Update mimalloc to v2.0.9 (#4211)

I recently [upstreamed the mimalloc fixes we developed in Git for
Windows](microsoft/mimalloc#654), most notably
the [fix for running in Windows Nano
Server](#4074). In the
meantime, that PR was accepted and a new version was created from it
(that also includes a couple of other fixes). Let's integrate the latest
version.

compat/mimalloc/bitmap.c

@@ -108,6 +108,25 @@ bool _mi_bitmap_try_find_from_claim(mi_bitmap_t bitmap, const size_t bitmap_fiel
   return false;
 }
 
+// Like _mi_bitmap_try_find_from_claim but with an extra predicate that must be fullfilled
+bool _mi_bitmap_try_find_from_claim_pred(mi_bitmap_t bitmap, const size_t bitmap_fields,
+	    const size_t start_field_idx, const size_t count,
+	    mi_bitmap_pred_fun_t pred_fun, void* pred_arg,
+	    mi_bitmap_index_t* bitmap_idx) {
+  size_t idx = start_field_idx;
+  for (size_t visited = 0; visited < bitmap_fields; visited++, idx++) {
+    if (idx >= bitmap_fields) idx = 0; // wrap
+    if (_mi_bitmap_try_find_claim_field(bitmap, idx, count, bitmap_idx)) {
+      if (pred_fun == NULL || pred_fun(*bitmap_idx, pred_arg)) {
+	return true;
+      }
+      // predicate returned false, unclaim and look further
+      _mi_bitmap_unclaim(bitmap, bitmap_fields, count, *bitmap_idx);
+    }
+  }
+  return false;
+}
+
 /*
 // Find `count` bits of 0 and set them to 1 atomically; returns `true` on success.
 // For now, `count` can be at most MI_BITMAP_FIELD_BITS and will never span fields.
@@ -283,7 +302,7 @@ bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitm
 static size_t mi_bitmap_mask_across(mi_bitmap_index_t bitmap_idx, size_t bitmap_fields, size_t count, size_t* pre_mask, size_t* mid_mask, size_t* post_mask) {
   MI_UNUSED_RELEASE(bitmap_fields);
   const size_t bitidx = mi_bitmap_index_bit_in_field(bitmap_idx);
-  if (mi_likely(bitidx + count <= MI_BITMAP_FIELD_BITS)) {
+  if mi_likely(bitidx + count <= MI_BITMAP_FIELD_BITS) {
     *pre_mask = mi_bitmap_mask_(count, bitidx);
     *mid_mask = 0;
     *post_mask = 0;

compat/mimalloc/bitmap.h

@@ -72,6 +72,10 @@ bool _mi_bitmap_try_find_claim_field(mi_bitmap_t bitmap, size_t idx, const size_
 // For now, `count` can be at most MI_BITMAP_FIELD_BITS and will never cross fields.
 bool _mi_bitmap_try_find_from_claim(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_index_t* bitmap_idx);
 
+// Like _mi_bitmap_try_find_from_claim but with an extra predicate that must be fullfilled
+typedef bool (mi_cdecl *mi_bitmap_pred_fun_t)(mi_bitmap_index_t bitmap_idx, void* pred_arg);
+bool _mi_bitmap_try_find_from_claim_pred(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_pred_fun_t pred_fun, void* pred_arg, mi_bitmap_index_t* bitmap_idx);
+
 // Set `count` bits at `bitmap_idx` to 0 atomically
 // Returns `true` if all `count` bits were 1 previously.
 bool _mi_bitmap_unclaim(mi_bitmap_t bitmap, size_t bitmap_fields, size_t count, mi_bitmap_index_t bitmap_idx);

compat/mimalloc/heap.c

@@ -139,9 +139,9 @@ static void mi_heap_collect_ex(mi_heap_t* heap, mi_collect_t collect)
     mi_heap_visit_pages(heap, &mi_heap_page_never_delayed_free, NULL, NULL);
   }
 
-  // free thread delayed blocks.
+  // free all current thread delayed blocks.
   // (if abandoning, after this there are no more thread-delayed references into the pages.)
-  _mi_heap_delayed_free(heap);
+  _mi_heap_delayed_free_all(heap);
 
