mimalloc/src/init.c
2025-03-31 21:33:07 -07:00

699 lines
25 KiB
C

/* ----------------------------------------------------------------------------
Copyright (c) 2018-2022, Microsoft Research, Daan Leijen
This is free software; you can redistribute it and/or modify it under the
terms of the MIT license. A copy of the license can be found in the file
"LICENSE" at the root of this distribution.
-----------------------------------------------------------------------------*/
#include "mimalloc.h"
#include "mimalloc/internal.h"
#include "mimalloc/prim.h"
#include <string.h> // memcpy, memset
#include <stdlib.h> // atexit
// Empty page used to initialize the small free pages array
const mi_page_t _mi_page_empty = {
0,
false, false, false, false,
0, // capacity
0, // reserved capacity
{ 0 }, // flags
false, // is_zero
0, // retire_expire
NULL, // free
NULL, // local_free
0, // used
0, // block size shift
0, // heap tag
0, // block_size
NULL, // page_start
#if (MI_PADDING || MI_ENCODE_FREELIST)
{ 0, 0 },
#endif
MI_ATOMIC_VAR_INIT(0), // xthread_free
MI_ATOMIC_VAR_INIT(0), // xheap
NULL, NULL
#if MI_INTPTR_SIZE==4
, { NULL }
#endif
};
#define MI_PAGE_EMPTY() ((mi_page_t*)&_mi_page_empty)
#if (MI_PADDING>0) && (MI_INTPTR_SIZE >= 8)
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY(), MI_PAGE_EMPTY() }
#elif (MI_PADDING>0)
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY(), MI_PAGE_EMPTY(), MI_PAGE_EMPTY() }
#else
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY() }
#endif
// Empty page queues for every bin
#define QNULL(sz) { NULL, NULL, (sz)*sizeof(uintptr_t) }
#define MI_PAGE_QUEUES_EMPTY \
{ QNULL(1), \
QNULL( 1), QNULL( 2), QNULL( 3), QNULL( 4), QNULL( 5), QNULL( 6), QNULL( 7), QNULL( 8), /* 8 */ \
QNULL( 10), QNULL( 12), QNULL( 14), QNULL( 16), QNULL( 20), QNULL( 24), QNULL( 28), QNULL( 32), /* 16 */ \
QNULL( 40), QNULL( 48), QNULL( 56), QNULL( 64), QNULL( 80), QNULL( 96), QNULL( 112), QNULL( 128), /* 24 */ \
QNULL( 160), QNULL( 192), QNULL( 224), QNULL( 256), QNULL( 320), QNULL( 384), QNULL( 448), QNULL( 512), /* 32 */ \
QNULL( 640), QNULL( 768), QNULL( 896), QNULL( 1024), QNULL( 1280), QNULL( 1536), QNULL( 1792), QNULL( 2048), /* 40 */ \
QNULL( 2560), QNULL( 3072), QNULL( 3584), QNULL( 4096), QNULL( 5120), QNULL( 6144), QNULL( 7168), QNULL( 8192), /* 48 */ \
QNULL( 10240), QNULL( 12288), QNULL( 14336), QNULL( 16384), QNULL( 20480), QNULL( 24576), QNULL( 28672), QNULL( 32768), /* 56 */ \
QNULL( 40960), QNULL( 49152), QNULL( 57344), QNULL( 65536), QNULL( 81920), QNULL( 98304), QNULL(114688), QNULL(131072), /* 64 */ \
QNULL(163840), QNULL(196608), QNULL(229376), QNULL(262144), QNULL(327680), QNULL(393216), QNULL(458752), QNULL(524288), /* 72 */ \
QNULL(MI_LARGE_OBJ_WSIZE_MAX + 1 /* 655360, Huge queue */), \
QNULL(MI_LARGE_OBJ_WSIZE_MAX + 2) /* Full queue */ }
#define MI_STAT_COUNT_NULL() {0,0,0}
// Empty statistics
#define MI_STATS_NULL \
MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), \
MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), \
MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), MI_STAT_COUNT_NULL(), \
{ 0 }, { 0 }, { 0 }, { 0 }, \
{ 0 }, { 0 }, { 0 }, { 0 }, \
\
