From 7f5e5706166442186ce0ccbf89f34603781ac94a Mon Sep 17 00:00:00 2001 From: Josh Bialkowski Date: Fri, 27 Jul 2018 15:46:19 -0700 Subject: docs/examples: add hiperfifo example using linux epoll/timerfd Closes #2804 --- docs/examples/Makefile.inc | 2 +- docs/examples/ephiperfifo.c | 540 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 541 insertions(+), 1 deletion(-) create mode 100644 docs/examples/ephiperfifo.c (limited to 'docs') diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc index 9215b82fb..72eb0d4b8 100644 --- a/docs/examples/Makefile.inc +++ b/docs/examples/Makefile.inc @@ -43,4 +43,4 @@ COMPLICATED_EXAMPLES = curlgtk.c curlx.c htmltitle.cpp cacertinmem.c \ sampleconv.c synctime.c threaded-ssl.c evhiperfifo.c \ smooth-gtk-thread.c version-check.pl href_extractor.c asiohiper.cpp \ multi-uv.c xmlstream.c usercertinmem.c sessioninfo.c \ - threaded-shared-conn.c crawler.c + threaded-shared-conn.c crawler.c ephiperfifo.c diff --git a/docs/examples/ephiperfifo.c b/docs/examples/ephiperfifo.c new file mode 100644 index 000000000..e11715f1c --- /dev/null +++ b/docs/examples/ephiperfifo.c @@ -0,0 +1,540 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2018, Daniel Stenberg, , et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ +/* + * multi socket API usage with epoll and timerfd + * + */ +/* Example application source code using the multi socket interface to + * download many files at once. + * + * This example features the same basic functionality as hiperfifo.c does, + * but this uses epoll and timerfd instead of libevent. + * + * Written by Jeff Pohlmeyer, converted to use epoll by Josh Bialkowski + +Requires a linux system with epoll + +When running, the program creates the named pipe "hiper.fifo" + +Whenever there is input into the fifo, the program reads the input as a list +of URL's and creates some new easy handles to fetch each URL via the +curl_multi "hiper" API. + + +Thus, you can try a single URL: + % echo http://www.yahoo.com > hiper.fifo + +Or a whole bunch of them: + % cat my-url-list > hiper.fifo + +The fifo buffer is handled almost instantly, so you can even add more URL's +while the previous requests are still being downloaded. + +Note: + For the sake of simplicity, URL length is limited to 1023 char's ! + +This is purely a demo app, all retrieved data is simply discarded by the write +callback. + +*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#ifdef __GNUC__ +#define _Unused __attribute__((unused)) +#else +#define _Unused +#endif + +#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */ + + +/* Global information, common to all connections */ +typedef struct _GlobalInfo +{ + int epfd; /* epoll filedescriptor */ + int tfd; /* timer filedescriptor */ + int fifofd; /* fifo filedescriptor */ + CURLM *multi; + int still_running; + FILE *input; +} GlobalInfo; + + +/* Information associated with a specific easy handle */ +typedef struct _ConnInfo +{ + CURL *easy; + char *url; + GlobalInfo *global; + char error[CURL_ERROR_SIZE]; +} ConnInfo; + + +/* Information associated with a specific socket */ +typedef struct _SockInfo +{ + curl_socket_t sockfd; + CURL *easy; + int action; + long timeout; + GlobalInfo *global; +} SockInfo; + +#define __case(code) \ + case code: s = __STRING(code) + +/* 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) { + __case(CURLM_BAD_HANDLE); break; + __case(CURLM_BAD_EASY_HANDLE); break; + __case(CURLM_OUT_OF_MEMORY); break; + __case(CURLM_INTERNAL_ERROR); break; + __case(CURLM_UNKNOWN_OPTION); break; + __case(CURLM_LAST); break; + default: s = "CURLM_unknown"; break; + __case(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); + } +} + +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; + CURLMcode rc; + + fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms); + + timerfd_settime(g->tfd, /*flags=*/0, &its, NULL); + 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; + timerfd_settime(g->tfd, /*flags=*/0, &its, NULL); + } else if (timeout_ms == 0) { + rc = curl_multi_socket_action(g->multi, + CURL_SOCKET_TIMEOUT, 0, &g->still_running); + mcode_or_die("multi_timer_cb: curl_multi_socket_action", rc); + } 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; + CURLcode res; + + fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running); + 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); + fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error); + curl_multi_remove_handle(g->multi, easy); + free(conn->url); + 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_POLL_IN : 0) | + (revents & EPOLLOUT ? CURL_POLL_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); +} + + + +/* Clean up the SockInfo structure */ +static void remsock(SockInfo *f, GlobalInfo* g) +{ + if(f) { + if(f->sockfd) { + epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL); + } + free(f); + } +} + + + +/* 