly freed block may complete a span of bytes that cover a page. Mark it with MADV_FREE.
+ if (round_safe < trunc_extent) { // Coalesced area covers a page (perhaps many)
+ // Extend the freed block by the free region header and tail sizes to include pages
+ // we may have coalesced that no longer host free region tails and headers.
+ // This may extend over in-use ranges, but the MIN/MAX clamping below will fix that up.
+ uintptr_t lo = trunc_page_kernel((uintptr_t)headptr - free_tail_size);
+ uintptr_t hi = round_page_kernel((uintptr_t)headptr + headsize + free_header_size);
+
+ uintptr_t free_lo = MAX(round_safe, lo);
+ uintptr_t free_hi = MIN(trunc_extent, hi);
+
+ if (free_lo < free_hi) {
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, ptr, msize);
+ set_tiny_meta_header_in_use(ptr, msize);
+
+ OSAtomicIncrement32Barrier(&(node->pinned_to_depot));
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ madvise_free_range(szone, region, free_lo, free_hi, &szone->last_tiny_advise);
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+ OSAtomicDecrement32Barrier(&(node->pinned_to_depot));
+
+ set_tiny_meta_header_free(ptr, msize);
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, ptr, msize);
+ }
+ }
+}
+
+static boolean_t
+tiny_get_region_from_depot(szone_t *szone, magazine_t *tiny_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ magazine_t *depot_ptr = &(szone->tiny_magazines[DEPOT_MAGAZINE_INDEX]);
+
+ /* FIXME: Would Uniprocessor benefit from recirc and MADV_FREE? */
+ if (szone->num_tiny_magazines == 1) { // Uniprocessor, single magazine, so no recirculation necessary
+ return 0;
+ }
+
+#if DEBUG_MALLOC
+ if (DEPOT_MAGAZINE_INDEX == mag_index) {
+ szone_error(szone, 1, "tiny_get_region_from_depot called for magazine index -1", NULL, NULL);
+ return 0;
+ }
+#endif
+
+ SZONE_MAGAZINE_PTR_LOCK(szone, depot_ptr);
+
+ // Appropriate a Depot'd region that can satisfy requested msize.
+ region_trailer_t *node;
+ region_t sparse_region;
+
+ while (1) {
+ sparse_region = tiny_find_msize_region(szone, depot_ptr, DEPOT_MAGAZINE_INDEX, msize);
+ if (NULL == sparse_region) { // Depot empty?
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, depot_ptr);
+ return 0;
+ }
+
+ node = REGION_TRAILER_FOR_TINY_REGION(sparse_region);
+ if (0 >= node->pinned_to_depot) {
+ break;
+ }
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, depot_ptr);
+ yield();
+ SZONE_MAGAZINE_PTR_LOCK(szone, depot_ptr);
+ }
+
+ // disconnect node from Depot
+ recirc_list_extract(szone, depot_ptr, node);
+
+ // Iterate the region pulling its free entries off the (locked) Depot's free list
+ int objects_in_use = tiny_free_detach_region(szone, depot_ptr, sparse_region);
+
+ // Transfer ownership of the region
+ MAGAZINE_INDEX_FOR_TINY_REGION(sparse_region) = mag_index;
+ node->pinned_to_depot = 0;
+
+ // Iterate the region putting its free entries on its new (locked) magazine's free list
+ size_t bytes_inplay = tiny_free_reattach_region(szone, tiny_mag_ptr, sparse_region);
+
+ depot_ptr->mag_num_bytes_in_objects -= bytes_inplay;
+ depot_ptr->num_bytes_in_magazine -= TINY_REGION_PAYLOAD_BYTES;
+ depot_ptr->mag_num_objects -= objects_in_use;
+
+ tiny_mag_ptr->mag_num_bytes_in_objects += bytes_inplay;
+ tiny_mag_ptr->num_bytes_in_magazine += TINY_REGION_PAYLOAD_BYTES;
+ tiny_mag_ptr->mag_num_objects += objects_in_use;
+
+ // connect to magazine as first node
+ recirc_list_splice_first(szone, tiny_mag_ptr, node);
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, depot_ptr);
+
+ // madvise() outside the Depot lock
+ (void)madvise_reuse_range(szone, sparse_region, (uintptr_t)sparse_region, (uintptr_t)sparse_region + TINY_REGION_PAYLOAD_BYTES);
+
+ MAGMALLOC_DEPOTREGION((void *)szone, (int)mag_index, (void *)sparse_region, TINY_REGION_SIZE,
+ (int)BYTES_USED_FOR_TINY_REGION(sparse_region)); // DTrace USDT Probe
+
+ return 1;
+}
+
+#if CONFIG_RECIRC_DEPOT
+static region_t
+tiny_free_try_depot_unmap_no_lock(szone_t *szone, magazine_t *depot_ptr, region_trailer_t *node)
+{
+ if (0 < node->bytes_used || 0 < node->pinned_to_depot || depot_ptr->recirculation_entries < (szone->num_tiny_magazines * 2)) {
+ return NULL;
+ }
+
+ // disconnect node from Depot
+ recirc_list_extract(szone, depot_ptr, node);
+
+ // Iterate the region pulling its free entries off the (locked) Depot's free list
+ region_t sparse_region = TINY_REGION_FOR_PTR(node);
+ int objects_in_use = tiny_free_detach_region(szone, depot_ptr, sparse_region);
+
+ if (0 == objects_in_use) {
+ // Invalidate the hash table entry for this region with HASHRING_REGION_DEALLOCATED.
+ // Using HASHRING_REGION_DEALLOCATED preserves the collision chain, using HASHRING_OPEN_ENTRY (0) would not.
+ rgnhdl_t pSlot = hash_lookup_region_no_lock(szone->tiny_region_generation->hashed_regions,
+ szone->tiny_region_generation->num_regions_allocated, szone->tiny_region_generation->num_regions_allocated_shift,
+ sparse_region);
+ if (NULL == pSlot) {
+ szone_error(szone, 1, "tiny_free_try_depot_unmap_no_lock hash lookup failed:", NULL, "%p\n", sparse_region);
+ return NULL;
+ }
+ *pSlot = HASHRING_REGION_DEALLOCATED;
+ depot_ptr->num_bytes_in_magazine -= TINY_REGION_PAYLOAD_BYTES;
+ __sync_fetch_and_add(&(szone->num_tiny_regions_dealloc), 1); // Atomically increment num_tiny_regions_dealloc
+
+ // Caller will transfer ownership of the region back to the OS with no locks held
+ MAGMALLOC_DEALLOCREGION((void *)szone, (void *)sparse_region, TINY_REGION_SIZE); // DTrace USDT Probe
+ return sparse_region;
+ } else {
+ szone_error(szone, 1, "tiny_free_try_depot_unmap_no_lock objects_in_use not zero:", NULL, "%d\n", objects_in_use);
+ return NULL;
+ }
+}
+
+static boolean_t
+tiny_free_do_recirc_to_depot(szone_t *szone, magazine_t *tiny_mag_ptr, mag_index_t mag_index)
+{
+ // The entire magazine crossed the "emptiness threshold". Transfer a region
+ // from this magazine to the Depot. Choose a region that itself has crossed the emptiness threshold (i.e
+ // is at least fraction "f" empty.) Such a region will be marked "suitable" on the recirculation list.
