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cpython/Objects/mimalloc/prim/unix/prim.c

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/* ----------------------------------------------------------------------------
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.
-----------------------------------------------------------------------------*/
// This file is included in `src/prim/prim.c`
#ifndef _DEFAULT_SOURCE
#define _DEFAULT_SOURCE // ensure mmap flags and syscall are defined
#endif
#if defined(__sun)
// illumos provides new mman.h api when any of these are defined
// otherwise the old api based on caddr_t which predates the void pointers one.
// stock solaris provides only the former, chose to atomically to discard those
// flags only here rather than project wide tough.
#undef _XOPEN_SOURCE
#undef _POSIX_C_SOURCE
#endif
#include "mimalloc.h"
#include "mimalloc/internal.h"
#include "mimalloc/atomic.h"
#include "mimalloc/prim.h"
#include <sys/mman.h> // mmap
#include <unistd.h> // sysconf
#if defined(__linux__)
#include <features.h>
#include <fcntl.h>
#if defined(__GLIBC__)
#include <linux/mman.h> // linux mmap flags
#else
#include <sys/mman.h>
#endif
#elif defined(__APPLE__)
#include <TargetConditionals.h>
#if !TARGET_IOS_IPHONE && !TARGET_IOS_SIMULATOR
#include <mach/vm_statistics.h>
#endif
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <sys/param.h>
#if __FreeBSD_version >= 1200000
#include <sys/cpuset.h>
#include <sys/domainset.h>
#endif
#include <sys/sysctl.h>
#endif
#if !defined(__HAIKU__) && !defined(__APPLE__) && !defined(__CYGWIN__) && !defined(_AIX) && !defined(__FreeBSD__)
#define MI_HAS_SYSCALL_H
#include <sys/syscall.h>
#endif
//------------------------------------------------------------------------------------
// Use syscalls for some primitives to allow for libraries that override open/read/close etc.
// and do allocation themselves; using syscalls prevents recursion when mimalloc is
// still initializing (issue #713)
//------------------------------------------------------------------------------------
#if defined(MI_HAS_SYSCALL_H) && defined(SYS_open) && defined(SYS_close) && defined(SYS_read) && defined(SYS_access)
static int mi_prim_open(const char* fpath, int open_flags) {
return syscall(SYS_open,fpath,open_flags,0);
}
static ssize_t mi_prim_read(int fd, void* buf, size_t bufsize) {
return syscall(SYS_read,fd,buf,bufsize);
}
static int mi_prim_close(int fd) {
return syscall(SYS_close,fd);
}
static int mi_prim_access(const char *fpath, int mode) {
return syscall(SYS_access,fpath,mode);
}
#elif !defined(__APPLE__) && !defined(_AIX) && !defined(__FreeBSD__) // avoid unused warnings
static int mi_prim_open(const char* fpath, int open_flags) {
return open(fpath,open_flags);
}
static ssize_t mi_prim_read(int fd, void* buf, size_t bufsize) {
return read(fd,buf,bufsize);
}
static int mi_prim_close(int fd) {
return close(fd);
}
static int mi_prim_access(const char *fpath, int mode) {
return access(fpath,mode);
}
#endif
//---------------------------------------------
// init
//---------------------------------------------
static bool unix_detect_overcommit(void) {
bool os_overcommit = true;
#if defined(__linux__)
int fd = mi_prim_open("/proc/sys/vm/overcommit_memory", O_RDONLY);
if (fd >= 0) {
char buf[32] = {0};
ssize_t nread = mi_prim_read(fd, &buf, sizeof(buf));
mi_prim_close(fd);
// <https://www.kernel.org/doc/Documentation/vm/overcommit-accounting>
// 0: heuristic overcommit, 1: always overcommit, 2: never overcommit (ignore NORESERVE)
if (nread >= 1) {
os_overcommit = (buf[0] == '0' || buf[0] == '1');
}
}
#elif defined(__FreeBSD__)
int val = 0;
size_t olen = sizeof(val);
if (sysctlbyname("vm.overcommit", &val, &olen, NULL, 0) == 0) {
os_overcommit = (val != 0);
}
#else
// default: overcommit is true
#endif
return os_overcommit;
}
void _mi_prim_mem_init( mi_os_mem_config_t* config ) {
long psize = sysconf(_SC_PAGESIZE);
if (psize > 0) {
config->page_size = (size_t)psize;
config->alloc_granularity = (size_t)psize;
}
config->large_page_size = 2*MI_MiB; // TODO: can we query the OS for this?