   // collect retired pages
   _mi_heap_collect_retired(heap, force);
@@ -200,13 +200,14 @@ mi_heap_t* mi_heap_get_backing(void) {
   return bheap;
 }
 
-mi_heap_t* mi_heap_new(void) {
+mi_decl_nodiscard mi_heap_t* mi_heap_new_in_arena( mi_arena_id_t arena_id ) {
   mi_heap_t* bheap = mi_heap_get_backing();
   mi_heap_t* heap = mi_heap_malloc_tp(bheap, mi_heap_t);  // todo: OS allocate in secure mode?
   if (heap==NULL) return NULL;
   _mi_memcpy_aligned(heap, &_mi_heap_empty, sizeof(mi_heap_t));
   heap->tld = bheap->tld;
   heap->thread_id = _mi_thread_id();
+  heap->arena_id = arena_id;
   _mi_random_split(&bheap->random, &heap->random);
   heap->cookie  = _mi_heap_random_next(heap) | 1;
   heap->keys[0] = _mi_heap_random_next(heap);
@@ -218,6 +219,14 @@ mi_heap_t* mi_heap_new(void) {
   return heap;
 }
 
+mi_decl_nodiscard mi_heap_t* mi_heap_new(void) {
+  return mi_heap_new_in_arena(_mi_arena_id_none());
+}
+
+bool _mi_heap_memid_is_suitable(mi_heap_t* heap, size_t memid) {
+  return _mi_arena_memid_is_suitable(memid, heap->arena_id);
+}
+
 uintptr_t _mi_heap_random_next(mi_heap_t* heap) {
   return _mi_random_next(&heap->random);
 }
@@ -338,7 +347,20 @@ void mi_heap_destroy(mi_heap_t* heap) {
   }
 }
 
-
+void _mi_heap_destroy_all(void) {
+  mi_heap_t* bheap = mi_heap_get_backing();
+  mi_heap_t* curr = bheap->tld->heaps;
+  while (curr != NULL) {
+    mi_heap_t* next = curr->next;
+    if (curr->no_reclaim) {
+      mi_heap_destroy(curr);
+    }
+    else {
+      _mi_heap_destroy_pages(curr);
+    }
+    curr = next;
+  }
+}
 
 /* -----------------------------------------------------------
   Safe Heap delete
@@ -350,7 +372,7 @@ static void mi_heap_absorb(mi_heap_t* heap, mi_heap_t* from) {
   if (from==NULL || from->page_count == 0) return;
 
   // reduce the size of the delayed frees
-  _mi_heap_delayed_free(from);
+  _mi_heap_delayed_free_partial(from);
 
   // transfer all pages by appending the queues; this will set a new heap field
   // so threads may do delayed frees in either heap for a while.
@@ -369,7 +391,7 @@ static void mi_heap_absorb(mi_heap_t* heap, mi_heap_t* from) {
   // note: be careful here as the `heap` field in all those pages no longer point to `from`,
   // turns out to be ok as `_mi_heap_delayed_free` only visits the list and calls a
   // the regular `_mi_free_delayed_block` which is safe.
-  _mi_heap_delayed_free(from);
+  _mi_heap_delayed_free_all(from);
   #if !defined(_MSC_VER) || (_MSC_VER > 1900) // somehow the following line gives an error in VS2015, issue #353
   mi_assert_internal(mi_atomic_load_ptr_relaxed(mi_block_t,&from->thread_delayed_free) == NULL);
   #endif
@@ -421,7 +443,7 @@ static mi_heap_t* mi_heap_of_block(const void* p) {
   mi_segment_t* segment = _mi_ptr_segment(p);
   bool valid = (_mi_ptr_cookie(segment) == segment->cookie);
   mi_assert_internal(valid);
-  if (mi_unlikely(!valid)) return NULL;
+  if mi_unlikely(!valid) return NULL;
   return mi_page_heap(_mi_segment_page_of(segment,p));
 }
 
