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--- libmalloc/libmalloc-317.40.8/src/magazine_tiny.c
+++ libmalloc/libmalloc-374.60.3/src/magazine_tiny.c
@@ -44,13 +44,13 @@
{
#if CONFIG_TINY_USES_HYPER_SHIFT
if (os_likely(_os_cpu_number_override == -1)) {
- return _os_cpu_number() >> hyper_shift;
+ return _malloc_cpu_number() >> hyper_shift;
} else {
return _os_cpu_number_override >> hyper_shift;
}
#else // CONFIG_SMALL_USES_HYPER_SHIFT
if (os_likely(_os_cpu_number_override == -1)) {
- return _os_cpu_number();
+ return _malloc_cpu_number();
} else {
return _os_cpu_number_override;
}
@@ -81,7 +81,11 @@
if (BITARRAY_BIT(prev_header, prev_index)) {
return 1;
}
- return TINY_PREVIOUS_MSIZE(ptr);
+ msize_t *prev_msize_ptr = &TINY_PREVIOUS_MSIZE(ptr);
+ // This is a speculative read of potentially in-use app memory, we need
+ // to use _malloc_read_uint16_via_rsp to avoid triggering warnings in
+ // memory diagnostic tools.
+ return _malloc_read_uint16_via_rsp(prev_msize_ptr);
}
// don't read possibly unmapped memory before the beginning of the region
return 0;
@@ -836,18 +840,30 @@
for (mag_index = 0; mag_index < rack->num_magazines; mag_index++) {
size_t index;
for (index = 0; index < rack->region_generation->num_regions_allocated; ++index) {
- SZONE_LOCK(TINY_SZONE_FROM_RACK(rack));
+ rack_region_lock(rack);
region_t tiny = rack->region_generation->hashed_regions[index];
if (!tiny || tiny == HASHRING_REGION_DEALLOCATED) {
- SZONE_UNLOCK(TINY_SZONE_FROM_RACK(rack));
+ rack_region_unlock(rack);
continue;
}
+ region_trailer_t *trailer = REGION_TRAILER_FOR_TINY_REGION(tiny);
+ // Make sure that the owning magazine doesn't try and take this out
+ // from under our feet.
+ trailer->dispose_flags |= RACK_DISPOSE_DELAY;
+ rack_region_unlock(rack);
+
magazine_t *mag_ptr = mag_lock_zine_for_region_trailer(rack->magazines,
- REGION_TRAILER_FOR_TINY_REGION(tiny),
- MAGAZINE_INDEX_FOR_TINY_REGION(tiny));
- SZONE_UNLOCK(TINY_SZONE_FROM_RACK(rack));
+ trailer, MAGAZINE_INDEX_FOR_TINY_REGION(tiny));
+
+ // If acquiring the region lock was enough to prevent the owning
+ // magazine from deallocating the region, free it now so we don't
+ // do wasted work.
+ if (rack_region_maybe_dispose(rack, tiny, TINY_REGION_SIZE, trailer)) {
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+ continue;
+ }
/* Ordering is important here, the magazine of a region may potentially change
* during mag_lock_zine_for_region_trailer, so src_mag_index must be taken
@@ -861,6 +877,11 @@
continue;
}
+ if (REGION_TRAILER_FOR_TINY_REGION(tiny)->pinned_to_depot > 0) {
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+ continue;
+ }
+
if (tiny == mag_ptr->mag_last_region && (mag_ptr->mag_bytes_free_at_end || mag_ptr->mag_bytes_free_at_start)) {
tiny_finalize_region(rack, mag_ptr);
}
@@ -875,7 +896,7 @@
SZONE_MAGAZINE_PTR_LOCK(tiny_depot_ptr);
MAGAZINE_INDEX_FOR_TINY_REGION(tiny) = DEPOT_MAGAZINE_INDEX;
- REGION_TRAILER_FOR_TINY_REGION(tiny)->pinned_to_depot = 0;
+ MALLOC_ASSERT(REGION_TRAILER_FOR_TINY_REGION(tiny)->pinned_to_depot == 0);
size_t bytes_inplay = tiny_free_reattach_region(rack, tiny_depot_ptr, tiny);
@@ -981,22 +1002,32 @@
// Appropriate a Depot'd region that can satisfy requested msize.
region_trailer_t *node;
region_t sparse_region;
+ msize_t try_msize = msize;
while (1) {
- sparse_region = tiny_find_msize_region(rack, depot_ptr, DEPOT_MAGAZINE_INDEX, msize);
+ sparse_region = tiny_find_msize_region(rack, depot_ptr, DEPOT_MAGAZINE_INDEX, try_msize);
if (NULL == sparse_region) { // Depot empty?
SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
return 0;
}
node = REGION_TRAILER_FOR_TINY_REGION(sparse_region);
- if (0 >= node->pinned_to_depot) {
+ if (0 == node->pinned_to_depot) {
+ // Found one!
break;
}
- SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
- yield();
- SZONE_MAGAZINE_PTR_LOCK(depot_ptr);
+ // Try the next msize up - maybe the head of its free list will be in
+ // a region we can use. Once we get the region we'll still allocate the
+ // original msize.
+ try_msize++;
+
+ if (try_msize > NUM_TINY_SLOTS) {
+ // Tried all the msizes but couldn't get a usable region. Let's
+ // give up for now and we'll allocate a new region from the kernel.
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ return 0;
+ }
}
// disconnect node from Depot
@@ -1007,7 +1038,7 @@
// Transfer ownership of the region
MAGAZINE_INDEX_FOR_TINY_REGION(sparse_region) = mag_index;
- node->pinned_to_depot = 0;
+ MALLOC_ASSERT(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(rack, tiny_mag_ptr, sparse_region);
@@ -1049,32 +1080,19 @@
int objects_in_use = tiny_free_detach_region(rack, 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(rack->region_generation->hashed_regions,
- rack->region_generation->num_regions_allocated,
- rack->region_generation->num_regions_allocated_shift,
- sparse_region);
-
- if (NULL == pSlot) {
- malloc_zone_error(rack->debug_flags, true, "tiny_free_try_depot_unmap_no_lock hash lookup failed: %p\n", sparse_region);
+ if (!rack_region_remove(rack, sparse_region, node)) {
return NULL;
}
- *pSlot = HASHRING_REGION_DEALLOCATED;
depot_ptr->num_bytes_in_magazine -= TINY_HEAP_SIZE;
- // Atomically increment num_regions_dealloc
-#ifdef __LP64___
- OSAtomicIncrement64(&rack->num_regions_dealloc);
-#else
- OSAtomicIncrement32((int32_t *)&rack->num_regions_dealloc);
-#endif
-
// Caller will transfer ownership of the region back to the OS with no locks held
- MAGMALLOC_DEALLOCREGION(TINY_SZONE_FROM_RACK(rack), (void *)sparse_region, TINY_REGION_SIZE); // DTrace USDT Probe
+ MAGMALLOC_DEALLOCREGION(TINY_SZONE_FROM_RACK(rack),
+ (void *)sparse_region, TINY_REGION_SIZE); // DTrace USDT Probe
return sparse_region;
} else {
- malloc_zone_error(rack->debug_flags, true, "tiny_free_try_depot_unmap_no_lock objects_in_use not zero: %d\n", objects_in_use);
+ malloc_zone_error(rack->debug_flags, true,
+ "tiny_free_try_depot_unmap_no_lock objects_in_use not zero: %d\n",
+ objects_in_use);
return NULL;
}
}