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

Copyright (c) 2018-2021, 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/atomic.h"

#include "mimalloc/prim.h"  // mi_prim_out_stderr

#include <stdio.h>      // FILE

#include <stdlib.h>     // abort

#include <stdarg.h>

static long mi_max_error_count   = 16; // stop outputting errors after this (use < 0 for no limit)

static long mi_max_warning_count = 16; // stop outputting warnings after this (use < 0 for no limit)

static void mi_add_stderr_output(void);

int mi_version(void) mi_attr_noexcept {

  return MI_MALLOC_VERSION;

}

// --------------------------------------------------------

// Options

// These can be accessed by multiple threads and may be

// concurrently initialized, but an initializing data race

// is ok since they resolve to the same value.

// --------------------------------------------------------

typedef enum mi_init_e {

  UNINIT,       // not yet initialized

  DEFAULTED,    // not found in the environment, use default value

  INITIALIZED   // found in environment or set explicitly

} mi_init_t;

typedef struct mi_option_desc_s {

  long        value;  // the value

  mi_init_t   init;   // is it initialized yet? (from the environment)

  mi_option_t option; // for debugging: the option index should match the option

  const char* name;   // option name without `mimalloc_` prefix

  const char* legacy_name; // potential legacy option name

} mi_option_desc_t;

#define MI_OPTION(opt)                  mi_option_##opt, #opt, NULL

#define MI_OPTION_LEGACY(opt,legacy)    mi_option_##opt, #opt, #legacy

static mi_option_desc_t options[_mi_option_last] =

{

  // stable options

  #if MI_DEBUG || defined(MI_SHOW_ERRORS)

  { 1, UNINIT, MI_OPTION(show_errors) },

  #else

  { 0, UNINIT, MI_OPTION(show_errors) },

  #endif

  { 0, UNINIT, MI_OPTION(show_stats) },

  { 0, UNINIT, MI_OPTION(verbose) },

  // the following options are experimental and not all combinations make sense.

  { 1, UNINIT, MI_OPTION(eager_commit) },               // commit per segment directly (4MiB)  (but see also `eager_commit_delay`)

  { 2, UNINIT, MI_OPTION_LEGACY(arena_eager_commit,eager_region_commit) }, // eager commit arena's? 2 is used to enable this only on an OS that has overcommit (i.e. linux)

  { 1, UNINIT, MI_OPTION_LEGACY(purge_decommits,reset_decommits) },        // purge decommits memory (instead of reset) (note: on linux this uses MADV_DONTNEED for decommit)

  { 0, UNINIT, MI_OPTION_LEGACY(allow_large_os_pages,large_os_pages) },    // use large OS pages, use only with eager commit to prevent fragmentation of VMA's

  { 0, UNINIT, MI_OPTION(reserve_huge_os_pages) },      // per 1GiB huge pages

  {-1, UNINIT, MI_OPTION(reserve_huge_os_pages_at) },   // reserve huge pages at node N

  { 0, UNINIT, MI_OPTION(reserve_os_memory)     },

  { 0, UNINIT, MI_OPTION(deprecated_segment_cache) },   // cache N segments per thread

  { 0, UNINIT, MI_OPTION(deprecated_page_reset) },      // reset page memory on free

  { 0, UNINIT, MI_OPTION_LEGACY(abandoned_page_purge,abandoned_page_reset) },       // reset free page memory when a thread terminates

  { 0, UNINIT, MI_OPTION(deprecated_segment_reset) },   // reset segment memory on free (needs eager commit)

#if defined(__NetBSD__)

  { 0, UNINIT, MI_OPTION(eager_commit_delay) },         // the first N segments per thread are not eagerly committed

#else

  { 1, UNINIT, MI_OPTION(eager_commit_delay) },         // the first N segments per thread are not eagerly committed (but per page in the segment on demand)

#endif

  { 10,  UNINIT, MI_OPTION_LEGACY(purge_delay,reset_delay) },  // purge delay in milli-seconds

  { 0,   UNINIT, MI_OPTION(use_numa_nodes) },           // 0 = use available numa nodes, otherwise use at most N nodes.

