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 <stdbool.h>
  25 #include <stddef.h>
  26 #include <stdint.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include "compiler.h"
  31 #include "openvswitch/types.h"
  32 #include "openvswitch/util.h"
  33
  34 #ifndef va_copy
  35 #ifdef __va_copy
  36 #define va_copy __va_copy
  37 #else
  38 #define va_copy(dst, src) ((dst) = (src))
  39 #endif
  40 #endif
  41
  42 extern char *program_name;
  43
  44 #define __ARRAY_SIZE_NOCHECK(ARRAY) (sizeof(ARRAY) / sizeof((ARRAY)[0]))
  45 #ifdef __GNUC__
  46 /* return 0 for array types, 1 otherwise */
  47 #define __ARRAY_CHECK(ARRAY)                                    \
  48     !__builtin_types_compatible_p(typeof(ARRAY), typeof(&ARRAY[0]))
  49
  50 /* compile-time fail if not array */
  51 #define __ARRAY_FAIL(ARRAY) (sizeof(char[-2*!__ARRAY_CHECK(ARRAY)]))
  52 #define __ARRAY_SIZE(ARRAY)                                     \
  53     __builtin_choose_expr(__ARRAY_CHECK(ARRAY),                 \
  54         __ARRAY_SIZE_NOCHECK(ARRAY), __ARRAY_FAIL(ARRAY))
  55 #else
  56 #define __ARRAY_SIZE(ARRAY) __ARRAY_SIZE_NOCHECK(ARRAY)
  57 #endif
  58
  59 /* Returns the number of elements in ARRAY. */
  60 #define ARRAY_SIZE(ARRAY) __ARRAY_SIZE(ARRAY)
  61
  62 /* Returns X / Y, rounding up.  X must be nonnegative to round correctly. */
  63 #define DIV_ROUND_UP(X, Y) (((X) + ((Y) - 1)) / (Y))
  64
  65 /* Returns X rounded up to the nearest multiple of Y. */
  66 #define ROUND_UP(X, Y) (DIV_ROUND_UP(X, Y) * (Y))
  67
  68 /* Returns the least number that, when added to X, yields a multiple of Y. */
  69 #define PAD_SIZE(X, Y) (ROUND_UP(X, Y) - (X))
  70
  71 /* Returns X rounded down to the nearest multiple of Y. */
  72 #define ROUND_DOWN(X, Y) ((X) / (Y) * (Y))
  73
  74 /* Returns true if X is a power of 2, otherwise false. */
  75 #define IS_POW2(X) ((X) && !((X) & ((X) - 1)))
  76
  77 static inline bool
  78 is_pow2(uintmax_t x)
  79 {
  80     return IS_POW2(x);
  81 }
  82
  83 /* Returns X rounded up to a power of 2.  X must be a constant expression. */
  84 #define ROUND_UP_POW2(X) RUP2__(X)
  85 #define RUP2__(X) (RUP2_1(X) + 1)
  86 #define RUP2_1(X) (RUP2_2(X) | (RUP2_2(X) >> 16))
  87 #define RUP2_2(X) (RUP2_3(X) | (RUP2_3(X) >> 8))
  88 #define RUP2_3(X) (RUP2_4(X) | (RUP2_4(X) >> 4))
  89 #define RUP2_4(X) (RUP2_5(X) | (RUP2_5(X) >> 2))
  90 #define RUP2_5(X) (RUP2_6(X) | (RUP2_6(X) >> 1))
  91 #define RUP2_6(X) ((X) - 1)
  92
  93 /* Returns X rounded down to a power of 2.  X must be a constant expression. */
  94 #define ROUND_DOWN_POW2(X) RDP2__(X)
  95 #define RDP2__(X) (RDP2_1(X) - (RDP2_1(X) >> 1))
  96 #define RDP2_1(X) (RDP2_2(X) | (RDP2_2(X) >> 16))
  97 #define RDP2_2(X) (RDP2_3(X) | (RDP2_3(X) >> 8))
  98 #define RDP2_3(X) (RDP2_4(X) | (RDP2_4(X) >> 4))
  99 #define RDP2_4(X) (RDP2_5(X) | (RDP2_5(X) >> 2))
 100 #define RDP2_5(X) (      (X) | (      (X) >> 1))
 101
 102 /* This system's cache line size, in bytes.
