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 /* Comparisons for ints with modular arithmetic */
  74 #define INT_MOD_LT(a,b)     ((int) ((a)-(b)) < 0)
  75 #define INT_MOD_LEQ(a,b)    ((int) ((a)-(b)) <= 0)
  76 #define INT_MOD_GT(a,b)     ((int) ((a)-(b)) > 0)
  77 #define INT_MOD_GEQ(a,b)    ((int) ((a)-(b)) >= 0)
  78
  79 #define INT_MOD_MIN(a, b)   ((INT_MOD_LT(a, b)) ? (a) : (b))
  80 #define INT_MOD_MAX(a, b)   ((INT_MOD_GT(a, b)) ? (a) : (b))
  81
  82 #define OVS_NOT_REACHED() abort()
  83
  84 /* Use "%"PRIuSIZE to format size_t with printf(). */
  85 #ifdef _WIN32
  86 #define PRIdSIZE "Id"
  87 #define PRIiSIZE "Ii"
  88 #define PRIoSIZE "Io"
  89 #define PRIuSIZE "Iu"
  90 #define PRIxSIZE "Ix"
  91 #define PRIXSIZE "IX"
  92 #else
  93 #define PRIdSIZE "zd"
  94 #define PRIiSIZE "zi"
  95 #define PRIoSIZE "zo"
  96 #define PRIuSIZE "zu"
  97 #define PRIxSIZE "zx"
  98 #define PRIXSIZE "zX"
  99 #endif
 100
 101 #ifndef _WIN32
 102 typedef uint32_t HANDLE;
 103 #endif
 104
 105 #ifdef  __cplusplus
 106 extern "C" {
 107 #endif
 108
 109 #define set_program_name(name) \
 110         ovs_set_program_name(name, OVS_PACKAGE_VERSION)
 111
 112 const char *get_subprogram_name(void);
 113     void set_subprogram_name(const char *);
 114
 115 void ovs_print_version(uint8_t min_ofp, uint8_t max_ofp);
 116
 117 OVS_NO_RETURN void out_of_memory(void);
 118 void *xmalloc(size_t) MALLOC_LIKE;
 119 void *xcalloc(size_t, size_t) MALLOC_LIKE;
 120 void *xzalloc(size_t) MALLOC_LIKE;
 121 void *xrealloc(void *, size_t);
 122 void *xmemdup(const void *, size_t) MALLOC_LIKE;
 123 char *xmemdup0(const char *, size_t) MALLOC_LIKE;
 124 char *xstrdup(const char *) MALLOC_LIKE;
 125 char *nullable_xstrdup(const char *) MALLOC_LIKE;
 126 bool nullable_string_is_equal(const char *a, const char *b);
 127 char *xasprintf(const char *format, ...) OVS_PRINTF_FORMAT(1, 2) MALLOC_LIKE;
 128 char *xvasprintf(const char *format, va_list) OVS_PRINTF_FORMAT(1, 0) MALLOC_LIKE;
 129 void *x2nrealloc(void *p, size_t *n, size_t s);
 130
 131 void *xmalloc_cacheline(size_t) MALLOC_LIKE;
 132 void *xzalloc_cacheline(size_t) MALLOC_LIKE;
 133 void free_cacheline(void *);
 134
 135 void ovs_strlcpy(char *dst, const char *src, size_t size);
 136 void ovs_strzcpy(char *dst, const char *src, size_t size);
