Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 757 insertions, 0 deletions

diff --git a/src/zstd/programs/util.h b/src/zstd/programs/util.h
new file mode 100644
index 00000000..c8be5f5f
--- /dev/null
+++ b/src/zstd/programs/util.h
@@ -0,0 +1,757 @@
+/*
+ * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#ifndef UTIL_H_MODULE
+#define UTIL_H_MODULE
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+
+/*-****************************************
+*  Dependencies
+******************************************/
+#include "platform.h"     /* PLATFORM_POSIX_VERSION */
+#include <stdlib.h>       /* malloc */
+#include <stddef.h>       /* size_t, ptrdiff_t */
+#include <stdio.h>        /* fprintf */
+#include <string.h>       /* strncmp */
+#include <sys/types.h>    /* stat, utime */
+#include <sys/stat.h>     /* stat */
+#if defined(_MSC_VER)
+#  include <sys/utime.h>  /* utime */
+#  include <io.h>         /* _chmod */
+#else
+#  include <unistd.h>     /* chown, stat */
+#  include <utime.h>      /* utime */
+#endif
+#include <time.h>         /* time */
+#include <errno.h>
+#include "mem.h"          /* U32, U64 */
+
+
+/* ************************************************************
+* Avoid fseek()'s 2GiB barrier with MSVC, MacOS, *BSD, MinGW
+***************************************************************/
+#if defined(_MSC_VER) && (_MSC_VER >= 1400)
+#   define UTIL_fseek _fseeki64
+#elif !defined(__64BIT__) && (PLATFORM_POSIX_VERSION >= 200112L) /* No point defining Large file for 64 bit */
+#  define UTIL_fseek fseeko
+#elif defined(__MINGW32__) && defined(__MSVCRT__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS)
+#   define UTIL_fseek fseeko64
+#else
+#   define UTIL_fseek fseek
+#endif
+
+
+/*-****************************************
+*  Sleep functions: Windows - Posix - others
+******************************************/
+#if defined(_WIN32)
+#  include <windows.h>
+#  define SET_REALTIME_PRIORITY SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS)
+#  define UTIL_sleep(s) Sleep(1000*s)
+#  define UTIL_sleepMilli(milli) Sleep(milli)
+#elif PLATFORM_POSIX_VERSION >= 0 /* Unix-like operating system */
+#  include <unistd.h>
+#  include <sys/resource.h> /* setpriority */
+#  include <time.h>         /* clock_t, nanosleep, clock, CLOCKS_PER_SEC */
+#  if defined(PRIO_PROCESS)
+#    define SET_REALTIME_PRIORITY setpriority(PRIO_PROCESS, 0, -20)
+#  else
+#    define SET_REALTIME_PRIORITY /* disabled */
+#  endif
+#  define UTIL_sleep(s) sleep(s)
+#  if (defined(__linux__) && (PLATFORM_POSIX_VERSION >= 199309L)) || (PLATFORM_POSIX_VERSION >= 200112L)  /* nanosleep requires POSIX.1-2001 */
+#      define UTIL_sleepMilli(milli) { struct timespec t; t.tv_sec=0; t.tv_nsec=milli*1000000ULL; nanosleep(&t, NULL); }
+#  else
+#      define UTIL_sleepMilli(milli) /* disabled */
+#  endif
+#else
+#  define SET_REALTIME_PRIORITY      /* disabled */
+#  define UTIL_sleep(s)          /* disabled */
+#  define UTIL_sleepMilli(milli) /* disabled */
+#endif
+
+
+/* *************************************
+*  Constants
+***************************************/
+#define LIST_SIZE_INCREASE   (8*1024)
+
+
+/*-****************************************
+*  Compiler specifics
+******************************************/
+#if defined(__INTEL_COMPILER)
+#  pragma warning(disable : 177)    /* disable: message #177: function was declared but never referenced, useful with UTIL_STATIC */
+#endif
+#if defined(__GNUC__)