+ region_trailer_t *node = tiny_mag_ptr->firstNode;
+
+ while (node && !node->recirc_suitable) {
+ node = node->next;
+ }
+
+ if (NULL == node) {
+#if DEBUG_MALLOC
+ malloc_printf("*** tiny_free_do_recirc_to_depot end of list\n");
+#endif
+ return TRUE; // Caller must SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ }
+
+ region_t sparse_region = TINY_REGION_FOR_PTR(node);
+
+ // Deal with unclaimed memory -- mag_bytes_free_at_end or mag_bytes_free_at_start
+ if (sparse_region == tiny_mag_ptr->mag_last_region &&
+ (tiny_mag_ptr->mag_bytes_free_at_end || tiny_mag_ptr->mag_bytes_free_at_start)) {
+ tiny_finalize_region(szone, tiny_mag_ptr);
+ }
+
+ // disconnect "suitable" node from magazine
+ recirc_list_extract(szone, tiny_mag_ptr, node);
+
+ // Iterate the region pulling its free entries off its (locked) magazine's free list
+ int objects_in_use = tiny_free_detach_region(szone, tiny_mag_ptr, sparse_region);
+ magazine_t *depot_ptr = &(szone->tiny_magazines[DEPOT_MAGAZINE_INDEX]);
+
+ // hand over the region to the (locked) Depot
+ SZONE_MAGAZINE_PTR_LOCK(szone, depot_ptr);
+ // this will cause tiny_free_list_add_ptr called by tiny_free_reattach_region to use
+ // the depot as its target magazine, rather than magazine formerly associated with sparse_region
+ MAGAZINE_INDEX_FOR_TINY_REGION(sparse_region) = DEPOT_MAGAZINE_INDEX;
+ node->pinned_to_depot = 0;
+
+ // Iterate the region putting its free entries on Depot's free list
+ size_t bytes_inplay = tiny_free_reattach_region(szone, depot_ptr, sparse_region);
+
+ tiny_mag_ptr->mag_num_bytes_in_objects -= bytes_inplay;
+ tiny_mag_ptr->num_bytes_in_magazine -= TINY_REGION_PAYLOAD_BYTES;
+ tiny_mag_ptr->mag_num_objects -= objects_in_use;
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr); // Unlock the originating magazine
+
+ depot_ptr->mag_num_bytes_in_objects += bytes_inplay;
+ depot_ptr->num_bytes_in_magazine += TINY_REGION_PAYLOAD_BYTES;
+ depot_ptr->mag_num_objects += objects_in_use;
+
+ // connect to Depot as last node
+ recirc_list_splice_last(szone, depot_ptr, node);
+
+ MAGMALLOC_RECIRCREGION((void *)szone, (int)mag_index, (void *)sparse_region, TINY_REGION_SIZE,
+ (int)BYTES_USED_FOR_TINY_REGION(sparse_region)); // DTrace USDT Probe
+
+#if !CONFIG_AGGRESSIVE_MADVISE
+ // Mark free'd dirty pages with MADV_FREE to reduce memory pressure
+ tiny_free_scan_madvise_free(szone, depot_ptr, sparse_region);
+#endif
+
+ // If the region is entirely empty vm_deallocate() it outside the depot lock
+ region_t r_dealloc = tiny_free_try_depot_unmap_no_lock(szone, depot_ptr, node);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, depot_ptr);
+ if (r_dealloc) {
+ deallocate_pages(szone, r_dealloc, TINY_REGION_SIZE, 0);
+ }
+ return FALSE; // Caller need not unlock the originating magazine
+}
+
+static MALLOC_INLINE boolean_t
+tiny_free_try_recirc_to_depot(szone_t *szone,
+ magazine_t *tiny_mag_ptr,
+ mag_index_t mag_index,
+ region_t region,
+ void *headptr,
+ size_t headsize,
+ void *ptr,
+ msize_t msize)
+{
+ region_trailer_t *node = REGION_TRAILER_FOR_TINY_REGION(region);
+ size_t bytes_used = node->bytes_used;
+
+ /* FIXME: Would Uniprocessor benefit from recirc and MADV_FREE? */
+ if (szone->num_tiny_magazines == 1) { // Uniprocessor, single magazine, so no recirculation necessary
+ /* NOTHING */
+ return TRUE; // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr)
+ } else if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(TINY_REGION_PAYLOAD_BYTES)) {
+ /* Region has crossed threshold from density to sparsity. Mark it "suitable" on the
+ * recirculation candidates list. */
+ node->recirc_suitable = TRUE;
+ } else {
+ /* After this free, we've found the region is still dense, so it must have been even more so before
+ * the free. That implies the region is already correctly marked. Do nothing. */
+ }
+
+ // Has the entire magazine crossed the "emptiness threshold"? If so, transfer a region
+ // from this magazine to the Depot. Choose a region that itself has crossed the emptiness threshold (i.e
+ // is at least fraction "f" empty.) Such a region will be marked "suitable" on the recirculation list.
+ size_t a = tiny_mag_ptr->num_bytes_in_magazine; // Total bytes allocated to this magazine
+ size_t u = tiny_mag_ptr->mag_num_bytes_in_objects; // In use (malloc'd) from this magaqzine
+
+ if (a - u > ((3 * TINY_REGION_PAYLOAD_BYTES) / 2) && u < DENSITY_THRESHOLD(a)) {
+ return tiny_free_do_recirc_to_depot(szone, tiny_mag_ptr, mag_index);
+ }
+ } else {
+#if !CONFIG_AGGRESSIVE_MADVISE
+ // We are free'ing into the depot, so madvise as we do so unless we were madvising every incoming
+ // allocation anyway.
+ tiny_madvise_free_range_no_lock(szone, tiny_mag_ptr, region, headptr, headsize, ptr, msize);
+#endif
+
+ if (0 < bytes_used || 0 < node->pinned_to_depot) {
+ /* Depot'd region is still live. Leave it in place on the Depot's recirculation list
+ * so as to avoid thrashing between the Depot's free list and a magazines's free list
+ * with detach_region/reattach_region */
+ } else {
+ /* Depot'd region is just now empty. Consider return to OS. */
+ region_t r_dealloc = tiny_free_try_depot_unmap_no_lock(szone, tiny_mag_ptr, node);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ if (r_dealloc) {
+ deallocate_pages(szone, r_dealloc, TINY_REGION_SIZE, 0);
+ }
+ return FALSE; // Caller need not unlock
+ }
+ }
+ return TRUE; // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr)
+}
+#endif // CONFIG_RECIRC_DEPOT
+
+boolean_t
+tiny_free_no_lock(szone_t *szone, magazine_t *tiny_mag_ptr, mag_index_t mag_index, region_t region, void *ptr, msize_t msize)
+{
+ void *original_ptr = ptr;
+ size_t original_size = TINY_BYTES_FOR_MSIZE(msize);
+ void *next_block = ((unsigned char *)ptr + original_size);
+ msize_t previous_msize, next_msize;
+ void *previous;
+ tiny_free_list_t *big_free_block;
+ tiny_free_list_t *after_next_block;
+ tiny_free_list_t *before_next_block;
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_free_no_lock(), ptr=%p, msize=%d\n", ptr, msize);
+ }
+ if (!msize) {
+ szone_error(szone, 1, "trying to free tiny block that is too small", ptr, "in tiny_free_no_lock(), ptr=%p, msize=%d\n", ptr,
+ msize);
+ }
+#endif
+
+ // We try to coalesce this block with the preceeding one
+ previous = tiny_previous_preceding_free(ptr, &previous_msize);
+ if (previous) {
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr) || LOG(szone, previous)) {
+ malloc_printf("in tiny_free_no_lock(), coalesced backwards for %p previous=%p\n", ptr, previous);
+ }
+#endif
+
+ // clear the meta_header since this is no longer the start of a block
+ set_tiny_meta_header_middle(ptr);
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, previous, previous_msize);
+ ptr = previous;
+ msize += previous_msize;
+ }
+ // We try to coalesce with the next block
+ if ((next_block < TINY_REGION_END(region)) && tiny_meta_header_is_free(next_block)) {
+ next_msize = get_tiny_free_size(next_block);
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr) || LOG(szone, next_block)) {
+ malloc_printf("in tiny_free_no_lock(), for ptr=%p, msize=%d coalesced forward=%p next_msize=%d\n", ptr, msize,
+ next_block, next_msize);
+ }
+#endif
+ // If we are coalescing with the next block, and the next block is in
+ // the last slot of the free list, then we optimize this case here to
+ // avoid removing next_block from the slot (NUM_TINY_SLOTS - 1) and then adding ptr back
+ // to slot (NUM_TINY_SLOTS - 1).