 137
 138 OVS_NO_RETURN void ovs_abort(int err_no, const char *format, ...)
 139     OVS_PRINTF_FORMAT(2, 3);
 140 OVS_NO_RETURN void ovs_abort_valist(int err_no, const char *format, va_list)
 141     OVS_PRINTF_FORMAT(2, 0);
 142 OVS_NO_RETURN void ovs_fatal(int err_no, const char *format, ...)
 143     OVS_PRINTF_FORMAT(2, 3);
 144 OVS_NO_RETURN void ovs_fatal_valist(int err_no, const char *format, va_list)
 145     OVS_PRINTF_FORMAT(2, 0);
 146 void ovs_error(int err_no, const char *format, ...) OVS_PRINTF_FORMAT(2, 3);
 147 void ovs_error_valist(int err_no, const char *format, va_list)
 148     OVS_PRINTF_FORMAT(2, 0);
 149 const char *ovs_retval_to_string(int);
 150 const char *ovs_strerror(int);
 151 void ovs_hex_dump(FILE *, const void *, size_t, uintptr_t offset, bool ascii);
 152
 153 bool str_to_int(const char *, int base, int *);
 154 bool str_to_long(const char *, int base, long *);
 155 bool str_to_llong(const char *, int base, long long *);
 156 bool str_to_uint(const char *, int base, unsigned int *);
 157
 158 bool ovs_scan(const char *s, const char *format, ...) OVS_SCANF_FORMAT(2, 3);
 159 bool ovs_scan_len(const char *s, int *n, const char *format, ...);
 160
 161 bool str_to_double(const char *, double *);
 162
 163 int hexit_value(int c);
 164 uintmax_t hexits_value(const char *s, size_t n, bool *ok);
 165
 166 int parse_int_string(const char *s, uint8_t *valuep, int field_width,
 167                      char **tail);
 168
 169 const char *english_list_delimiter(size_t index, size_t total);
 170
 171 char *get_cwd(void);
 172 #ifndef _WIN32
 173 char *dir_name(const char *file_name);
 174 char *base_name(const char *file_name);
 175 #endif
 176 char *abs_file_name(const char *dir, const char *file_name);
 177
 178 char *follow_symlinks(const char *filename);
 179
 180 void ignore(bool x OVS_UNUSED);
 181 \f
 182 /* Bitwise tests. */
 183
 184 /* Returns the number of trailing 0-bits in 'n'.  Undefined if 'n' == 0. */
 185 #if __GNUC__ >= 4
 186 static inline int
 187 raw_ctz(uint64_t n)
 188 {
 189     /* With GCC 4.7 on 32-bit x86, if a 32-bit integer is passed as 'n', using
 190      * a plain __builtin_ctzll() here always generates an out-of-line function
 191      * call.  The test below helps it to emit a single 'bsf' instruction. */
 192     return (__builtin_constant_p(n <= UINT32_MAX) && n <= UINT32_MAX
 193             ? __builtin_ctz(n)
 194             : __builtin_ctzll(n));
 195 }
 196
 197 static inline int
 198 raw_clz64(uint64_t n)
 199 {
 200     return __builtin_clzll(n);
 201 }
 202 #elif _MSC_VER
 203 static inline int
 204 raw_ctz(uint64_t n)
 205 {
 206 #ifdef _WIN64
 207     unsigned long r = 0;
 208     _BitScanForward64(&r, n);
 209     return r;
 210 #else
 211     unsigned long low = n, high, r = 0;
 212     if (_BitScanForward(&r, low)) {
 213         return r;
 214     }
 215     high = n >> 32;
 216     _BitScanForward(&r, high);
 217     return r + 32;
 218 #endif
 219 }
 220
 221 static inline int
 222 raw_clz64(uint64_t n)
 223 {
 224 #ifdef _WIN64
 225     unsigned long r = 0;
 226     _BitScanReverse64(&r, n);
 227     return 63 - r;
 228 #else
 229     unsigned long low, high = n >> 32, r = 0;
 230     if (_BitScanReverse(&r, high)) {
 231         return 31 - r;
 232     }
 233     low = n;
 234     _BitScanReverse(&r, low);
 235     return 63 - r;
 236 #endif
 237 }
 238 #else
 239 /* Defined in util.c. */
 240 int raw_ctz(uint64_t n);
 241 int raw_clz64(uint64_t n);
 242 #endif
 243
 244 /* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
 245 static inline int
 246 ctz32(uint32_t n)
 247 {
 248     return n ? raw_ctz(n) : 32;
 249 }
 250
 251 /* Returns the number of trailing 0-bits in 'n', or 64 if 'n' is 0. */
 252 static inline int
 253 ctz64(uint64_t n)
 254 {
 255     return n ? raw_ctz(n) : 64;
