lib/util.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef UTIL_H
  18 #define UTIL_H 1
  19
  20 #include <arpa/inet.h>
  21 #include <inttypes.h>
  22 #include <limits.h>
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include "compiler.h"
  28 #include "util.h"
  29 #include "openvswitch/util.h"
  30
  31 extern char *program_name;
  32
  33 #define __ARRAY_SIZE_NOCHECK(ARRAY) (sizeof(ARRAY) / sizeof((ARRAY)[0]))
  34 #ifdef __GNUC__
  35 /* return 0 for array types, 1 otherwise */
  36 #define __ARRAY_CHECK(ARRAY)                                    \
  37     !__builtin_types_compatible_p(typeof(ARRAY), typeof(&ARRAY[0]))
  38
  39 /* compile-time fail if not array */
  40 #define __ARRAY_FAIL(ARRAY) (sizeof(char[-2*!__ARRAY_CHECK(ARRAY)]))
  41 #define __ARRAY_SIZE(ARRAY)                                     \
  42     __builtin_choose_expr(__ARRAY_CHECK(ARRAY),                 \
  43         __ARRAY_SIZE_NOCHECK(ARRAY), __ARRAY_FAIL(ARRAY))
  44 #else
  45 #define __ARRAY_SIZE(ARRAY) __ARRAY_SIZE_NOCHECK(ARRAY)
  46 #endif
  47
  48
  49 /* This system's cache line size, in bytes.
  50  * Being wrong hurts performance but not correctness. */
  51 #define CACHE_LINE_SIZE 64
  52 BUILD_ASSERT_DECL(IS_POW2(CACHE_LINE_SIZE));
  53
  54 static inline void
  55 ovs_prefetch_range(const void *start, size_t size)
  56 {
  57     const char *addr = (const char *)start;
  58     size_t ofs;
  59
  60     for (ofs = 0; ofs < size; ofs += CACHE_LINE_SIZE) {
  61         OVS_PREFETCH(addr + ofs);
  62     }
  63 }
  64
  65 #ifndef MIN
  66 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
  67 #endif
  68
  69 #ifndef MAX
  70 #define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
  71 #endif
  72
  73 #define OVS_NOT_REACHED() abort()
  74
  75 /* Use "%"PRIuSIZE to format size_t with printf(). */
  76 #ifdef _WIN32
  77 #define PRIdSIZE "Id"
  78 #define PRIiSIZE "Ii"
  79 #define PRIoSIZE "Io"
  80 #define PRIuSIZE "Iu"
  81 #define PRIxSIZE "Ix"
  82 #define PRIXSIZE "IX"
  83 #else
  84 #define PRIdSIZE "zd"
  85 #define PRIiSIZE "zi"
  86 #define PRIoSIZE "zo"
  87 #define PRIuSIZE "zu"
  88 #define PRIxSIZE "zx"
  89 #define PRIXSIZE "zX"
  90 #endif
  91
  92 #ifndef _WIN32
  93 typedef uint32_t HANDLE;
  94 #endif
  95
  96 #ifdef  __cplusplus
  97 extern "C" {
  98 #endif
  99
 100 #define set_program_name(name) \
 101         ovs_set_program_name(name, OVS_PACKAGE_VERSION)
 102
 103 const char *get_subprogram_name(void);
 104     void set_subprogram_name(const char *);
 105
 106 void ovs_print_version(uint8_t min_ofp, uint8_t max_ofp);
 107
 108 OVS_NO_RETURN void out_of_memory(void);
 109 void *xmalloc(size_t) MALLOC_LIKE;
 110 void *xcalloc(size_t, size_t) MALLOC_LIKE;
 111 void *xzalloc(size_t) MALLOC_LIKE;
 112 void *xrealloc(void *, size_t);
 113 void *xmemdup(const void *, size_t) MALLOC_LIKE;
 114 char *xmemdup0(const char *, size_t) MALLOC_LIKE;
 115 char *xstrdup(const char *) MALLOC_LIKE;
 116 char *nullable_xstrdup(const char *) MALLOC_LIKE;
 117 char *xasprintf(const char *format, ...) OVS_PRINTF_FORMAT(1, 2) MALLOC_LIKE;
 118 char *xvasprintf(const char *format, va_list) OVS_PRINTF_FORMAT(1, 0) MALLOC_LIKE;
 119 void *x2nrealloc(void *p, size_t *n, size_t s);
 120
 121 void *xmalloc_cacheline(size_t) MALLOC_LIKE;
 122 void *xzalloc_cacheline(size_t) MALLOC_LIKE;
 123 void free_cacheline(void *);
 124
 125 void ovs_strlcpy(char *dst, const char *src, size_t size);
 126 void ovs_strzcpy(char *dst, const char *src, size_t size);