@@ -543,7 +565,7 @@ static bool mi_heap_visit_areas_page(mi_heap_t* heap, mi_page_queue_t* pq, mi_pa
   xarea.area.reserved = page->reserved * bsize;
   xarea.area.committed = page->capacity * bsize;
   xarea.area.blocks = _mi_page_start(_mi_page_segment(page), page, NULL);
-  xarea.area.used = page->used * bsize;
+  xarea.area.used = page->used;   // number of blocks in use (#553)
   xarea.area.block_size = ubsize;
   xarea.area.full_block_size = bsize;
   return fun(heap, &xarea, arg);

compat/mimalloc/init.c

@@ -19,12 +19,12 @@ const mi_page_t _mi_page_empty = {
   false,   // is_zero
   0,       // retire_expire
   NULL,    // free
-  #if MI_ENCODE_FREELIST
-  { 0, 0 },
-  #endif
   0,       // used
   0,       // xblock_size
   NULL,    // local_free
+  #if MI_ENCODE_FREELIST
+  { 0, 0 },
+  #endif
   MI_ATOMIC_VAR_INIT(0), // xthread_free
   MI_ATOMIC_VAR_INIT(0), // xheap
   NULL, NULL
@@ -109,8 +109,9 @@ mi_decl_cache_align const mi_heap_t _mi_heap_empty = {
   MI_ATOMIC_VAR_INIT(NULL),
   0,                // tid
   0,                // cookie
+  0,                // arena id
   { 0, 0 },         // keys
-  { {0}, {0}, 0 },
+  { {0}, {0}, 0, true }, // random
   0,                // page count
   MI_BIN_FULL, 0,   // page retired min/max
   NULL,             // next
@@ -149,8 +150,9 @@ mi_heap_t _mi_heap_main = {
   MI_ATOMIC_VAR_INIT(NULL),
   0,                // thread id
   0,                // initial cookie
+  0,                // arena id
   { 0, 0 },         // the key of the main heap can be fixed (unlike page keys that need to be secure!)
-  { {0x846ca68b}, {0}, 0 },  // random
+  { {0x846ca68b}, {0}, 0, true },  // random
   0,                // page count
   MI_BIN_FULL, 0,   // page retired min/max
   NULL,             // next heap
@@ -165,8 +167,13 @@ mi_stats_t _mi_stats_main = { MI_STATS_NULL };
 static void mi_heap_main_init(void) {
   if (_mi_heap_main.cookie == 0) {
     _mi_heap_main.thread_id = _mi_thread_id();
-    _mi_heap_main.cookie = _mi_os_random_weak((uintptr_t)&mi_heap_main_init);
-    _mi_random_init(&_mi_heap_main.random);
+    _mi_heap_main.cookie = 1;
+    #if defined(_WIN32) && !defined(MI_SHARED_LIB)
+      _mi_random_init_weak(&_mi_heap_main.random);    // prevent allocation failure during bcrypt dll initialization with static linking
+    #else
+      _mi_random_init(&_mi_heap_main.random);
+    #endif
+    _mi_heap_main.cookie  = _mi_heap_random_next(&_mi_heap_main);
     _mi_heap_main.keys[0] = _mi_heap_random_next(&_mi_heap_main);
     _mi_heap_main.keys[1] = _mi_heap_random_next(&_mi_heap_main);
   }
@@ -372,7 +379,11 @@ static void _mi_thread_done(mi_heap_t* default_heap);
   #endif
   static DWORD mi_fls_key = (DWORD)(-1);
   static void NTAPI mi_fls_done(PVOID value) {
-    if (value!=NULL) _mi_thread_done((mi_heap_t*)value);
+    mi_heap_t* heap = (mi_heap_t*)value;
+    if (heap != NULL) {
+      _mi_thread_done(heap);
+      FlsSetValue(mi_fls_key, NULL);  // prevent recursion as _mi_thread_done may set it back to the main heap, issue #672
+    }
   }
 #elif defined(MI_USE_PTHREADS)
   // use pthread local storage keys to detect thread ending
@@ -475,7 +486,7 @@ void _mi_heap_set_default_direct(mi_heap_t* heap)  {
 // --------------------------------------------------------
 // Run functions on process init/done, and thread init/done
 // --------------------------------------------------------
-static void mi_process_done(void);
+static void mi_cdecl mi_process_done(void);
 
 static bool os_preloading = true;    // true until this module is initialized
 static bool mi_redirected = false;   // true if malloc redirects to mi_malloc
@@ -490,7 +501,7 @@ mi_decl_nodiscard bool mi_is_redirected(void) mi_attr_noexcept {
 }
 