config->has_overcommit = unix_detect_overcommit();
config->must_free_whole = false; // mmap can free in parts
config->has_virtual_reserve = true; // todo: check if this true for NetBSD? (for anonymous mmap with PROT_NONE)
}
//---------------------------------------------
// free
//---------------------------------------------
int _mi_prim_free(void* addr, size_t size ) {
bool err = (munmap(addr, size) == -1);
return (err ? errno : 0);
}
//---------------------------------------------
// mmap
//---------------------------------------------
static int unix_madvise(void* addr, size_t size, int advice) {
#if defined(__sun)
return madvise((caddr_t)addr, size, advice); // Solaris needs cast (issue #520)
#else
return madvise(addr, size, advice);
#endif
}
static void* unix_mmap_prim(void* addr, size_t size, size_t try_alignment, int protect_flags, int flags, int fd) {
MI_UNUSED(try_alignment);
void* p = NULL;
#if defined(MAP_ALIGNED) // BSD
if (addr == NULL && try_alignment > 1 && (try_alignment % _mi_os_page_size()) == 0) {
size_t n = mi_bsr(try_alignment);
if (((size_t)1 << n) == try_alignment && n >= 12 && n <= 30) { // alignment is a power of 2 and 4096 <= alignment <= 1GiB
p = mmap(addr, size, protect_flags, flags | MAP_ALIGNED(n), fd, 0);
if (p==MAP_FAILED || !_mi_is_aligned(p,try_alignment)) {
int err = errno;
_mi_warning_message("unable to directly request aligned OS memory (error: %d (0x%x), size: 0x%zx bytes, alignment: 0x%zx, hint address: %p)\n", err, err, size, try_alignment, addr);
}
if (p!=MAP_FAILED) return p;
// fall back to regular mmap
}
}
#elif defined(MAP_ALIGN) // Solaris
if (addr == NULL && try_alignment > 1 && (try_alignment % _mi_os_page_size()) == 0) {
p = mmap((void*)try_alignment, size, protect_flags, flags | MAP_ALIGN, fd, 0); // addr parameter is the required alignment
if (p!=MAP_FAILED) return p;
// fall back to regular mmap
}
#endif
#if (MI_INTPTR_SIZE >= 8) && !defined(MAP_ALIGNED)
// on 64-bit systems, use the virtual address area after 2TiB for 4MiB aligned allocations
if (addr == NULL) {
void* hint = _mi_os_get_aligned_hint(try_alignment, size);
if (hint != NULL) {
p = mmap(hint, size, protect_flags, flags, fd, 0);
if (p==MAP_FAILED || !_mi_is_aligned(p,try_alignment)) {
#if MI_TRACK_ENABLED // asan sometimes does not instrument errno correctly?