 103  * Being wrong hurts performance but not correctness. */
 104 #define CACHE_LINE_SIZE 64
 105 BUILD_ASSERT_DECL(IS_POW2(CACHE_LINE_SIZE));
 106
 107 static inline void
 108 ovs_prefetch_range(const void *start, size_t size)
 109 {
 110     const char *addr = (const char *)start;
 111     size_t ofs;
 112
 113     for (ofs = 0; ofs < size; ofs += CACHE_LINE_SIZE) {
 114         OVS_PREFETCH(addr + ofs);
 115     }
 116 }
 117
 118 #ifndef MIN
 119 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
 120 #endif
 121
 122 #ifndef MAX
 123 #define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
 124 #endif
 125
 126 #define OVS_NOT_REACHED() abort()
 127
 128 /* Given ATTR, and TYPE, cast the ATTR to TYPE by first casting ATTR to
 129  * (void *). This is to suppress the alignment warning issued by clang. */
 130 #define ALIGNED_CAST(TYPE, ATTR) ((TYPE) (void *) (ATTR))
 131
 132 /* Use "%"PRIuSIZE to format size_t with printf(). */
 133 #ifdef _WIN32
 134 #define PRIdSIZE "Id"
 135 #define PRIiSIZE "Ii"
 136 #define PRIoSIZE "Io"
 137 #define PRIuSIZE "Iu"
 138 #define PRIxSIZE "Ix"
 139 #define PRIXSIZE "IX"
 140 #else
 141 #define PRIdSIZE "zd"
 142 #define PRIiSIZE "zi"
 143 #define PRIoSIZE "zo"
 144 #define PRIuSIZE "zu"
 145 #define PRIxSIZE "zx"
 146 #define PRIXSIZE "zX"
 147 #endif
 148
 149 #ifndef _WIN32
 150 typedef uint32_t HANDLE;
 151 #endif
 152
 153 #ifdef  __cplusplus
 154 extern "C" {
 155 #endif
 156
 157 #define set_program_name(name) \
 158         ovs_set_program_name(name, OVS_PACKAGE_VERSION)
 159
 160 const char *get_subprogram_name(void);
 161     void set_subprogram_name(const char *);
 162
 163 void ovs_print_version(uint8_t min_ofp, uint8_t max_ofp);
 164
 165 OVS_NO_RETURN void out_of_memory(void);
 166 void *xmalloc(size_t) MALLOC_LIKE;
 167 void *xcalloc(size_t, size_t) MALLOC_LIKE;
 168 void *xzalloc(size_t) MALLOC_LIKE;
 169 void *xrealloc(void *, size_t);
 170 void *xmemdup(const void *, size_t) MALLOC_LIKE;
 171 char *xmemdup0(const char *, size_t) MALLOC_LIKE;
 172 char *xstrdup(const char *) MALLOC_LIKE;
 173 char *xasprintf(const char *format, ...) OVS_PRINTF_FORMAT(1, 2) MALLOC_LIKE;
 174 char *xvasprintf(const char *format, va_list) OVS_PRINTF_FORMAT(1, 0) MALLOC_LIKE;
 175 void *x2nrealloc(void *p, size_t *n, size_t s);
 176
 177 void *xmalloc_cacheline(size_t) MALLOC_LIKE;
 178 void *xzalloc_cacheline(size_t) MALLOC_LIKE;
 179 void free_cacheline(void *);
 180
 181 void ovs_strlcpy(char *dst, const char *src, size_t size);
 182 void ovs_strzcpy(char *dst, const char *src, size_t size);
