patacongo commented on a change in pull request #3170: URL: https://github.com/apache/incubator-nuttx/pull/3170#discussion_r601529393
########## File path: libs/libc/unistd/lib_getoptvars.c ########## @@ -0,0 +1,166 @@ +/**************************************************************************** + * libs/libc/unistd/lib_getoptvars.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <unistd.h> +#include <pthread.h> + +#include "unistd.h" +#include "libc.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define INVALID_KEY CONFIG_TLS_NELEM +#define VALID_KEY(key) ((key) >= 0 && key < CONFIG_TLS_NELEM) + +/* Configuration. Currently no thread-specific data destructors. */ + +#undef HAVE_DESTRUCTOR +#define HAVE_CLEANUP 1 +#define HAVE_TLSVARS 1 + +/* Check if we have some way to avoid a memory leak */ + +#if defined(CONFIG_DISABLE_PTHREAD) || !defined(CONFIG_PTHREAD_CLEANUP) +# undef HAVE_CLEANUP +#endif + +/* Don't use TLS if we cannot avoid the memory leak or if TLS is disabled */ + +#if (!defined(HAVE_DESTRUCTOR) && !defined(HAVE_CLEANUP)) || \ + CONFIG_TLS_NELEM == 0 +# undef HAVE_TLSVARS +#endif + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +#ifdef HAVE_TLSVARS +static pthread_key_t g_getopt_key = (pthread_key_t)INVALID_KEY; +static pthread_mutex_t g_getopt_mutex = PTHREAD_MUTEX_INITIALIZER; + +#else +/* Fallback to avoid memory leak when there is no destructor and no cleanup + * or when there is no TLS. + */ + +FAR struct getopt_s g_getopt_vars = +{ + NULL, + 0, + 1, + '?' +}; +#endif + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +#ifdef HAVE_TLSVARS +void _getopt_destructor(FAR void *getoptvars) +{ + lib_free(getoptvars); +} +#endif + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: getoptvars + * + * Description: + * Returns a pointer to to the thread-specific getopt() data. + * + ****************************************************************************/ + +FAR struct getopt_s *getoptvars(void) +{ +#ifdef HAVE_TLSVARS + FAR struct getopt_s *go; + int ret; + + ret = pthread_mutex_lock(&g_getopt_mutex); + DEBUGASSERT(ret == OK); + UNUSED(ret); + + /* Check if a key has been assigned */ + + if (!VALID_KEY(g_getopt_key)) + { + ret = pthread_key_create(&g_getopt_key, _getopt_destructor); + DEBUGASSERT(ret == OK); + UNUSED(ret); + } + + /* Get the structure of getopt() variables using the key. */ + + go = (FAR struct getopt_s *)pthread_getspecific(g_getopt_key); + if (go == NULL) + { + /* The instance has not yet been created. Allocate getopt() + * it now. + */ + + go = (FAR struct getopt_s *)lib_malloc(sizeof(struct getopt_s)); Review comment: > Both options are disabled by default? The change will break almost project. No, that case is handled. It is not a serious problem. It will simply revert to the previous behavior: ``` 52 /* Don't use TLS if we cannot avoid the memory leak or if TLS is disabled. 53 * Furthermore, TLS is not needed in the KERNEL build because it naturally 54 * supports per-process data. 55 */ 56 57 #if !defined(HAVE_DESTRUCTOR) && !defined(HAVE_CLEANUP) 58 # undef HAVE_TLSVARS 59 #endif 60 61 #ifdef CONFIG_BUILD_KERNEL 62 # undef HAVE_TLSVARS 63 #endif 69 #ifdef HAVE_TLSVARS 73 #else 74 /* Fallback to avoid memory leak when there is no destructor and no cleanup 75 * or when there is no TLS. 76 */ 77 78 FAR struct getopt_s g_getopt_vars = 79 { 80 NULL, 81 0, 82 1, 83 '?', 84 NULL, 85 false 86 }; 87 #endif ``` -- This is an automated message from the Apache Git Service. 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