int err = 0;
#else
int err = errno;
#endif
_mi_warning_message("unable to directly request hinted aligned OS memory (error: %d (0x%x), size: 0x%zx bytes, alignment: 0x%zx, hint address: %p)\n", err, err, size, try_alignment, hint);
}
if (p!=MAP_FAILED) return p;
// fall back to regular mmap
}
}
#endif
// regular mmap
p = mmap(addr, size, protect_flags, flags, fd, 0);
if (p!=MAP_FAILED) return p;
// failed to allocate
return NULL;
}
static int unix_mmap_fd(void) {
#if defined(VM_MAKE_TAG)
// macOS: tracking anonymous page with a specific ID. (All up to 98 are taken officially but LLVM sanitizers had taken 99)
int os_tag = (int)mi_option_get(mi_option_os_tag);
if (os_tag < 100 || os_tag > 255) { os_tag = 100; }
return VM_MAKE_TAG(os_tag);
#else
return -1;
#endif
}
static void* unix_mmap(void* addr, size_t size, size_t try_alignment, int protect_flags, bool large_only, bool allow_large, bool* is_large) {
#if !defined(MAP_ANONYMOUS)
#define MAP_ANONYMOUS MAP_ANON
#endif
#if !defined(MAP_NORESERVE)
#define MAP_NORESERVE 0
#endif
void* p = NULL;
const int fd = unix_mmap_fd();
int flags = MAP_PRIVATE | MAP_ANONYMOUS;
if (_mi_os_has_overcommit()) {
flags |= MAP_NORESERVE;
}
#if defined(PROT_MAX)
protect_flags |= PROT_MAX(PROT_READ | PROT_WRITE); // BSD
#endif
// huge page allocation
if ((large_only || _mi_os_use_large_page(size, try_alignment)) && allow_large) {
static _Atomic(size_t) large_page_try_ok; // = 0;
size_t try_ok = mi_atomic_load_acquire(&large_page_try_ok);
if (!large_only && try_ok > 0) {
// If the OS is not configured for large OS pages, or the user does not have
// enough permission, the `mmap` will always fail (but it might also fail for other reasons).
// Therefore, once a large page allocation failed, we don't try again for `large_page_try_ok` times
// to avoid too many failing calls to mmap.
mi_atomic_cas_strong_acq_rel(&large_page_try_ok, &try_ok, try_ok - 1);
}
else {
int lflags = flags & ~MAP_NORESERVE; // using NORESERVE on huge pages seems to fail on Linux
int lfd = fd;
#ifdef MAP_ALIGNED_SUPER
lflags |= MAP_ALIGNED_SUPER;
#endif
#ifdef MAP_HUGETLB
lflags |= MAP_HUGETLB;
#endif
#ifdef MAP_HUGE_1GB
static bool mi_huge_pages_available = true;
if ((size % MI_GiB) == 0 && mi_huge_pages_available) {
lflags |= MAP_HUGE_1GB;
}
else
#endif
{
#ifdef MAP_HUGE_2MB
lflags |= MAP_HUGE_2MB;
#endif
}
#ifdef VM_FLAGS_SUPERPAGE_SIZE_2MB
lfd |= VM_FLAGS_SUPERPAGE_SIZE_2MB;
#endif
if (large_only || lflags != flags) {
// try large OS page allocation
*is_large = true;
p = unix_mmap_prim(addr, size, try_alignment, protect_flags, lflags, lfd);
#ifdef MAP_HUGE_1GB
if (p == NULL && (lflags & MAP_HUGE_1GB) != 0) {
mi_huge_pages_available = false; // don't try huge 1GiB pages again
_mi_warning_message("unable to allocate huge (1GiB) page, trying large (2MiB) pages instead (errno: %i)\n", errno);
lflags = ((lflags & ~MAP_HUGE_1GB) | MAP_HUGE_2MB);
p = unix_mmap_prim(addr, size, try_alignment, protect_flags, lflags, lfd);
}
#endif
if (large_only) return p;
if (p == NULL) {
mi_atomic_store_release(&large_page_try_ok, (size_t)8); // on error, don't try again for the next N allocations
}
}
}
}
// regular allocation
if (p == NULL) {
*is_large = false;
p = unix_mmap_prim(addr, size, try_alignment, protect_flags, flags, fd);
if (p != NULL) {
#if defined(MADV_HUGEPAGE)
// Many Linux systems don't allow MAP_HUGETLB but they support instead
// transparent huge pages (THP). Generally, it is not required to call `madvise` with MADV_HUGE
// though since properly aligned allocations will already use large pages if available
// in that case -- in particular for our large regions (in `memory.c`).