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){ + epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL); + } + + f->sockfd = s; + f->action = act; + f->easy = e; + + ev.events = kind; + ev.data.fd = s; + epoll_ctl(g->epfd, EPOLL_CTL_ADD, s, &ev); +} + + + +/* 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); +} + +/* 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; + const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" }; + + fprintf(MSG_OUT, + "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]); + if(what == CURL_POLL_REMOVE) { + fprintf(MSG_OUT, "\n"); + remsock(fdp, g); + } + else { + if(!fdp) { + fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]); + addsock(s, e, what, g); + } + else { + fprintf(MSG_OUT, + "Changing action from %s to %s\n", + whatstr[fdp->action], whatstr[what]); + setsock(fdp, s, e, what, g); + } + } + return 0; +} + + + +/* CURLOPT_WRITEFUNCTION */ +static size_t write_cb(void *ptr _Unused, size_t size, size_t nmemb, + void *data) +{ + size_t realsize = size * nmemb; + ConnInfo *conn _Unused = (ConnInfo*) data; + + return realsize; +} + + +/* CURLOPT_PROGRESSFUNCTION */ +static int prog_cb(void *p, double dltotal, double dlnow, double ult _Unused, + double uln _Unused) +{ + ConnInfo *conn = (ConnInfo *)p; + + fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal); + return 0; +} + + +/* Create a new easy handle, and add it to the global curl_multi */ +static void new_conn(char *url, GlobalInfo *g) +{ + ConnInfo *conn; + CURLMcode rc; + + conn = (ConnInfo*)calloc(1, sizeof(ConnInfo)); + conn->error[0]='\0'; + + conn->easy = curl_easy_init(); + if(!conn->easy) { + fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n"); + exit(2); + } + conn->global = g; + conn->url = strdup(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_VERBOSE, 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, 0L); + curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb); + 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, 10L); + fprintf(MSG_OUT, + "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url); + 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 */ +} + +/* This gets called whenever data is received from the fifo */ +static void fifo_cb(GlobalInfo* g, int revents) +{ + char s[1024]; + long int rv = 0; + int n = 0; + + do { + s[0]='\0'; + rv = fscanf(g->input, "%1023s%n", s, &n); + s[n]='\0'; + if(n && s[0]) { + new_conn(s, g); /* if we read a URL, go get it! */ + } else + break; + } while(rv != EOF); +} + +/* Create a named pipe and tell libevent to monitor it */ +static const char *fifo = "hiper.fifo"; +static int init_fifo(GlobalInfo *g) +{ + struct stat st; + curl_socket_t sockfd; + struct epoll_event epev; + + fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo); + if(lstat (fifo, &st) == 0) { + if((st.st_mode & S_IFMT) == S_IFREG) { + errno = EEXIST; + perror("lstat"); + exit(1); + } + } + unlink(fifo); + if(mkfifo (fifo, 0600) == -1) { + perror("mkfifo"); + exit(1); + } + sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0); + if(sockfd == -1) { + perror("open"); + exit(1); + } + + g->fifofd = sockfd; + g->input = fdopen(sockfd, "r"); + + epev.events = EPOLLIN; + epev.data.fd = sockfd; + epoll_ctl(g->epfd, EPOLL_CTL_ADD, sockfd, &epev); + + fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo); + return 0; +} + +static void clean_fifo(GlobalInfo *g) +{ + epoll_ctl(g->epfd, EPOLL_CTL_DEL, g->fifofd, NULL); + fclose(g->input); + unlink(fifo); +} + + +int g_should_exit_ = 0; + +void SignalHandler(int signo) { + if (signo == SIGINT) { + g_should_exit_ = 1; + } +} + +int main(int argc _Unused, char **argv _Unused) +{ + GlobalInfo g; + int err; + int idx; + struct itimerspec its; + struct epoll_event ev; + struct epoll_event events[10]; + + g_should_exit_ = 0; + signal(SIGINT, SignalHandler); + + memset(&g, 0, sizeof(GlobalInfo)); + g.epfd = epoll_create1(EPOLL_CLOEXEC); + if(g.epfd == -1) { + perror("epoll_create1 failed"); + exit(1); + } + + g.tfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC); + if(g.tfd == -1) { + perror("timerfd_create failed"); + 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); + + init_fifo(&g); + 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! */ + + fprintf(MSG_OUT, "Entering wait loop\n"); + fflush(MSG_OUT); + while (!g_should_exit_) { + /* TODO(josh): use epoll_pwait to avoid a race on the signal. Mask the + * signal before the while loop, and then re-enable the signal during + * epoll wait. Mask at the end of the loop. */ + err = epoll_wait(g.epfd, events, sizeof(events)/sizeof(struct epoll_event), + 10000); + 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.fifofd) { + fifo_cb(&g, events[idx].events); + } else 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); + return 0; +} -- cgit v1.2.3