+#  define UTIL_STATIC static __attribute__((unused))
+#elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+#  define UTIL_STATIC static inline
+#elif defined(_MSC_VER)
+#  define UTIL_STATIC static __inline
+#else
+#  define UTIL_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
+#endif
+
+
+/*-****************************************
+*  Console log
+******************************************/
+static int g_utilDisplayLevel;
+#define UTIL_DISPLAY(...)         fprintf(stderr, __VA_ARGS__)
+#define UTIL_DISPLAYLEVEL(l, ...) { if (g_utilDisplayLevel>=l) { UTIL_DISPLAY(__VA_ARGS__); } }
+
+
+/*-****************************************
+*  Time functions
+******************************************/
+#if defined(_WIN32)   /* Windows */
+    typedef LARGE_INTEGER UTIL_time_t;
+    UTIL_STATIC UTIL_time_t UTIL_getTime(void) { UTIL_time_t x; QueryPerformanceCounter(&x); return x; }
+    UTIL_STATIC U64 UTIL_getSpanTimeMicro(UTIL_time_t clockStart, UTIL_time_t clockEnd)
+    {
+        static LARGE_INTEGER ticksPerSecond;
+        static int init = 0;
+        if (!init) {
+            if (!QueryPerformanceFrequency(&ticksPerSecond))
+                UTIL_DISPLAYLEVEL(1, "ERROR: QueryPerformanceFrequency() failure\n");
+            init = 1;
+        }
+        return 1000000ULL*(clockEnd.QuadPart - clockStart.QuadPart)/ticksPerSecond.QuadPart;
+    }
+    UTIL_STATIC U64 UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd)
+    {
+        static LARGE_INTEGER ticksPerSecond;
+        static int init = 0;
+        if (!init) {
+            if (!QueryPerformanceFrequency(&ticksPerSecond))
+                UTIL_DISPLAYLEVEL(1, "ERROR: QueryPerformanceFrequency() failure\n");
+            init = 1;
+        }
+        return 1000000000ULL*(clockEnd.QuadPart - clockStart.QuadPart)/ticksPerSecond.QuadPart;
+    }
+#elif defined(__APPLE__) && defined(__MACH__)
+    #include <mach/mach_time.h>
+    typedef U64 UTIL_time_t;
+    UTIL_STATIC UTIL_time_t UTIL_getTime(void) { return mach_absolute_time(); }
+    UTIL_STATIC U64 UTIL_getSpanTimeMicro(UTIL_time_t clockStart, UTIL_time_t clockEnd)
+    {
+        static mach_timebase_info_data_t rate;
+        static int init = 0;
+        if (!init) {
+            mach_timebase_info(&rate);
+            init = 1;
+        }
+        return (((clockEnd - clockStart) * (U64)rate.numer) / ((U64)rate.denom))/1000ULL;
+    }
+    UTIL_STATIC U64 UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd)
+    {
+        static mach_timebase_info_data_t rate;
+        static int init = 0;
+        if (!init) {
+            mach_timebase_info(&rate);
+            init = 1;
+        }
+        return ((clockEnd - clockStart) * (U64)rate.numer) / ((U64)rate.denom);
+    }
+#elif (PLATFORM_POSIX_VERSION >= 200112L)
+    #include <time.h>
+    typedef struct timespec UTIL_freq_t;
+    typedef struct timespec UTIL_time_t;
+    UTIL_STATIC UTIL_time_t UTIL_getTime(void)
+    {
+        UTIL_time_t time;
+        if (clock_gettime(CLOCK_MONOTONIC, &time))
+            UTIL_DISPLAYLEVEL(1, "ERROR: Failed to get time\n");   /* we could also exit() */
+        return time;
+    }
+    UTIL_STATIC UTIL_time_t UTIL_getSpanTime(UTIL_time_t begin, UTIL_time_t end)
+    {
+        UTIL_time_t diff;
+        if (end.tv_nsec < begin.tv_nsec) {
+            diff.tv_sec = (end.tv_sec - 1) - begin.tv_sec;
+            diff.tv_nsec = (end.tv_nsec + 1000000000ULL) - begin.tv_nsec;