 127
 128 OVS_NO_RETURN void ovs_abort(int err_no, const char *format, ...)
 129     OVS_PRINTF_FORMAT(2, 3);
 130 OVS_NO_RETURN void ovs_abort_valist(int err_no, const char *format, va_list)
 131     OVS_PRINTF_FORMAT(2, 0);
 132 OVS_NO_RETURN void ovs_fatal(int err_no, const char *format, ...)
 133     OVS_PRINTF_FORMAT(2, 3);
 134 OVS_NO_RETURN void ovs_fatal_valist(int err_no, const char *format, va_list)
 135     OVS_PRINTF_FORMAT(2, 0);
 136 void ovs_error(int err_no, const char *format, ...) OVS_PRINTF_FORMAT(2, 3);
 137 void ovs_error_valist(int err_no, const char *format, va_list)
 138     OVS_PRINTF_FORMAT(2, 0);
 139 const char *ovs_retval_to_string(int);
 140 const char *ovs_strerror(int);
 141 void ovs_hex_dump(FILE *, const void *, size_t, uintptr_t offset, bool ascii);
 142
 143 bool str_to_int(const char *, int base, int *);
 144 bool str_to_long(const char *, int base, long *);
 145 bool str_to_llong(const char *, int base, long long *);
 146 bool str_to_uint(const char *, int base, unsigned int *);
 147
 148 bool ovs_scan(const char *s, const char *format, ...) OVS_SCANF_FORMAT(2, 3);
 149 bool ovs_scan_len(const char *s, int *n, const char *format, ...);
 150
 151 bool str_to_double(const char *, double *);
 152
 153 int hexit_value(int c);
 154 uintmax_t hexits_value(const char *s, size_t n, bool *ok);
 155
 156 int parse_int_string(const char *s, uint8_t *valuep, int field_width,
 157                      char **tail);
 158
 159 const char *english_list_delimiter(size_t index, size_t total);
 160
 161 char *get_cwd(void);
 162 #ifndef _WIN32
 163 char *dir_name(const char *file_name);
 164 char *base_name(const char *file_name);
 165 #endif
 166 char *abs_file_name(const char *dir, const char *file_name);
 167
 168 char *follow_symlinks(const char *filename);
 169
 170 void ignore(bool x OVS_UNUSED);
 171 \f
 172 /* Bitwise tests. */
 173
 174 /* Returns the number of trailing 0-bits in 'n'.  Undefined if 'n' == 0. */
 175 #if __GNUC__ >= 4
 176 static inline int
 177 raw_ctz(uint64_t n)
 178 {
 179     /* With GCC 4.7 on 32-bit x86, if a 32-bit integer is passed as 'n', using
 180      * a plain __builtin_ctzll() here always generates an out-of-line function
 181      * call.  The test below helps it to emit a single 'bsf' instruction. */
 182     return (__builtin_constant_p(n <= UINT32_MAX) && n <= UINT32_MAX
 183             ? __builtin_ctz(n)
 184             : __builtin_ctzll(n));
 185 }
 186
 187 static inline int
 188 raw_clz64(uint64_t n)
 189 {
 190     return __builtin_clzll(n);
 191 }
 192 #elif _MSC_VER
 193 static inline int
 194 raw_ctz(uint64_t n)
 195 {
 196 #ifdef _WIN64
 197     unsigned long r = 0;
 198     _BitScanForward64(&r, n);
 199     return r;
 200 #else
 201     unsigned long low = n, high, r = 0;
 202     if (_BitScanForward(&r, low)) {
 203         return r;
 204     }
 205     high = n >> 32;
 206     _BitScanForward(&r, high);
 207     return r + 32;
 208 #endif
 209 }
 210
 211 static inline int
 212 raw_clz64(uint64_t n)
 213 {
 214 #ifdef _WIN64
 215     unsigned long r = 0;
 216     _BitScanReverse64(&r, n);
 217     return 63 - r;
 218 #else
 219     unsigned long low, high = n >> 32, r = 0;
 220     if (_BitScanReverse(&r, high)) {
 221         return 31 - r;
 222     }
 223     low = n;
 224     _BitScanReverse(&r, low);
 225     return 63 - r;
 226 #endif
 227 }
 228 #else
 229 /* Defined in util.c. */
 230 int raw_ctz(uint64_t n);
 231 int raw_clz64(uint64_t n);
 232 #endif
 233
 234 /* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
 235 static inline int
 236 ctz32(uint32_t n)
 237 {
 238     return n ? raw_ctz(n) : 32;
 239 }
 240
 241 /* Returns the number of trailing 0-bits in 'n', or 64 if 'n' is 0. */
 242 static inline int
 243 ctz64(uint64_t n)
 244 {
 245     return n ? raw_ctz(n) : 64;