+ if (next_msize >= NUM_TINY_SLOTS) {
+ msize += next_msize;
+
+ big_free_block = (tiny_free_list_t *)next_block;
+ after_next_block = free_list_unchecksum_ptr(szone, &big_free_block->next);
+ before_next_block = free_list_unchecksum_ptr(szone, &big_free_block->previous);
+
+ if (!before_next_block) {
+ tiny_mag_ptr->mag_free_list[NUM_TINY_SLOTS - 1].p = ptr;
+ } else {
+ before_next_block->next.u = free_list_checksum_ptr(szone, ptr);
+ }
+
+ if (after_next_block) {
+ after_next_block->previous.u = free_list_checksum_ptr(szone, ptr);
+ }
+
+ // we don't need to checksum these since they are already checksummed
+ ((tiny_free_list_t *)ptr)->previous = big_free_block->previous;
+ ((tiny_free_list_t *)ptr)->next = big_free_block->next;
+
+ // clear the meta_header to enable coalescing backwards
+ set_tiny_meta_header_middle(big_free_block);
+ set_tiny_meta_header_free(ptr, msize);
+
+ goto tiny_free_ending;
+ }
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, next_block, next_msize);
+ set_tiny_meta_header_middle(next_block); // clear the meta_header to enable coalescing backwards
+ msize += next_msize;
+ }
+
+ // The tiny cache already scribbles free blocks as they go through the
+ // cache whenever msize < TINY_QUANTUM , so we do not need to do it here.
+ if ((szone->debug_flags & MALLOC_DO_SCRIBBLE) && msize && (msize >= TINY_QUANTUM)) {
+ memset(ptr, SCRABBLE_BYTE, TINY_BYTES_FOR_MSIZE(msize));
+ }
+
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, ptr, msize);
+
+tiny_free_ending:
+
+ tiny_mag_ptr->mag_num_objects--;
+ // we use original_size and not msize to avoid double counting the coalesced blocks
+ tiny_mag_ptr->mag_num_bytes_in_objects -= original_size;
+
+ // Update this region's bytes in use count
+ region_trailer_t *node = REGION_TRAILER_FOR_TINY_REGION(region);
+ size_t bytes_used = node->bytes_used - original_size;
+ node->bytes_used = (unsigned int)bytes_used;
+
+#if CONFIG_AGGRESSIVE_MADVISE
+ // Platforms that want to madvise every freed allocation do so here, even if we continue
+ // on to use the recirc depot after.
+ tiny_madvise_free_range_no_lock(szone, tiny_mag_ptr, region, original_ptr, original_size, ptr, msize);
+#endif
+
+ // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr) if this function
+ // returns TRUE.
+ boolean_t needs_unlock = TRUE;
+
+#if CONFIG_RECIRC_DEPOT
+ needs_unlock = tiny_free_try_recirc_to_depot(szone, tiny_mag_ptr, mag_index, region, original_ptr, original_size, ptr, msize);
+#endif
+ return needs_unlock;
+}
+
+// Allocates from the last region or a freshly allocated region
+static void *
+tiny_malloc_from_region_no_lock(szone_t *szone,
+ magazine_t *tiny_mag_ptr,
+ mag_index_t mag_index,
+ msize_t msize,
+ void *aligned_address)
+{
+ void *ptr;
+
+ // Deal with unclaimed memory -- mag_bytes_free_at_end or mag_bytes_free_at_start
+ if (tiny_mag_ptr->mag_bytes_free_at_end || tiny_mag_ptr->mag_bytes_free_at_start) {
+ tiny_finalize_region(szone, tiny_mag_ptr);
+ }
+
+ // We set the unused bits of the header in the last pair to be all ones, and those of the inuse to zeroes.
+ ((tiny_region_t)aligned_address)->pairs[CEIL_NUM_TINY_BLOCKS_WORDS - 1].header =
+ (NUM_TINY_BLOCKS & 31) ? (0xFFFFFFFFU << (NUM_TINY_BLOCKS & 31)) : 0;
+ ((tiny_region_t)aligned_address)->pairs[CEIL_NUM_TINY_BLOCKS_WORDS - 1].inuse = 0;
+
+ // Here find the only place in tinyland that (infrequently) takes the tiny_regions_lock.
+ // Only one thread at a time should be permitted to assess the density of the hash
+ // ring and adjust if needed.
+ // Only one thread at a time should be permitted to insert its new region on
+ // the hash ring.
+ // It is safe for all other threads to read the hash ring (hashed_regions) and
+ // the associated sizes (num_regions_allocated and num_tiny_regions).
+
+ _malloc_lock_lock(&szone->tiny_regions_lock);
+
+ // Check to see if the hash ring of tiny regions needs to grow. Try to
+ // avoid the hash ring becoming too dense.
+ if (szone->tiny_region_generation->num_regions_allocated < (2 * szone->num_tiny_regions)) {
+ region_t *new_regions;
+ size_t new_size;
+ size_t new_shift = szone->tiny_region_generation->num_regions_allocated_shift; // In/Out parameter
+ new_regions = hash_regions_grow_no_lock(szone, szone->tiny_region_generation->hashed_regions,
+ szone->tiny_region_generation->num_regions_allocated, &new_shift, &new_size);
+ // Do not deallocate the current hashed_regions allocation since someone may
+ // be iterating it. Instead, just leak it.
+
+ // Prepare to advance to the "next generation" of the hash ring.
+ szone->tiny_region_generation->nextgen->hashed_regions = new_regions;
+ szone->tiny_region_generation->nextgen->num_regions_allocated = new_size;
+ szone->tiny_region_generation->nextgen->num_regions_allocated_shift = new_shift;
+
+ // Throw the switch to atomically advance to the next generation.
+ szone->tiny_region_generation = szone->tiny_region_generation->nextgen;
+ // Ensure everyone sees the advance.
+ OSMemoryBarrier();
+ }
+ // Tag the region at "aligned_address" as belonging to us,
+ // and so put it under the protection of the magazine lock we are holding.
+ // Do this before advertising "aligned_address" on the hash ring(!)
+ MAGAZINE_INDEX_FOR_TINY_REGION(aligned_address) = mag_index;
+
+ // Insert the new region into the hash ring, and update malloc statistics
+ hash_region_insert_no_lock(szone->tiny_region_generation->hashed_regions, szone->tiny_region_generation->num_regions_allocated,
+ szone->tiny_region_generation->num_regions_allocated_shift, aligned_address);
+
+ szone->num_tiny_regions++;
+ _malloc_lock_unlock(&szone->tiny_regions_lock);
+
+ tiny_mag_ptr->mag_last_region = aligned_address;
+ BYTES_USED_FOR_TINY_REGION(aligned_address) = TINY_BYTES_FOR_MSIZE(msize);
+#if CONFIG_ASLR_INTERNAL
+ int offset_msize = malloc_entropy[0] & TINY_ENTROPY_MASK;
+#if DEBUG_MALLOC
+ if (getenv("MallocASLRForce")) {
+ offset_msize = strtol(getenv("MallocASLRForce"), NULL, 0) & TINY_ENTROPY_MASK;
+ }
+ if (getenv("MallocASLRPrint")) {
+ malloc_printf("Region: %p offset: %d\n", aligned_address, offset_msize);
+ }
+#endif
+#else
+ int offset_msize = 0;
+#endif
+ ptr = (void *)((uintptr_t)aligned_address + TINY_BYTES_FOR_MSIZE(offset_msize));
+ set_tiny_meta_header_in_use(ptr, msize);
+ tiny_mag_ptr->mag_num_objects++;
+ tiny_mag_ptr->mag_num_bytes_in_objects += TINY_BYTES_FOR_MSIZE(msize);
+ tiny_mag_ptr->num_bytes_in_magazine += TINY_REGION_PAYLOAD_BYTES;
+
+ // We put a header on the last block so that it appears in use (for coalescing, etc...)
