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Editing: prim.h
/* ---------------------------------------------------------------------------- Copyright (c) 2018-2023, 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. -----------------------------------------------------------------------------*/ #pragma once #ifndef MIMALLOC_PRIM_H #define MIMALLOC_PRIM_H // -------------------------------------------------------------------------- // This file specifies the primitive portability API. // Each OS/host needs to implement these primitives, see `src/prim` // for implementations on Window, macOS, WASI, and Linux/Unix. // // note: on all primitive functions, we always have result parameters != NUL, and: // addr != NULL and page aligned // size > 0 and page aligned // return value is an error code an int where 0 is success. // -------------------------------------------------------------------------- // OS memory configuration typedef struct mi_os_mem_config_s { size_t page_size; // 4KiB size_t large_page_size; // 2MiB size_t alloc_granularity; // smallest allocation size (on Windows 64KiB) bool has_overcommit; // can we reserve more memory than can be actually committed? bool must_free_whole; // must allocated blocks be freed as a whole (false for mmap, true for VirtualAlloc) bool has_virtual_reserve; // supports virtual address space reservation? (if true we can reserve virtual address space without using commit or physical memory) } mi_os_mem_config_t; // Initialize void _mi_prim_mem_init( mi_os_mem_config_t* config ); // Free OS memory int _mi_prim_free(void* addr, size_t size ); // Allocate OS memory. Return NULL on error. // The `try_alignment` is just a hint and the returned pointer does not have to be aligned. // If `commit` is false, the virtual memory range only needs to be reserved (with no access) // which will later be committed explicitly using `_mi_prim_commit`. // `is_zero` is set to true if the memory was zero initialized (as on most OS's) // pre: !commit => !allow_large // try_alignment >= _mi_os_page_size() and a power of 2 int _mi_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, void** addr); // Commit memory. Returns error code or 0 on success. // For example, on Linux this would make the memory PROT_READ|PROT_WRITE. // `is_zero` is set to true if the memory was zero initialized (e.g. on Windows) int _mi_prim_commit(void* addr, size_t size, bool* is_zero); // Decommit memory. Returns error code or 0 on success. The `needs_recommit` result is true // if the memory would need to be re-committed. For example, on Windows this is always true, // but on Linux we could use MADV_DONTNEED to decommit which does not need a recommit. // pre: needs_recommit != NULL int _mi_prim_decommit(void* addr, size_t size, bool* needs_recommit); // Reset memory. The range keeps being accessible but the content might be reset. // Returns error code or 0 on success. int _mi_prim_reset(void* addr, size_t size); // Protect memory. Returns error code or 0 on success. int _mi_prim_protect(void* addr, size_t size, bool protect); // Allocate huge (1GiB) pages possibly associated with a NUMA node. // `is_zero` is set to true if the memory was zero initialized (as on most OS's) // pre: size > 0 and a multiple of 1GiB. // numa_node is either negative (don't care), or a numa node number. int _mi_prim_alloc_huge_os_pages(void* hint_addr, size_t size, int numa_node, bool* is_zero, void** addr); // Return the current NUMA node size_t _mi_prim_numa_node(void); // Return the number of logical NUMA nodes size_t _mi_prim_numa_node_count(void); // Clock ticks mi_msecs_t _mi_prim_clock_now(void); // Return process information (only for statistics) typedef struct mi_process_info_s { mi_msecs_t elapsed; mi_msecs_t utime; mi_msecs_t stime; size_t current_rss; size_t peak_rss; size_t current_commit; size_t peak_commit; size_t page_faults; } mi_process_info_t; void _mi_prim_process_info(mi_process_info_t* pinfo); // Default stderr output. (only for warnings etc. with verbose enabled) // msg != NULL && _mi_strlen(msg) > 0 void _mi_prim_out_stderr( const char* msg ); // Get an environment variable. (only for options) // name != NULL, result != NULL, result_size >= 64 bool _mi_prim_getenv(const char* name, char* result, size_t result_size); // Fill a buffer with strong randomness; return `false` on error or if // there is no strong randomization available. bool _mi_prim_random_buf(void* buf, size_t buf_len); // Called on the first thread start, and should ensure `_mi_thread_done` is called on thread termination. void _mi_prim_thread_init_auto_done(void); // Called on process exit and may take action to clean up resources associated with the thread auto done. void _mi_prim_thread_done_auto_done(void); // Called when the default heap for a thread changes void _mi_prim_thread_associate_default_heap(mi_heap_t* heap); //------------------------------------------------------------------- // Thread id: `_mi_prim_thread_id()` // // Getting the thread id should be performant as it is called in the // fast path of `_mi_free` and we specialize for various platforms as // inlined definitions. Regular code should call `init.c:_mi_thread_id()`. // We only require _mi_prim_thread_id() to return a unique id // for each thread (unequal to zero). //------------------------------------------------------------------- // defined in `init.c`; do not use these directly extern mi_decl_thread mi_heap_t* _mi_heap_default; // default heap to allocate from extern bool _mi_process_is_initialized; // has mi_process_init been called? static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept; #ifdef MI_PRIM_THREAD_ID static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept { return MI_PRIM_THREAD_ID(); } #elif defined(_WIN32) #define WIN32_LEAN_AND_MEAN #include <windows.h> static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept { // Windows: works on Intel and ARM in both 32- and 64-bit return (uintptr_t)NtCurrentTeb(); } // We use assembly for a fast thread id on the main platforms. The TLS layout depends on // both the OS and libc implementation so we use specific tests for each main platform. // If you test on another platform and it works please send a PR :-) // see also https://akkadia.org/drepper/tls.pdf for more info on the TLS register. #elif defined(__GNUC__) && ( \ (defined(__GLIBC__) && (defined(__x86_64__) || defined(__i386__) || (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__))) \ || (defined(__APPLE__) && (defined(__x86_64__) || defined(__aarch64__))) \ || (defined(__BIONIC__) && (defined(__x86_64__) || defined(__i386__) || (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__))) \ || (defined(__FreeBSD__) && (defined(__x86_64__) || defined(__i386__) || defined(__aarch64__))) \ || (defined(__OpenBSD__) && (defined(__x86_64__) || defined(__i386__) || defined(__aarch64__))) \ ) static inline void* mi_prim_tls_slot(size_t slot) mi_attr_noexcept { void* res; const size_t ofs = (slot*sizeof(void*)); #if defined(__i386__) __asm__("movl %%gs:%1, %0" : "=r" (res) : "m" (*((void**)ofs)) : ); // x86 32-bit always uses GS #elif defined(__APPLE__) && defined(__x86_64__) __asm__("movq %%gs:%1, %0" : "=r" (res) : "m" (*((void**)ofs)) : ); // x86_64 macOSX uses GS #elif defined(__x86_64__) && (MI_INTPTR_SIZE==4) __asm__("movl %%fs:%1, %0" : "=r" (res) : "m" (*((void**)ofs)) : ); // x32 ABI #elif defined(__x86_64__) __asm__("movq %%fs:%1, %0" : "=r" (res) : "m" (*((void**)ofs)) : ); // x86_64 Linux, BSD uses FS #elif defined(__arm__) void** tcb; MI_UNUSED(ofs); __asm__ volatile ("mrc p15, 0, %0, c13, c0, 3\nbic %0, %0, #3" : "=r" (tcb)); res = tcb[slot]; #elif defined(__aarch64__) void** tcb; MI_UNUSED(ofs); #if defined(__APPLE__) // M1, issue #343 __asm__ volatile ("mrs %0, tpidrro_el0\nbic %0, %0, #7" : "=r" (tcb)); #else __asm__ volatile ("mrs %0, tpidr_el0" : "=r" (tcb)); #endif res = tcb[slot]; #endif return res; } // setting a tls slot is only used on macOS for now static inline void mi_prim_tls_slot_set(size_t slot, void* value) mi_attr_noexcept { const size_t ofs = (slot*sizeof(void*)); #if defined(__i386__) __asm__("movl %1,%%gs:%0" : "=m" (*((void**)ofs)) : "rn" (value) : ); // 32-bit always uses GS #elif defined(__APPLE__) && defined(__x86_64__) __asm__("movq %1,%%gs:%0" : "=m" (*((void**)ofs)) : "rn" (value) : ); // x86_64 macOS uses GS #elif defined(__x86_64__) && (MI_INTPTR_SIZE==4) __asm__("movl %1,%%fs:%0" : "=m" (*((void**)ofs)) : "rn" (value) : ); // x32 ABI #elif defined(__x86_64__) __asm__("movq %1,%%fs:%0" : "=m" (*((void**)ofs)) : "rn" (value) : ); // x86_64 Linux, BSD uses FS #elif defined(__arm__) void** tcb; MI_UNUSED(ofs); __asm__ volatile ("mrc p15, 0, %0, c13, c0, 3\nbic %0, %0, #3" : "=r" (tcb)); tcb[slot] = value; #elif defined(__aarch64__) void** tcb; MI_UNUSED(ofs); #if defined(__APPLE__) // M1, issue #343 __asm__ volatile ("mrs %0, tpidrro_el0\nbic %0, %0, #7" : "=r" (tcb)); #else __asm__ volatile ("mrs %0, tpidr_el0" : "=r" (tcb)); #endif tcb[slot] = value; #endif } static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept { #if defined(__BIONIC__) // issue #384, #495: on