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Diffstat (limited to 'sysdeps/generic/dl-tunables-parse.h')
| -rw-r--r-- | sysdeps/generic/dl-tunables-parse.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/sysdeps/generic/dl-tunables-parse.h b/sysdeps/generic/dl-tunables-parse.h new file mode 100644 index 0000000000..b37be0443b --- /dev/null +++ b/sysdeps/generic/dl-tunables-parse.h @@ -0,0 +1,134 @@ +/* Helper functions to handle tunable strings. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _DL_TUNABLES_PARSE_H +#define _DL_TUNABLES_PARSE_H 1 + +#include <assert.h> +#include <string.h> + +/* Compare the contents of STRVAL with STR of size LEN. The STR might not + be null-terminated. */ +static __always_inline bool +tunable_strcmp (const struct tunable_str_t *strval, const char *str, + size_t len) +{ + return strval->len == len && memcmp (strval->str, str, len) == 0; +} +#define tunable_strcmp_cte(__tunable, __str) \ + tunable_strcmp (&__tunable->strval, __str, sizeof (__str) - 1) + +/* + Helper functions to iterate over a tunable string composed by multiple + suboptions separated by commaxi; this is a common pattern for CPU. Each + suboptions is return in the form of { address, size } (no null terminated). + For instance: + + struct tunable_str_comma_t ts; + tunable_str_comma_init (&ts, valp); + + struct tunable_str_t t; + while (tunable_str_comma_next (&ts, &t)) + { + _dl_printf ("[%s] %.*s (%d)\n", + __func__, + (int) tstr.len, + tstr.str, + (int) tstr.len); + + if (tunable_str_comma_strcmp (&t, opt, opt1_len)) + { + [...] + } + else if (tunable_str_comma_strcmp_cte (&t, "opt2")) + { + [...] + } + } + + NB: These function are expected to be called from tunable callback + functions along with tunable_val_t with string types. +*/ + +struct tunable_str_comma_state_t +{ + const char *p; + size_t plen; + size_t maxplen; +}; + +struct tunable_str_comma_t +{ + const char *str; + size_t len; + bool disable; +}; + +static inline void +tunable_str_comma_init (struct tunable_str_comma_state_t *state, + tunable_val_t *valp) +{ + assert (valp->strval.str != NULL); + state->p = valp->strval.str; + state->plen = 0; + state->maxplen = valp->strval.len; +} + +static inline bool +tunable_str_comma_next (struct tunable_str_comma_state_t *state, + struct tunable_str_comma_t *str) +{ + if (*state->p == '\0' || state->plen >= state->maxplen) + return false; + + const char *c; + for (c = state->p; *c != ','; c++, state->plen++) + if (*c == '\0' || state->plen == state->maxplen) + break; + + str->str = state->p; + str->len = c - state->p; + + if (str->len > 0) + { + str->disable = *str->str == '-'; + if (str->disable) + { + str->str = str->str + 1; + str->len = str->len - 1; + } + } + + state->p = c + 1; + state->plen++; + + return true; +} + +/* Compare the contents of T with STR of size LEN. The STR might not be + null-terminated. */ +static __always_inline bool +tunable_str_comma_strcmp (const struct tunable_str_comma_t *t, const char *str, + size_t len) +{ + return t->len == len && memcmp (t->str, str, len) == 0; +} +#define tunable_str_comma_strcmp_cte(__t, __str) \ + tunable_str_comma_strcmp (__t, __str, sizeof (__str) - 1) + +#endif |