 183
 184 OVS_NO_RETURN void ovs_abort(int err_no, const char *format, ...)
 185     OVS_PRINTF_FORMAT(2, 3);
 186 OVS_NO_RETURN void ovs_abort_valist(int err_no, const char *format, va_list)
 187     OVS_PRINTF_FORMAT(2, 0);
 188 OVS_NO_RETURN void ovs_fatal(int err_no, const char *format, ...)
 189     OVS_PRINTF_FORMAT(2, 3);
 190 OVS_NO_RETURN void ovs_fatal_valist(int err_no, const char *format, va_list)
 191     OVS_PRINTF_FORMAT(2, 0);
 192 void ovs_error(int err_no, const char *format, ...) OVS_PRINTF_FORMAT(2, 3);
 193 void ovs_error_valist(int err_no, const char *format, va_list)
 194     OVS_PRINTF_FORMAT(2, 0);
 195 const char *ovs_retval_to_string(int);
 196 const char *ovs_strerror(int);
 197 void ovs_hex_dump(FILE *, const void *, size_t, uintptr_t offset, bool ascii);
 198
 199 bool str_to_int(const char *, int base, int *);
 200 bool str_to_long(const char *, int base, long *);
 201 bool str_to_llong(const char *, int base, long long *);
 202 bool str_to_uint(const char *, int base, unsigned int *);
 203
 204 bool ovs_scan(const char *s, const char *format, ...) OVS_SCANF_FORMAT(2, 3);
 205 bool ovs_scan_len(const char *s, int *n, const char *format, ...);
 206
 207 bool str_to_double(const char *, double *);
 208
 209 int hexit_value(int c);
 210 uintmax_t hexits_value(const char *s, size_t n, bool *ok);
 211
 212 int parse_int_string(const char *s, uint8_t *valuep, int field_width,
 213                      char **tail);
 214
 215 const char *english_list_delimiter(size_t index, size_t total);
 216
 217 char *get_cwd(void);
 218 #ifndef _WIN32
 219 char *dir_name(const char *file_name);
 220 char *base_name(const char *file_name);
 221 #endif
 222 char *abs_file_name(const char *dir, const char *file_name);
 223
 224 char *follow_symlinks(const char *filename);
 225
 226 void ignore(bool x OVS_UNUSED);
 227 \f
 228 /* Bitwise tests. */
 229
 230 /* Returns the number of trailing 0-bits in 'n'.  Undefined if 'n' == 0. */
 231 #if __GNUC__ >= 4
 232 static inline int
 233 raw_ctz(uint64_t n)
 234 {
 235     /* With GCC 4.7 on 32-bit x86, if a 32-bit integer is passed as 'n', using
 236      * a plain __builtin_ctzll() here always generates an out-of-line function
 237      * call.  The test below helps it to emit a single 'bsf' instruction. */
 238     return (__builtin_constant_p(n <= UINT32_MAX) && n <= UINT32_MAX
 239             ? __builtin_ctz(n)
 240             : __builtin_ctzll(n));
 241 }
 242
 243 static inline int
 244 raw_clz64(uint64_t n)
 245 {
 246     return __builtin_clzll(n);
 247 }
 248 #elif _MSC_VER
 249 static inline int
 250 raw_ctz(uint64_t n)
 251 {
 252 #ifdef _WIN64
 253     unsigned long r = 0;
 254     _BitScanForward64(&r, n);
 255     return r;
 256 #else
 257     unsigned long low = n, high, r = 0;
 258     if (_BitScanForward(&r, low)) {
 259         return r;
 260     }
 261     high = n >> 32;
 262     _BitScanForward(&r, high);
 263     return r + 32;
 264 #endif
 265 }
 266
 267 static inline int
 268 raw_clz64(uint64_t n)
 269 {
 270 #ifdef _WIN64
 271     unsigned long r = 0;
 272     _BitScanReverse64(&r, n);
 273     return 63 - r;
 274 #else
 275     unsigned long low, high = n >> 32, r = 0;
 276     if (_BitScanReverse(&r, high)) {
 277         return 31 - r;
 278     }
 279     low = n;
 280     _BitScanReverse(&r, low);
 281     return 63 - r;
 282 #endif
 283 }
 284 #else
 285 /* Defined in util.c. */
 286 int raw_ctz(uint64_t n);
 287 int raw_clz64(uint64_t n);
 288 #endif
 289
 290 /* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
 291 static inline int
 292 ctz32(uint32_t n)
 293 {
 294     return n ? raw_ctz(n) : 32;
 295 }
 296
 297 /* Returns the number of trailing 0-bits in 'n', or 64 if 'n' is 0. */
 298 static inline int
 299 ctz64(uint64_t n)
 300 {
 301     return n ? raw_ctz(n) : 64;