 246 }
 247
 248 /* Returns the number of leading 0-bits in 'n', or 32 if 'n' is 0. */
 249 static inline int
 250 clz32(uint32_t n)
 251 {
 252     return n ? raw_clz64(n) - 32 : 32;
 253 }
 254
 255 /* Returns the number of leading 0-bits in 'n', or 64 if 'n' is 0. */
 256 static inline int
 257 clz64(uint64_t n)
 258 {
 259     return n ? raw_clz64(n) : 64;
 260 }
 261
 262 /* Given a word 'n', calculates floor(log_2('n')).  This is equivalent
 263  * to finding the bit position of the most significant one bit in 'n'.  It is
 264  * an error to call this function with 'n' == 0. */
 265 static inline int
 266 log_2_floor(uint64_t n)
 267 {
 268     return 63 - raw_clz64(n);
 269 }
 270
 271 /* Given a word 'n', calculates ceil(log_2('n')).  It is an error to
 272  * call this function with 'n' == 0. */
 273 static inline int
 274 log_2_ceil(uint64_t n)
 275 {
 276     return log_2_floor(n) + !is_pow2(n);
 277 }
 278
 279 /* unsigned int count_1bits(uint64_t x):
 280  *
 281  * Returns the number of 1-bits in 'x', between 0 and 64 inclusive. */
 282 #if UINTPTR_MAX == UINT64_MAX
 283 static inline unsigned int
 284 count_1bits(uint64_t x)
 285 {
 286 #if __GNUC__ >= 4 && __POPCNT__
 287     return __builtin_popcountll(x);
 288 #else
 289     /* This portable implementation is the fastest one we know of for 64
 290      * bits, and about 3x faster than GCC 4.7 __builtin_popcountll(). */
 291     const uint64_t h55 = UINT64_C(0x5555555555555555);
 292     const uint64_t h33 = UINT64_C(0x3333333333333333);
 293     const uint64_t h0F = UINT64_C(0x0F0F0F0F0F0F0F0F);
 294     const uint64_t h01 = UINT64_C(0x0101010101010101);
 295     x -= (x >> 1) & h55;               /* Count of each 2 bits in-place. */
 296     x = (x & h33) + ((x >> 2) & h33);  /* Count of each 4 bits in-place. */
 297     x = (x + (x >> 4)) & h0F;          /* Count of each 8 bits in-place. */
 298     return (x * h01) >> 56;            /* Sum of all bytes. */
 299 #endif
 300 }
 301 #else /* Not 64-bit. */
 302 #if __GNUC__ >= 4 && __POPCNT__
 303 static inline unsigned int
 304 count_1bits_32__(uint32_t x)
 305 {
 306     return __builtin_popcount(x);
 307 }
 308 #else
 309 #define NEED_COUNT_1BITS_8 1
 310 extern const uint8_t count_1bits_8[256];
 311 static inline unsigned int
 312 count_1bits_32__(uint32_t x)
 313 {
 314     /* This portable implementation is the fastest one we know of for 32 bits,
 315      * and faster than GCC __builtin_popcount(). */
 316     return (count_1bits_8[x & 0xff] +
 317             count_1bits_8[(x >> 8) & 0xff] +
 318             count_1bits_8[(x >> 16) & 0xff] +
 319             count_1bits_8[x >> 24]);
 320 }
 321 #endif
 322 static inline unsigned int
 323 count_1bits(uint64_t x)
 324 {
 325     return count_1bits_32__(x) + count_1bits_32__(x >> 32);
 326 }
 327 #endif
 328
 329 /* Returns the rightmost 1-bit in 'x' (e.g. 01011000 => 00001000), or 0 if 'x'
 330  * is 0. */
 331 static inline uintmax_t
 332 rightmost_1bit(uintmax_t x)
 333 {
 334     return x & -x;
 335 }
 336
 337 /* Returns 'x' with its rightmost 1-bit changed to a zero (e.g. 01011000 =>
 338  * 01010000), or 0 if 'x' is 0. */
 339 static inline uintmax_t
 340 zero_rightmost_1bit(uintmax_t x)
 341 {
 342     return x & (x - 1);
 343 }
 344
 345 /* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or an
 346  * undefined value if 'x' is 0. */
 347 static inline int
 348 rightmost_1bit_idx(uint64_t x)
 349 {
 350     return ctz64(x);
 351 }
 352
 353 /* Returns the index of the leftmost 1-bit in 'x' (e.g. 01011000 => 6), or an
 354  * undefined value if 'x' is 0. */
 355 static inline uint32_t
 356 leftmost_1bit_idx(uint64_t x)
 357 {
 358     return log_2_floor(x);
 359 }
 360
 361 /* Return a ovs_be32 prefix in network byte order with 'plen' highest bits set.