// However, some systems only allow THP if called with explicit `madvise`, so
// when large OS pages are enabled for mimalloc, we call `madvise` anyways.
if (allow_large && _mi_os_use_large_page(size, try_alignment)) {
if (unix_madvise(p, size, MADV_HUGEPAGE) == 0) {
*is_large = true; // possibly
};
}
#elif defined(__sun)
if (allow_large && _mi_os_use_large_page(size, try_alignment)) {
struct memcntl_mha cmd = {0};
cmd.mha_pagesize = large_os_page_size;
cmd.mha_cmd = MHA_MAPSIZE_VA;
if (memcntl((caddr_t)p, size, MC_HAT_ADVISE, (caddr_t)&cmd, 0, 0) == 0) {
*is_large = true;
}
}
#endif
}
}
return p;
}
// Note: the `try_alignment` is just a hint and the returned pointer is not guaranteed to be aligned.
int _mi_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, void** addr) {
mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0);
mi_assert_internal(commit || !allow_large);
mi_assert_internal(try_alignment > 0);
*is_zero = true;
int protect_flags = (commit ? (PROT_WRITE | PROT_READ) : PROT_NONE);
*addr = unix_mmap(NULL, size, try_alignment, protect_flags, false, allow_large, is_large);
return (*addr != NULL ? 0 : errno);
}
//---------------------------------------------
// Commit/Reset
//---------------------------------------------
static void unix_mprotect_hint(int err) {
#if defined(__linux__) && (MI_SECURE>=2) // guard page around every mimalloc page
if (err == ENOMEM) {
_mi_warning_message("The next warning may be caused by a low memory map limit.\n"
" On Linux this is controlled by the vm.max_map_count -- maybe increase it?\n"
" For example: sudo sysctl -w vm.max_map_count=262144\n");
}
#else
MI_UNUSED(err);
#endif
}
int _mi_prim_commit(void* start, size_t size, bool* is_zero) {
// commit: ensure we can access the area
// note: we may think that *is_zero can be true since the memory
// was either from mmap PROT_NONE, or from decommit MADV_DONTNEED, but
// we sometimes call commit on a range with still partially committed
// memory and `mprotect` does not zero the range.
*is_zero = false;
int err = mprotect(start, size, (PROT_READ | PROT_WRITE));
if (err != 0) {
err = errno;
unix_mprotect_hint(err);
}
return err;
}
int _mi_prim_decommit(void* start, size_t size, bool* needs_recommit) {
int err = 0;
// decommit: use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
err = unix_madvise(start, size, MADV_DONTNEED);
#if !MI_DEBUG && !MI_SECURE
*needs_recommit = false;
#else
*needs_recommit = true;
mprotect(start, size, PROT_NONE);
#endif
/*
// decommit: use mmap with MAP_FIXED and PROT_NONE to discard the existing memory (and reduce rss)
*needs_recommit = true;
const int fd = unix_mmap_fd();
void* p = mmap(start, size, PROT_NONE, (MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE), fd, 0);
if (p != start) { err = errno; }
*/
return err;
}
int _mi_prim_reset(void* start, size_t size) {
// We try to use `MADV_FREE` as that is the fastest. A drawback though is that it
// will not reduce the `rss` stats in tools like `top` even though the memory is available
// to other processes. With the default `MIMALLOC_PURGE_DECOMMITS=1` we ensure that by
// default `MADV_DONTNEED` is used though.
