C语言libcurl例程：multi 多线程，多任务
目录
A multi-threaded example that uses pthreads to fetch several files at once
multi_socket API using libuv
using the multi interface to do a single download
using the multi interface to do a multipart formpost without blocking
single download with the multi interface's curl_multi_poll
using the multi interface to do a multipart formpost without blocking
multi_socket API using libevent
multi interface code doing two parallel HTTP transfers
multi interface and debug callback
A basic application source code using the multi interface doing two transfers in parallel.
A multi-threaded example that uses pthreads to fetch several files at once
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, 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.
*
***************************************************************************/
/*
* A multi-threaded example that uses pthreads to fetch several files at once
*
*/
#include
#include
#include
#define NUMT 4
/*
List of URLs to fetch.
If you intend to use a SSL-based protocol here you might need to setup TLS
library mutex callbacks as described here:
https://curl.haxx.se/libcurl/c/threadsafe.html
*/
const char * const urls[NUMT]= {
// "https://curl.haxx.se/",
// "ftp://cool.haxx.se/",
// "https://www.cag.se/",
// "www.haxx.se"
"http://10.170.6.66",
"http://localhost",
"http://10.170.6.66/crtl-docs/",
"http://10.170.6.66/crtl-docs/linux-kernel-map/index.html"
};
static void *pull_one_url(void *url)
{
CURL *curl;
curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_perform(curl); /* ignores error */
curl_easy_cleanup(curl);
return NULL;
}
/*
int pthread_create(pthread_t *new_thread_ID,
const pthread_attr_t *attr,
void * (*start_func)(void *), void *arg);
*/
int main(int argc, char **argv)
{
pthread_t tid[NUMT];
int i;
/* Must initialize libcurl before any threads are started */
curl_global_init(CURL_GLOBAL_ALL);
for(i = 0; i< NUMT; i++) {
int error = pthread_create(&tid[i],
NULL, /* default attributes please */
pull_one_url,
(void *)urls[i]);
if(0 != error)
fprintf(stderr, "Couldn't run thread number %d, errno %d\n", i, error);
else
fprintf(stderr, "Thread %d, gets %s\n", i, urls[i]);
}
/* now wait for all threads to terminate */
for(i = 0; i< NUMT; i++) {
pthread_join(tid[i], NULL);
fprintf(stderr, "Thread %d terminated\n", i);
}
return 0;
}
multi_socket API using libuv
https://rtoax.blog.csdn.net/article/details/105711077#%E6%96%87%E4%BB%B6I%20%2F%C2%A0
/***************************************************************************
* _ _ ____ _
* 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 using libuv
*
*/
/* Example application using the multi socket interface to download multiple
files in parallel, powered by libuv.
Requires libuv and (of course) libcurl.
See https://nikhilm.github.io/uvbook/ for more information on libuv.
*/
#include
#include
#include
#include
uv_loop_t *loop;
CURLM *curl_handle;
uv_timer_t timeout;
typedef struct curl_context_s {
uv_poll_t poll_handle;
curl_socket_t sockfd;
} curl_context_t;
static curl_context_t* create_curl_context(curl_socket_t sockfd)
{
curl_context_t *context;
context = (curl_context_t *) malloc(sizeof(*context));
context->sockfd = sockfd;
uv_poll_init_socket(loop, &context->poll_handle, sockfd);
context->poll_handle.data = context;
return context;
}
static void curl_close_cb(uv_handle_t *handle)
{
curl_context_t *context = (curl_context_t *) handle->data;
free(context);
}
static void destroy_curl_context(curl_context_t *context)
{
uv_close((uv_handle_t *) &context->poll_handle, curl_close_cb);
}
static void add_download(const char *url, int num)
{
char filename[50];
FILE *file;
CURL *handle;
snprintf(filename, 50, "%d.download", num);
file = fopen(filename, "wb");
if(!file) {
fprintf(stderr, "Error opening %s\n", filename);
return;
}
handle = curl_easy_init();
curl_easy_setopt(handle, CURLOPT_WRITEDATA, file);
curl_easy_setopt(handle, CURLOPT_PRIVATE, file);
curl_easy_setopt(handle, CURLOPT_URL, url);
curl_multi_add_handle(curl_handle, handle);
fprintf(stderr, "Added download %s -> %s\n", url, filename);
}
static void check_multi_info(void)
{
char *done_url;
CURLMsg *message;
int pending;
CURL *easy_handle;
FILE *file;
while((message = curl_multi_info_read(curl_handle, &pending))) {
switch(message->msg) {
case CURLMSG_DONE:
/* Do not use message data after calling curl_multi_remove_handle() and
curl_easy_cleanup(). As per curl_multi_info_read() docs:
"WARNING: The data the returned pointer points to will not survive
calling curl_multi_cleanup, curl_multi_remove_handle or
curl_easy_cleanup." */
easy_handle = message->easy_handle;
curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url);
curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file);
printf("%s DONE\n", done_url);
curl_multi_remove_handle(curl_handle, easy_handle);
curl_easy_cleanup(easy_handle);
if(file) {
fclose(file);
}
break;
default:
fprintf(stderr, "CURLMSG default\n");
break;
}
}
}
static void curl_perform(uv_poll_t *req, int status, int events)
{
int running_handles;
int flags = 0;
curl_context_t *context;
if(events & UV_READABLE)
flags |= CURL_CSELECT_IN;
if(events & UV_WRITABLE)
flags |= CURL_CSELECT_OUT;
context = (curl_context_t *) req->data;
curl_multi_socket_action(curl_handle, context->sockfd, flags,
&running_handles);
check_multi_info();
}
static void on_timeout(uv_timer_t *req)
{
int running_handles;
curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
&running_handles);
check_multi_info();
}
static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
{
if(timeout_ms < 0) {
uv_timer_stop(&timeout);
}
else {
if(timeout_ms == 0)
timeout_ms = 1; /* 0 means directly call socket_action, but we'll do it
in a bit */
uv_timer_start(&timeout, on_timeout, timeout_ms, 0);
}
return 0;
}
static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
void *socketp)
{
curl_context_t *curl_context;
int events = 0;
switch(action) {
case CURL_POLL_IN:
case CURL_POLL_OUT:
case CURL_POLL_INOUT:
curl_context = socketp ?
(curl_context_t *) socketp : create_curl_context(s);
curl_multi_assign(curl_handle, s, (void *) curl_context);
if(action != CURL_POLL_IN)
events |= UV_WRITABLE;
if(action != CURL_POLL_OUT)
events |= UV_READABLE;
uv_poll_start(&curl_context->poll_handle, events, curl_perform);
break;
case CURL_POLL_REMOVE:
if(socketp) {
uv_poll_stop(&((curl_context_t*)socketp)->poll_handle);
destroy_curl_context((curl_context_t*) socketp);
curl_multi_assign(curl_handle, s, NULL);
}
break;
default:
abort();
}
return 0;
}
int main(int argc, char **argv)
{
loop = uv_default_loop();
if(argc <= 1)
return 0;
if(curl_global_init(CURL_GLOBAL_ALL)) {
fprintf(stderr, "Could not init curl\n");
return 1;
}
uv_timer_init(loop, &timeout);
curl_handle = curl_multi_init();
curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
while(argc-- > 1) {
add_download(argv[argc], argc);
}
uv_run(loop, UV_RUN_DEFAULT);
curl_multi_cleanup(curl_handle);
return 0;
}
using the multi interface to do a single download
/***************************************************************************
* _ _ ____ _
* 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.
*
***************************************************************************/
/*
* using the multi interface to do a single download
*
*/
#include
#include
/* somewhat unix-specific */
#include
#include
/* curl stuff */
#include
#ifdef _WIN32
#define WAITMS(x) Sleep(x)
#else
/* Portable sleep for platforms other than Windows. */
#define WAITMS(x) \
struct timeval wait = { 0, (x) * 1000 }; \
(void)select(0, NULL, NULL, NULL, &wait);
#endif
/*
* Simply download a HTTP file.
*/
int main(void)
{
CURL *http_handle;
CURLM *multi_handle;
int still_running = 0; /* keep number of running handles */
int repeats = 0;
curl_global_init(CURL_GLOBAL_DEFAULT);
http_handle = curl_easy_init();
/* set the options (I left out a few, you'll get the point anyway) */
curl_easy_setopt(http_handle, CURLOPT_URL, "https://10.170.6.66/");
/* init a multi stack */
multi_handle = curl_multi_init();
/* add the individual transfers */
curl_multi_add_handle(multi_handle, http_handle);
/* we start some action by calling perform right away */
curl_multi_perform(multi_handle, &still_running);
while(still_running) {
CURLMcode mc; /* curl_multi_wait() return code */
int numfds;
/* wait for activity, timeout or "nothing" */
mc = curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_wait() failed, code %d.\n", mc);
break;
}
/* 'numfds' being zero means either a timeout or no file descriptors to
wait for. Try timeout on first occurrence, then assume no file
descriptors and no file descriptors to wait for means wait for 100
milliseconds. */
if(!numfds) {
repeats++; /* count number of repeated zero numfds */
if(repeats > 1) {
WAITMS(100); /* sleep 100 milliseconds */
}
}
else
repeats = 0;
curl_multi_perform(multi_handle, &still_running);
}
curl_multi_remove_handle(multi_handle, http_handle);
curl_easy_cleanup(http_handle);
curl_multi_cleanup(multi_handle);
curl_global_cleanup();
return 0;
}
using the multi interface to do a multipart formpost without blocking
/***************************************************************************
* _ _ ____ _
* 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.