+ set_tiny_meta_header_in_use_1((void *)((uintptr_t)ptr + TINY_BYTES_FOR_MSIZE(msize)));
+ tiny_mag_ptr->mag_bytes_free_at_end = TINY_BYTES_FOR_MSIZE(NUM_TINY_BLOCKS - msize - offset_msize);
+
+#if CONFIG_ASLR_INTERNAL
+ // Put a header on the previous block for same reason
+ tiny_mag_ptr->mag_bytes_free_at_start = TINY_BYTES_FOR_MSIZE(offset_msize);
+ if (offset_msize) {
+ set_tiny_meta_header_in_use_1((void *)((uintptr_t)ptr - TINY_QUANTUM));
+ }
+#else
+ tiny_mag_ptr->mag_bytes_free_at_start = 0;
+#endif
+
+ // connect to magazine as last node
+ recirc_list_splice_last(szone, tiny_mag_ptr, REGION_TRAILER_FOR_TINY_REGION(aligned_address));
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_region_no_lock(), ptr=%p, msize=%d\n", ptr, msize);
+ }
+#endif
+ return ptr;
+}
+
+void *
+tiny_memalign(szone_t *szone, size_t alignment, size_t size, size_t span)
+{
+ msize_t mspan = TINY_MSIZE_FOR_BYTES(span + TINY_QUANTUM - 1);
+ void *p = szone_malloc(szone, span); // avoids inlining tiny_malloc_should_clear(szone, mspan, 0);
+
+ if (NULL == p) {
+ return NULL;
+ }
+
+ size_t offset = ((uintptr_t)p) & (alignment - 1); // p % alignment
+ size_t pad = (0 == offset) ? 0 : alignment - offset; // p + pad achieves desired alignment
+
+ msize_t msize = TINY_MSIZE_FOR_BYTES(size + TINY_QUANTUM - 1);
+ msize_t mpad = TINY_MSIZE_FOR_BYTES(pad + TINY_QUANTUM - 1);
+ msize_t mwaste = mspan - msize - mpad; // excess blocks
+
+ if (mpad > 0) {
+ void *q = (void *)(((uintptr_t)p) + pad);
+
+ // Mark q as a block header and in-use, thus creating two blocks.
+ magazine_t *tiny_mag_ptr = mag_lock_zine_for_region_trailer(szone, szone->tiny_magazines,
+ REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(p)), MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(p)));
+ set_tiny_meta_header_in_use(q, msize);
+ tiny_mag_ptr->mag_num_objects++;
+
+ // set_tiny_meta_header_in_use() "reaffirms" the block_header on the *following* block, so
+ // now set its in_use bit as well. But only if its within the original allocation made above.
+ if (mwaste > 0) {
+ BITARRAY_SET(TINY_INUSE_FOR_HEADER(TINY_BLOCK_HEADER_FOR_PTR(q)), TINY_INDEX_FOR_PTR(q) + msize);
+ }
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+
+ // Give up mpad blocks beginning at p to the tiny free list
+ // region_t r = TINY_REGION_FOR_PTR(p);
+ szone_free(szone, p); // avoids inlining free_tiny(szone, p, &r);
+
+ p = q; // advance p to the desired alignment
+ }
+
+ if (mwaste > 0) {
+ void *q = (void *)(((uintptr_t)p) + TINY_BYTES_FOR_MSIZE(msize));
+ // Mark q as block header and in-use, thus creating two blocks.
+ magazine_t *tiny_mag_ptr = mag_lock_zine_for_region_trailer(szone, szone->tiny_magazines,
+ REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(p)), MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(p)));
+ set_tiny_meta_header_in_use(q, mwaste);
+ tiny_mag_ptr->mag_num_objects++;
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+
+ // Give up mwaste blocks beginning at q to the tiny free list
+ // region_t r = TINY_REGION_FOR_PTR(q);
+ szone_free(szone, q); // avoids inlining free_tiny(szone, q, &r);
+ }
+
+ return p; // p has the desired size and alignment, and can later be free()'d
+}
+
+void *
+tiny_try_shrink_in_place(szone_t *szone, void *ptr, size_t old_size, size_t new_good_size)
+{
+ msize_t new_msize = TINY_MSIZE_FOR_BYTES(new_good_size);
+ msize_t mshrinkage = TINY_MSIZE_FOR_BYTES(old_size) - new_msize;
+
+ if (mshrinkage) {
+ void *q = (void *)((uintptr_t)ptr + TINY_BYTES_FOR_MSIZE(new_msize));
+ magazine_t *tiny_mag_ptr = mag_lock_zine_for_region_trailer(szone, szone->tiny_magazines,
+ REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr)), MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr)));
+
+ // Mark q as block header and in-use, thus creating two blocks.
+ set_tiny_meta_header_in_use(q, mshrinkage);
+ tiny_mag_ptr->mag_num_objects++;
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ szone_free(szone, q); // avoid inlining free_tiny(szone, q, ...);
+ }
+ return ptr;
+}
+
+boolean_t
+tiny_try_realloc_in_place(szone_t *szone, void *ptr, size_t old_size, size_t new_size)
+{
+ // returns 1 on success
+ msize_t index;
+ msize_t old_msize;
+ unsigned next_index;
+ void *next_block;
+ boolean_t is_free;
+ msize_t next_msize, coalesced_msize, leftover_msize;
+ void *leftover;
+
+ index = TINY_INDEX_FOR_PTR(ptr);
+ old_msize = TINY_MSIZE_FOR_BYTES(old_size);
+ next_index = index + old_msize;
+
+ if (next_index >= NUM_TINY_BLOCKS) {
+ return 0;
+ }
+ next_block = (char *)ptr + old_size;
+
+ magazine_t *tiny_mag_ptr = mag_lock_zine_for_region_trailer(szone, szone->tiny_magazines,
+ REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr)), MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr)));
+
+ if (DEPOT_MAGAZINE_INDEX == MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr))) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0;
+ }
+
+ /*
+ * Look for a free block immediately afterwards. If it's large enough, we can consume (part of)
+ * it.
+ */
+ is_free = tiny_meta_header_is_free(next_block);
+ if (!is_free) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0; // next_block is in use;
+ }
+ next_msize = get_tiny_free_size(next_block);
+ if (old_size + TINY_BYTES_FOR_MSIZE(next_msize) < new_size) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0; // even with next block, not enough
+ }
+ /*
+ * The following block is big enough; pull it from its freelist and chop off enough to satisfy
+ * our needs.
+ */
+ tiny_free_list_remove_ptr(szone, tiny_mag_ptr, next_block, next_msize);
+ set_tiny_meta_header_middle(next_block); // clear the meta_header to enable coalescing backwards
+ coalesced_msize = TINY_MSIZE_FOR_BYTES(new_size - old_size + TINY_QUANTUM - 1);
+ leftover_msize = next_msize - coalesced_msize;
+ if (leftover_msize) {
+ /* there's some left, so put the remainder back */
+ leftover = (void *)((uintptr_t)next_block + TINY_BYTES_FOR_MSIZE(coalesced_msize));
+
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, leftover, leftover_msize);
+ }
+ set_tiny_meta_header_in_use(ptr, old_msize + coalesced_msize);
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_try_realloc_in_place(), ptr=%p, msize=%d\n", ptr, old_msize + coalesced_msize);
+ }
+#endif
+ tiny_mag_ptr->mag_num_bytes_in_objects += TINY_BYTES_FOR_MSIZE(coalesced_msize);
+
+ // Update this region's bytes in use count
+ region_trailer_t *node = REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr));
+ size_t bytes_used = node->bytes_used + TINY_BYTES_FOR_MSIZE(coalesced_msize);
+ node->bytes_used = (unsigned int)bytes_used;
+
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(TINY_REGION_PAYLOAD_BYTES)) {
+ /* After this reallocation the region is still sparse, so it must have been even more so before
+ * the reallocation. That implies the region is already correctly marked. Do nothing. */
+ } else {
+ /* Region has crossed threshold from sparsity to density. Mark it not "suitable" on the
+ * recirculation candidates list. */
+ node->recirc_suitable = FALSE;
+ }
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return 1;
+}
+
+boolean_t
+tiny_check_region(szone_t *szone, region_t region)
+{
+ uintptr_t start, ptr, region_end;
+ boolean_t prev_free = 0;
+ boolean_t is_free;
+ msize_t msize;
+ tiny_free_list_t *free_head;
+ void *follower, *previous, *next;
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_TINY_REGION(region);
+ magazine_t *tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+
+ // Assumes locked
+ CHECK_MAGAZINE_PTR_LOCKED(szone, tiny_mag_ptr, __PRETTY_FUNCTION__);
+
+ /* establish region limits */
+ start = (uintptr_t)TINY_REGION_ADDRESS(region);
+ ptr = start;
+ if (region == tiny_mag_ptr->mag_last_region) {
+ ptr += tiny_mag_ptr->mag_bytes_free_at_start;
+
+ /*
+ * Check the leading block's integrity here also.
+ */
+ if (tiny_mag_ptr->mag_bytes_free_at_start) {
+ msize = get_tiny_meta_header((void *)(ptr - TINY_QUANTUM), &is_free);
+ if (is_free || (msize != 1)) {
+ malloc_printf("*** invariant broken for leader block %p - %d %d\n", ptr - TINY_QUANTUM, msize, is_free);
+ }
+ }
+ }
+ region_end = (uintptr_t)TINY_REGION_END(region);
+
+ /*
+ * The last region may have a trailing chunk which has not been converted into inuse/freelist
+ * blocks yet.