#if defined(MADV_FREE)
static _Atomic(size_t) advice = MI_ATOMIC_VAR_INIT(MADV_FREE);
int oadvice = (int)mi_atomic_load_relaxed(&advice);
int err;
while ((err = unix_madvise(start, size, oadvice)) != 0 && errno == EAGAIN) { errno = 0; };
if (err != 0 && errno == EINVAL && oadvice == MADV_FREE) {
// if MADV_FREE is not supported, fall back to MADV_DONTNEED from now on
mi_atomic_store_release(&advice, (size_t)MADV_DONTNEED);
err = unix_madvise(start, size, MADV_DONTNEED);
}
#else
int err = unix_madvise(start, size, MADV_DONTNEED);
#endif
return err;
}
int _mi_prim_protect(void* start, size_t size, bool protect) {
int err = mprotect(start, size, protect ? PROT_NONE : (PROT_READ | PROT_WRITE));
if (err != 0) { err = errno; }
unix_mprotect_hint(err);
return err;
}
//---------------------------------------------
// Huge page allocation
//---------------------------------------------
#if (MI_INTPTR_SIZE >= 8) && !defined(__HAIKU__) && !defined(__CYGWIN__)
#ifndef MPOL_PREFERRED
#define MPOL_PREFERRED 1
#endif
#if defined(MI_HAS_SYSCALL_H) && defined(SYS_mbind)
static long mi_prim_mbind(void* start, unsigned long len, unsigned long mode, const unsigned long* nmask, unsigned long maxnode, unsigned flags) {
return syscall(SYS_mbind, start, len, mode, nmask, maxnode, flags);
}
#else
static long mi_prim_mbind(void* start, unsigned long len, unsigned long mode, const unsigned long* nmask, unsigned long maxnode, unsigned flags) {
MI_UNUSED(start); MI_UNUSED(len); MI_UNUSED(mode); MI_UNUSED(nmask); MI_UNUSED(maxnode); MI_UNUSED(flags);
return 0;
}
#endif
int _mi_prim_alloc_huge_os_pages(void* hint_addr, size_t size, int numa_node, bool* is_zero, void** addr) {
bool is_large = true;
*is_zero = true;
*addr = unix_mmap(hint_addr, size, MI_SEGMENT_SIZE, PROT_READ | PROT_WRITE, true, true, &is_large);
if (*addr != NULL && numa_node >= 0 && numa_node < 8*MI_INTPTR_SIZE) { // at most 64 nodes
unsigned long numa_mask = (1UL << numa_node);
// TODO: does `mbind` work correctly for huge OS pages? should we
// use `set_mempolicy` before calling mmap instead?
// see: <https://lkml.org/lkml/2017/2/9/875>
long err = mi_prim_mbind(*addr, size, MPOL_PREFERRED, &numa_mask, 8*MI_INTPTR_SIZE, 0);
if (err != 0) {
err = errno;
_mi_warning_message("failed to bind huge (1GiB) pages to numa node %d (error: %d (0x%x))\n", numa_node, err, err);
}
}
return (*addr != NULL ? 0 : errno);
}
#else
int _mi_prim_alloc_huge_os_pages(void* hint_addr, size_t size, int numa_node, bool* is_zero, void** addr) {
MI_UNUSED(hint_addr); MI_UNUSED(size); MI_UNUSED(numa_node);
*is_zero = false;
*addr = NULL;
return ENOMEM;
}
#endif
//---------------------------------------------
// NUMA nodes
//---------------------------------------------
#if defined(__linux__)
#include <stdio.h> // snprintf
size_t _mi_prim_numa_node(void) {
#if defined(MI_HAS_SYSCALL_H) && defined(SYS_getcpu)
unsigned long node = 0;
unsigned long ncpu = 0;
long err = syscall(SYS_getcpu, &ncpu, &node, NULL);
if (err != 0) return 0;
return node;
#else
return 0;
#endif
}
size_t _mi_prim_numa_node_count(void) {
char buf[128];
unsigned node = 0;
for(node = 0; node < 256; node++) {
// enumerate node entries -- todo: it there a more efficient way to do this? (but ensure there is no allocation)
snprintf(buf, 127, "/sys/devices/system/node/node%u", node + 1);
if (mi_prim_access(buf,R_OK) != 0) break;
}
return (node+1);
}
#elif defined(__FreeBSD__) && __FreeBSD_version >= 1200000
size_t _mi_prim_numa_node(void) {
domainset_t dom;
size_t node;
int policy;
if (cpuset_getdomain(CPU_LEVEL_CPUSET, CPU_WHICH_PID, -1, sizeof(dom), &dom, &policy) == -1) return 0ul;
for (node = 0; node < MAXMEMDOM; node++) {
if (DOMAINSET_ISSET(node, &dom)) return node;
}
return 0ul;
}
size_t _mi_prim_numa_node_count(void) {
size_t ndomains = 0;
size_t len = sizeof(ndomains);
if (sysctlbyname("vm.ndomains", &ndomains, &len, NULL, 0) == -1) return 0ul;
return ndomains;
}
#elif defined(__DragonFly__)
size_t _mi_prim_numa_node(void) {
// TODO: DragonFly does not seem to provide any userland means to get this information.
