From 8b8f62850231148e4471e421288fa0d175e48039 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 19 May 2025 22:33:59 +0300 Subject: [PATCH 2/3] Invent custom pg_getopt_ctx that is thread-safe The standard getopt(3) function is not re-entrant nor thread-safe. That's OK for current usage, but it's one more little thing we need to change in order to make the server multi-threaded. There's no standard getopt_r() function on any platform, because command line arguments are usually parsed early when you start a program, usually before launching any threads, so there's not much need for it. However, we call it at backend startup to parse options from the startup packet. We are therefore free to define our own. The pg_getopt_start/next() implementation is based on the old getopt implementation, I just gathered all the state variables to a struct. The non-re-entrant getopt() function is now a wrapper around the custom re-entrant variant, on platforms that don't have getopt(3). getopt_long() is not used in the server, so we don't need to provide a re-entrant variant of that. --- src/include/port/pg_getopt_ctx.h | 29 +++++++ src/port/Makefile | 1 + src/port/getopt.c | 91 +++++---------------- src/port/meson.build | 1 + src/port/pg_getopt_ctx.c | 136 +++++++++++++++++++++++++++++++ src/tools/pgindent/typedefs.list | 1 + 6 files changed, 189 insertions(+), 70 deletions(-) create mode 100644 src/include/port/pg_getopt_ctx.h create mode 100644 src/port/pg_getopt_ctx.c diff --git a/src/include/port/pg_getopt_ctx.h b/src/include/port/pg_getopt_ctx.h new file mode 100644 index 00000000000..5066915d259 --- /dev/null +++ b/src/include/port/pg_getopt_ctx.h @@ -0,0 +1,29 @@ +/* + * Re-entrant version of the standard getopt(3) function. + * + * Portions Copyright (c) 2025, PostgreSQL Global Development Group + * + * src/include/port/pg_getopt_ctx.h + */ +#ifndef PG_GETOPT_CTX_H +#define PG_GETOPT_CTX_H + +typedef struct +{ + int nargc; + char *const *nargv; + const char *ostr; + + char *optarg; + int optind; + int opterr; + int optopt; + + /* internal state */ + char *place; +} pg_getopt_ctx; + +extern void pg_getopt_start(pg_getopt_ctx *ctx, int nargc, char *const *nargv, const char *ostr); +extern int pg_getopt_next(pg_getopt_ctx *ctx); + +#endif /* PG_GETOPT_CTX_H */ diff --git a/src/port/Makefile b/src/port/Makefile index 4274949dfa4..5aa5867b5ea 100644 --- a/src/port/Makefile +++ b/src/port/Makefile @@ -44,6 +44,7 @@ OBJS = \ noblock.o \ path.o \ pg_bitutils.o \ + pg_getopt_ctx.o \ pg_localeconv_r.o \ pg_numa.o \ pg_popcount_aarch64.o \ diff --git a/src/port/getopt.c b/src/port/getopt.c index 655fef3b0c7..34a60d5f32d 100644 --- a/src/port/getopt.c +++ b/src/port/getopt.c @@ -32,11 +32,7 @@ #include "c.h" #include "pg_getopt.h" - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)getopt.c 8.3 (Berkeley) 4/27/95"; -#endif /* LIBC_SCCS and not lint */ - +#include "port/pg_getopt_ctx.h" /* * On OpenBSD and some versions of Solaris, opterr and friends are defined in @@ -54,84 +50,39 @@ char *optarg; /* argument associated with option */ #endif -#define BADCH (int)'?' -#define BADARG (int)':' -#define EMSG "" - /* * getopt * Parse argc/argv argument vector. * + * We use the re-entrant pg_getopt_ctx() function under the hood, but expose the + * standard non re-entrant API. + * * This implementation does not use optreset. Instead, we guarantee that * it can be restarted on a new argv array after a previous call returned -1, * if the caller resets optind to 1 before the first call of the new series. - * (Internally, this means we must be sure to reset "place" to EMSG before + * (Internally, this means we must be sure to reset "active" before * returning -1.) */ int getopt(int nargc, char *const *nargv, const char *ostr) { - static char *place = EMSG; /* option letter processing */ - char *oli; /* option letter list index */ + static bool active = false; + static pg_getopt_ctx ctx; + int result; - if (!*place) - { /* update scanning pointer */ - if (optind >= nargc || *(place = nargv[optind]) != '-') - { - place = EMSG; - return -1; - } - if (place[1] && *++place == '-' && place[1] == '\0') - { /* found "--" */ - ++optind; - place = EMSG; - return -1; - } - } /* option letter okay? */ - if ((optopt = (int) *place++) == (int) ':' || - !(oli = strchr(ostr, optopt))) + if (!active) { - /* - * if the user didn't specify '-' as an option, assume it means -1. - */ - if (optopt == (int) '-') - { - place = EMSG; - return -1; - } - if (!