Re: Memory leak with curl_multi_socket_action

On Mon, May 25, 2020 at 11:15 PM James Read <jamesread5737_at_gmail.com> wrote:

>
>
> On Mon, May 25, 2020 at 10:37 PM Daniel Stenberg <daniel_at_haxx.se> wrote:
>
>> On Mon, 25 May 2020, James Read wrote:
>>
>> > I call curl_multi_cleanup here:
>>
>> > I call curl_easy_cleanup here:
>>
>> > What am I missing?
>>
>> I don't think we'll be able to tell you that. We can't reproduce this
>> problem.
>> We don't see any memory leak in any builds on any platforms.
>>
>> I suggest you write up a sample program based on your experiences that
>> reproduces the problem, and show that to us. Then we can help out more!
>>
>
> #include <errno.h>
> #include <fcntl.h>
> #include <signal.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <sys/epoll.h>
> #include <sys/stat.h>
> #include <sys/time.h>
> #include <sys/timerfd.h>
> #include <sys/types.h>
> #include <sys/resource.h>
> #include <sys/socket.h>
> #include <arpa/inet.h>
> #include <time.h>
> #include <unistd.h>
> #include <pthread.h>
> #include <netdb.h>
> #include <time.h>
> #include <netinet/in.h>
>
> #include <curl/curl.h>
>
> #define MSG_OUT stdout
> #define DEFAULT_QUEUE_LENGTH 10000
> #define mycase(code) \
> case code: s = __STRING(code)
>
> typedef struct _CrawlerConfig
> {
> char redis_address[1024];
> int redis_port;
> char mongo_address[1024];
> int mongo_port;
>
> char url_file[1024];
>
> int queue_length;
> } CrawlerConfig;
>
> /* Global information, common to all connections */
> typedef struct _GlobalInfo
> {
> int epfd; /* epoll filedescriptor */
> int tfd; /* timer filedescriptor */
> CURLM *multi;
> int still_running;
> pthread_mutex_t lock;
> int concurrent_connections;
> pthread_mutex_t parsed_lock;
> int parsed_sites;
>
> CrawlerConfig config;
> } GlobalInfo;
>
> /* Information associated with a specific easy handle */
> typedef struct _ConnInfo
> {
> CURL *easy;
> char *url;
> GlobalInfo *global;
> char error[CURL_ERROR_SIZE];
> size_t size;
> char *data;
> } ConnInfo;
>
> /* Information associated with a specific socket */
> typedef struct _SockInfo
> {
> curl_socket_t sockfd;
> CURL *easy;
> int action;
> long timeout;
> GlobalInfo *global;
> } SockInfo;
>
> /* Die if we get a bad CURLMcode somewhere */
> static void
> mcode_or_die(const char *where, CURLMcode code)
> {
> if (CURLM_OK != code) {
> const char *s;
>
> switch (code) {
> mycase(CURLM_BAD_HANDLE); break;
> mycase(CURLM_BAD_EASY_HANDLE); break;
> mycase(CURLM_OUT_OF_MEMORY); break;
> mycase(CURLM_INTERNAL_ERROR); break;
> mycase(CURLM_UNKNOWN_OPTION); break;
> mycase(CURLM_LAST); break;
> default: s = "CURLM_unknown"; break;
> mycase(CURLM_BAD_SOCKET);
> fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
> /* ignore this error */
> return;
> }
>
> fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
> exit(code);
> }
> }
>
> void
> concurrent_connections_inc(GlobalInfo *g)
> {
> g->concurrent_connections++;
>
> printf("\rParsed sites: %d, %d parallel connections, %d still running\t",
> g->parsed_sites, g->concurrent_connections, g->still_running);
> fflush(stdout);
> }
>
> void
> concurrent_connections_dec(GlobalInfo *g)
> {
> g->concurrent_connections--;
>
> printf("\rParsed sites: %d, %d parallel connections, %d still running\t",
> g->parsed_sites, g->concurrent_connections, g->still_running);
> fflush(stdout);
> }
>