  { 0,   UNINIT, MI_OPTION(limit_os_alloc) },           // 1 = do not use OS memory for allocation (but only reserved arenas)

  { 100, UNINIT, MI_OPTION(os_tag) },                   // only apple specific for now but might serve more or less related purpose

  { 16,  UNINIT, MI_OPTION(max_errors) },               // maximum errors that are output

  { 16,  UNINIT, MI_OPTION(max_warnings) },             // maximum warnings that are output

  { 8,   UNINIT, MI_OPTION(max_segment_reclaim)},       // max. number of segment reclaims from the abandoned segments per try.

  { 0,   UNINIT, MI_OPTION(destroy_on_exit)},           // release all OS memory on process exit; careful with dangling pointer or after-exit frees!

  #if (MI_INTPTR_SIZE>4)

  { 1024L * 1024L, UNINIT, MI_OPTION(arena_reserve) },  // reserve memory N KiB at a time

  #else

  {  128L * 1024L, UNINIT, MI_OPTION(arena_reserve) },

  #endif

  { 10,  UNINIT, MI_OPTION(arena_purge_mult) },        // purge delay multiplier for arena's

  { 1,   UNINIT, MI_OPTION_LEGACY(purge_extend_delay, decommit_extend_delay) },

};

static void mi_option_init(mi_option_desc_t* desc);

void _mi_options_init(void) {

  // called on process load; should not be called before the CRT is initialized!

  // (e.g. do not call this from process_init as that may run before CRT initialization)

  mi_add_stderr_output(); // now it safe to use stderr for output

  for(int i = 0; i < _mi_option_last; i++ ) {

    mi_option_t option = (mi_option_t)i;

    long l = mi_option_get(option); MI_UNUSED(l); // initialize

    // if (option != mi_option_verbose)

    {

      mi_option_desc_t* desc = &options[option];

      _mi_verbose_message("option '%s': %ld\n", desc->name, desc->value);

    }

  }

  mi_max_error_count = mi_option_get(mi_option_max_errors);

  mi_max_warning_count = mi_option_get(mi_option_max_warnings);

}

mi_decl_nodiscard long mi_option_get(mi_option_t option) {

  mi_assert(option >= 0 && option < _mi_option_last);

  if (option < 0 || option >= _mi_option_last) return 0;

  mi_option_desc_t* desc = &options[option];

  mi_assert(desc->option == option);  // index should match the option

  if mi_unlikely(desc->init == UNINIT) {

    mi_option_init(desc);

  }

  return desc->value;

}

mi_decl_nodiscard long mi_option_get_clamp(mi_option_t option, long min, long max) {

  long x = mi_option_get(option);

  return (x < min ? min : (x > max ? max : x));

}

mi_decl_nodiscard size_t mi_option_get_size(mi_option_t option) {

  mi_assert_internal(option == mi_option_reserve_os_memory || option == mi_option_arena_reserve);

  long x = mi_option_get(option);

  return (x < 0 ? 0 : (size_t)x * MI_KiB);

}

void mi_option_set(mi_option_t option, long value) {

  mi_assert(option >= 0 && option < _mi_option_last);

  if (option < 0 || option >= _mi_option_last) return;

  mi_option_desc_t* desc = &options[option];

  mi_assert(desc->option == option);  // index should match the option

  desc->value = value;

  desc->init = INITIALIZED;

}

void mi_option_set_default(mi_option_t option, long value) {

  mi_assert(option >= 0 && option < _mi_option_last);

  if (option < 0 || option >= _mi_option_last) return;

  mi_option_desc_t* desc = &options[option];

  if (desc->init != INITIALIZED) {

    desc->value = value;

  }

}

mi_decl_nodiscard bool mi_option_is_enabled(mi_option_t option) {

  return (mi_option_get(option) != 0);