*place) - ++optind; - if (opterr && *ostr != ':') - (void) fprintf(stderr, - "illegal option -- %c\n", optopt); - return BADCH; + pg_getopt_start(&ctx, nargc, nargv, ostr); + ctx.opterr = opterr; + active = true; } - if (*++oli != ':') - { /* don't need argument */ - optarg = NULL; - if (!*place) - ++optind; - } - else - { /* need an argument */ - if (*place) /* no white space */ - optarg = place; - else if (nargc <= ++optind) - { /* no arg */ - place = EMSG; - if (*ostr == ':') - return BADARG; - if (opterr) - (void) fprintf(stderr, - "option requires an argument -- %c\n", - optopt); - return BADCH; - } - else - /* white space */ - optarg = nargv[optind]; - place = EMSG; - ++optind; - } - return optopt; /* dump back option letter */ + + result = pg_getopt_next(&ctx); + opterr = ctx.opterr; + optind = ctx.optind; + optopt = ctx.optopt; + optarg = ctx.optarg; + if (result == -1) + active = false; + return result; } diff --git a/src/port/meson.build b/src/port/meson.build index fc7b059fee5..a6ec9c82f3a 100644 --- a/src/port/meson.build +++ b/src/port/meson.build @@ -7,6 +7,7 @@ pgport_sources = [ 'noblock.c', 'path.c', 'pg_bitutils.c', + 'pg_getopt_ctx.c', 'pg_localeconv_r.c', 'pg_numa.c', 'pg_popcount_aarch64.c', diff --git a/src/port/pg_getopt_ctx.c b/src/port/pg_getopt_ctx.c new file mode 100644 index 00000000000..c125f47813f --- /dev/null +++ b/src/port/pg_getopt_ctx.c @@ -0,0 +1,136 @@ +/*------------------------------------------------------------------------- + * + * pg_getopt_ctx.c + * Thread-safe implementation of getopt() + * + * Copyright (c) 1987, 1993, 1994 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * + * IDENTIFICATION + * src/port/pg_getopt_ctx.c + * + *------------------------------------------------------------------------- + */ + +#include "c.h" + +#include "port/pg_getopt_ctx.h" + +#define BADCH (int)'?' +#define BADARG (int)':' +#define EMSG "" + +/* + * Start parsing argc/argv argument vector. + * + * This is a re-entrant version of the standard library getopt(3) function. To + * use, first call pg_getopt_start() to initialize the state, and then call + * pg_getopt_next() until it returns -1. + */ +void +pg_getopt_start(pg_getopt_ctx *ctx, int nargc, char *const *nargv, const char *ostr) +{ + ctx->nargc = nargc; + ctx->nargv = nargv; + ctx->ostr = ostr; + + ctx->optind = 1; + ctx->optarg = NULL; + ctx->opterr = 0; /* Caller may set this after the call */ + ctx->optopt = 0; + + ctx->place = EMSG; /* option letter processing */ +} + +/* + * Parse next option in argc/argv argument vector + */ +int +pg_getopt_next(pg_getopt_ctx *ctx) +{ + char *oli; /* option letter list index */ + + if (!*ctx->place) + { /* update scanning pointer */ + if (ctx->optind >= ctx->nargc || *(ctx->place = ctx->nargv[ctx->optind]) != '-') + { + ctx->place = EMSG; + return -1; + } + if (ctx->place[1] && *++ctx->place == '-' && ctx->place[1] == '\0') + { /* found "--" */ + ++ctx->optind; + ctx->place = EMSG; + return -1; + } + } /* option letter okay? */ + if ((ctx->optopt = (int) *ctx->place++) == (int) ':' || + !(oli = strchr(ctx->ostr, ctx->optopt))) + { + /* + * if the user didn't specify '-' as an option, assume it means -1. + */ + if (ctx->optopt == (int) '-') + { + ctx->place = EMSG; + return -1; + } + if (!*ctx->place) + ++ctx->optind; + if (ctx->opterr && *ctx->ostr != ':') + (void) fprintf(stderr, + "illegal option -- %c\n", ctx->optopt); + return BADCH; + } + if (*++oli != ':') + { /* don't need argument */ + ctx->optarg = NULL; + if (!*ctx->place) + ++ctx->optind; + } + else + { /* need an argument */ + if (*ctx->place) /* no white space */ + ctx->optarg = ctx->place; + else if (ctx->nargc <= ++ctx->optind) + { /* no arg */ + ctx->place = EMSG; + if (*ctx->ostr == ':') + return BADARG; + if (ctx->opterr) + (void) fprintf(stderr, + "option requires an argument -- %c\n", + ctx->optopt); + return BADCH; + } + else + /* white space */ + ctx->optarg = ctx->nargv[ctx->optind]; + ctx->place = EMSG; + ++ctx->optind; + } + return ctx->optopt; /* dump back option letter */ +} diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 9ea573fae21..49ac9a1e47c 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -3830,6 +3830,7 @@ pg_enc2name pg_encname pg_fe_sasl_mech pg_funcptr_t +pg_getopt_ctx pg_gssinfo pg_hmac_ctx pg_hmac_errno -- 2.39.5