> static void timer_cb(GlobalInfo* g, int revents);
>
> /* Update the timer after curl_multi library does it's thing. Curl will
> * inform us through this callback what it wants the new timeout to be,
> * after it does some work. */
> static int
> multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
> {
> struct itimerspec its;
>
> //fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n",
> timeout_ms);
>
> if (timeout_ms > 0) {
> its.it_interval.tv_sec = 1;
> its.it_interval.tv_nsec = 0;
> its.it_value.tv_sec = timeout_ms / 1000;
> its.it_value.tv_nsec = (timeout_ms % 1000) * 1000 * 1000;
> } else if(timeout_ms == 0) {
> /* libcurl wants us to timeout now, however setting both fields of
> * new_value.it_value to zero disarms the timer. The closest we can
> * do is to schedule the timer to fire in 1 ns. */
> its.it_interval.tv_sec = 1;
> its.it_interval.tv_nsec = 0;
> its.it_value.tv_sec = 0;
> its.it_value.tv_nsec = 1;
> } else {
> memset(&its, 0, sizeof(struct itimerspec));
> }
>
> timerfd_settime(g->tfd, /*flags=*/ 0, &its, NULL);
>
> return (0);
> }
>
> /* Check for completed transfers, and remove their easy handles */
> static void
> check_multi_info(GlobalInfo *g)
> {
> char *eff_url;
> CURLMsg *msg;
> int msgs_left;
> ConnInfo *conn;
> CURL *easy;
> char *ct;
> double time;
> double dl;
> //CURLcode res;
>
> while ((msg = curl_multi_info_read(g->multi, &msgs_left))) {
> if (msg->msg == CURLMSG_DONE) {
> easy = msg->easy_handle;
> //res = msg->data.result;
> curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
> curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
> curl_easy_getinfo(easy, CURLINFO_CONTENT_TYPE, &ct);
> curl_easy_getinfo(easy, CURLINFO_TOTAL_TIME, &time);
> curl_easy_getinfo(easy, CURLINFO_SIZE_DOWNLOAD, &dl);
>
> //fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
>
> curl_multi_remove_handle(g->multi, easy);
> //free(conn->url);
> free(conn->data);
> curl_easy_cleanup(easy);
> free(conn);
> }
> }
> }
>
> /* Called by libevent when we get action on a multi socket
> filedescriptor*/
> static void
> event_cb(GlobalInfo *g, int fd, int revents)
> {
> CURLMcode rc;
> struct itimerspec its;
>
> int action = ((revents & EPOLLIN) ? CURL_CSELECT_IN : 0) |
> ((revents & EPOLLOUT) ? CURL_CSELECT_OUT : 0);
>
> rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running);
> mcode_or_die("event_cb: curl_multi_socket_action", rc);
>
> check_multi_info(g);
>
> if (g->still_running <= 0) {
> //fprintf(MSG_OUT, "last transfer done, kill timeout\n");
> memset(&its, 0, sizeof(struct itimerspec));
> timerfd_settime(g->tfd, 0, &its, NULL);
> }
> }
>
> /* Called by main loop when our timeout expires */
> static void
> timer_cb(GlobalInfo* g, int revents)
> {
> CURLMcode rc;
> uint64_t count = 0;
> ssize_t err = 0;
>
> err = read(g->tfd, &count, sizeof(uint64_t));
> if (err == -1) {
> /* Note that we may call the timer callback even if the timerfd isn't
> * readable. It's possible that there are multiple events stored in the
> * epoll buffer (i.e. the timer may have fired multiple times). The
> * event count is cleared after the first call so future events in the
> * epoll buffer will fail to read from the timer. */
> if (errno == EAGAIN) {
> //fprintf(MSG_OUT, "EAGAIN on tfd %d\n", g->tfd);
> return;
> }
> }
>
> if (err != sizeof(uint64_t)) {
> fprintf(stderr, "read(tfd) == %ld", err);
> perror("read(tfd)");