 362  * Shift with 32 is undefined behavior, but we rather use 64-bit shift than
 363  * compare. */
 364 static inline ovs_be32 be32_prefix_mask(int plen)
 365 {
 366     return htonl((uint64_t)UINT32_MAX << (32 - plen));
 367 }
 368 \f
 369 bool is_all_zeros(const void *, size_t);
 370 bool is_all_ones(const void *, size_t);
 371 void bitwise_copy(const void *src, unsigned int src_len, unsigned int src_ofs,
 372                   void *dst, unsigned int dst_len, unsigned int dst_ofs,
 373                   unsigned int n_bits);
 374 void bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 375                   unsigned int n_bits);
 376 void bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 377                  unsigned int n_bits);
 378 bool bitwise_is_all_zeros(const void *, unsigned int len, unsigned int ofs,
 379                           unsigned int n_bits);
 380 unsigned int bitwise_scan(const void *, unsigned int len,
 381                           bool target, unsigned int start, unsigned int end);
 382 int bitwise_rscan(const void *, unsigned int len, bool target,
 383                   int start, int end);
 384 void bitwise_put(uint64_t value,
 385                  void *dst, unsigned int dst_len, unsigned int dst_ofs,
 386                  unsigned int n_bits);
 387 uint64_t bitwise_get(const void *src, unsigned int src_len,
 388                      unsigned int src_ofs, unsigned int n_bits);
 389 bool bitwise_get_bit(const void *src, unsigned int len, unsigned int ofs);
 390 void bitwise_put0(void *dst, unsigned int len, unsigned int ofs);
 391 void bitwise_put1(void *dst, unsigned int len, unsigned int ofs);
 392 void bitwise_put_bit(void *dst, unsigned int len, unsigned int ofs, bool);
 393 void bitwise_toggle_bit(void *dst, unsigned int len, unsigned int ofs);
 394
 395 /* Returns non-zero if the parameters have equal value. */
 396 static inline int
 397 ovs_u128_equals(const ovs_u128 a, const ovs_u128 b)
 398 {
 399     return (a.u64.hi == b.u64.hi) && (a.u64.lo == b.u64.lo);
 400 }
 401
 402 /* Returns true if 'val' is 0. */
 403 static inline bool
 404 ovs_u128_is_zero(const ovs_u128 val)
 405 {
 406     return !(val.u64.hi || val.u64.lo);
 407 }
 408
 409 /* Returns true if 'val' is all ones. */
 410 static inline bool
 411 ovs_u128_is_ones(const ovs_u128 val)
 412 {
 413     return ovs_u128_equals(val, OVS_U128_MAX);
 414 }
 415
 416 /* Returns non-zero if the parameters have equal value. */
 417 static inline int
 418 ovs_be128_equals(const ovs_be128 a, const ovs_be128 b)
 419 {
 420     return (a.be64.hi == b.be64.hi) && (a.be64.lo == b.be64.lo);
 421 }
 422
 423 /* Returns true if 'val' is 0. */
 424 static inline bool
 425 ovs_be128_is_zero(const ovs_be128 val)
 426 {
 427     return !(val.be64.hi || val.be64.lo);
 428 }
 429
 430 static inline ovs_u128
 431 ovs_u128_and(const ovs_u128 a, const ovs_u128 b)
 432 {
 433     ovs_u128 dst;
 434
 435     dst.u64.hi = a.u64.hi & b.u64.hi;
 436     dst.u64.lo = a.u64.lo & b.u64.lo;
 437
 438     return dst;
 439 }
 440
 441 void xsleep(unsigned int seconds);
 442
 443 bool is_stdout_a_tty(void);
 444
 445 #ifdef _WIN32
 446 \f
 447 char *ovs_format_message(int error);
 448 char *ovs_lasterror_to_string(void);
 449 int ftruncate(int fd, off_t length);
 450 #endif
 451
 452 #ifdef  __cplusplus
 453 }
 454 #endif
 455
 456 #endif /* util.h */