+        } else {
+            diff.tv_sec = end.tv_sec - begin.tv_sec;
+            diff.tv_nsec = end.tv_nsec - begin.tv_nsec;
+        }
+        return diff;
+    }
+    UTIL_STATIC U64 UTIL_getSpanTimeMicro(UTIL_time_t begin, UTIL_time_t end)
+    {
+        UTIL_time_t const diff = UTIL_getSpanTime(begin, end);
+        U64 micro = 0;
+        micro += 1000000ULL * diff.tv_sec;
+        micro += diff.tv_nsec / 1000ULL;
+        return micro;
+    }
+    UTIL_STATIC U64 UTIL_getSpanTimeNano(UTIL_time_t begin, UTIL_time_t end)
+    {
+        UTIL_time_t const diff = UTIL_getSpanTime(begin, end);
+        U64 nano = 0;
+        nano += 1000000000ULL * diff.tv_sec;
+        nano += diff.tv_nsec;
+        return nano;
+    }
+#else   /* relies on standard C (note : clock_t measurements can be wrong when using multi-threading) */
+    typedef clock_t UTIL_time_t;
+    UTIL_STATIC UTIL_time_t UTIL_getTime(void) { return clock(); }
+    UTIL_STATIC U64 UTIL_getSpanTimeMicro(UTIL_time_t clockStart, UTIL_time_t clockEnd) { return 1000000ULL * (clockEnd - clockStart) / CLOCKS_PER_SEC; }
+    UTIL_STATIC U64 UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd) { return 1000000000ULL * (clockEnd - clockStart) / CLOCKS_PER_SEC; }
+#endif
+
+
+/* returns time span in microseconds */
+UTIL_STATIC U64 UTIL_clockSpanMicro( UTIL_time_t clockStart )
+{
+    UTIL_time_t const clockEnd = UTIL_getTime();
+    return UTIL_getSpanTimeMicro(clockStart, clockEnd);
+}
+
+
+UTIL_STATIC void UTIL_waitForNextTick(void)
+{
+    UTIL_time_t const clockStart = UTIL_getTime();
+    UTIL_time_t clockEnd;
+    do {
+        clockEnd = UTIL_getTime();
+    } while (UTIL_getSpanTimeNano(clockStart, clockEnd) == 0);
+}
+
+
+
+/*-****************************************
+*  File functions
+******************************************/
+#if defined(_MSC_VER)
+    #define chmod _chmod
+    typedef struct __stat64 stat_t;
+#else
+    typedef struct stat stat_t;
+#endif
+
+
+UTIL_STATIC int UTIL_setFileStat(const char *filename, stat_t *statbuf)
+{
+    int res = 0;
+    struct utimbuf timebuf;
+
+    timebuf.actime = time(NULL);
+    timebuf.modtime = statbuf->st_mtime;
+    res += utime(filename, &timebuf);  /* set access and modification times */
+
+#if !defined(_WIN32)
+    res += chown(filename, statbuf->st_uid, statbuf->st_gid);  /* Copy ownership */
+#endif
+
+    res += chmod(filename, statbuf->st_mode & 07777);  /* Copy file permissions */
+
+    errno = 0;
+    return -res; /* number of errors is returned */
+}
+
+
+UTIL_STATIC int UTIL_getFileStat(const char* infilename, stat_t *statbuf)
+{
+    int r;
+#if defined(_MSC_VER)
+    r = _stat64(infilename, statbuf);
+    if (r || !(statbuf->st_mode & S_IFREG)) return 0;   /* No good... */
+#else
+    r = stat(infilename, statbuf);
+    if (r || !S_ISREG(statbuf->st_mode)) return 0;   /* No good... */
+#endif
+    return 1;
+}
+
+
+UTIL_STATIC int UTIL_isRegularFile(const char* infilename)
+{
+    stat_t statbuf;
+    return UTIL_getFileStat(infilename, &statbuf); /* Only need to know whether it is a regular file */
+}
+
+
+UTIL_STATIC U32 UTIL_isDirectory(const char* infilename)
+{
+    int r;
+    stat_t statbuf;
+#if defined(_MSC_VER)
+    r = _stat64(infilename, &statbuf);
+    if (!r && (statbuf.st_mode & _S_IFDIR)) return 1;
+#else
+    r = stat(infilename, &statbuf);
+    if (!r && S_ISDIR(statbuf.st_mode)) return 1;
+#endif
+    return 0;
+}
+
+UTIL_STATIC U32 UTIL_isLink(const char* infilename)