> }
>
> rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
> &g->still_running);
> mcode_or_die("timer_cb: curl_multi_socket_action", rc);
> check_multi_info(g);
> }
>
> /* Assign information to a SockInfo structure */
> static void
> setsock(SockInfo *f, curl_socket_t s, CURL *e, int act, GlobalInfo *g)
> {
> struct epoll_event ev;
> int kind = ((act & CURL_POLL_IN) ? EPOLLIN : 0) |
> ((act & CURL_POLL_OUT) ? EPOLLOUT : 0);
>
> if (f->sockfd) {
> concurrent_connections_dec(g);
> if (epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL))
> fprintf(stderr, "EPOLL_CTL_DEL failed for fd: %d : %s\n",
> f->sockfd, strerror(errno));
> }
>
> f->sockfd = s;
> f->action = act;
> f->easy = e;
>
> ev.events = kind;
> ev.data.fd = s;
>
> concurrent_connections_inc(g);
> if (epoll_ctl(g->epfd, EPOLL_CTL_ADD, s, &ev)) {
> fprintf(stderr, "EPOLL_CTL_ADD failed for fd: %d : %s\n",
> s, strerror(errno));
> }
> }
>
> /* Initialize a new SockInfo structure */
> static void
> addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
> {
> SockInfo *fdp = (SockInfo *)calloc(sizeof(SockInfo), 1);
>
> fdp->global = g;
> setsock(fdp, s, easy, action, g);
> curl_multi_assign(g->multi, s, fdp);
> }
>
> static size_t
> write_cb(void *contents, size_t size, size_t nmemb, void *p)
> {
> ConnInfo *conn = (ConnInfo *)p;
> size_t realsize = size * nmemb;
>
> conn->data = realloc(conn->data, conn->size + realsize + 1);
> if (conn->data == NULL) {
> /* out of memory! */
> printf("not enough memory (realloc returned NULL)\n");
> return 0;
> }
>
> memcpy(&(conn->data[conn->size]), contents, realsize);
> conn->size += realsize;
> conn->data[conn->size] = 0;
>
> return realsize;
> }
>
> /* Create a new easy handle, and add it to the global curl_multi */
> int
> new_conn(char *url, GlobalInfo *g)
> {
> ConnInfo *conn;
> CURLMcode rc;
> char buffer1[1024];
> char buffer2[1024];
>
> memset(buffer1, 0, sizeof(buffer1));
> memset(buffer2, 0, sizeof(buffer2));
>
> conn = (ConnInfo*)calloc(1, sizeof(ConnInfo));
> conn->error[0]='\0';
> conn->global = g;
>
> conn->easy = curl_easy_init();
> if (!conn->easy) {
> fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
> exit(2);
> }
>
> int autoresolve = 0;
>
> conn->global = g;
> conn->url = url;
> curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
> curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
> curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
> curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
> curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
> curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
> curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 1L);
> curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
> curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
> curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
> curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 100L);
> curl_easy_setopt(conn->easy, CURLOPT_CONNECTTIMEOUT, 10L);
> curl_easy_setopt(conn->easy, CURLOPT_CLOSESOCKETDATA, g);
>
> rc = curl_multi_add_handle(g->multi, conn->easy);
> mcode_or_die("new_conn: curl_multi_add_handle", rc);
>
> /* note that the add_handle() will set a time-out to trigger very soon so
> that the necessary socket_action() call will be called by this app */
>
> return (0);
> }
>
> /* Clean up the SockInfo structure */
> static void
