/* ----------------------------------------------------------------------------

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