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Objects/mimalloc/prim/unix/prim.c
860 строк
28 KB
Carlo Bramini
gh-148461: Use arc4random_buf() in mimalloc on Cygwin (#148462)
13 май 2026, 22:09
Не верифицирован
13 май 2026, 22:09
fdf064c
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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 #include <fcntl.h> // open, close, read, access #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(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__sun) && !defined(__NetBSD__) #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(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__sun) && !defined(__NetBSD__) // 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_verbose_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_verbose_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 = 2*MI_MiB; 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 prefer 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) || defined(__CYGWIN__) #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