}

void mi_option_set_enabled(mi_option_t option, bool enable) {

  mi_option_set(option, (enable ? 1 : 0));

}

void mi_option_set_enabled_default(mi_option_t option, bool enable) {

  mi_option_set_default(option, (enable ? 1 : 0));

}

void mi_option_enable(mi_option_t option) {

  mi_option_set_enabled(option,true);

}

void mi_option_disable(mi_option_t option) {

  mi_option_set_enabled(option,false);

}

static void mi_cdecl mi_out_stderr(const char* msg, void* arg) {

  MI_UNUSED(arg);

  if (msg != NULL && msg[0] != 0) {

    _mi_prim_out_stderr(msg);

  }

}

// Since an output function can be registered earliest in the `main`

// function we also buffer output that happens earlier. When

// an output function is registered it is called immediately with

// the output up to that point.

#ifndef MI_MAX_DELAY_OUTPUT

#define MI_MAX_DELAY_OUTPUT ((size_t)(32*1024))

#endif

static char out_buf[MI_MAX_DELAY_OUTPUT+1];

static _Atomic(size_t) out_len;

static void mi_cdecl mi_out_buf(const char* msg, void* arg) {

  MI_UNUSED(arg);

  if (msg==NULL) return;

  if (mi_atomic_load_relaxed(&out_len)>=MI_MAX_DELAY_OUTPUT) return;

  size_t n = _mi_strlen(msg);

  if (n==0) return;

  // claim space

  size_t start = mi_atomic_add_acq_rel(&out_len, n);

  if (start >= MI_MAX_DELAY_OUTPUT) return;

  // check bound

  if (start+n >= MI_MAX_DELAY_OUTPUT) {

    n = MI_MAX_DELAY_OUTPUT-start-1;

  }

  _mi_memcpy(&out_buf[start], msg, n);

}

static void mi_out_buf_flush(mi_output_fun* out, bool no_more_buf, void* arg) {

  if (out==NULL) return;

  // claim (if `no_more_buf == true`, no more output will be added after this point)

  size_t count = mi_atomic_add_acq_rel(&out_len, (no_more_buf ? MI_MAX_DELAY_OUTPUT : 1));

  // and output the current contents

  if (count>MI_MAX_DELAY_OUTPUT) count = MI_MAX_DELAY_OUTPUT;

  out_buf[count] = 0;

  out(out_buf,arg);

  if (!no_more_buf) {

    out_buf[count] = '\n'; // if continue with the buffer, insert a newline

  }

}

// Once this module is loaded, switch to this routine

// which outputs to stderr and the delayed output buffer.

static void mi_cdecl mi_out_buf_stderr(const char* msg, void* arg) {

  mi_out_stderr(msg,arg);

  mi_out_buf(msg,arg);

}

// --------------------------------------------------------

// Default output handler

// --------------------------------------------------------

// Should be atomic but gives errors on many platforms as generally we cannot cast a function pointer to a uintptr_t.

// For now, don't register output from multiple threads.

static mi_output_fun* volatile mi_out_default; // = NULL

static _Atomic(void*) mi_out_arg; // = NULL

static mi_output_fun* mi_out_get_default(void** parg) {

  if (parg != NULL) { *parg = mi_atomic_load_ptr_acquire(void,&mi_out_arg); }

  mi_output_fun* out = mi_out_default;

  return (out == NULL ? &mi_out_buf : out);

}

void mi_register_output(mi_output_fun* out, void* arg) mi_attr_noexcept {

  mi_out_default = (out == NULL ? &mi_out_stderr : out); // stop using the delayed output buffer

  mi_atomic_store_ptr_release(void,&mi_out_arg, arg);

  if (out!=NULL) mi_out_buf_flush(out,true,arg);         // output all the delayed output now

}

// add stderr to the delayed output after the module is loaded

static void mi_add_stderr_output(void) {

  mi_assert_internal(mi_out_default == NULL);

  mi_out_buf_flush(&mi_out_stderr, false, NULL); // flush current contents to stderr

  mi_out_default = &mi_out_buf_stderr;           // and add stderr to the delayed output

}

// --------------------------------------------------------

// Messages, all end up calling `_mi_fputs`.