the Bionic libc (Android), slot 1 is the thread id // see: https://github.com/aosp-mirror/platform_bionic/blob/c44b1d0676ded732df4b3b21c5f798eacae93228/libc/platform/bionic/tls_defines.h#L86 return (uintptr_t)mi_prim_tls_slot(1); #else // in all our other targets, slot 0 is the thread id // glibc: https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=sysdeps/x86_64/nptl/tls.h // apple: https://github.com/apple/darwin-xnu/blob/main/libsyscall/os/tsd.h#L36 return (uintptr_t)mi_prim_tls_slot(0); #endif } #else // otherwise use portable C, taking the address of a thread local variable (this is still very fast on most platforms). static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept { return (uintptr_t)&_mi_heap_default; } #endif /* ---------------------------------------------------------------------------------------- The thread local default heap: `_mi_prim_get_default_heap()` This is inlined here as it is on the fast path for allocation functions. On most platforms (Windows, Linux, FreeBSD, NetBSD, etc), this just returns a __thread local variable (`_mi_heap_default`). With the initial-exec TLS model this ensures that the storage will always be available (allocated on the thread stacks). On some platforms though we cannot use that when overriding `malloc` since the underlying TLS implementation (or the loader) will call itself `malloc` on a first access and recurse. We try to circumvent this in an efficient way: - macOSX : we use an unused TLS slot from the OS allocated slots (MI_TLS_SLOT). On OSX, the loader itself calls `malloc` even before the modules are initialized. - OpenBSD: we use an unused slot from the pthread block (MI_TLS_PTHREAD_SLOT_OFS). - DragonFly: defaults are working but seem slow compared to freeBSD (see PR #323) ------------------------------------------------------------------------------------------- */ static inline mi_heap_t* mi_prim_get_default_heap(void); #if defined(MI_MALLOC_OVERRIDE) #if defined(__APPLE__) // macOS #define MI_TLS_SLOT 89 // seems unused? // #define MI_TLS_RECURSE_GUARD 1 // other possible unused ones are 9, 29, __PTK_FRAMEWORK_JAVASCRIPTCORE_KEY4 (94), __PTK_FRAMEWORK_GC_KEY9 (112) and __PTK_FRAMEWORK_OLDGC_KEY9 (89) // see <https://github.com/rweichler/substrate/blob/master/include/pthread_machdep.h> #elif defined(__OpenBSD__) // use end bytes of a name; goes wrong if anyone uses names > 23 characters (ptrhread specifies 16) // see <https://github.com/openbsd/src/blob/master/lib/libc/include/thread_private.h#L371> #define MI_TLS_PTHREAD_SLOT_OFS (6*sizeof(int) + 4*sizeof(void*) + 24) // #elif defined(__DragonFly__) // #warning "mimalloc is not working correctly on DragonFly yet." // #define MI_TLS_PTHREAD_SLOT_OFS (4 + 1*sizeof(void*)) // offset `uniqueid` (also used by gdb?) <https://github.com/DragonFlyBSD/DragonFlyBSD/blob/master/lib/libthread_xu/thread/thr_private.h#L458> #elif defined(__ANDROID__) // See issue #381 #define MI_TLS_PTHREAD #endif #endif #if defined(MI_TLS_SLOT) static inline mi_heap_t* mi_prim_get_default_heap(void) { mi_heap_t* heap = (mi_heap_t*)mi_prim_tls_slot(MI_TLS_SLOT); if mi_unlikely(heap == NULL) { #ifdef __GNUC__ __asm(""); // prevent conditional load of the address of _mi_heap_empty #endif heap = (mi_heap_t*)&_mi_heap_empty; } return heap; } #elif defined(MI_TLS_PTHREAD_SLOT_OFS) static inline mi_heap_t** mi_prim_tls_pthread_heap_slot(void) { pthread_t self = pthread_self(); #if defined(__DragonFly__) if (self==NULL) return NULL; #endif return (mi_heap_t**)((uint8_t*)self + MI_TLS_PTHREAD_SLOT_OFS); } static inline mi_heap_t* mi_prim_get_default_heap(void) { mi_heap_t** pheap = mi_prim_tls_pthread_heap_slot(); if mi_unlikely(pheap == NULL) return _mi_heap_main_get(); mi_heap_t* heap = *pheap; if mi_unlikely(heap == NULL) return (mi_heap_t*)&_mi_heap_empty; return heap; } #elif defined(MI_TLS_PTHREAD) extern pthread_key_t _mi_heap_default_key; static inline mi_heap_t* mi_prim_get_default_heap(void) { mi_heap_t* heap = (mi_unlikely(_mi_heap_default_key == (pthread_key_t)(-1)) ? _mi_heap_main_get() : (mi_heap_t*)pthread_getspecific(_mi_heap_default_key)); return (mi_unlikely(heap == NULL) ? (mi_heap_t*)&_mi_heap_empty : heap); } #else // default using a thread local variable; used on most platforms. static inline mi_heap_t* mi_prim_get_default_heap(void) { #if defined(MI_TLS_RECURSE_GUARD) if (mi_unlikely(!_mi_process_is_initialized)) return _mi_heap_main_get(); #endif return _mi_heap_default; } #endif // mi_prim_get_default_heap() #endif // MIMALLOC_PRIM_H
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