+{
+#if defined(_WIN32)
+    /* no symlinks on windows */
+    (void)infilename;
+#else
+    int r;
+    stat_t statbuf;
+    r = lstat(infilename, &statbuf);
+    if (!r && S_ISLNK(statbuf.st_mode)) return 1;
+#endif
+    return 0;
+}
+
+
+UTIL_STATIC U64 UTIL_getFileSize(const char* infilename)
+{
+    int r;
+#if defined(_MSC_VER)
+    struct __stat64 statbuf;
+    r = _stat64(infilename, &statbuf);
+    if (r || !(statbuf.st_mode & S_IFREG)) return 0;   /* No good... */
+#elif defined(__MINGW32__) && defined (__MSVCRT__)
+    struct _stati64 statbuf;
+    r = _stati64(infilename, &statbuf);
+    if (r || !(statbuf.st_mode & S_IFREG)) return 0;   /* No good... */
+#else
+    struct stat statbuf;
+    r = stat(infilename, &statbuf);
+    if (r || !S_ISREG(statbuf.st_mode)) return 0;   /* No good... */
+#endif
+    return (U64)statbuf.st_size;
+}
+
+
+UTIL_STATIC U64 UTIL_getTotalFileSize(const char** fileNamesTable, unsigned nbFiles)
+{
+    U64 total = 0;
+    unsigned n;
+    for (n=0; n<nbFiles; n++)
+        total += UTIL_getFileSize(fileNamesTable[n]);
+    return total;
+}
+
+
+/*
+ * A modified version of realloc().
+ * If UTIL_realloc() fails the original block is freed.
+*/
+UTIL_STATIC void *UTIL_realloc(void *ptr, size_t size)
+{
+    void *newptr = realloc(ptr, size);
+    if (newptr) return newptr;
+    free(ptr);
+    return NULL;
+}
+
+#ifdef _WIN32
+#  define UTIL_HAS_CREATEFILELIST
+
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
+{
+    char* path;
+    int dirLength, fnameLength, pathLength, nbFiles = 0;
+    WIN32_FIND_DATAA cFile;
+    HANDLE hFile;
+
+    dirLength = (int)strlen(dirName);
+    path = (char*) malloc(dirLength + 3);
+    if (!path) return 0;
+
+    memcpy(path, dirName, dirLength);
+    path[dirLength] = '\\';
+    path[dirLength+1] = '*';
+    path[dirLength+2] = 0;
+
+    hFile=FindFirstFileA(path, &cFile);
+    if (hFile == INVALID_HANDLE_VALUE) {
+        UTIL_DISPLAYLEVEL(1, "Cannot open directory '%s'\n", dirName);
+        return 0;
+    }
+    free(path);
+
+    do {
+        fnameLength = (int)strlen(cFile.cFileName);
+        path = (char*) malloc(dirLength + fnameLength + 2);
+        if (!path) { FindClose(hFile); return 0; }
+        memcpy(path, dirName, dirLength);
+        path[dirLength] = '\\';
+        memcpy(path+dirLength+1, cFile.cFileName, fnameLength);
+        pathLength = dirLength+1+fnameLength;
+        path[pathLength] = 0;
+        if (cFile.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+            if (strcmp (cFile.cFileName, "..") == 0 ||
+                strcmp (cFile.cFileName, ".") == 0) continue;
+
+            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd, followLinks);  /* Recursively call "UTIL_prepareFileList" with the new path. */
+            if (*bufStart == NULL) { free(path); FindClose(hFile); return 0; }
+        }
+        else if ((cFile.dwFileAttributes & FILE_ATTRIBUTE_NORMAL) || (cFile.dwFileAttributes & FILE_ATTRIBUTE_ARCHIVE) || (cFile.dwFileAttributes & FILE_ATTRIBUTE_COMPRESSED)) {
+            if (*bufStart + *pos + pathLength >= *bufEnd) {
+                ptrdiff_t newListSize = (*bufEnd - *bufStart) + LIST_SIZE_INCREASE;
+                *bufStart = (char*)UTIL_realloc(*bufStart, newListSize);
+                *bufEnd = *bufStart + newListSize;
+                if (*bufStart == NULL) { free(path); FindClose(hFile); return 0; }
+            }