// --------------------------------------------------------

static _Atomic(size_t) error_count;   // = 0;  // when >= max_error_count stop emitting errors

static _Atomic(size_t) warning_count; // = 0;  // when >= max_warning_count stop emitting warnings

// When overriding malloc, we may recurse into mi_vfprintf if an allocation

// inside the C runtime causes another message.

// In some cases (like on macOS) the loader already allocates which

// calls into mimalloc; if we then access thread locals (like `recurse`)

// this may crash as the access may call _tlv_bootstrap that tries to

// (recursively) invoke malloc again to allocate space for the thread local

// variables on demand. This is why we use a _mi_preloading test on such

// platforms. However, C code generator may move the initial thread local address

// load before the `if` and we therefore split it out in a separate function.

static mi_decl_thread bool recurse = false;

static mi_decl_noinline bool mi_recurse_enter_prim(void) {

  if (recurse) return false;

  recurse = true;

  return true;

}

static mi_decl_noinline void mi_recurse_exit_prim(void) {

  recurse = false;

}

static bool mi_recurse_enter(void) {

  #if defined(__APPLE__) || defined(MI_TLS_RECURSE_GUARD)

  if (_mi_preloading()) return false;

  #endif

  return mi_recurse_enter_prim();

}

static void mi_recurse_exit(void) {

  #if defined(__APPLE__) || defined(MI_TLS_RECURSE_GUARD)

  if (_mi_preloading()) return;

  #endif

  mi_recurse_exit_prim();

}

void _mi_fputs(mi_output_fun* out, void* arg, const char* prefix, const char* message) {

  if (out==NULL || (void*)out==(void*)stdout || (void*)out==(void*)stderr) { // TODO: use mi_out_stderr for stderr?

    if (!mi_recurse_enter()) return;

    out = mi_out_get_default(&arg);

    if (prefix != NULL) out(prefix, arg);

    out(message, arg);

    mi_recurse_exit();

  }

  else {

    if (prefix != NULL) out(prefix, arg);

    out(message, arg);

  }

}

// Define our own limited `fprintf` that avoids memory allocation.

// We do this using `snprintf` with a limited buffer.

static void mi_vfprintf( mi_output_fun* out, void* arg, const char* prefix, const char* fmt, va_list args ) {

  char buf[512];

  if (fmt==NULL) return;

  if (!mi_recurse_enter()) return;

  vsnprintf(buf,sizeof(buf)-1,fmt,args);

  mi_recurse_exit();

  _mi_fputs(out,arg,prefix,buf);

}

void _mi_fprintf( mi_output_fun* out, void* arg, const char* fmt, ... ) {

  va_list args;

  va_start(args,fmt);

  mi_vfprintf(out,arg,NULL,fmt,args);

  va_end(args);

}

static void mi_vfprintf_thread(mi_output_fun* out, void* arg, const char* prefix, const char* fmt, va_list args) {

  if (prefix != NULL && _mi_strnlen(prefix,33) <= 32 && !_mi_is_main_thread()) {

    char tprefix[64];

    snprintf(tprefix, sizeof(tprefix), "%sthread 0x%llx: ", prefix, (unsigned long long)_mi_thread_id());

    mi_vfprintf(out, arg, tprefix, fmt, args);

  }

  else {

    mi_vfprintf(out, arg, prefix, fmt, args);

  }

}

void _mi_trace_message(const char* fmt, ...) {

  if (mi_option_get(mi_option_verbose) <= 1) return;  // only with verbose level 2 or higher

  va_list args;

  va_start(args, fmt);

  mi_vfprintf_thread(NULL, NULL, "mimalloc: ", fmt, args);

  va_end(args);

}

void _mi_verbose_message(const char* fmt, ...) {

  if (!mi_option_is_enabled(mi_option_verbose)) return;

  va_list args;

  va_start(args,fmt);

  mi_vfprintf(NULL, NULL, "mimalloc: ", fmt, args);

  va_end(args);