*
***************************************************************************/
/*
* using the multi interface to do a multipart formpost without blocking
*
*/
#include
#include
#include
#include
int main(void)
{
CURL *curl;
CURLM *multi_handle;
int still_running = 0;
curl_mime *form = NULL;
curl_mimepart *field = NULL;
struct curl_slist *headerlist = NULL;
static const char buf[] = "Expect:";
curl = curl_easy_init();
multi_handle = curl_multi_init();
if(curl && multi_handle) {
/* Create the form */
form = curl_mime_init(curl);
/* Fill in the file upload field */
field = curl_mime_addpart(form);
curl_mime_name(field, "sendfile");
curl_mime_filedata(field, "multi-post.c");
/* Fill in the filename field */
field = curl_mime_addpart(form);
curl_mime_name(field, "filename");
curl_mime_data(field, "multi-post.c", CURL_ZERO_TERMINATED);
/* Fill in the submit field too, even if this is rarely needed */
field = curl_mime_addpart(form);
curl_mime_name(field, "submit");
curl_mime_data(field, "send", CURL_ZERO_TERMINATED);
/* initialize custom header list (stating that Expect: 100-continue is not
wanted */
headerlist = curl_slist_append(headerlist, buf);
/* what URL that receives this POST */
curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/upload.cgi");
//CGI: 公共网关接口（Common Gateway Interface，CGI）是Web 服务器运行时外部程序的规范，按CGI 编写的程序可以扩展服务器功能。
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
curl_easy_setopt(curl, CURLOPT_MIMEPOST, form);
curl_multi_add_handle(multi_handle, curl);
curl_multi_perform(multi_handle, &still_running);
while(still_running) {
struct timeval timeout;
int rc; /* select() return code */
CURLMcode mc; /* curl_multi_fdset() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
}
switch(rc) {
case -1:
/* select error */
break;
case 0:
default:
/* timeout or readable/writable sockets */
printf("perform!\n");
curl_multi_perform(multi_handle, &still_running);
printf("running: %d!\n", still_running);
break;
}
}
curl_multi_cleanup(multi_handle);
/* always cleanup */
curl_easy_cleanup(curl);
/* then cleanup the form */
curl_mime_free(form);
/* free slist */
curl_slist_free_all(headerlist);
}
return 0;
}
single download with the multi interface's curl_multi_poll
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, 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.
*
***************************************************************************/
/*
* single download with the multi interface's curl_multi_poll
*
*/
#include
#include
/* somewhat unix-specific */
#include
#include
/* curl stuff */
#include
int main(void)
{
CURL *http_handle;
CURLM *multi_handle;
int still_running = 1; /* keep number of running handles */
curl_global_init(CURL_GLOBAL_DEFAULT);
http_handle = curl_easy_init();
curl_easy_setopt(http_handle, CURLOPT_URL, "https://10.170.6.66/");
multi_handle = curl_multi_init();
curl_multi_add_handle(multi_handle, http_handle);
while(still_running) {
CURLMcode mc; /* curl_multi_poll() return code */
int numfds;
/* we start some action by calling perform right away */
mc = curl_multi_perform(multi_handle, &still_running);
if(still_running)
/* wait for activity, timeout or "nothing" */
mc = curl_multi_poll(multi_handle, NULL, 0, 1000, &numfds);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_wait() failed, code %d.\n", mc);
break;
}
}
curl_multi_remove_handle(multi_handle, http_handle);
curl_easy_cleanup(http_handle);
curl_multi_cleanup(multi_handle);
curl_global_cleanup();
return 0;
}
using the multi interface to do a multipart formpost without blocking
/***************************************************************************
* _ _ ____ _
* 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.