{ 0 }, { 0 }, { 0 }, { 0 }, { 0 }, \
MI_INIT4(MI_STAT_COUNT_NULL), \
{ 0 }, { 0 }, { 0 }, { 0 }, \
\
{ MI_INIT4(MI_STAT_COUNT_NULL) }, \
{ { 0 }, { 0 }, { 0 }, { 0 } }, \
\
{ MI_INIT74(MI_STAT_COUNT_NULL) }, \
{ MI_INIT74(MI_STAT_COUNT_NULL) }
// --------------------------------------------------------
// Statically allocate an empty heap as the initial
// thread local value for the default heap,
// and statically allocate the backing heap for the main
// thread so it can function without doing any allocation
// itself (as accessing a thread local for the first time
// may lead to allocation itself on some platforms)
// --------------------------------------------------------
mi_decl_cache_align const mi_heap_t _mi_heap_empty = {
NULL,
MI_ATOMIC_VAR_INIT(NULL),
0, // tid
0, // cookie
0, // arena id
{ 0, 0 }, // keys
{ {0}, {0}, 0, true }, // random
0, // page count
MI_BIN_FULL, 0, // page retired min/max
0, 0, // generic count
NULL, // next
false, // can reclaim
0, // tag
#if MI_GUARDED
0, 0, 0, 0, 1, // count is 1 so we never write to it (see `internal.h:mi_heap_malloc_use_guarded`)
#endif
MI_SMALL_PAGES_EMPTY,
MI_PAGE_QUEUES_EMPTY
};
mi_threadid_t _mi_thread_id(void) mi_attr_noexcept {
return _mi_prim_thread_id();
}
// the thread-local default heap for allocation
mi_decl_thread mi_heap_t* _mi_heap_default = (mi_heap_t*)&_mi_heap_empty;
extern mi_decl_hidden mi_heap_t _mi_heap_main;
static mi_decl_cache_align mi_subproc_t mi_subproc_default;
static mi_decl_cache_align mi_tld_t tld_main = {
0, false,
&_mi_heap_main, &_mi_heap_main,
{ { NULL, NULL }, {NULL ,NULL}, {NULL ,NULL, 0},
0, 0, 0, 0, 0, &mi_subproc_default,
&tld_main.stats
}, // segments
{ MI_STAT_VERSION, MI_STATS_NULL } // stats
};
mi_decl_cache_align mi_heap_t _mi_heap_main = {
&tld_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, true }, // random
0, // page count
MI_BIN_FULL, 0, // page retired min/max
0, 0, // generic count
NULL, // next heap
false, // can reclaim
0, // tag
#if MI_GUARDED
0, 0, 0, 0, 0,
#endif
MI_SMALL_PAGES_EMPTY,
MI_PAGE_QUEUES_EMPTY
};
bool _mi_process_is_initialized = false; // set to `true` in `mi_process_init`.
mi_stats_t _mi_stats_main = { MI_STAT_VERSION, MI_STATS_NULL };
#if MI_GUARDED
mi_decl_export void mi_heap_guarded_set_sample_rate(mi_heap_t* heap, size_t sample_rate, size_t seed) {
heap->guarded_sample_seed = seed;
if (heap->guarded_sample_seed == 0) {
heap->guarded_sample_seed = _mi_heap_random_next(heap);
}
heap->guarded_sample_rate = sample_rate;
if (heap->guarded_sample_rate >= 1) {
heap->guarded_sample_seed = heap->guarded_sample_seed % heap->guarded_sample_rate;
}
heap->guarded_sample_count = heap->guarded_sample_seed; // count down samples
}
mi_decl_export void mi_heap_guarded_set_size_bound(mi_heap_t* heap, size_t min, size_t max) {
heap->guarded_size_min = min;
heap->guarded_size_max = (min > max ? min : max);
}
void _mi_heap_guarded_init(mi_heap_t* heap) {
mi_heap_guarded_set_sample_rate(heap,
(size_t)mi_option_get_clamp(mi_option_guarded_sample_rate, 0, LONG_MAX),
(size_t)mi_option_get(mi_option_guarded_sample_seed));
mi_heap_guarded_set_size_bound(heap,
(size_t)mi_option_get_clamp(mi_option_guarded_min, 0, LONG_MAX),