+            if (*bufStart + *pos + pathLength < *bufEnd) {
+                strncpy(*bufStart + *pos, path, *bufEnd - (*bufStart + *pos));
+                *pos += pathLength + 1;
+                nbFiles++;
+            }
+        }
+        free(path);
+    } while (FindNextFileA(hFile, &cFile));
+
+    FindClose(hFile);
+    return nbFiles;
+}
+
+#elif defined(__linux__) || (PLATFORM_POSIX_VERSION >= 200112L)  /* opendir, readdir require POSIX.1-2001 */
+#  define UTIL_HAS_CREATEFILELIST
+#  include <dirent.h>       /* opendir, readdir */
+#  include <string.h>       /* strerror, memcpy */
+
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
+{
+    DIR *dir;
+    struct dirent *entry;
+    char* path;
+    int dirLength, fnameLength, pathLength, nbFiles = 0;
+
+    if (!(dir = opendir(dirName))) {
+        UTIL_DISPLAYLEVEL(1, "Cannot open directory '%s': %s\n", dirName, strerror(errno));
+        return 0;
+    }
+
+    dirLength = (int)strlen(dirName);
+    errno = 0;
+    while ((entry = readdir(dir)) != NULL) {
+        if (strcmp (entry->d_name, "..") == 0 ||
+            strcmp (entry->d_name, ".") == 0) continue;
+        fnameLength = (int)strlen(entry->d_name);
+        path = (char*) malloc(dirLength + fnameLength + 2);
+        if (!path) { closedir(dir); return 0; }
+        memcpy(path, dirName, dirLength);
+
+        path[dirLength] = '/';
+        memcpy(path+dirLength+1, entry->d_name, fnameLength);
+        pathLength = dirLength+1+fnameLength;
+        path[pathLength] = 0;
+
+        if (!followLinks && UTIL_isLink(path)) {
+            UTIL_DISPLAYLEVEL(2, "Warning : %s is a symbolic link, ignoring\n", path);
+            continue;
+        }
+
+        if (UTIL_isDirectory(path)) {
+            nbFiles += UTIL_prepareFileList(path, bufStart, pos, bufEnd, followLinks);  /* Recursively call "UTIL_prepareFileList" with the new path. */
+            if (*bufStart == NULL) { free(path); closedir(dir); return 0; }
+        } else {
+            if (*bufStart + *pos + pathLength >= *bufEnd) {
+                ptrdiff_t newListSize = (*bufEnd - *bufStart) + LIST_SIZE_INCREASE;
+                *bufStart = (char*)UTIL_realloc(*bufStart, newListSize);
+                *bufEnd = *bufStart + newListSize;
+                if (*bufStart == NULL) { free(path); closedir(dir); return 0; }
+            }
+            if (*bufStart + *pos + pathLength < *bufEnd) {
+                strncpy(*bufStart + *pos, path, *bufEnd - (*bufStart + *pos));
+                *pos += pathLength + 1;
+                nbFiles++;
+            }
+        }
+        free(path);
+        errno = 0; /* clear errno after UTIL_isDirectory, UTIL_prepareFileList */
+    }
+
+    if (errno != 0) {
+        UTIL_DISPLAYLEVEL(1, "readdir(%s) error: %s\n", dirName, strerror(errno));
+        free(*bufStart);
+        *bufStart = NULL;
+    }
+    closedir(dir);
+    return nbFiles;
+}
+
+#else
+
+UTIL_STATIC int UTIL_prepareFileList(const char *dirName, char** bufStart, size_t* pos, char** bufEnd, int followLinks)
+{
+    (void)bufStart; (void)bufEnd; (void)pos;
+    UTIL_DISPLAYLEVEL(1, "Directory %s ignored (compiled without _WIN32 or _POSIX_C_SOURCE)\n", dirName);
+    return 0;
+}
+
+#endif /* #ifdef _WIN32 */
+
+/*
+ * UTIL_createFileList - takes a list of files and directories (params: inputNames, inputNamesNb), scans directories,
+ *                       and returns a new list of files (params: return value, allocatedBuffer, allocatedNamesNb).