 256 }
 257
 258 /* Returns the number of leading 0-bits in 'n', or 32 if 'n' is 0. */
 259 static inline int
 260 clz32(uint32_t n)
 261 {
 262     return n ? raw_clz64(n) - 32 : 32;
 263 }
 264
 265 /* Returns the number of leading 0-bits in 'n', or 64 if 'n' is 0. */
 266 static inline int
 267 clz64(uint64_t n)
 268 {
 269     return n ? raw_clz64(n) : 64;
 270 }
 271
 272 /* Given a word 'n', calculates floor(log_2('n')).  This is equivalent
 273  * to finding the bit position of the most significant one bit in 'n'.  It is
 274  * an error to call this function with 'n' == 0. */
 275 static inline int
 276 log_2_floor(uint64_t n)
 277 {
 278     return 63 - raw_clz64(n);
 279 }
 280
 281 /* Given a word 'n', calculates ceil(log_2('n')).  It is an error to
 282  * call this function with 'n' == 0. */
 283 static inline int
 284 log_2_ceil(uint64_t n)
 285 {
 286     return log_2_floor(n) + !is_pow2(n);
 287 }
 288
 289 /* unsigned int count_1bits(uint64_t x):
 290  *
 291  * Returns the number of 1-bits in 'x', between 0 and 64 inclusive. */
 292 #if UINTPTR_MAX == UINT64_MAX
 293 static inline unsigned int
 294 count_1bits(uint64_t x)
 295 {
 296 #if __GNUC__ >= 4 && __POPCNT__
 297     return __builtin_popcountll(x);
 298 #else
 299     /* This portable implementation is the fastest one we know of for 64
 300      * bits, and about 3x faster than GCC 4.7 __builtin_popcountll(). */
 301     const uint64_t h55 = UINT64_C(0x5555555555555555);
 302     const uint64_t h33 = UINT64_C(0x3333333333333333);
 303     const uint64_t h0F = UINT64_C(0x0F0F0F0F0F0F0F0F);
 304     const uint64_t h01 = UINT64_C(0x0101010101010101);
 305     x -= (x >> 1) & h55;               /* Count of each 2 bits in-place. */
 306     x = (x & h33) + ((x >> 2) & h33);  /* Count of each 4 bits in-place. */
 307     x = (x + (x >> 4)) & h0F;          /* Count of each 8 bits in-place. */
 308     return (x * h01) >> 56;            /* Sum of all bytes. */
 309 #endif
 310 }
 311 #else /* Not 64-bit. */
 312 #if __GNUC__ >= 4 && __POPCNT__
 313 static inline unsigned int
 314 count_1bits_32__(uint32_t x)
 315 {
 316     return __builtin_popcount(x);
 317 }
 318 #else
 319 #define NEED_COUNT_1BITS_8 1
 320 extern const uint8_t count_1bits_8[256];
 321 static inline unsigned int
 322 count_1bits_32__(uint32_t x)
 323 {
 324     /* This portable implementation is the fastest one we know of for 32 bits,
 325      * and faster than GCC __builtin_popcount(). */
 326     return (count_1bits_8[x & 0xff] +
 327             count_1bits_8[(x >> 8) & 0xff] +
 328             count_1bits_8[(x >> 16) & 0xff] +
 329             count_1bits_8[x >> 24]);
 330 }
 331 #endif
 332 static inline unsigned int
 333 count_1bits(uint64_t x)
 334 {
 335     return count_1bits_32__(x) + count_1bits_32__(x >> 32);
 336 }
 337 #endif
 338
 339 /* Returns the rightmost 1-bit in 'x' (e.g. 01011000 => 00001000), or 0 if 'x'
 340  * is 0. */
 341 static inline uintmax_t
 342 rightmost_1bit(uintmax_t x)
 343 {
 344     return x & -x;
 345 }
 346
 347 /* Returns 'x' with its rightmost 1-bit changed to a zero (e.g. 01011000 =>
 348  * 01010000), or 0 if 'x' is 0. */
 349 static inline uintmax_t
 350 zero_rightmost_1bit(uintmax_t x)
 351 {
 352     return x & (x - 1);
 353 }
 354
 355 /* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or an
 356  * undefined value if 'x' is 0. */
 357 static inline int
 358 rightmost_1bit_idx(uint64_t x)
 359 {
 360     return ctz64(x);
 361 }
 362
 363 /* Returns the index of the leftmost 1-bit in 'x' (e.g. 01011000 => 6), or an
 364  * undefined value if 'x' is 0. */
 365 static inline uint32_t
 366 leftmost_1bit_idx(uint64_t x)
 367 {
 368     return log_2_floor(x);
 369 }
 370
 371 /* Return a ovs_be32 prefix in network byte order with 'plen' highest bits set.