 // Communicate with the redirection module on Windows
-#if defined(_WIN32) && defined(MI_SHARED_LIB)
+#if defined(_WIN32) && defined(MI_SHARED_LIB) && !defined(MI_WIN_NOREDIRECT)
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -506,8 +517,8 @@ mi_decl_export void _mi_redirect_entry(DWORD reason) {
     mi_thread_done();
   }
 }
-__declspec(dllimport) bool mi_allocator_init(const char** message);
-__declspec(dllimport) void mi_allocator_done(void);
+__declspec(dllimport) bool mi_cdecl mi_allocator_init(const char** message);
+__declspec(dllimport) void mi_cdecl mi_allocator_done(void);
 #ifdef __cplusplus
 }
 #endif
@@ -529,12 +540,13 @@ static void mi_process_load(void) {
   MI_UNUSED(dummy);
   #endif
   os_preloading = false;
+  mi_assert_internal(_mi_is_main_thread());
   #if !(defined(_WIN32) && defined(MI_SHARED_LIB))  // use Dll process detach (see below) instead of atexit (issue #521)
   atexit(&mi_process_done);
   #endif
   _mi_options_init();
+  mi_process_setup_auto_thread_done();
   mi_process_init();
-  //mi_stats_reset();-
   if (mi_redirected) _mi_verbose_message("malloc is redirected.\n");
 
   // show message from the redirector (if present)
@@ -543,6 +555,9 @@ static void mi_process_load(void) {
   if (msg != NULL && (mi_option_is_enabled(mi_option_verbose) || mi_option_is_enabled(mi_option_show_errors))) {
     _mi_fputs(NULL,NULL,NULL,msg);
   }
+
+  // reseed random
+  _mi_random_reinit_if_weak(&_mi_heap_main.random);
 }
 
 #if defined(_WIN32) && (defined(_M_IX86) || defined(_M_X64))
@@ -569,14 +584,14 @@ void mi_process_init(void) mi_attr_noexcept {
   _mi_process_is_initialized = true;
   mi_process_setup_auto_thread_done();
 
-
   mi_detect_cpu_features();
   _mi_os_init();
   mi_heap_main_init();
   #if (MI_DEBUG)
   _mi_verbose_message("debug level : %d\n", MI_DEBUG);
   #endif
   _mi_verbose_message("secure level: %d\n", MI_SECURE);
+  _mi_verbose_message("mem tracking: %s\n", MI_TRACK_TOOL);
   mi_thread_init();
 
   #if defined(_WIN32) && !defined(MI_SHARED_LIB)
@@ -606,7 +621,7 @@ void mi_process_init(void) mi_attr_noexcept {
 }
 
 // Called when the process is done (through `at_exit`)
-static void mi_process_done(void) {
+static void mi_cdecl mi_process_done(void) {
   // only shutdown if we were initialized
   if (!_mi_process_is_initialized) return;
   // ensure we are called once
@@ -627,6 +642,14 @@ static void mi_process_done(void) {
     #endif
   #endif
 
+  // Forcefully release all retained memory; this can be dangerous in general if overriding regular malloc/free
+  // since after process_done there might still be other code running that calls `free` (like at_exit routines,
+  // or C-runtime termination code.
+  if (mi_option_is_enabled(mi_option_destroy_on_exit)) {
+    _mi_heap_destroy_all();                          // forcefully release all memory held by all heaps (of this thread only!)
+    _mi_segment_cache_free_all(&_mi_heap_main_get()->tld->os);  // release all cached segments
+  }
+
   if (mi_option_is_enabled(mi_option_show_stats) || mi_option_is_enabled(mi_option_verbose)) {
     mi_stats_print(NULL);
   }