+ * After finishing usage of the list the structures should be freed with UTIL_freeFileList(params: return value, allocatedBuffer)
+ * In case of error UTIL_createFileList returns NULL and UTIL_freeFileList should not be called.
+ */
+UTIL_STATIC const char** UTIL_createFileList(const char **inputNames, unsigned inputNamesNb, char** allocatedBuffer, unsigned* allocatedNamesNb, int followLinks)
+{
+    size_t pos;
+    unsigned i, nbFiles;
+    char* buf = (char*)malloc(LIST_SIZE_INCREASE);
+    char* bufend = buf + LIST_SIZE_INCREASE;
+    const char** fileTable;
+
+    if (!buf) return NULL;
+
+    for (i=0, pos=0, nbFiles=0; i<inputNamesNb; i++) {
+        if (!UTIL_isDirectory(inputNames[i])) {
+            size_t const len = strlen(inputNames[i]);
+            if (buf + pos + len >= bufend) {
+                ptrdiff_t newListSize = (bufend - buf) + LIST_SIZE_INCREASE;
+                buf = (char*)UTIL_realloc(buf, newListSize);
+                bufend = buf + newListSize;
+                if (!buf) return NULL;
+            }
+            if (buf + pos + len < bufend) {
+                strncpy(buf + pos, inputNames[i], bufend - (buf + pos));
+                pos += len + 1;
+                nbFiles++;
+            }
+        } else {
+            nbFiles += UTIL_prepareFileList(inputNames[i], &buf, &pos, &bufend, followLinks);
+            if (buf == NULL) return NULL;
+    }   }
+
+    if (nbFiles == 0) { free(buf); return NULL; }
+
+    fileTable = (const char**)malloc((nbFiles+1) * sizeof(const char*));
+    if (!fileTable) { free(buf); return NULL; }
+
+    for (i=0, pos=0; i<nbFiles; i++) {
+        fileTable[i] = buf + pos;
+        pos += strlen(fileTable[i]) + 1;
+    }
+
+    if (buf + pos > bufend) { free(buf); free((void*)fileTable); return NULL; }
+
+    *allocatedBuffer = buf;
+    *allocatedNamesNb = nbFiles;
+
+    return fileTable;
+}
+
+
+UTIL_STATIC void UTIL_freeFileList(const char** filenameTable, char* allocatedBuffer)
+{
+    if (allocatedBuffer) free(allocatedBuffer);
+    if (filenameTable) free((void*)filenameTable);
+}
+
+/* count the number of physical cores */
+#if defined(_WIN32) || defined(WIN32)
+
+#include <windows.h>
+
+typedef BOOL(WINAPI* LPFN_GLPI)(PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);
+
+UTIL_STATIC int UTIL_countPhysicalCores(void)
+{
+    static int numPhysicalCores = 0;
+    if (numPhysicalCores != 0) return numPhysicalCores;
+
+    {   LPFN_GLPI glpi;
+        BOOL done = FALSE;
+        PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
+        PSYSTEM_LOGICAL_PROCESSOR_INFORMATION ptr = NULL;
+        DWORD returnLength = 0;
+        size_t byteOffset = 0;
+
+        glpi = (LPFN_GLPI)GetProcAddress(GetModuleHandle(TEXT("kernel32")),
+                                         "GetLogicalProcessorInformation");
+
+        if (glpi == NULL) {
+            goto failed;
+        }
+
+        while(!done) {
+            DWORD rc = glpi(buffer, &returnLength);
+            if (FALSE == rc) {
+                if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+                    if (buffer)
+                        free(buffer);
+                    buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)malloc(returnLength);
+
+                    if (buffer == NULL) {
+                        perror("zstd");
+                        exit(1);
+                    }
+                } else {
+                    /* some other error */
+                    goto failed;
+                }
+            } else {
+                done = TRUE;
+            }
+        }
+
+        ptr = buffer;
+
+        while (byteOffset + sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) <= returnLength) {
+
+            if (ptr->Relationship == RelationProcessorCore) {
+                numPhysicalCores++;
+            }
+
+            ptr++;
+            byteOffset += sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION);