(size_t)mi_option_get_clamp(mi_option_guarded_max, 0, LONG_MAX) );
}
#else
mi_decl_export void mi_heap_guarded_set_sample_rate(mi_heap_t* heap, size_t sample_rate, size_t seed) {
MI_UNUSED(heap); MI_UNUSED(sample_rate); MI_UNUSED(seed);
}
mi_decl_export void mi_heap_guarded_set_size_bound(mi_heap_t* heap, size_t min, size_t max) {
MI_UNUSED(heap); MI_UNUSED(min); MI_UNUSED(max);
}
void _mi_heap_guarded_init(mi_heap_t* heap) {
MI_UNUSED(heap);
}
#endif
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 = 1;
mi_thread_init();
#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);
mi_lock_init(&mi_subproc_default.abandoned_os_lock);
mi_lock_init(&mi_subproc_default.abandoned_os_visit_lock);
_mi_heap_guarded_init(&_mi_heap_main);
}
}
mi_heap_t* _mi_heap_main_get(void) {
mi_heap_main_init();
return &_mi_heap_main;
}
/* -----------------------------------------------------------
Sub process
----------------------------------------------------------- */
mi_subproc_id_t mi_subproc_main(void) {
return NULL;
}
mi_subproc_id_t mi_subproc_new(void) {
mi_memid_t memid = _mi_memid_none();
mi_subproc_t* subproc = (mi_subproc_t*)_mi_arena_meta_zalloc(sizeof(mi_subproc_t), &memid);
if (subproc == NULL) return NULL;
subproc->memid = memid;
subproc->abandoned_os_list = NULL;
mi_lock_init(&subproc->abandoned_os_lock);
mi_lock_init(&subproc->abandoned_os_visit_lock);
return subproc;
}
mi_subproc_t* _mi_subproc_from_id(mi_subproc_id_t subproc_id) {
return (subproc_id == NULL ? &mi_subproc_default : (mi_subproc_t*)subproc_id);
}
void mi_subproc_delete(mi_subproc_id_t subproc_id) {
if (subproc_id == NULL) return;
mi_subproc_t* subproc = _mi_subproc_from_id(subproc_id);
// check if there are no abandoned segments still..
bool safe_to_delete = false;
mi_lock(&subproc->abandoned_os_lock) {
if (subproc->abandoned_os_list == NULL) {
safe_to_delete = true;
}
}
if (!safe_to_delete) return;
// safe to release
// todo: should we refcount subprocesses?
mi_lock_done(&subproc->abandoned_os_lock);
mi_lock_done(&subproc->abandoned_os_visit_lock);
_mi_arena_meta_free(subproc, subproc->memid, sizeof(mi_subproc_t));
}
void mi_subproc_add_current_thread(mi_subproc_id_t subproc_id) {
mi_heap_t* heap = mi_heap_get_default();
if (heap == NULL) return;
mi_assert(heap->tld->segments.subproc == &mi_subproc_default);
if (heap->tld->segments.subproc != &mi_subproc_default) return;
heap->tld->segments.subproc = _mi_subproc_from_id(subproc_id);
}
/* -----------------------------------------------------------
Initialization and freeing of the thread local heaps
----------------------------------------------------------- */
// note: in x64 in release build `sizeof(mi_thread_data_t)` is under 4KiB (= OS page size).
typedef struct mi_thread_data_s {
mi_heap_t heap; // must come first due to cast in `_mi_heap_done`
mi_tld_t tld;
mi_memid_t memid; // must come last due to zero'ing
} mi_thread_data_t;
// Thread meta-data is allocated directly from the OS. For
// some programs that do not use thread pools and allocate and
// destroy many OS threads, this may causes too much overhead
// per thread so we maintain a small cache of recently freed metadata.