*
***************************************************************************/
/*
* using the multi interface to do a multipart formpost without blocking
*
*/
#include
#include
#include
#include
int main(void)
{
CURL *curl;
CURLM *multi_handle;
int still_running = 0;
struct curl_httppost *formpost = NULL;
struct curl_httppost *lastptr = NULL;
struct curl_slist *headerlist = NULL;
static const char buf[] = "Expect:";
/* Fill in the file upload field. This makes libcurl load data from
the given file name when curl_easy_perform() is called. */
//curl_formadd : 用于为multipart/formdata HTTP POST请求添加部分。
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "sendfile",
CURLFORM_FILE, "postit2.c",
CURLFORM_END);
/* Fill in the filename field */
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "filename",
CURLFORM_COPYCONTENTS, "postit2.c",
CURLFORM_END);
/* Fill in the submit field too, even if this is rarely needed */
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "submit",
CURLFORM_COPYCONTENTS, "send",
CURLFORM_END);
curl = curl_easy_init();
multi_handle = curl_multi_init();
/* initialize custom header list (stating that Expect: 100-continue is not
wanted */
headerlist = curl_slist_append(headerlist, buf);
if(curl && multi_handle) {
/* what URL that receives this POST */
curl_easy_setopt(curl, CURLOPT_URL, "https://10.170.6.66/study/");
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
curl_multi_add_handle(multi_handle, curl);
curl_multi_perform(multi_handle, &still_running);
while(still_running) {
struct timeval timeout;
int rc; /* select() return code */
CURLMcode mc; /* curl_multi_fdset() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
}
switch(rc) {
case -1:
/* select error */
break;
case 0:
default:
/* timeout or readable/writable sockets */
printf("perform!\n");
curl_multi_perform(multi_handle, &still_running);
printf("running: %d!\n", still_running);
break;
}
}
curl_multi_cleanup(multi_handle);
/* always cleanup */
curl_easy_cleanup(curl);
/* then cleanup the formpost chain */
curl_formfree(formpost);
/* free slist */
curl_slist_free_all(headerlist);
}
return 0;
}
multi_socket API using libevent
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, 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 using libevent
*
*/
#include
#include
#include
#include
struct event_base *base;
CURLM *curl_handle;
struct event *timeout;
typedef struct curl_context_s {
struct event *event;
curl_socket_t sockfd;
} curl_context_t;
static void curl_perform(int fd, short event, void *arg);
static curl_context_t* create_curl_context(curl_socket_t sockfd)
{
curl_context_t *context;
context = (curl_context_t *) malloc(sizeof(*context));
context->sockfd = sockfd;
context->event = event_new(base, sockfd, 0, curl_perform, context);
return context;
}
static void destroy_curl_context(curl_context_t *context)
{
event_del(context->event);
event_free(context->event);
free(context);
}
static void add_download(const char *url, int num)
{
char filename[50];
FILE *file;
CURL *handle;
snprintf(filename, 50, "%d.download", num);
file = fopen(filename, "wb");
if(!file) {
fprintf(stderr, "Error opening %s\n", filename);
return;
}
handle = curl_easy_init();
curl_easy_setopt(handle, CURLOPT_WRITEDATA, file);
curl_easy_setopt(handle, CURLOPT_PRIVATE, file);
curl_easy_setopt(handle, CURLOPT_URL, url);
curl_multi_add_handle(curl_handle, handle);
fprintf(stderr, "Added download %s -> %s\n", url, filename);
}
static void check_multi_info(void)
{
char *done_url;
CURLMsg *message;
int pending;
CURL *easy_handle;
FILE *file;
while((message = curl_multi_info_read(curl_handle, &pending))) {
switch(message->msg) {
case CURLMSG_DONE:
/* Do not use message data after calling curl_multi_remove_handle() and
curl_easy_cleanup(). As per curl_multi_info_read() docs:
"WARNING: The data the returned pointer points to will not survive
calling curl_multi_cleanup, curl_multi_remove_handle or
curl_easy_cleanup." */
easy_handle = message->easy_handle;
curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url);
curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file);
printf("%s DONE\n", done_url);
curl_multi_remove_handle(curl_handle, easy_handle);
curl_easy_cleanup(easy_handle);
if(file) {
fclose(file);
}
break;
default:
fprintf(stderr, "CURLMSG default\n");
break;
}
}
}
static void curl_perform(int fd, short event, void *arg)
{
int running_handles;
int flags = 0;
curl_context_t *context;
if(event & EV_READ)
flags |= CURL_CSELECT_IN;
if(event & EV_WRITE)
flags |= CURL_CSELECT_OUT;
context = (curl_context_t *) arg;
curl_multi_socket_action(curl_handle, context->sockfd, flags,
&running_handles);
check_multi_info();
}
static void on_timeout(evutil_socket_t fd, short events, void *arg)
{
int running_handles;
curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
&running_handles);
check_multi_info();
}
static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
{
if(timeout_ms < 0) {
evtimer_del(timeout);
}
else {
if(timeout_ms == 0)
timeout_ms = 1; /* 0 means directly call socket_action, but we'll do it
in a bit */
struct timeval tv;
tv.tv_sec = timeout_ms / 1000;
tv.tv_usec = (timeout_ms % 1000) * 1000;
evtimer_del(timeout);
evtimer_add(timeout, &tv);
}
return 0;
}
static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
void *socketp)
{
curl_context_t *curl_context;
int events = 0;
switch(action) {
case CURL_POLL_IN:
case CURL_POLL_OUT:
case CURL_POLL_INOUT:
curl_context = socketp ?