+        }
+
+        free(buffer);
+
+        return numPhysicalCores;
+    }
+
+failed:
+    /* try to fall back on GetSystemInfo */
+    {   SYSTEM_INFO sysinfo;
+        GetSystemInfo(&sysinfo);
+        numPhysicalCores = sysinfo.dwNumberOfProcessors;
+        if (numPhysicalCores == 0) numPhysicalCores = 1; /* just in case */
+    }
+    return numPhysicalCores;
+}
+
+#elif defined(__APPLE__)
+
+#include <sys/sysctl.h>
+
+/* Use apple-provided syscall
+ * see: man 3 sysctl */
+UTIL_STATIC int UTIL_countPhysicalCores(void)
+{
+    static S32 numPhysicalCores = 0; /* apple specifies int32_t */
+    if (numPhysicalCores != 0) return numPhysicalCores;
+
+    {   size_t size = sizeof(S32);
+        int const ret = sysctlbyname("hw.physicalcpu", &numPhysicalCores, &size, NULL, 0);
+        if (ret != 0) {
+            if (errno == ENOENT) {
+                /* entry not present, fall back on 1 */
+                numPhysicalCores = 1;
+            } else {
+                perror("zstd: can't get number of physical cpus");
+                exit(1);
+            }
+        }
+
+        return numPhysicalCores;
+    }
+}
+
+#elif defined(__linux__)
+
+/* parse /proc/cpuinfo
+ * siblings / cpu cores should give hyperthreading ratio
+ * otherwise fall back on sysconf */
+UTIL_STATIC int UTIL_countPhysicalCores(void)
+{
+    static int numPhysicalCores = 0;
+
+    if (numPhysicalCores != 0) return numPhysicalCores;
+
+    numPhysicalCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
+    if (numPhysicalCores == -1) {
+        /* value not queryable, fall back on 1 */
+        return numPhysicalCores = 1;
+    }
+
+    /* try to determine if there's hyperthreading */
+    {   FILE* const cpuinfo = fopen("/proc/cpuinfo", "r");
+#define BUF_SIZE 80
+        char buff[BUF_SIZE];
+
+        int siblings = 0;
+        int cpu_cores = 0;
+        int ratio = 1;
+
+        if (cpuinfo == NULL) {
+            /* fall back on the sysconf value */
+            return numPhysicalCores;
+        }
+
+        /* assume the cpu cores/siblings values will be constant across all
+         * present processors */
+        while (!feof(cpuinfo)) {
+            if (fgets(buff, BUF_SIZE, cpuinfo) != NULL) {
+                if (strncmp(buff, "siblings", 8) == 0) {
+                    const char* const sep = strchr(buff, ':');
+                    if (*sep == '\0') {
+                        /* formatting was broken? */
+                        goto failed;
+                    }
+
+                    siblings = atoi(sep + 1);
+                }
+                if (strncmp(buff, "cpu cores", 9) == 0) {
+                    const char* const sep = strchr(buff, ':');
+                    if (*sep == '\0') {
+                        /* formatting was broken? */
+                        goto failed;
+                    }
+
+                    cpu_cores = atoi(sep + 1);
+                }
+            } else if (ferror(cpuinfo)) {
+                /* fall back on the sysconf value */
+                goto failed;
+            }
+        }
+        if (siblings && cpu_cores) {
+            ratio = siblings / cpu_cores;
+        }
+failed:
+        fclose(cpuinfo);
+        return numPhysicalCores = numPhysicalCores / ratio;
+    }
+}
+
+#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+
+/* Use apple-provided syscall
+ * see: man 3 sysctl */
+UTIL_STATIC int UTIL_countPhysicalCores(void)
+{
+    static int numPhysicalCores = 0;
+
+    if (numPhysicalCores != 0) return numPhysicalCores;
+
+    numPhysicalCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
+    if (numPhysicalCores == -1) {
+        /* value not queryable, fall back on 1 */
+        return numPhysicalCores = 1;
+    }
+    return numPhysicalCores;
+}
+
+#else
+
+UTIL_STATIC int UTIL_countPhysicalCores(void)
+{
+    /* assume 1 */
+    return 1;
+}
+
+#endif
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* UTIL_H_MODULE */