#define TD_CACHE_SIZE (32)
static _Atomic(mi_thread_data_t*) td_cache[TD_CACHE_SIZE];
static mi_thread_data_t* mi_thread_data_zalloc(void) {
// try to find thread metadata in the cache
bool is_zero = false;
mi_thread_data_t* td = NULL;
for (int i = 0; i < TD_CACHE_SIZE; i++) {
td = mi_atomic_load_ptr_relaxed(mi_thread_data_t, &td_cache[i]);
if (td != NULL) {
// found cached allocation, try use it
td = mi_atomic_exchange_ptr_acq_rel(mi_thread_data_t, &td_cache[i], NULL);
if (td != NULL) {
break;
}
}
}
// if that fails, allocate as meta data
if (td == NULL) {
mi_memid_t memid;
td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid);
if (td == NULL) {
// if this fails, try once more. (issue #257)
td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid);
if (td == NULL) {
// really out of memory
_mi_error_message(ENOMEM, "unable to allocate thread local heap metadata (%zu bytes)\n", sizeof(mi_thread_data_t));
}
}
if (td != NULL) {
td->memid = memid;
is_zero = memid.initially_zero;
}
}
if (td != NULL && !is_zero) {
_mi_memzero_aligned(td, offsetof(mi_thread_data_t,memid));
}
return td;
}
static void mi_thread_data_free( mi_thread_data_t* tdfree ) {
// try to add the thread metadata to the cache
for (int i = 0; i < TD_CACHE_SIZE; i++) {
mi_thread_data_t* td = mi_atomic_load_ptr_relaxed(mi_thread_data_t, &td_cache[i]);
if (td == NULL) {
mi_thread_data_t* expected = NULL;
if (mi_atomic_cas_ptr_weak_acq_rel(mi_thread_data_t, &td_cache[i], &expected, tdfree)) {
return;
}
}
}
// if that fails, just free it directly
_mi_os_free(tdfree, sizeof(mi_thread_data_t), tdfree->memid);
}
void _mi_thread_data_collect(void) {
// free all thread metadata from the cache
for (int i = 0; i < TD_CACHE_SIZE; i++) {
mi_thread_data_t* td = mi_atomic_load_ptr_relaxed(mi_thread_data_t, &td_cache[i]);
if (td != NULL) {
td = mi_atomic_exchange_ptr_acq_rel(mi_thread_data_t, &td_cache[i], NULL);
if (td != NULL) {
_mi_os_free(td, sizeof(mi_thread_data_t), td->memid);
}
}
}
}
// Initialize the thread local default heap, called from `mi_thread_init`
static bool _mi_thread_heap_init(void) {
if (mi_heap_is_initialized(mi_prim_get_default_heap())) return true;
if (_mi_is_main_thread()) {
// mi_assert_internal(_mi_heap_main.thread_id != 0); // can happen on freeBSD where alloc is called before any initialization
// the main heap is statically allocated
mi_heap_main_init();
_mi_heap_set_default_direct(&_mi_heap_main);
//mi_assert_internal(_mi_heap_default->tld->heap_backing == mi_prim_get_default_heap());
}
else {
// use `_mi_os_alloc` to allocate directly from the OS
mi_thread_data_t* td = mi_thread_data_zalloc();
if (td == NULL) return false;
mi_tld_t* tld = &td->tld;
mi_heap_t* heap = &td->heap;
_mi_tld_init(tld, heap); // must be before `_mi_heap_init`
_mi_heap_init(heap, tld, _mi_arena_id_none(), false /* can reclaim */, 0 /* default tag */);
_mi_heap_set_default_direct(heap);
}
return false;
}
// initialize thread local data
void _mi_tld_init(mi_tld_t* tld, mi_heap_t* bheap) {
_mi_memzero_aligned(tld,sizeof(mi_tld_t));
tld->heap_backing = bheap;
tld->heaps = NULL;
tld->segments.subproc = &mi_subproc_default;
tld->segments.stats = &tld->stats;
}
// Free the thread local default heap (called from `mi_thread_done`)
static bool _mi_thread_heap_done(mi_heap_t* heap) {
if (!mi_heap_is_initialized(heap)) return true;
// reset default heap
_mi_heap_set_default_direct(_mi_is_main_thread() ? &_mi_heap_main : (mi_heap_t*)&_mi_heap_empty);
// switch to backing heap
heap = heap->tld->heap_backing;
if (!mi_heap_is_initialized(heap)) return false;
// delete all non-backing heaps in this thread
mi_heap_t* curr = heap->tld->heaps;
while (curr != NULL) {
mi_heap_t* next = curr->next; // save `next` as `curr` will be freed
if (curr != heap) {
mi_assert_internal(!mi_heap_is_backing(curr));
mi_heap_delete(curr);
}
curr = next;
}
mi_assert_internal(heap->tld->heaps == heap && heap->next == NULL);
mi_assert_internal(mi_heap_is_backing(heap));
// collect if not the main thread
if (heap != &_mi_heap_main) {
_mi_heap_collect_abandon(heap);
}
// merge stats
_mi_stats_done(&heap->tld->stats);
// free if not the main thread
if (heap != &_mi_heap_main) {
mi_assert_internal(heap->tld->segments.count == 0 || heap->thread_id != _mi_thread_id());
mi_thread_data_free((mi_thread_data_t*)heap);
}
else {
#if 0
// never free the main thread even in debug mode; if a dll is linked statically with mimalloc,
// there may still be delete/free calls after the mi_fls_done is called. Issue #207
_mi_heap_destroy_pages(heap);
mi_assert_internal(heap->tld->heap_backing == &_mi_heap_main);
#endif
}
return false;
}
// --------------------------------------------------------
// Try to run `mi_thread_done()` automatically so any memory
// owned by the thread but not yet released can be abandoned
// and re-owned by another thread.