+ */
+ if (region == tiny_mag_ptr->mag_last_region) {
+ region_end -= tiny_mag_ptr->mag_bytes_free_at_end;
+ }
+
+ /*
+ * Scan blocks within the region.
+ */
+ while (ptr < region_end) {
+ /*
+ * If the first block is free, and its size is 65536 (msize = 0) then the entire region is
+ * free.
+ */
+ msize = get_tiny_meta_header((void *)ptr, &is_free);
+ if (is_free && !msize && (ptr == start)) {
+ return 1;
+ }
+
+ /*
+ * If the block's size is 65536 (msize = 0) then since we're not the first entry the size is
+ * corrupt.
+ */
+ if (!msize) {
+ malloc_printf("*** invariant broken for tiny block %p this msize=%d - size is too small\n", ptr, msize);
+ return 0;
+ }
+
+ if (!is_free) {
+ /*
+ * In use blocks cannot be more than (NUM_TINY_SLOTS - 1) quanta large.
+ */
+ prev_free = 0;
+ if (msize > (NUM_TINY_SLOTS - 1)) {
+ malloc_printf("*** invariant broken for %p this tiny msize=%d - size is too large\n", ptr, msize);
+ return 0;
+ }
+ /* move to next block */
+ ptr += TINY_BYTES_FOR_MSIZE(msize);
+ } else {
+#if !CONFIG_RELAXED_INVARIANT_CHECKS
+ /*
+ * Free blocks must have been coalesced, we cannot have a free block following another
+ * free block.
+ */
+ if (prev_free) {
+ malloc_printf("*** invariant broken for free block %p this tiny msize=%d: two free blocks in a row\n", ptr, msize);
+ return 0;
+ }
+#endif // CONFIG_RELAXED_INVARIANT_CHECKS
+ prev_free = 1;
+ /*
+ * Check the integrity of this block's entry in its freelist.
+ */
+ free_head = (tiny_free_list_t *)ptr;
+ previous = free_list_unchecksum_ptr(szone, &free_head->previous);
+ next = free_list_unchecksum_ptr(szone, &free_head->next);
+ if (previous && !tiny_meta_header_is_free(previous)) {
+ malloc_printf("*** invariant broken for %p (previous %p is not a free pointer)\n", ptr, previous);
+ return 0;
+ }
+ if (next && !tiny_meta_header_is_free(next)) {
+ malloc_printf("*** invariant broken for %p (next in free list %p is not a free pointer)\n", ptr, next);
+ return 0;
+ }
+ /*
+ * Check the free block's trailing size value.
+ */
+ follower = FOLLOWING_TINY_PTR(ptr, msize);
+ if (((uintptr_t)follower != region_end) && (get_tiny_previous_free_msize(follower) != msize)) {
+ malloc_printf(
+ "*** invariant broken for tiny free %p followed by %p in region [%p-%p] "
+ "(end marker incorrect) should be %d; in fact %d\n",
+ ptr, follower, TINY_REGION_ADDRESS(region), region_end, msize, get_tiny_previous_free_msize(follower));
+ return 0;
+ }
+ /* move to next block */
+ ptr = (uintptr_t)follower;
+ }
+ }
+ /*
+ * Ensure that we scanned the entire region
+ */
+ if (ptr != region_end) {
+ malloc_printf("*** invariant broken for region end %p - %p\n", ptr, region_end);
+ return 0;
+ }
+ /*
+ * Check the trailing block's integrity.
+ */
+ if (region == tiny_mag_ptr->mag_last_region) {
+ if (tiny_mag_ptr->mag_bytes_free_at_end) {
+ msize = get_tiny_meta_header((void *)ptr, &is_free);
+ if (is_free || (msize != 1)) {
+ malloc_printf("*** invariant broken for blocker block %p - %d %d\n", ptr, msize, is_free);
+ }
+ }
+ }
+ return 1;
+}
+
+kern_return_t
+tiny_in_use_enumerator(task_t task,
+ void *context,
+ unsigned type_mask,
+ szone_t *szone,
+ memory_reader_t reader,
+ vm_range_recorder_t recorder)
+{
+ size_t num_regions;
+ size_t index;
+ region_t *regions;
+ vm_range_t buffer[MAX_RECORDER_BUFFER];
+ unsigned count = 0;
+ kern_return_t err;
+ region_t region;
+ vm_range_t range;
+ vm_range_t admin_range;
+ vm_range_t ptr_range;
+ unsigned char *mapped_region;
+ uint32_t *block_header;
+ uint32_t *in_use;
+ unsigned block_index;
+ unsigned block_limit;
+ boolean_t is_free;
+ msize_t msize;
+ void *mapped_ptr;
+ unsigned bit;
+ magazine_t *tiny_mag_base = NULL;
+
+ region_hash_generation_t *trg_ptr;
+ err = reader(task, (vm_address_t)szone->tiny_region_generation, sizeof(region_hash_generation_t), (void **)&trg_ptr);
+ if (err) {
+ return err;
+ }
+
+ num_regions = trg_ptr->num_regions_allocated;
+ err = reader(task, (vm_address_t)trg_ptr->hashed_regions, sizeof(region_t) * num_regions, (void **)®ions);
+ if (err) {
+ return err;
+ }
+
+ if (type_mask & MALLOC_PTR_IN_USE_RANGE_TYPE) {
+ // Map in all active magazines. Do this outside the iteration over regions.
+ err = reader(task, (vm_address_t)(szone->tiny_magazines), szone->num_tiny_magazines * sizeof(magazine_t),
+ (void **)&tiny_mag_base);
+ if (err) {
+ return err;
+ }
+ }
+
+ for (index = 0; index < num_regions; ++index) {
+ region = regions[index];
+ if (HASHRING_OPEN_ENTRY != region && HASHRING_REGION_DEALLOCATED != region) {
+ range.address = (vm_address_t)TINY_REGION_ADDRESS(region);
+ range.size = (vm_size_t)TINY_REGION_SIZE;
+ if (type_mask & MALLOC_ADMIN_REGION_RANGE_TYPE) {
+ admin_range.address = range.address + TINY_METADATA_START;
+ admin_range.size = TINY_METADATA_SIZE;
+ recorder(task, context, MALLOC_ADMIN_REGION_RANGE_TYPE, &admin_range, 1);
+ }
+ if (type_mask & (MALLOC_PTR_REGION_RANGE_TYPE | MALLOC_ADMIN_REGION_RANGE_TYPE)) {
+ ptr_range.address = range.address;
+ ptr_range.size = NUM_TINY_BLOCKS * TINY_QUANTUM;
+ recorder(task, context, MALLOC_PTR_REGION_RANGE_TYPE, &ptr_range, 1);
+ }
+ if (type_mask & MALLOC_PTR_IN_USE_RANGE_TYPE) {
+ void *mag_last_free;
+ vm_address_t mag_last_free_ptr = 0;
+ msize_t mag_last_free_msize = 0;
+
+ err = reader(task, range.address, range.size, (void **)&mapped_region);
+ if (err) {
+ return err;
+ }
+
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_TINY_REGION(mapped_region);
+ magazine_t *tiny_mag_ptr = tiny_mag_base + mag_index;
+
+ if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ mag_last_free = tiny_mag_ptr->mag_last_free;
+ if (mag_last_free) {
+ mag_last_free_ptr = (uintptr_t)mag_last_free & ~(TINY_QUANTUM - 1);
+ mag_last_free_msize = (uintptr_t)mag_last_free & (TINY_QUANTUM - 1);
+ }
+ } else {
+ for (mag_index = 0; mag_index < szone->num_tiny_magazines; mag_index++) {
+ if ((void *)range.address == (tiny_mag_base + mag_index)->mag_last_free_rgn) {
+ mag_last_free = (tiny_mag_base + mag_index)->mag_last_free;
+ if (mag_last_free) {
+ mag_last_free_ptr = (uintptr_t)mag_last_free & ~(TINY_QUANTUM - 1);
+ mag_last_free_msize = (uintptr_t)mag_last_free & (TINY_QUANTUM - 1);
+ }
+ }
+ }
+ }
+
+ block_header = (uint32_t *)(mapped_region + TINY_METADATA_START + sizeof(region_trailer_t));
+ in_use = TINY_INUSE_FOR_HEADER(block_header);
+ block_index = 0;
+ block_limit = NUM_TINY_BLOCKS;
+ if (region == tiny_mag_ptr->mag_last_region) {
+ block_index += TINY_MSIZE_FOR_BYTES(tiny_mag_ptr->mag_bytes_free_at_start);
+ block_limit -= TINY_MSIZE_FOR_BYTES(tiny_mag_ptr->mag_bytes_free_at_end);
+ }
+
+ while (block_index < block_limit) {
+ vm_size_t block_offset = TINY_BYTES_FOR_MSIZE(block_index);
+ is_free = !BITARRAY_BIT(in_use, block_index);
+ if (is_free) {
+ mapped_ptr = mapped_region + block_offset;
+
+ // mapped_region, the address at which 'range' in 'task' has been
+ // mapped into our process, is not necessarily aligned to
+ // TINY_BLOCKS_ALIGN.