return 0ul;
}
size_t _mi_prim_numa_node_count(void) {
size_t ncpus = 0, nvirtcoresperphys = 0;
size_t len = sizeof(size_t);
if (sysctlbyname("hw.ncpu", &ncpus, &len, NULL, 0) == -1) return 0ul;
if (sysctlbyname("hw.cpu_topology_ht_ids", &nvirtcoresperphys, &len, NULL, 0) == -1) return 0ul;
return nvirtcoresperphys * ncpus;
}
#else
size_t _mi_prim_numa_node(void) {
return 0;
}
size_t _mi_prim_numa_node_count(void) {
return 1;
}
#endif
// ----------------------------------------------------------------
// Clock
// ----------------------------------------------------------------
#include <time.h>
#if defined(CLOCK_REALTIME) || defined(CLOCK_MONOTONIC)
mi_msecs_t _mi_prim_clock_now(void) {
struct timespec t;
#ifdef CLOCK_MONOTONIC
clock_gettime(CLOCK_MONOTONIC, &t);
#else
clock_gettime(CLOCK_REALTIME, &t);
#endif
return ((mi_msecs_t)t.tv_sec * 1000) + ((mi_msecs_t)t.tv_nsec / 1000000);
}
#else
// low resolution timer
mi_msecs_t _mi_prim_clock_now(void) {
#if !defined(CLOCKS_PER_SEC) || (CLOCKS_PER_SEC == 1000) || (CLOCKS_PER_SEC == 0)
return (mi_msecs_t)clock();
#elif (CLOCKS_PER_SEC < 1000)
return (mi_msecs_t)clock() * (1000 / (mi_msecs_t)CLOCKS_PER_SEC);
#else
return (mi_msecs_t)clock() / ((mi_msecs_t)CLOCKS_PER_SEC / 1000);
#endif
}
#endif
//----------------------------------------------------------------
// Process info
//----------------------------------------------------------------
#if defined(__unix__) || defined(__unix) || defined(unix) || defined(__APPLE__) || defined(__HAIKU__)
#include <stdio.h>
#include <unistd.h>
#include <sys/resource.h>
#if defined(__APPLE__)
#include <mach/mach.h>
#endif
#if defined(__HAIKU__)
#include <kernel/OS.h>
#endif
static mi_msecs_t timeval_secs(const struct timeval* tv) {
return ((mi_msecs_t)tv->tv_sec * 1000L) + ((mi_msecs_t)tv->tv_usec / 1000L);
}
void _mi_prim_process_info(mi_process_info_t* pinfo)
{
struct rusage rusage;
getrusage(RUSAGE_SELF, &rusage);
pinfo->utime = timeval_secs(&rusage.ru_utime);
pinfo->stime = timeval_secs(&rusage.ru_stime);
#if !defined(__HAIKU__)
pinfo->page_faults = rusage.ru_majflt;
#endif
#if defined(__HAIKU__)
// Haiku does not have (yet?) a way to
// get these stats per process
thread_info tid;
area_info mem;
ssize_t c;
get_thread_info(find_thread(0), &tid);
while (get_next_area_info(tid.team, &c, &mem) == B_OK) {
pinfo->peak_rss += mem.ram_size;
}
pinfo->page_faults = 0;
#elif defined(__APPLE__)
pinfo->peak_rss = rusage.ru_maxrss; // macos reports in bytes
#ifdef MACH_TASK_BASIC_INFO