//
// 1. windows dynamic library:
// call from DllMain on DLL_THREAD_DETACH
// 2. windows static library:
// use `FlsAlloc` to call a destructor when the thread is done
// 3. unix, pthreads:
// use a pthread key to call a destructor when a pthread is done
//
// In the last two cases we also need to call `mi_process_init`
// to set up the thread local keys.
// --------------------------------------------------------
// Set up handlers so `mi_thread_done` is called automatically
static void mi_process_setup_auto_thread_done(void) {
static bool tls_initialized = false; // fine if it races
if (tls_initialized) return;
tls_initialized = true;
_mi_prim_thread_init_auto_done();
_mi_heap_set_default_direct(&_mi_heap_main);
}
bool _mi_is_main_thread(void) {
return (_mi_heap_main.thread_id==0 || _mi_heap_main.thread_id == _mi_thread_id());
}
static _Atomic(size_t) thread_count = MI_ATOMIC_VAR_INIT(1);
size_t _mi_current_thread_count(void) {
return mi_atomic_load_relaxed(&thread_count);
}
// This is called from the `mi_malloc_generic`
void mi_thread_init(void) mi_attr_noexcept
{
// ensure our process has started already
mi_process_init();
// initialize the thread local default heap
// (this will call `_mi_heap_set_default_direct` and thus set the
// fiber/pthread key to a non-zero value, ensuring `_mi_thread_done` is called)
if (_mi_thread_heap_init()) return; // returns true if already initialized
_mi_stat_increase(&_mi_stats_main.threads, 1);
mi_atomic_increment_relaxed(&thread_count);
//_mi_verbose_message("thread init: 0x%zx\n", _mi_thread_id());
}
void mi_thread_done(void) mi_attr_noexcept {
_mi_thread_done(NULL);
}
void _mi_thread_done(mi_heap_t* heap)
{
// calling with NULL implies using the default heap
if (heap == NULL) {
heap = mi_prim_get_default_heap();
if (heap == NULL) return;
}
// prevent re-entrancy through heap_done/heap_set_default_direct (issue #699)
if (!mi_heap_is_initialized(heap)) {
return;
}
// adjust stats
mi_atomic_decrement_relaxed(&thread_count);
_mi_stat_decrease(&_mi_stats_main.threads, 1);
// check thread-id as on Windows shutdown with FLS the main (exit) thread may call this on thread-local heaps...
if (heap->thread_id != _mi_thread_id()) return;
// abandon the thread local heap
if (_mi_thread_heap_done(heap)) return; // returns true if already ran
}
void _mi_heap_set_default_direct(mi_heap_t* heap) {
mi_assert_internal(heap != NULL);
#if defined(MI_TLS_SLOT)
mi_prim_tls_slot_set(MI_TLS_SLOT,heap);
#elif defined(MI_TLS_PTHREAD_SLOT_OFS)
*mi_prim_tls_pthread_heap_slot() = heap;
#elif defined(MI_TLS_PTHREAD)
// we use _mi_heap_default_key
#else
_mi_heap_default = heap;
#endif
// ensure the default heap is passed to `_mi_thread_done`
// setting to a non-NULL value also ensures `mi_thread_done` is called.
_mi_prim_thread_associate_default_heap(heap);
}
void mi_thread_set_in_threadpool(void) mi_attr_noexcept {
// nothing
}
// --------------------------------------------------------
// Run functions on process init/done, and thread init/done
// --------------------------------------------------------
static bool os_preloading = true; // true until this module is initialized
// Returns true if this module has not been initialized; Don't use C runtime routines until it returns false.