 302 }
 303
 304 /* Returns the number of leading 0-bits in 'n', or 32 if 'n' is 0. */
 305 static inline int
 306 clz32(uint32_t n)
 307 {
 308     return n ? raw_clz64(n) - 32 : 32;
 309 }
 310
 311 /* Returns the number of leading 0-bits in 'n', or 64 if 'n' is 0. */
 312 static inline int
 313 clz64(uint64_t n)
 314 {
 315     return n ? raw_clz64(n) : 64;
 316 }
 317
 318 /* Given a word 'n', calculates floor(log_2('n')).  This is equivalent
 319  * to finding the bit position of the most significant one bit in 'n'.  It is
 320  * an error to call this function with 'n' == 0. */
 321 static inline int
 322 log_2_floor(uint64_t n)
 323 {
 324     return 63 - raw_clz64(n);
 325 }
 326
 327 /* Given a word 'n', calculates ceil(log_2('n')).  It is an error to
 328  * call this function with 'n' == 0. */
 329 static inline int
 330 log_2_ceil(uint64_t n)
 331 {
 332     return log_2_floor(n) + !is_pow2(n);
 333 }
 334
 335 /* unsigned int count_1bits(uint64_t x):
 336  *
 337  * Returns the number of 1-bits in 'x', between 0 and 64 inclusive. */
 338 #if UINTPTR_MAX == UINT64_MAX
 339 static inline unsigned int
 340 count_1bits(uint64_t x)
 341 {
 342 #if __GNUC__ >= 4 && __POPCNT__
 343     return __builtin_popcountll(x);
 344 #else
 345     /* This portable implementation is the fastest one we know of for 64
 346      * bits, and about 3x faster than GCC 4.7 __builtin_popcountll(). */
 347     const uint64_t h55 = UINT64_C(0x5555555555555555);
 348     const uint64_t h33 = UINT64_C(0x3333333333333333);
 349     const uint64_t h0F = UINT64_C(0x0F0F0F0F0F0F0F0F);
 350     const uint64_t h01 = UINT64_C(0x0101010101010101);
 351     x -= (x >> 1) & h55;               /* Count of each 2 bits in-place. */
 352     x = (x & h33) + ((x >> 2) & h33);  /* Count of each 4 bits in-place. */
 353     x = (x + (x >> 4)) & h0F;          /* Count of each 8 bits in-place. */
 354     return (x * h01) >> 56;            /* Sum of all bytes. */
 355 #endif
 356 }
 357 #else /* Not 64-bit. */
 358 #if __GNUC__ >= 4 && __POPCNT__
 359 static inline unsigned int
 360 count_1bits_32__(uint32_t x)
 361 {
 362     return __builtin_popcount(x);
 363 }
 364 #else
 365 #define NEED_COUNT_1BITS_8 1
 366 extern const uint8_t count_1bits_8[256];
 367 static inline unsigned int
 368 count_1bits_32__(uint32_t x)
 369 {
 370     /* This portable implementation is the fastest one we know of for 32 bits,
 371      * and faster than GCC __builtin_popcount(). */
 372     return (count_1bits_8[x & 0xff] +
 373             count_1bits_8[(x >> 8) & 0xff] +
 374             count_1bits_8[(x >> 16) & 0xff] +
 375             count_1bits_8[x >> 24]);
 376 }
 377 #endif
 378 static inline unsigned int
 379 count_1bits(uint64_t x)
 380 {
 381     return count_1bits_32__(x) + count_1bits_32__(x >> 32);
 382 }
 383 #endif
 384
 385 /* Returns the rightmost 1-bit in 'x' (e.g. 01011000 => 00001000), or 0 if 'x'
 386  * is 0. */
 387 static inline uintmax_t
 388 rightmost_1bit(uintmax_t x)
 389 {
 390     return x & -x;
 391 }
 392
 393 /* Returns 'x' with its rightmost 1-bit changed to a zero (e.g. 01011000 =>
 394  * 01010000), or 0 if 'x' is 0. */
 395 static inline uintmax_t
 396 zero_rightmost_1bit(uintmax_t x)
 397 {
 398     return x & (x - 1);
 399 }
 400
 401 /* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or an
 402  * undefined value if 'x' is 0. */
 403 static inline int
 404 rightmost_1bit_idx(uint64_t x)
 405 {
 406     return ctz64(x);
 407 }
 408
 409 /* Returns the index of the leftmost 1-bit in 'x' (e.g. 01011000 => 6), or an
 410  * undefined value if 'x' is 0. */
 411 static inline uint32_t
 412 leftmost_1bit_idx(uint64_t x)
 413 {
 414     return log_2_floor(x);
 415 }
 416
 417 /* Return a ovs_be32 prefix in network byte order with 'plen' highest bits set.
