具有multithreadingcurl请求的Segfault

我在这里遇到了一些C ++程序的麻烦。 基本上我已经为http请求写了一个简单的包装,可以一次执行多个请求。 工作绝对好,但是当我做httpS请求时,它在multithreading模式下随机崩溃。 我使用curl和posix线程。 Backtrace看起来像这样:

======= Backtrace: ========= /lib/x86_64-linux-gnu/libc.so.6(+0x80996)[0x7fea9046d996] /lib/x86_64-linux-gnu/libc.so.6(+0x82b80)[0x7fea9046fb80] /lib/x86_64-linux-gnu/libc.so.6(realloc+0xf2)[0x7fea90470ae2] /lib/x86_64-linux-gnu/libcrypto.so.1.0.0(CRYPTO_realloc+0x49)[0x7fea8f9c6169] /lib/x86_64-linux-gnu/libcrypto.so.1.0.0(lh_insert+0x101)[0x7fea8fa4bfb1] /lib/x86_64-linux-gnu/libcrypto.so.1.0.0(+0xe844e)[0x7fea8fa4e44e] /lib/x86_64-linux-gnu/libcrypto.so.1.0.0(ERR_get_state+0xde)[0x7fea8fa4eeee] /lib/x86_64-linux-gnu/libcrypto.so.1.0.0(ERR_clear_error+0x15)[0x7fea8fa4f065] /usr/lib/x86_64-linux-gnu/libcurl.so.4(+0x24e79)[0x7fea90f10e79] /usr/lib/x86_64-linux-gnu/libcurl.so.4(+0x39ea0)[0x7fea90f25ea0] /usr/lib/x86_64-linux-gnu/libcurl.so.4(+0xf8fd)[0x7fea90efb8fd] /usr/lib/x86_64-linux-gnu/libcurl.so.4(+0x219f5)[0x7fea90f0d9f5] /usr/lib/x86_64-linux-gnu/libcurl.so.4(+0x35538)[0x7fea90f21538] /usr/lib/x86_64-linux-gnu/libcurl.so.4(curl_multi_perform+0x91)[0x7fea90f21d31] /usr/lib/x86_64-linux-gnu/libcurl.so.4(curl_easy_perform+0x107)[0x7fea90f19457] ./exbot[0x40273a] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7f6e)[0x7fea90cd6f6e] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7fea904e79cd] 

这可能是libcrypto中的一个错误? 我可以不知何故告诉curl不要使用libcrypto? 任何替代品? 它只使用httpS请求来启动文件,并且即使10000个同时http查询也能正常工作。

干杯,托马斯

只是为了完整我的代码:

 // simple wrapper for http requests #ifndef _REQUEST_H_ #define _REQUEST_H_ #include <curl/curl.h> #include <pthread.h> #include <string> #include <iostream> ////////////////////////////////// // MACROS ////////////////////////////////// #define ERR(_msg) std::cerr << __FUNCTION__ << ": " << _msg << std::endl ////////////////////////////////// // REQUEST WRAPPER ////////////////////////////////// typedef unsigned int uint; class RequestWrapper { private: // non copyable RequestWrapper(); RequestWrapper(const RequestWrapper &that); RequestWrapper &operator=(const RequestWrapper &that); public: struct Response { Response() : msg(""), success(false) {} std::string msg; bool success; }; static Response simpleGET(std::string url, uint timeout); static size_t write(char *content, size_t size, size_t nmemb, void *userp); }; ////////////////////////////////// // GET ////////////////////////////////// inline size_t RequestWrapper::write(char *content, size_t size, size_t nmemb, void *userp) { std::string *buf = static_cast<std::string *>(userp); size_t realsize = size * nmemb; for (uint i = 0; i < realsize; ++i) { buf->push_back(content[i]); } return realsize; } inline RequestWrapper::Response RequestWrapper::simpleGET(std::string url, uint timeout) { Response resp; CURL *curl; CURLcode res; std::string buf; // send request buf.clear(); curl = curl_easy_init(); if (!curl) { //ERR("libcurl init failed"); return resp; } curl_easy_setopt(curl, CURLOPT_URL, url.c_str()); curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write); curl_easy_setopt(curl, CURLOPT_WRITEDATA, static_cast<void *>(&buf)); curl_easy_setopt(curl, CURLOPT_TIMEOUT, timeout); res = curl_easy_perform(curl); if(res != CURLE_OK) { //ERR("libcurl request failed, CODE: " << res); return resp; } curl_easy_cleanup(curl); // done resp.msg = buf; resp.success = true; return resp; } ////////////////////////////////// // MULTITHREADED REQUEST ////////////////////////////////// class RequestList { private: std::vector<std::string> _reqs; static void *sender(void *payload); static pthread_mutex_t _mutex; public: inline void add(std::string request) { _reqs.push_back(request); } inline void clear() { _reqs.clear(); } std::vector<std::string> send(uint timeout) const; struct Payload { std::string url; std::vector<std::string> *out; uint tout, index; Payload(std::string url, std::vector<std::string> *out, uint tout, uint index) : url(url), out(out), tout(tout), index(index) { } Payload() : url(""), out(NULL), tout(0), index(0) { } }; }; ////////////////////////////////// // SEND MT REQUEST ////////////////////////////////// pthread_mutex_t RequestList::_mutex; void *RequestList::sender(void *payload) { Payload *pl = static_cast<Payload *>(payload); RequestWrapper::Response resp = RequestWrapper::simpleGET(pl->url, pl->tout); pthread_mutex_lock(&_mutex); if (resp.success) { pl->out->at(pl->index) = resp.msg; std::cerr << "."; } else { std::cerr << "x"; } pthread_mutex_unlock(&_mutex); return NULL; } inline std::vector<std::string> RequestList::send(uint timeout) const { std::vector<std::string> resp; resp.resize(_reqs.size()); Payload *payloads = new Payload[_reqs.size()]; pthread_t *tids = new pthread_t[_reqs.size()]; // create mutex pthread_mutex_init(&_mutex, NULL); // prepare payload and create thread for (uint i = 0; i < _reqs.size(); ++i) { payloads[i] = Payload(_reqs[i], &resp, timeout, i); pthread_create(&tids[i], NULL, RequestList::sender, static_cast<void *>(&payloads[i])); } // wait for threads to finish for (uint i = 0; i < _reqs.size(); ++i) { pthread_join(tids[i], NULL); } std::cerr << std::endl; //destroy mutex pthread_mutex_destroy(&_mutex); delete[] payloads; delete[] tids; return resp; } #endif 

Solutions Collecting From Web of "具有multithreadingcurl请求的Segfault"

Libcrypto是OpenSSL的一部分,它不是线程安全的,除非你提供必要的回调。 根据文档 ,在符合POSIX的系统(具有线程本地errno )上,缺省的thread-id实现是可以接受的,所以你只需要一个锁定函数:

 void locking_function(int mode, int n, const char *file, int line); 

这个函数将需要维护一组CRYPTO_num_locks()互斥锁,并根据mode的值锁定或解锁第n个互斥锁。 您可以阅读文档以获取更多详细信息。 libcurl网站实际上有一些示例代码展示了如何做到这一点。

或者,您可以使用不同的线程安全SSL库(如GnuTLS)来构建libcurl。