examples: Remove threaded-shared-conn.c due to bug

Known bug 11.11 is the shared object's connection cache is not thread
safe, so we should not have an example for it.

Ref: https://github.com/curl/curl/issues/4915
Ref: https://curl.se/docs/knownbugs.html#A_shared_connection_cache_is_not

Closes https://github.com/curl/curl/pull/6795

2 files changed, 0 insertions, 157 deletions

diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc
index 84a2bdac6..4ca12fe1c 100644
--- a/docs/examples/Makefile.inc
+++ b/docs/examples/Makefile.inc
@@ -139,7 +139,6 @@ COMPLICATED_EXAMPLES = \
   sessioninfo.c \
   smooth-gtk-thread.c \
   synctime.c \
-  threaded-shared-conn.c \
   threaded-ssl.c \
   usercertinmem.c \
   version-check.pl \
diff --git a/docs/examples/threaded-shared-conn.c b/docs/examples/threaded-shared-conn.c
deleted file mode 100644
index 8ff8fcece..000000000
--- a/docs/examples/threaded-shared-conn.c
+++ /dev/null
@@ -1,156 +0,0 @@
-/***************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, 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.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.
- *
- ***************************************************************************/
-/* <DESC>
- * Multi-threaded transfers sharing a single connection pool
- * </DESC>
- *
- * This example fires up NUM_THREADS threads and in each single thread, it
- * downloads the same fixed URL a URL_ITERATIONS number of times. The received
- * data is just thrown away. It sets up a single shared object that holds the
- * connection cache and all easy handles in all threads share that same cache.
- *
- * This example uses pthreads for threads and mutexes, but should be easy to
- * modify to use different thread/mutex system should you want to.
- *
- */
-
-#include <stdio.h>
-#include <pthread.h>
-#include <curl/curl.h>
-
-/*
-  URL to fetch. If you select HTTPS, you need to use a TLS backend with mutex
-  locks taken care of (OpenSSL 1.1.x, NSS, etc) or add SSL mutex callbacks!
-*/
-#define URL "http://localhost/4KB"
-
-/* number of threads to fire up in parallel */
-#define NUM_THREADS 67
-
-/* how many times each URL is transferred per thread */
-#define URL_ITERATIONS 11235
-
-static pthread_mutex_t connlock;
-
-static size_t write_db(void *ptr, size_t size, size_t nmemb, void *data)
-{
-  /* not interested in the downloaded bytes, return the size */
-  (void)ptr;  /* unused */
-  (void)data; /* unused */
-  return (size_t)(size * nmemb);
-}
-
-static void lock_cb(CURL *handle, curl_lock_data data,
-                    curl_lock_access access, void *userptr)
-{
-  (void)access; /* unused */
-  (void)userptr; /* unused */
-  (void)handle; /* unused */
-  (void)data; /* unused */
-  pthread_mutex_lock(&connlock);
-}
-
-static void unlock_cb(CURL *handle, curl_lock_data data,
-                      void *userptr)
-{
-  (void)userptr; /* unused */
-  (void)handle;  /* unused */
-  (void)data;    /* unused */
-  pthread_mutex_unlock(&connlock);
-}
-
-static void init_locks(void)
-{
-  pthread_mutex_init(&connlock, NULL);
-}
-
-static void kill_locks(void)
-{
-  pthread_mutex_destroy(&connlock);
-}
-
-struct initurl {
-  const char *url;
-  CURLSH *share;
-  int threadno;
-};
-
-static void *run_thread(void *ptr)
-{
-  struct initurl *u = (struct initurl *)ptr;
-  int i;
-
-  for(i = 0; i < URL_ITERATIONS; i++) {
-    CURL *curl = curl_easy_init();
-    curl_easy_setopt(curl, CURLOPT_URL, u->url);
-    curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L);
-    curl_easy_setopt(curl, CURLOPT_SHARE, u->share);
-    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_db);
-    curl_easy_perform(curl); /* ignores error */
-    curl_easy_cleanup(curl);
-    fprintf(stderr, "Thread %d transfer %d\n", u->threadno, i);
-  }
-
-  return NULL;
-}
-
-int main(void)
-{
-  pthread_t tid[NUM_THREADS];
-  int i;
-  CURLSH *share;
-  struct initurl url[NUM_THREADS];
-
-  /* Must initialize libcurl before any threads are started */
-  curl_global_init(CURL_GLOBAL_ALL);
-
-  share = curl_share_init();
-  curl_share_setopt(share, CURLSHOPT_LOCKFUNC, lock_cb);
-  curl_share_setopt(share, CURLSHOPT_UNLOCKFUNC, unlock_cb);
-  curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
-
-  init_locks();
-
-  for(i = 0; i< NUM_THREADS; i++) {
-    int error;
-    url[i].url = URL;
-    url[i].share = share;
-    url[i].threadno = i;
-    error = pthread_create(&tid[i], NULL, run_thread, &url[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, URL);
-  }
-
-  /* now wait for all threads to terminate */
-  for(i = 0; i< NUM_THREADS; i++) {
-    pthread_join(tid[i], NULL);
-    fprintf(stderr, "Thread %d terminated\n", i);
-  }
-
-  kill_locks();
-
-  curl_share_cleanup(share);
-  curl_global_cleanup();
-  return 0;
-}