 372  * Shift with 32 is undefined behavior, but we rather use 64-bit shift than
 373  * compare. */
 374 static inline ovs_be32 be32_prefix_mask(int plen)
 375 {
 376     return htonl((uint64_t)UINT32_MAX << (32 - plen));
 377 }
 378 \f
 379 bool is_all_zeros(const void *, size_t);
 380 bool is_all_ones(const void *, size_t);
 381 void bitwise_copy(const void *src, unsigned int src_len, unsigned int src_ofs,
 382                   void *dst, unsigned int dst_len, unsigned int dst_ofs,
 383                   unsigned int n_bits);
 384 void bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 385                   unsigned int n_bits);
 386 void bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
 387                  unsigned int n_bits);
 388 bool bitwise_is_all_zeros(const void *, unsigned int len, unsigned int ofs,
 389                           unsigned int n_bits);
 390 unsigned int bitwise_scan(const void *, unsigned int len,
 391                           bool target, unsigned int start, unsigned int end);
 392 int bitwise_rscan(const void *, unsigned int len, bool target,
 393                   int start, int end);
 394 void bitwise_put(uint64_t value,
 395                  void *dst, unsigned int dst_len, unsigned int dst_ofs,
 396                  unsigned int n_bits);
 397 uint64_t bitwise_get(const void *src, unsigned int src_len,
 398                      unsigned int src_ofs, unsigned int n_bits);
 399 bool bitwise_get_bit(const void *src, unsigned int len, unsigned int ofs);
 400 void bitwise_put0(void *dst, unsigned int len, unsigned int ofs);
 401 void bitwise_put1(void *dst, unsigned int len, unsigned int ofs);
 402 void bitwise_put_bit(void *dst, unsigned int len, unsigned int ofs, bool);
 403 void bitwise_toggle_bit(void *dst, unsigned int len, unsigned int ofs);
 404
 405 /* Returns non-zero if the parameters have equal value. */
 406 static inline int
 407 ovs_u128_equals(const ovs_u128 a, const ovs_u128 b)
 408 {
 409     return (a.u64.hi == b.u64.hi) && (a.u64.lo == b.u64.lo);
 410 }
 411
 412 /* Returns true if 'val' is 0. */
 413 static inline bool
 414 ovs_u128_is_zero(const ovs_u128 val)
 415 {
 416     return !(val.u64.hi || val.u64.lo);
 417 }
 418
 419 /* Returns true if 'val' is all ones. */
 420 static inline bool
 421 ovs_u128_is_ones(const ovs_u128 val)
 422 {
 423     return ovs_u128_equals(val, OVS_U128_MAX);
 424 }
 425
 426 /* Returns non-zero if the parameters have equal value. */
 427 static inline int
 428 ovs_be128_equals(const ovs_be128 a, const ovs_be128 b)
 429 {
 430     return (a.be64.hi == b.be64.hi) && (a.be64.lo == b.be64.lo);
 431 }
 432
 433 /* Returns true if 'val' is 0. */
 434 static inline bool
 435 ovs_be128_is_zero(const ovs_be128 val)
 436 {
 437     return !(val.be64.hi || val.be64.lo);
 438 }
 439
 440 static inline ovs_u128
 441 ovs_u128_and(const ovs_u128 a, const ovs_u128 b)
 442 {
 443     ovs_u128 dst;
 444
 445     dst.u64.hi = a.u64.hi & b.u64.hi;
 446     dst.u64.lo = a.u64.lo & b.u64.lo;
 447
 448     return dst;
 449 }
 450
 451 void xsleep(unsigned int seconds);
 452
 453 bool is_stdout_a_tty(void);
 454
 455 #ifdef _WIN32
 456 \f
 457 char *ovs_format_message(int error);
 458 char *ovs_lasterror_to_string(void);
 459 int ftruncate(int fd, off_t length);
 460 #endif
 461
 462 #ifdef  __cplusplus
 463 }
 464 #endif
 465
 466 #endif /* util.h */