(curl_context_t *) socketp : create_curl_context(s);
curl_multi_assign(curl_handle, s, (void *) curl_context);
if(action != CURL_POLL_IN)
events |= EV_WRITE;
if(action != CURL_POLL_OUT)
events |= EV_READ;
events |= EV_PERSIST;
event_del(curl_context->event);
event_assign(curl_context->event, base, curl_context->sockfd, events,
curl_perform, curl_context);
event_add(curl_context->event, NULL);
break;
case CURL_POLL_REMOVE:
if(socketp) {
event_del(((curl_context_t*) socketp)->event);
destroy_curl_context((curl_context_t*) socketp);
curl_multi_assign(curl_handle, s, NULL);
}
break;
default:
abort();
}
return 0;
}
int main(int argc, char **argv)
{
if(argc <= 1)
return 0;
if(curl_global_init(CURL_GLOBAL_ALL)) {
fprintf(stderr, "Could not init curl\n");
return 1;
}
base = event_base_new();
timeout = evtimer_new(base, on_timeout, NULL);
curl_handle = curl_multi_init();
curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
while(argc-- > 1) {
add_download(argv[argc], argc);
}
event_base_dispatch(base);
curl_multi_cleanup(curl_handle);
event_free(timeout);
event_base_free(base);
libevent_global_shutdown();
curl_global_cleanup();
return 0;
}
multi interface code doing two parallel HTTP transfers
/***************************************************************************
* _ _ ____ _
* 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 interface code doing two parallel HTTP transfers
*
*/
#include
#include
/* somewhat unix-specific */
#include
#include
/* curl stuff */
#include
/*
* Simply download two HTTP files!
*/
int main(void)
{
CURL *http_handle;
CURL *http_handle2;
CURLM *multi_handle;
int still_running = 0; /* keep number of running handles */
http_handle = curl_easy_init();
http_handle2 = curl_easy_init();
/* set options */
curl_easy_setopt(http_handle, CURLOPT_URL, "https://10.170.6.66/");
/* set options */
curl_easy_setopt(http_handle2, CURLOPT_URL, "http://localhost/");
/* init a multi stack */
multi_handle = curl_multi_init();
/* add the individual transfers */
curl_multi_add_handle(multi_handle, http_handle);
curl_multi_add_handle(multi_handle, http_handle2);
/* we start some action by calling perform right away */
curl_multi_perform(multi_handle, &still_running);
while(still_running) {
struct timeval timeout;
int rc; /* select() return code */
CURLMcode mc; /* curl_multi_fdset() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
}
switch(rc) {
case -1:
/* select error */
break;
case 0:
default:
/* timeout or readable/writable sockets */
curl_multi_perform(multi_handle, &still_running);
break;
}
}
curl_multi_cleanup(multi_handle);
curl_easy_cleanup(http_handle);
curl_easy_cleanup(http_handle2);
return 0;
}
multi interface and debug callback
/***************************************************************************
* _ _ ____ _
* 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 interface and debug callback
*
*/
#include
#include
/* somewhat unix-specific */
#include
#include
/* curl stuff */
#include
typedef char bool;
#define TRUE 1
static
void dump(const char *text,
FILE *stream, unsigned char *ptr, size_t size,
bool nohex)
{
size_t i;
size_t c;
unsigned int width = 0x10;
if(nohex)
/* without the hex output, we can fit more on screen */
width = 0x40;
fprintf(stream, "%s, %10.10lu bytes (0x%8.8lx)\n",
text, (unsigned long)size, (unsigned long)size);
for(i = 0; i= 0x20) && (ptr[i + c]<0x80)?ptr[i + c]:'.');
/* check again for 0D0A, to avoid an extra \n if it's at width */
if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D &&
ptr[i + c + 2] == 0x0A) {
i += (c + 3 - width);
break;
}
}
fputc('\n', stream); /* newline */
}
fflush(stream);
}
static
int my_trace(CURL *handle, curl_infotype type,
unsigned char *data, size_t size,
void *userp)/* debug回调函数 */
{
const char *text;
(void)userp;
(void)handle; /* prevent compiler warning */
switch(type) {
case CURLINFO_TEXT:
fprintf(stderr, "== Info: %s", data);
/* FALLTHROUGH */
default: /* in case a new one is introduced to shock us */
return 0;
case CURLINFO_HEADER_OUT:
text = "=> Send header";
break;
case CURLINFO_DATA_OUT:
text = "=> Send data";
break;
case CURLINFO_HEADER_IN:
text = "<= Recv header";
break;
case CURLINFO_DATA_IN:
text = "<= Recv data";
break;
}
dump(text, stderr, data, size, TRUE);
return 0;
}
/*
* Simply download a HTTP file.