struct mach_task_basic_info info;
mach_msg_type_number_t infoCount = MACH_TASK_BASIC_INFO_COUNT;
if (task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&info, &infoCount) == KERN_SUCCESS) {
pinfo->current_rss = (size_t)info.resident_size;
}
#else
struct task_basic_info info;
mach_msg_type_number_t infoCount = TASK_BASIC_INFO_COUNT;
if (task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &infoCount) == KERN_SUCCESS) {
pinfo->current_rss = (size_t)info.resident_size;
}
#endif
#else
pinfo->peak_rss = rusage.ru_maxrss * 1024; // Linux/BSD report in KiB
#endif
// use defaults for commit
}
#else
#ifndef __wasi__
// WebAssembly instances are not processes
#pragma message("define a way to get process info")
#endif
void _mi_prim_process_info(mi_process_info_t* pinfo)
{
// use defaults
MI_UNUSED(pinfo);
}
#endif
//----------------------------------------------------------------
// Output
//----------------------------------------------------------------
void _mi_prim_out_stderr( const char* msg ) {
fputs(msg,stderr);
}
//----------------------------------------------------------------
// Environment
//----------------------------------------------------------------
#if !defined(MI_USE_ENVIRON) || (MI_USE_ENVIRON!=0)
// On Posix systemsr use `environ` to access environment variables
// even before the C runtime is initialized.
#if defined(__APPLE__) && defined(__has_include) && __has_include(<crt_externs.h>)
#include <crt_externs.h>
static char** mi_get_environ(void) {
return (*_NSGetEnviron());
}
#else
extern char** environ;
static char** mi_get_environ(void) {
return environ;
}
#endif
bool _mi_prim_getenv(const char* name, char* result, size_t result_size) {
if (name==NULL) return false;
const size_t len = _mi_strlen(name);
if (len == 0) return false;
char** env = mi_get_environ();
if (env == NULL) return false;
// compare up to 10000 entries
for (int i = 0; i < 10000 && env[i] != NULL; i++) {
const char* s = env[i];
if (_mi_strnicmp(name, s, len) == 0 && s[len] == '=') { // case insensitive
// found it
_mi_strlcpy(result, s + len + 1, result_size);
return true;
}
}
return false;
}
#else
// fallback: use standard C `getenv` but this cannot be used while initializing the C runtime
bool _mi_prim_getenv(const char* name, char* result, size_t result_size) {
// cannot call getenv() when still initializing the C runtime.
if (_mi_preloading()) return false;
const char* s = getenv(name);
if (s == NULL) {
// we check the upper case name too.