+ //
+ // Since the code in get_tiny_free_size() assumes the pointer came
+ // from a properly aligned tiny region, and mapped_region is not
+ // necessarily aligned, then do the size calculation directly.
+ // If the next bit is set in the header bitmap, then the size is one
+ // quantum. Otherwise, read the size field.
+ if (!BITARRAY_BIT(block_header, (block_index + 1))) {
+ msize = TINY_FREE_SIZE(mapped_ptr);
+ } else {
+ msize = 1;
+ }
+
+ } else if (range.address + block_offset != mag_last_free_ptr) {
+ msize = 1;
+ bit = block_index + 1;
+ while (!BITARRAY_BIT(block_header, bit)) {
+ bit++;
+ msize++;
+ }
+ buffer[count].address = range.address + block_offset;
+ buffer[count].size = TINY_BYTES_FOR_MSIZE(msize);
+ count++;
+ if (count >= MAX_RECORDER_BUFFER) {
+ recorder(task, context, MALLOC_PTR_IN_USE_RANGE_TYPE, buffer, count);
+ count = 0;
+ }
+ } else {
+ // Block is not free but it matches mag_last_free_ptr so even
+ // though it is not marked free in the bitmap, we treat it as if
+ // it is and move on
+ msize = mag_last_free_msize;
+ }
+
+ if (!msize) {
+ return KERN_FAILURE; // Somethings amiss. Avoid looping at this block_index.
+ }
+ block_index += msize;
+ }
+ if (count) {
+ recorder(task, context, MALLOC_PTR_IN_USE_RANGE_TYPE, buffer, count);
+ count = 0;
+ }
+ }
+ }
+ }
+ return 0;
+}
+
+void *
+tiny_malloc_from_free_list(szone_t *szone, magazine_t *tiny_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ tiny_free_list_t *ptr;
+ msize_t this_msize;
+ grain_t slot = msize - 1;
+ free_list_t *free_list = tiny_mag_ptr->mag_free_list;
+ free_list_t *the_slot = free_list + slot;
+ tiny_free_list_t *next;
+ free_list_t *limit;
+#if defined(__LP64__)
+ uint64_t bitmap;
+#else
+ uint32_t bitmap;
+#endif
+ msize_t leftover_msize;
+ tiny_free_list_t *leftover_ptr;
+
+ // Assumes we've locked the region
+ CHECK_MAGAZINE_PTR_LOCKED(szone, tiny_mag_ptr, __PRETTY_FUNCTION__);
+
+ // Look for an exact match by checking the freelist for this msize.
+ //
+ ptr = the_slot->p;
+ if (ptr) {
+ next = free_list_unchecksum_ptr(szone, &ptr->next);
+ if (next) {
+ next->previous = ptr->previous;
+ } else {
+ BITMAPV_CLR(tiny_mag_ptr->mag_bitmap, slot);
+ }
+ the_slot->p = next;
+ this_msize = msize;
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_free_list(), exact match ptr=%p, this_msize=%d\n", ptr, this_msize);
+ }
+#endif
+ goto return_tiny_alloc;
+ }
+
+ // Mask off the bits representing slots holding free blocks smaller than the
+ // size we need. If there are no larger free blocks, try allocating from
+ // the free space at the end of the tiny region.
+#if defined(__LP64__)
+ bitmap = ((uint64_t *)(tiny_mag_ptr->mag_bitmap))[0] & ~((1ULL << slot) - 1);
+#else
+ bitmap = tiny_mag_ptr->mag_bitmap[0] & ~((1 << slot) - 1);
+#endif
+ if (!bitmap) {
+ goto try_tiny_malloc_from_end;
+ }
+
+ slot = BITMAPV_CTZ(bitmap);
+ limit = free_list + NUM_TINY_SLOTS - 1;
+ free_list += slot;
+
+ if (free_list < limit) {
+ ptr = free_list->p;
+ if (ptr) {
+ next = free_list_unchecksum_ptr(szone, &ptr->next);
+ free_list->p = next;
+ if (next) {
+ next->previous = ptr->previous;
+ } else {
+ BITMAPV_CLR(tiny_mag_ptr->mag_bitmap, slot);
+ }
+ this_msize = get_tiny_free_size(ptr);
+ goto add_leftover_and_proceed;
+ }
+#if DEBUG_MALLOC
+ malloc_printf("in tiny_malloc_from_free_list(), mag_bitmap out of sync, slot=%d\n", slot);
+#endif
+ }
+
+ // We are now looking at the last slot, which contains blocks equal to, or
+ // due to coalescing of free blocks, larger than (NUM_TINY_SLOTS - 1) * tiny quantum size.
+ // If the last freelist is not empty, and the head contains a block that is
+ // larger than our request, then the remainder is put back on the free list.
+ ptr = limit->p;
+ if (ptr) {
+ this_msize = get_tiny_free_size(ptr);
+ next = free_list_unchecksum_ptr(szone, &ptr->next);
+ if (this_msize - msize >= NUM_TINY_SLOTS) {
+ // the leftover will go back to the free list, so we optimize by
+ // modifying the free list rather than a pop and push of the head
+ leftover_msize = this_msize - msize;
+ leftover_ptr = (tiny_free_list_t *)((unsigned char *)ptr + TINY_BYTES_FOR_MSIZE(msize));
+ limit->p = leftover_ptr;
+ if (next) {
+ next->previous.u = free_list_checksum_ptr(szone, leftover_ptr);
+ }
+ leftover_ptr->previous = ptr->previous;
+ leftover_ptr->next = ptr->next;
+ set_tiny_meta_header_free(leftover_ptr, leftover_msize);
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf(
+ "in tiny_malloc_from_free_list(), last slot ptr=%p, msize=%d this_msize=%d\n", ptr, msize, this_msize);
+ }
+#endif
+ this_msize = msize;
+ goto return_tiny_alloc;
+ }
+ if (next) {
+ next->previous = ptr->previous;
+ }
+ limit->p = next;
+ goto add_leftover_and_proceed;
+ /* NOTREACHED */
+ }
+
+try_tiny_malloc_from_end:
+ // Let's see if we can use tiny_mag_ptr->mag_bytes_free_at_end
+ if (tiny_mag_ptr->mag_bytes_free_at_end >= TINY_BYTES_FOR_MSIZE(msize)) {
+ ptr = (tiny_free_list_t *)((uintptr_t)TINY_REGION_END(tiny_mag_ptr->mag_last_region) - tiny_mag_ptr->mag_bytes_free_at_end);
+ tiny_mag_ptr->mag_bytes_free_at_end -= TINY_BYTES_FOR_MSIZE(msize);
+ if (tiny_mag_ptr->mag_bytes_free_at_end) {
+ // let's add an in use block after ptr to serve as boundary
+ set_tiny_meta_header_in_use_1((unsigned char *)ptr + TINY_BYTES_FOR_MSIZE(msize));
+ }
+ this_msize = msize;
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_free_list(), from end ptr=%p, msize=%d\n", ptr, msize);
+ }
+#endif
+ goto return_tiny_alloc;
+ }
+#if CONFIG_ASLR_INTERNAL
+ // Try from start if nothing left at end
+ if (tiny_mag_ptr->mag_bytes_free_at_start >= TINY_BYTES_FOR_MSIZE(msize)) {
+ ptr = (tiny_free_list_t *)(TINY_REGION_ADDRESS(tiny_mag_ptr->mag_last_region) + tiny_mag_ptr->mag_bytes_free_at_start -
+ TINY_BYTES_FOR_MSIZE(msize));
+ tiny_mag_ptr->mag_bytes_free_at_start -= TINY_BYTES_FOR_MSIZE(msize);
+ if (tiny_mag_ptr->mag_bytes_free_at_start) {
+ // let's add an in use block before ptr to serve as boundary
+ set_tiny_meta_header_in_use_1((unsigned char *)ptr - TINY_QUANTUM);
+ }
+ this_msize = msize;
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_free_list(), from start ptr=%p, msize=%d\n", ptr, msize);
+ }
+#endif
+ goto return_tiny_alloc;
+ }
+#endif
+ return NULL;
+
+add_leftover_and_proceed:
+ if (!this_msize || (this_msize > msize)) {
+ leftover_msize = this_msize - msize;
+ leftover_ptr = (tiny_free_list_t *)((unsigned char *)ptr + TINY_BYTES_FOR_MSIZE(msize));
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_free_list(), adding leftover ptr=%p, this_msize=%d\n", ptr, this_msize);
+ }
+#endif
+ tiny_free_list_add_ptr(szone, tiny_mag_ptr, leftover_ptr, leftover_msize);
+ this_msize = msize;
+ }
+
+return_tiny_alloc:
+ tiny_mag_ptr->mag_num_objects++;
+ tiny_mag_ptr->mag_num_bytes_in_objects += TINY_BYTES_FOR_MSIZE(this_msize);