 418  * Shift with 32 is undefined behavior, but we rather use 64-bit shift than
 419  * compare. */
 420 static inline ovs_be32 be32_prefix_mask(int plen)
 421 {
 422     return htonl((uint64_t)UINT32_MAX << (32 - plen));
 423 }
 424 \f
 425 bool is_all_zeros(const void *, size_t);
 426 bool is_all_ones(const void *, size_t);
 427 void bitwise_copy(const void *src, unsigned int src_len, unsigned int src_ofs,
 428                   void *dst, unsigned int dst_len, unsigned int dst_ofs,
 429                   unsigned int n_bits);
 430 void bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 431                   unsigned int n_bits);
 432 void bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 433                  unsigned int n_bits);
 434 bool bitwise_is_all_zeros(const void *, unsigned int len, unsigned int ofs,
 435                           unsigned int n_bits);
 436 unsigned int bitwise_scan(const void *, unsigned int len,
 437                           bool target, unsigned int start, unsigned int end);
 438 int bitwise_rscan(const void *, unsigned int len, bool target,
 439                   int start, int end);
 440 void bitwise_put(uint64_t value,
 441                  void *dst, unsigned int dst_len, unsigned int dst_ofs,
 442                  unsigned int n_bits);
 443 uint64_t bitwise_get(const void *src, unsigned int src_len,
 444                      unsigned int src_ofs, unsigned int n_bits);
 445 bool bitwise_get_bit(const void *src, unsigned int len, unsigned int ofs);
 446 void bitwise_put0(void *dst, unsigned int len, unsigned int ofs);
 447 void bitwise_put1(void *dst, unsigned int len, unsigned int ofs);
 448 void bitwise_put_bit(void *dst, unsigned int len, unsigned int ofs, bool);
 449 void bitwise_toggle_bit(void *dst, unsigned int len, unsigned int ofs);
 450
 451 /* Returns non-zero if the parameters have equal value. */
 452 static inline int
 453 ovs_u128_equals(const ovs_u128 *a, const ovs_u128 *b)
 454 {
 455     return (a->u64.hi == b->u64.hi) && (a->u64.lo == b->u64.lo);
 456 }
 457
 458 /* Returns true if 'val' is 0. */
 459 static inline bool
 460 ovs_u128_is_zero(const ovs_u128 *val)
 461 {
 462     return !(val->u64.hi || val->u64.lo);
 463 }
 464
 465 /* Returns true if 'val' is all ones. */
 466 static inline bool
 467 ovs_u128_is_ones(const ovs_u128 *val)
 468 {
 469     return ovs_u128_equals(val, &OVS_U128_MAX);
 470 }
 471
 472 /* Returns non-zero if the parameters have equal value. */
 473 static inline int
 474 ovs_be128_equals(const ovs_be128 *a, const ovs_be128 *b)
 475 {
 476     return (a->be64.hi == b->be64.hi) && (a->be64.lo == b->be64.lo);
 477 }
 478
 479 /* Returns true if 'val' is 0. */
 480 static inline bool
 481 ovs_be128_is_zero(const ovs_be128 *val)
 482 {
 483     return !(val->be64.hi || val->be64.lo);
 484 }
 485
 486 void xsleep(unsigned int seconds);
 487
 488 bool is_stdout_a_tty(void);
 489
 490 #ifdef _WIN32
 491 \f
 492 char *ovs_format_message(int error);
 493 char *ovs_lasterror_to_string(void);
 494 int ftruncate(int fd, off_t length);
 495 #endif
 496
 497 #ifdef  __cplusplus
 498 }
 499 #endif
 500
 501 #endif /* util.h */