char buf[64+1];
size_t len = _mi_strnlen(name,sizeof(buf)-1);
for (size_t i = 0; i < len; i++) {
buf[i] = _mi_toupper(name[i]);
}
buf[len] = 0;
s = getenv(buf);
}
if (s == NULL || _mi_strnlen(s,result_size) >= result_size) return false;
_mi_strlcpy(result, s, result_size);
return true;
}
#endif // !MI_USE_ENVIRON
//----------------------------------------------------------------
// Random
//----------------------------------------------------------------
#if defined(__APPLE__)
#include <AvailabilityMacros.h>
#if defined(MAC_OS_X_VERSION_10_10) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_10
#include <CommonCrypto/CommonCryptoError.h>
#include <CommonCrypto/CommonRandom.h>
#endif
bool _mi_prim_random_buf(void* buf, size_t buf_len) {
#if defined(MAC_OS_X_VERSION_10_15) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_15
// We prefere CCRandomGenerateBytes as it returns an error code while arc4random_buf
// may fail silently on macOS. See PR #390, and <https://opensource.apple.com/source/Libc/Libc-1439.40.11/gen/FreeBSD/arc4random.c.auto.html>
return (CCRandomGenerateBytes(buf, buf_len) == kCCSuccess);
#else
// fall back on older macOS
arc4random_buf(buf, buf_len);
return true;
#endif
}
#elif defined(__ANDROID__) || defined(__DragonFly__) || \
defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || \
defined(__sun)
#include <stdlib.h>
bool _mi_prim_random_buf(void* buf, size_t buf_len) {
arc4random_buf(buf, buf_len);
return true;
}
#elif defined(__linux__) || defined(__HAIKU__)
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
bool _mi_prim_random_buf(void* buf, size_t buf_len) {
// Modern Linux provides `getrandom` but different distributions either use `sys/random.h` or `linux/random.h`
// and for the latter the actual `getrandom` call is not always defined.
// (see <https://stackoverflow.com/questions/45237324/why-doesnt-getrandom-compile>)
// We therefore use a syscall directly and fall back dynamically to /dev/urandom when needed.
#if defined(MI_HAS_SYSCALL_H) && defined(SYS_getrandom)
#ifndef GRND_NONBLOCK
#define GRND_NONBLOCK (1)
#endif
static _Atomic(uintptr_t) no_getrandom; // = 0
if (mi_atomic_load_acquire(&no_getrandom)==0) {
ssize_t ret = syscall(SYS_getrandom, buf, buf_len, GRND_NONBLOCK);
if (ret >= 0) return (buf_len == (size_t)ret);
if (errno != ENOSYS) return false;
mi_atomic_store_release(&no_getrandom, (uintptr_t)1); // don't call again, and fall back to /dev/urandom
}
#endif
int flags = O_RDONLY;
#if defined(O_CLOEXEC)
flags |= O_CLOEXEC;
#endif
int fd = mi_prim_open("/dev/urandom", flags);
if (fd < 0) return false;
size_t count = 0;
while(count < buf_len) {
ssize_t ret = mi_prim_read(fd, (char*)buf + count, buf_len - count);
if (ret<=0) {
if (errno!=EAGAIN && errno!=EINTR) break;
}
else {
count += ret;
}
}
mi_prim_close(fd);
return (count==buf_len);
}
#else
bool _mi_prim_random_buf(void* buf, size_t buf_len) {
return false;
}
#endif
//----------------------------------------------------------------
// Thread init/done
//----------------------------------------------------------------
#if defined(MI_USE_PTHREADS)
// use pthread local storage keys to detect thread ending
// (and used with MI_TLS_PTHREADS for the default heap)
pthread_key_t _mi_heap_default_key = (pthread_key_t)(-1);
static void mi_pthread_done(void* value) {
if (value!=NULL) {
_mi_thread_done((mi_heap_t*)value);
}
}
void _mi_prim_thread_init_auto_done(void) {
mi_assert_internal(_mi_heap_default_key == (pthread_key_t)(-1));
pthread_key_create(&_mi_heap_default_key, &mi_pthread_done);
}
void _mi_prim_thread_done_auto_done(void) {
// nothing to do
}
void _mi_prim_thread_associate_default_heap(mi_heap_t* heap) {
if (_mi_heap_default_key != (pthread_key_t)(-1)) { // can happen during recursive invocation on freeBSD
pthread_setspecific(_mi_heap_default_key, heap);
}
}
#else
void _mi_prim_thread_init_auto_done(void) {
// nothing
}
void _mi_prim_thread_done_auto_done(void) {
// nothing
}
void _mi_prim_thread_associate_default_heap(mi_heap_t* heap) {
MI_UNUSED(heap);
}
#endif
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