+
+ // Update this region's bytes in use count
+ region_trailer_t *node = REGION_TRAILER_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr));
+ size_t bytes_used = node->bytes_used + TINY_BYTES_FOR_MSIZE(this_msize);
+ node->bytes_used = (unsigned int)bytes_used;
+
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(TINY_REGION_PAYLOAD_BYTES)) {
+ /* After this allocation the region is still sparse, so it must have been even more so before
+ * the allocation. That implies the region is already correctly marked. Do nothing. */
+ } else {
+ /* Region has crossed threshold from sparsity to density. Mark it not "suitable" on the
+ * recirculation candidates list. */
+ node->recirc_suitable = FALSE;
+ }
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_from_free_list(), ptr=%p, this_msize=%d, msize=%d\n", ptr, this_msize, msize);
+ }
+#endif
+ if (this_msize > 1) {
+ set_tiny_meta_header_in_use(ptr, this_msize);
+ } else {
+ set_tiny_meta_header_in_use_1(ptr);
+ }
+ return ptr;
+}
+
+void *
+tiny_malloc_should_clear(szone_t *szone, msize_t msize, boolean_t cleared_requested)
+{
+ void *ptr;
+ mag_index_t mag_index = mag_get_thread_index(szone);
+ magazine_t *tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+
+ MALLOC_TRACE(TRACE_tiny_malloc, (uintptr_t)szone, TINY_BYTES_FOR_MSIZE(msize), (uintptr_t)tiny_mag_ptr, cleared_requested);
+
+#if DEBUG_MALLOC
+ if (DEPOT_MAGAZINE_INDEX == mag_index) {
+ szone_error(szone, 1, "malloc called for magazine index -1", NULL, NULL);
+ return (NULL);
+ }
+
+ if (!msize) {
+ szone_error(szone, 1, "invariant broken (!msize) in allocation (region)", NULL, NULL);
+ return (NULL);
+ }
+#endif
+
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+
+#if CONFIG_TINY_CACHE
+ ptr = tiny_mag_ptr->mag_last_free;
+
+ if ((((uintptr_t)ptr) & (TINY_QUANTUM - 1)) == msize) {
+ // we have a winner
+ tiny_mag_ptr->mag_last_free = NULL;
+ tiny_mag_ptr->mag_last_free_rgn = NULL;
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ ptr = (void *)((uintptr_t)ptr & ~(TINY_QUANTUM - 1));
+ if (cleared_requested) {
+ memset(ptr, 0, TINY_BYTES_FOR_MSIZE(msize));
+ }
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_printf("in tiny_malloc_should_clear(), tiny cache ptr=%p, msize=%d\n", ptr, msize);
+ }
+#endif
+ return ptr;
+ }
+#endif /* CONFIG_TINY_CACHE */
+
+ while (1) {
+ ptr = tiny_malloc_from_free_list(szone, tiny_mag_ptr, mag_index, msize);
+ if (ptr) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ if (cleared_requested) {
+ memset(ptr, 0, TINY_BYTES_FOR_MSIZE(msize));
+ }
+ return ptr;
+ }
+
+ if (tiny_get_region_from_depot(szone, tiny_mag_ptr, mag_index, msize)) {
+ ptr = tiny_malloc_from_free_list(szone, tiny_mag_ptr, mag_index, msize);
+ if (ptr) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ if (cleared_requested) {
+ memset(ptr, 0, TINY_BYTES_FOR_MSIZE(msize));
+ }
+ return ptr;
+ }
+ }
+
+ // The magazine is exhausted. A new region (heap) must be allocated to satisfy this call to malloc().
+ // The allocation, an mmap() system call, will be performed outside the magazine spin locks by the first
+ // thread that suffers the exhaustion. That thread sets "alloc_underway" and enters a critical section.
+ // Threads arriving here later are excluded from the critical section, yield the CPU, and then retry the
+ // allocation. After some time the magazine is resupplied, the original thread leaves with its allocation,
+ // and retry-ing threads succeed in the code just above.
+ if (!tiny_mag_ptr->alloc_underway) {
+ void *fresh_region;
+
+ // time to create a new region (do this outside the magazine lock)
+ tiny_mag_ptr->alloc_underway = TRUE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ fresh_region = allocate_pages_securely(szone, TINY_REGION_SIZE, TINY_BLOCKS_ALIGN, VM_MEMORY_MALLOC_TINY);
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+
+ MAGMALLOC_ALLOCREGION((void *)szone, (int)mag_index, fresh_region, TINY_REGION_SIZE); // DTrace USDT Probe
+
+ if (!fresh_region) { // out of memory!
+ tiny_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return NULL;
+ }
+
+ ptr = tiny_malloc_from_region_no_lock(szone, tiny_mag_ptr, mag_index, msize, fresh_region);
+
+ // we don't clear because this freshly allocated space is pristine
+ tiny_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return ptr;
+ } else {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ yield();
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+ }
+ }
+ /* NOTREACHED */
+}
+
+static MALLOC_NOINLINE void
+free_tiny_botch(szone_t *szone, tiny_free_list_t *ptr)
+{
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_TINY_REGION(TINY_REGION_FOR_PTR(ptr));
+ magazine_t *tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ szone_error(szone, 1, "double free", ptr, NULL);
+}
+
+void
+free_tiny(szone_t *szone, void *ptr, region_t tiny_region, size_t known_size)
+{
+ msize_t msize;
+ boolean_t is_free;
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_TINY_REGION(tiny_region);
+ magazine_t *tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+
+ MALLOC_TRACE(TRACE_tiny_free, (uintptr_t)szone, (uintptr_t)ptr, (uintptr_t)tiny_mag_ptr, known_size);
+
+ // ptr is known to be in tiny_region
+ if (known_size) {
+ msize = TINY_MSIZE_FOR_BYTES(known_size + TINY_QUANTUM - 1);
+ } else {
+ msize = get_tiny_meta_header(ptr, &is_free);
+ if (is_free) {
+ free_tiny_botch(szone, ptr);
+ return;
+ }
+ }
+#if DEBUG_MALLOC
+ if (!msize) {
+ malloc_printf("*** free_tiny() block in use is too large: %p\n", ptr);
+ return;
+ }
+#endif
+
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+
+#if CONFIG_TINY_CACHE
+ // Depot does not participate in CONFIG_TINY_CACHE since it can't be directly malloc()'d
+ if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ if (msize < TINY_QUANTUM) { // to see if the bits fit in the last 4 bits
+ void *ptr2 = tiny_mag_ptr->mag_last_free; // Might be NULL
+ region_t rgn2 = tiny_mag_ptr->mag_last_free_rgn;
+
+ /* check that we don't already have this pointer in the cache */
+ if (ptr == (void *)((uintptr_t)ptr2 & ~(TINY_QUANTUM - 1))) {
+ free_tiny_botch(szone, ptr);
+ return;
+ }
+
+ if ((szone->debug_flags & MALLOC_DO_SCRIBBLE) && msize) {
+ memset(ptr, SCRABBLE_BYTE, TINY_BYTES_FOR_MSIZE(msize));
+ }
+
+ tiny_mag_ptr->mag_last_free = (void *)(((uintptr_t)ptr) | msize);
+ tiny_mag_ptr->mag_last_free_rgn = tiny_region;
+
+ if (!ptr2) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return;
+ }
+
+ msize = (uintptr_t)ptr2 & (TINY_QUANTUM - 1);
+ ptr = (void *)(((uintptr_t)ptr2) & ~(TINY_QUANTUM - 1));
+ tiny_region = rgn2;
+ }
+ }
+#endif /* CONFIG_TINY_CACHE */
+
+ // Now in the time it took to acquire the lock, the region may have migrated
+ // from one magazine to another. I.e. trailer->mag_index is volatile.