}

static void mi_show_error_message(const char* fmt, va_list args) {

  if (!mi_option_is_enabled(mi_option_verbose)) {

    if (!mi_option_is_enabled(mi_option_show_errors)) return;

    if (mi_max_error_count >= 0 && (long)mi_atomic_increment_acq_rel(&error_count) > mi_max_error_count) return;

  }

  mi_vfprintf_thread(NULL, NULL, "mimalloc: error: ", fmt, args);

}

void _mi_warning_message(const char* fmt, ...) {

  if (!mi_option_is_enabled(mi_option_verbose)) {

    if (!mi_option_is_enabled(mi_option_show_errors)) return;

    if (mi_max_warning_count >= 0 && (long)mi_atomic_increment_acq_rel(&warning_count) > mi_max_warning_count) return;

  }

  va_list args;

  va_start(args,fmt);

  mi_vfprintf_thread(NULL, NULL, "mimalloc: warning: ", fmt, args);

  va_end(args);

}

#if MI_DEBUG

void _mi_assert_fail(const char* assertion, const char* fname, unsigned line, const char* func ) {

  _mi_fprintf(NULL, NULL, "mimalloc: assertion failed: at \"%s\":%u, %s\n  assertion: \"%s\"\n", fname, line, (func==NULL?"":func), assertion);

  abort();

}

#endif

// --------------------------------------------------------

// Errors

// --------------------------------------------------------

static mi_error_fun* volatile  mi_error_handler; // = NULL

static _Atomic(void*) mi_error_arg;     // = NULL

static void mi_error_default(int err) {

  MI_UNUSED(err);

#if (MI_DEBUG>0)

  if (err==EFAULT) {

    #ifdef _MSC_VER

    __debugbreak();

    #endif

    abort();

  }

#endif

#if (MI_SECURE>0)

  if (err==EFAULT) {  // abort on serious errors in secure mode (corrupted meta-data)

    abort();

  }

#endif

#if defined(MI_XMALLOC)

  if (err==ENOMEM || err==EOVERFLOW) { // abort on memory allocation fails in xmalloc mode

    abort();

  }

#endif

}

void mi_register_error(mi_error_fun* fun, void* arg) {

  mi_error_handler = fun;  // can be NULL

  mi_atomic_store_ptr_release(void,&mi_error_arg, arg);

}

void _mi_error_message(int err, const char* fmt, ...) {

  // show detailed error message

  va_list args;

  va_start(args, fmt);

  mi_show_error_message(fmt, args);

  va_end(args);

  // and call the error handler which may abort (or return normally)

  if (mi_error_handler != NULL) {

    mi_error_handler(err, mi_atomic_load_ptr_acquire(void,&mi_error_arg));

  }

  else {

    mi_error_default(err);

  }

}

// --------------------------------------------------------

// Initialize options by checking the environment

// --------------------------------------------------------

char _mi_toupper(char c) {

  if (c >= 'a' && c <= 'z') return (c - 'a' + 'A');

                       else return c;

}

int _mi_strnicmp(const char* s, const char* t, size_t n) {

  if (n == 0) return 0;

  for (; *s != 0 && *t != 0 && n > 0; s++, t++, n--) {

    if (_mi_toupper(*s) != _mi_toupper(*t)) break;

  }

  return (n == 0 ? 0 : *s - *t);

}

void _mi_strlcpy(char* dest, const char* src, size_t dest_size) {

  if (dest==NULL || src==NULL || dest_size == 0) return;

  // copy until end of src, or when dest is (almost) full

  while (*src != 0 && dest_size > 1) {

    *dest++ = *src++;

    dest_size--;

  }

  // always zero terminate

  *dest = 0;

}

void _mi_strlcat(char* dest, const char* src, size_t dest_size) {

  if (dest==NULL || src==NULL || dest_size == 0) return;