*/
int main(void)
{
CURL *http_handle;
CURLM *multi_handle;
int still_running = 0; /* keep number of running handles */
http_handle = curl_easy_init();
/* set the options (I left out a few, you'll get the point anyway) */
curl_easy_setopt(http_handle, CURLOPT_URL, "https://10.170.6.66/");
curl_easy_setopt(http_handle, CURLOPT_DEBUGFUNCTION, my_trace);/* debug回调函数 */
curl_easy_setopt(http_handle, CURLOPT_VERBOSE, 1L);//CURLOPT_VERBOSE:详细
/* init a multi stack */
multi_handle = curl_multi_init();
/* add the individual transfers */
curl_multi_add_handle(multi_handle, http_handle);/* 添加一个handle */
/* we start some action by calling perform right away */
curl_multi_perform(multi_handle, &still_running);/* 执行 */
while(still_running) {
struct timeval timeout;
int rc; /* select() return code */
CURLMcode mc; /* curl_multi_fdset() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
}
switch(rc) {
case -1:
/* select error */
still_running = 0;
printf("select() returns error, this is badness\n");
break;
case 0:
default:
/* timeout or readable/writable sockets */
curl_multi_perform(multi_handle, &still_running);/* 执行 */
break;
}
}
curl_multi_cleanup(multi_handle);
curl_easy_cleanup(http_handle);
return 0;
}
A basic application source code using the multi interface doing two transfers in parallel.
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, 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.
*
***************************************************************************/
/*
* A basic application source code using the multi interface doing two
* transfers in parallel.
*
*/
#include
#include
/* somewhat unix-specific */
#include
#include
/* curl stuff */
#include
/*
* Download a HTTP file and upload an FTP file simultaneously.
*/
#define HANDLECOUNT 2 /* Number of simultaneous transfers */
#define HTTP_HANDLE 0 /* Index for the HTTP transfer */
#define FTP_HANDLE 1 /* Index for the FTP transfer */
int main(void)
{
CURL *handles[HANDLECOUNT];
CURLM *multi_handle; /* 多任务句柄 */
int still_running = 0; /* keep number of running handles */
int i;
CURLMsg *msg; /* for picking up messages with the transfer status */
int msgs_left; /* how many messages are left */
/* Allocate one CURL handle per transfer */
for(i = 0; i= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);/* 多任务select fdset 设置 */
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);/* 等待时间：可以用sleep */
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);/* select多路复用 */
}
switch(rc) {
case -1:
/* select error */
break;
case 0: /* timeout */
default: /* action */
curl_multi_perform(multi_handle, &still_running);
break;
}
}
/* See how the transfers went */
while((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
if(msg->msg == CURLMSG_DONE) {
int idx;
/* Find out which handle this message is about */
for(idx = 0; idxeasy_handle == handles[idx]);
if(found)
break;
}
switch(idx) {
case HTTP_HANDLE:
printf("HTTP transfer completed with status %d\n", msg->data.result);
break;
case FTP_HANDLE:
printf("FTP transfer completed with status %d\n", msg->data.result);
break;
}
}
}
curl_multi_cleanup(multi_handle);
/* Free the CURL handles */
for(i = 0; i