+ // In which case the magazine lock we obtained (namely magazines[mag_index].mag_lock)
+ // is stale. If so, keep on tryin' ...
+ region_trailer_t *trailer = REGION_TRAILER_FOR_TINY_REGION(tiny_region);
+ mag_index_t refreshed_index;
+
+ while (mag_index != (refreshed_index = trailer->mag_index)) { // Note assignment
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+
+ mag_index = refreshed_index;
+ tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+ }
+
+ if (tiny_free_no_lock(szone, tiny_mag_ptr, mag_index, tiny_region, ptr, msize)) {
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ }
+
+ CHECK(szone, __PRETTY_FUNCTION__);
+}
+
+void
+print_tiny_free_list(szone_t *szone)
+{
+ tiny_free_list_t *ptr;
+ _SIMPLE_STRING b = _simple_salloc();
+ mag_index_t mag_index;
+
+ if (b) {
+ _simple_sappend(b, "tiny free sizes:\n");
+ for (mag_index = -1; mag_index < szone->num_tiny_magazines; mag_index++) {
+ grain_t slot = 0;
+ _simple_sprintf(b, "\tMagazine %d: ", mag_index);
+ while (slot < NUM_TINY_SLOTS) {
+ ptr = szone->tiny_magazines[mag_index].mag_free_list[slot].p;
+ if (ptr) {
+ _simple_sprintf(b, "%s%y[%d]; ", (slot == NUM_TINY_SLOTS - 1) ? ">=" : "", (slot + 1) * TINY_QUANTUM,
+ free_list_count(szone, (free_list_t){ .p = ptr }));
+ }
+ slot++;
+ }
+ _simple_sappend(b, "\n");
+ }
+ _malloc_printf(MALLOC_PRINTF_NOLOG | MALLOC_PRINTF_NOPREFIX, "%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+}
+
+void
+print_tiny_region(boolean_t verbose, region_t region, size_t bytes_at_start, size_t bytes_at_end)
+{
+ unsigned counts[1024];
+ unsigned in_use = 0;
+ uintptr_t start = (uintptr_t)TINY_REGION_ADDRESS(region);
+ uintptr_t current = start + bytes_at_start;
+ uintptr_t limit = (uintptr_t)TINY_REGION_END(region) - bytes_at_end;
+ boolean_t is_free;
+ msize_t msize;
+ unsigned ci;
+ _SIMPLE_STRING b;
+ uintptr_t pgTot = 0;
+
+ if (region == HASHRING_REGION_DEALLOCATED) {
+ if ((b = _simple_salloc()) != NULL) {
+ _simple_sprintf(b, "Tiny region [unknown address] was returned to the OS\n");
+ _malloc_printf(MALLOC_PRINTF_NOLOG | MALLOC_PRINTF_NOPREFIX, "%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+ return;
+ }
+
+ memset(counts, 0, sizeof(counts));
+ while (current < limit) {
+ msize = get_tiny_meta_header((void *)current, &is_free);
+ if (is_free && !msize && (current == start)) {
+ // first block is all free
+ uintptr_t pgLo = round_page_quanta(start + sizeof(tiny_free_list_t) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_quanta(start + TINY_REGION_SIZE - sizeof(msize_t));
+
+ if (pgLo < pgHi) {
+ pgTot += (pgHi - pgLo);
+ }
+ break;
+ }
+ if (!msize) {
+ malloc_printf("*** error with %p: msize=%d\n", (void *)current, (unsigned)msize);
+ break;
+ }
+ if (!is_free) {
+ // block in use
+ if (msize > NUM_TINY_SLOTS) {
+ malloc_printf("*** error at %p msize for in_use is %d\n", (void *)current, msize);
+ }
+ if (msize < 1024) {
+ counts[msize]++;
+ }
+ in_use++;
+ } else {
+ uintptr_t pgLo = round_page_quanta(current + sizeof(tiny_free_list_t) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_quanta(current + TINY_BYTES_FOR_MSIZE(msize) - sizeof(msize_t));
+
+ if (pgLo < pgHi) {
+ pgTot += (pgHi - pgLo);
+ }
+ }
+ current += TINY_BYTES_FOR_MSIZE(msize);
+ }
+ if ((b = _simple_salloc()) != NULL) {
+ _simple_sprintf(b, "Tiny region [%p-%p, %y] \t", (void *)start, TINY_REGION_END(region), (int)TINY_REGION_SIZE);
+ _simple_sprintf(b, "Magazine=%d \t", MAGAZINE_INDEX_FOR_TINY_REGION(region));
+ _simple_sprintf(b, "Allocations in use=%d \t Bytes in use=%ly \t", in_use, BYTES_USED_FOR_TINY_REGION(region));
+ if (bytes_at_end || bytes_at_start) {
+ _simple_sprintf(b, "Untouched=%ly ", bytes_at_end + bytes_at_start);
+ }
+ if (DEPOT_MAGAZINE_INDEX == MAGAZINE_INDEX_FOR_TINY_REGION(region)) {
+ _simple_sprintf(b, "Advised MADV_FREE=%ly", pgTot);
+ } else {
+ _simple_sprintf(b, "Fragments subject to reclamation=%ly", pgTot);
+ }
+ if (verbose && in_use) {
+ _simple_sappend(b, "\n\tSizes in use: ");
+ for (ci = 0; ci < 1024; ci++) {
+ if (counts[ci]) {
+ _simple_sprintf(b, "%d[%d] ", TINY_BYTES_FOR_MSIZE(ci), counts[ci]);
+ }
+ }
+ }
+ _malloc_printf(MALLOC_PRINTF_NOLOG | MALLOC_PRINTF_NOPREFIX, "%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+}
+
+boolean_t
+tiny_free_list_check(szone_t *szone, grain_t slot)
+{
+ mag_index_t mag_index;
+
+ for (mag_index = -1; mag_index < szone->num_tiny_magazines; mag_index++) {
+ magazine_t *tiny_mag_ptr = &(szone->tiny_magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_LOCK(szone, tiny_mag_ptr);
+
+ unsigned count = 0;
+ tiny_free_list_t *ptr = szone->tiny_magazines[mag_index].mag_free_list[slot].p;
+ boolean_t is_free;
+ tiny_free_list_t *previous = NULL;
+
+ while (ptr) {
+ is_free = tiny_meta_header_is_free(ptr);
+ if (!is_free) {
+ malloc_printf("*** in-use ptr in free list slot=%d count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0;
+ }
+ if (((uintptr_t)ptr) & (TINY_QUANTUM - 1)) {
+ malloc_printf("*** unaligned ptr in free list slot=%d count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0;
+ }
+ if (!tiny_region_for_ptr_no_lock(szone, ptr)) {
+ malloc_printf("*** ptr not in szone slot=%d count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0;
+ }
+ if (free_list_unchecksum_ptr(szone, &ptr->previous) != previous) {
+ malloc_printf("*** previous incorrectly set slot=%d count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ return 0;
+ }
+ previous = ptr;
+ ptr = free_list_unchecksum_ptr(szone, &ptr->next);
+ count++;
+ }
+
+ SZONE_MAGAZINE_PTR_UNLOCK(szone, tiny_mag_ptr);
+ }
+ return 1;
+}