  // find end of string in the dest buffer

  while (*dest != 0 && dest_size > 1) {

    dest++;

    dest_size--;

  }

  // and catenate

  _mi_strlcpy(dest, src, dest_size);

}

size_t _mi_strlen(const char* s) {

  if (s==NULL) return 0;

  size_t len = 0;

  while(s[len] != 0) { len++; }

  return len;

}

size_t _mi_strnlen(const char* s, size_t max_len) {

  if (s==NULL) return 0;

  size_t len = 0;

  while(s[len] != 0 && len < max_len) { len++; }

  return len;

}

#ifdef MI_NO_GETENV

static bool mi_getenv(const char* name, char* result, size_t result_size) {

  MI_UNUSED(name);

  MI_UNUSED(result);

  MI_UNUSED(result_size);

  return false;

}

#else

static bool mi_getenv(const char* name, char* result, size_t result_size) {

  if (name==NULL || result == NULL || result_size < 64) return false;

  return _mi_prim_getenv(name,result,result_size);

}

#endif

// TODO: implement ourselves to reduce dependencies on the C runtime

#include <stdlib.h> // strtol

#include <string.h> // strstr

static void mi_option_init(mi_option_desc_t* desc) {

  // Read option value from the environment

  char s[64 + 1];

  char buf[64+1];

  _mi_strlcpy(buf, "mimalloc_", sizeof(buf));

  _mi_strlcat(buf, desc->name, sizeof(buf));

  bool found = mi_getenv(buf, s, sizeof(s));

  if (!found && desc->legacy_name != NULL) {

    _mi_strlcpy(buf, "mimalloc_", sizeof(buf));

    _mi_strlcat(buf, desc->legacy_name, sizeof(buf));

    found = mi_getenv(buf, s, sizeof(s));

    if (found) {

      _mi_warning_message("environment option \"mimalloc_%s\" is deprecated -- use \"mimalloc_%s\" instead.\n", desc->legacy_name, desc->name);

    }

  }

  if (found) {

    size_t len = _mi_strnlen(s, sizeof(buf) - 1);

    for (size_t i = 0; i < len; i++) {

      buf[i] = _mi_toupper(s[i]);

    }

    buf[len] = 0;

    if (buf[0] == 0 || strstr("1;TRUE;YES;ON", buf) != NULL) {

      desc->value = 1;

      desc->init = INITIALIZED;

    }

    else if (strstr("0;FALSE;NO;OFF", buf) != NULL) {

      desc->value = 0;

      desc->init = INITIALIZED;

    }

    else {

      char* end = buf;

      long value = strtol(buf, &end, 10);

      if (desc->option == mi_option_reserve_os_memory || desc->option == mi_option_arena_reserve) {

        // this option is interpreted in KiB to prevent overflow of `long`

        if (*end == 'K') { end++; }

        else if (*end == 'M') { value *= MI_KiB; end++; }

        else if (*end == 'G') { value *= MI_MiB; end++; }

        else { value = (value + MI_KiB - 1) / MI_KiB; }

        if (end[0] == 'I' && end[1] == 'B') { end += 2; }

        else if (*end == 'B') { end++; }

      }

      if (*end == 0) {

        desc->value = value;

        desc->init = INITIALIZED;

      }

      else {

        // set `init` first to avoid recursion through _mi_warning_message on mimalloc_verbose.

        desc->init = DEFAULTED;

        if (desc->option == mi_option_verbose && desc->value == 0) {

          // if the 'mimalloc_verbose' env var has a bogus value we'd never know

          // (since the value defaults to 'off') so in that case briefly enable verbose

          desc->value = 1;

          _mi_warning_message("environment option mimalloc_%s has an invalid value.\n", desc->name);

          desc->value = 0;

        }

        else {

          _mi_warning_message("environment option mimalloc_%s has an invalid value.\n", desc->name);

        }

      }

    }

    mi_assert_internal(desc->init != UNINIT);

  }

  else if (!_mi_preloading()) {

    desc->init = DEFAULTED;

  }

}