bool mi_decl_noinline _mi_preloading(void) {
return os_preloading;
}
// Returns true if mimalloc was redirected
mi_decl_nodiscard bool mi_is_redirected(void) mi_attr_noexcept {
return _mi_is_redirected();
}
// Called once by the process loader from `src/prim/prim.c`
void _mi_process_load(void) {
mi_heap_main_init();
#if defined(__APPLE__) || defined(MI_TLS_RECURSE_GUARD)
volatile mi_heap_t* dummy = _mi_heap_default; // access TLS to allocate it before setting tls_initialized to true;
if (dummy == NULL) return; // use dummy or otherwise the access may get optimized away (issue #697)
#endif
os_preloading = false;
mi_assert_internal(_mi_is_main_thread());
_mi_options_init();
mi_process_setup_auto_thread_done();
mi_process_init();
if (_mi_is_redirected()) _mi_verbose_message("malloc is redirected.\n");
// show message from the redirector (if present)
const char* msg = NULL;
_mi_allocator_init(&msg);
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))
#include <intrin.h>
mi_decl_cache_align bool _mi_cpu_has_fsrm = false;
mi_decl_cache_align bool _mi_cpu_has_erms = false;
static void mi_detect_cpu_features(void) {
// FSRM for fast short rep movsb/stosb support (AMD Zen3+ (~2020) or Intel Ice Lake+ (~2017))
// EMRS for fast enhanced rep movsb/stosb support
int32_t cpu_info[4];
__cpuid(cpu_info, 7);
_mi_cpu_has_fsrm = ((cpu_info[3] & (1 << 4)) != 0); // bit 4 of EDX : see <https://en.wikipedia.org/wiki/CPUID#EAX=7,_ECX=0:_Extended_Features>
_mi_cpu_has_erms = ((cpu_info[1] & (1 << 9)) != 0); // bit 9 of EBX : see <https://en.wikipedia.org/wiki/CPUID#EAX=7,_ECX=0:_Extended_Features>
}
#else
static void mi_detect_cpu_features(void) {
// nothing
}
#endif
// Initialize the process; called by thread_init or the process loader
void mi_process_init(void) mi_attr_noexcept {
// ensure we are called once
static mi_atomic_once_t process_init;
#if _MSC_VER < 1920
mi_heap_main_init(); // vs2017 can dynamically re-initialize _mi_heap_main
#endif
if (!mi_atomic_once(&process_init)) return;
_mi_process_is_initialized = true;
_mi_verbose_message("process init: 0x%zx\n", _mi_thread_id());
mi_process_setup_auto_thread_done();
mi_detect_cpu_features();
_mi_os_init();
mi_heap_main_init();
mi_thread_init();
#if defined(_WIN32)
// On windows, when building as a static lib the FLS cleanup happens to early for the main thread.
// To avoid this, set the FLS value for the main thread to NULL so the fls cleanup
// will not call _mi_thread_done on the (still executing) main thread. See issue #508.
_mi_prim_thread_associate_default_heap(NULL);
#endif
mi_stats_reset(); // only call stat reset *after* thread init (or the heap tld == NULL)
mi_track_init();
if (mi_option_is_enabled(mi_option_reserve_huge_os_pages)) {
size_t pages = mi_option_get_clamp(mi_option_reserve_huge_os_pages, 0, 128*1024);
long reserve_at = mi_option_get(mi_option_reserve_huge_os_pages_at);
if (reserve_at != -1) {
mi_reserve_huge_os_pages_at(pages, reserve_at, pages*500);
} else {
mi_reserve_huge_os_pages_interleave(pages, 0, pages*500);
}
}
if (mi_option_is_enabled(mi_option_reserve_os_memory)) {
long ksize = mi_option_get(mi_option_reserve_os_memory);
if (ksize > 0) {
mi_reserve_os_memory((size_t)ksize*MI_KiB, true, true);
}
}
}
// Called when the process is done (through `at_exit`)
void mi_cdecl _mi_process_done(void) {
// only shutdown if we were initialized
if (!_mi_process_is_initialized) return;
// ensure we are called once
static bool process_done = false;
if (process_done) return;
process_done = true;
// get the default heap so we don't need to acces thread locals anymore
mi_heap_t* heap = mi_prim_get_default_heap(); // use prim to not initialize any heap
mi_assert_internal(heap != NULL);
// release any thread specific resources and ensure _mi_thread_done is called on all but the main thread
_mi_prim_thread_done_auto_done();
#ifndef MI_SKIP_COLLECT_ON_EXIT
#if (MI_DEBUG || !defined(MI_SHARED_LIB))
// free all memory if possible on process exit. This is not needed for a stand-alone process
// but should be done if mimalloc is statically linked into another shared library which
// is repeatedly loaded/unloaded, see issue #281.
mi_heap_collect(heap, true /* force */ );
#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_collect(heap, true /* force */);
_mi_heap_unsafe_destroy_all(heap); // forcefully release all memory held by all heaps (of this thread only!)
_mi_arena_unsafe_destroy_all();
_mi_segment_map_unsafe_destroy();
}
if (mi_option_is_enabled(mi_option_show_stats) || mi_option_is_enabled(mi_option_verbose)) {
mi_stats_print(NULL);
}
_mi_allocator_done();
_mi_verbose_message("process done: 0x%zx\n", _mi_heap_main.thread_id);
os_preloading = true; // don't call the C runtime anymore
}