> remsock(SockInfo *f, GlobalInfo* g)
> {
> if (f) {
> if (f->sockfd) {
> g->concurrent_connections--;
> if (epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL))
> fprintf(stderr, "EPOLL_CTL_DEL failed for fd: %d : %s\n",
> f->sockfd, strerror(errno));
> }
>
> free(f);
> }
> }
>
> /* CURLMOPT_SOCKETFUNCTION */
> static int
> sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
> {
> GlobalInfo *g = (GlobalInfo*) cbp;
> SockInfo *fdp = (SockInfo*) sockp;
>
> if (what == CURL_POLL_REMOVE) {
> remsock(fdp, g);
> } else {
> if (!fdp) {
> addsock(s, e, what, g);
> } else {
> setsock(fdp, s, e, what, g);
> }
> }
>
> return (0);
> }
>
> int should_exit = 0;
>
> void
> signal_handler(int signo)
> {
> should_exit = 1;
> }
>
> static void
> thread_sighandler(int signum)
> {
> printf("\nCrawler exiting.\n");
> pthread_exit(NULL);
> }
>
> void *
> crawler_init(void *arg)
> {
> GlobalInfo g;
> struct itimerspec its;
> struct epoll_event ev;
> struct epoll_event events[10000];
>
> signal(SIGUSR1, thread_sighandler);
>
> memset(&g, 0, sizeof(GlobalInfo));
>
> memcpy(&g.config, arg, sizeof(CrawlerConfig));
>
> g.epfd = epoll_create1(EPOLL_CLOEXEC);
> if (g.epfd == -1) {
> perror("epoll_create1 failed\n");
> exit(1);
> }
>
> g.tfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
> if (g.tfd == -1) {
> perror("timerfd_create failed\n");
> exit(1);
> }
>
> memset(&its, 0, sizeof(struct itimerspec));
> its.it_interval.tv_sec = 1;
> its.it_value.tv_sec = 1;
> timerfd_settime(g.tfd, 0, &its, NULL);
>
> ev.events = EPOLLIN;
> ev.data.fd = g.tfd;
> epoll_ctl(g.epfd, EPOLL_CTL_ADD, g.tfd, &ev);
>
> curl_global_init(CURL_GLOBAL_DEFAULT);
> g.multi = curl_multi_init();
>
> /* setup the generic multi interface options we want */
> curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
> curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
> curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
> curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
>
> /* we don't call any curl_multi_socket*() function yet as we have no
> handles added! */
>
> //printf("Starting crawler...\n");
>
> while (!should_exit) {
> int idx;
> int err = epoll_wait(g.epfd, events, sizeof(events)/sizeof(struct
> epoll_event), 10000);
>
>
> new_conn("www.google.com", &g);
> new_conn("www.yahoo.com", &g);
> new_conn("www.bing.com", &g);
>
> if (err == -1) {
> if (errno == EINTR) {
> fprintf(MSG_OUT, "note: wait interrupted\n");
> continue;
> } else {
> perror("epoll_wait");
> exit(1);
> }
> }
>
> for (idx = 0; idx < err; ++idx) {
> if (events[idx].data.fd == g.tfd) {
> timer_cb(&g, events[idx].events);
> } else {
> event_cb(&g, events[idx].data.fd, events[idx].events);
> }
> }
> }
>
> fprintf(MSG_OUT, "Exiting normally.\n");
> fflush(MSG_OUT);
>
> curl_multi_cleanup(g.multi);
> curl_global_cleanup();
>
> return (NULL);
> }
>
> int
> main(int argc, char **argv)
> {
> int cleanup = 0, opt, ret;
> CrawlerConfig config;
>
> memset(&config, 0, sizeof(config));
> config.queue_length = DEFAULT_QUEUE_LENGTH;
>
> should_exit = 0;
> signal(SIGINT, signal_handler);
> signal(SIGKILL, signal_handler);
>
> crawler_init( (void *)&config);
>
>
> printf("Exiting.\n");
>
> return (0);
> }
>
>
Gmail seems to have taken out all the formatting. Apologies. It should
still compile though.

James Read

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Received on 2020-05-26