WEBRTC for communication between agents and browsers (#14874)

* initial webrtc setup

* missing files

* rewrite of webrtc integration

* initialization and cleanup of webrtc connections

* make it compile without libdatachannel

* add missing webrtc_initialize() function when webrtc is not enabled

* make c++17 optional

* add build/m4/ax_compiler_vendor.m4

* add ax_cxx_compile_stdcxx.m4

* added new m4 files to makefile.am

* id all webrtc connections

* show warning when webrtc is disabled

* fixed message

* moved all webrtc error checking inside webrtc.cpp

* working webrtc connection establishment and cleanup

* remove obsolete code

* rewrote webrtc code in C to remove dependency for c++17

* fixed left-over reference

* detect binary and text messages

* minor fix

* naming of webrtc threads

* added webrtc configuration

* fix for thread_get_name_np()

* smaller web_client memory footprint

* universal web clients cache

* free web clients every 100 uses

* webrtc is now enabled by default only when compiled with internal checks

* webrtc responses to /api/ requests, including LZ4 compression

* fix for binary and text messages

* web_client_cache is now global

* unification of the internal web server API, for web requests, aclk request, webrtc requests

* more cleanup and unification of web client timings

* fixed compiler warnings

* update sent and received bytes

* eliminated of almost all big buffers in web client

* registry now uses the new json generation

* cookies are now an array; fixed redirects

* fix redirects, again

* write cookies directly to the header buffer, eliminating the need for cookie structures in web client

* reset the has_cookies flag

* gathered all web client cleanup to one function

* fixes redirects

* added summary.globals in /api/v2/data response

* ars to arc in /api/v2/data

* properly handle host impersonation

* set the context of mem.numa_nodes

2 files changed, 60 insertions, 1 deletions

diff --git a/libnetdata/threads/threads.c b/libnetdata/threads/threads.c
index 16de45fd14..c4026a7331 100644
--- a/libnetdata/threads/threads.c
+++ b/libnetdata/threads/threads.c
@@ -21,8 +21,63 @@ inline int netdata_thread_tag_exists(void) {
     return (netdata_thread && netdata_thread->tag && *netdata_thread->tag);
 }
 
+static const char *thread_name_get(bool recheck) {
+    static __thread char threadname[NETDATA_THREAD_NAME_MAX + 1] = "";
+
+    if(netdata_thread_tag_exists())
+        strncpyz(threadname, netdata_thread->tag, NETDATA_THREAD_NAME_MAX + 1);
+    else {
+        if(!recheck && threadname[0])
+            return threadname;
+
+#if defined(__FreeBSD__)
+        pthread_get_name_np(pthread_self(), threadname, NETDATA_THREAD_NAME_MAX + 1);
+        if(strcmp(threadname, "netdata") == 0)
+            strncpyz(threadname, "MAIN", NETDATA_THREAD_NAME_MAX + 1);
+#elif defined(__APPLE__)
+        strncpyz(threadname, "MAIN", NETDATA_THREAD_NAME_MAX + 1);
+#elif defined(HAVE_PTHREAD_GETNAME_NP)
+        pthread_getname_np(pthread_self(), threadname, NETDATA_THREAD_NAME_MAX + 1);
+        if(strcmp(threadname, "netdata") == 0)
+            strncpyz(threadname, "MAIN", NETDATA_THREAD_NAME_MAX + 1);
+#else
+        strncpyz(threadname, "MAIN", NETDATA_THREAD_NAME_MAX + 1);
+#endif
+    }
+
+    return threadname;
+}
+
 const char *netdata_thread_tag(void) {
-    return (netdata_thread_tag_exists() ? netdata_thread->tag : "MAIN");
+    return thread_name_get(false);
+}
+
+static size_t webrtc_id = 0;
+static __thread bool webrtc_name_set = false;
+void webrtc_set_thread_name(void) {
+    if(!netdata_thread && !webrtc_name_set) {
+        webrtc_name_set = true;
+        char threadname[NETDATA_THREAD_NAME_MAX + 1];
+
+#if defined(__FreeBSD__)
+        snprintfz(threadname, NETDATA_THREAD_NAME_MAX, "WEBRTC[%zu]", __atomic_fetch_add(&webrtc_id, 1, __ATOMIC_RELAXED));
+        pthread_set_name_np(pthread_self(), threadname);
+#elif defined(__APPLE__)
+        snprintfz(threadname, NETDATA_THREAD_NAME_MAX, "WEBRTC[%zu]", __atomic_fetch_add(&webrtc_id, 1, __ATOMIC_RELAXED));
+        pthread_setname_np(threadname);
+#elif defined(HAVE_PTHREAD_GETNAME_NP)
+        pthread_getname_np(pthread_self(), threadname, NETDATA_THREAD_NAME_MAX+1);
+        if(strcmp(threadname, "netdata") == 0) {
+            snprintfz(threadname, NETDATA_THREAD_NAME_MAX, "WEBRTC[%zu]", __atomic_fetch_add(&webrtc_id, 1, __ATOMIC_RELAXED));
+            pthread_setname_np(pthread_self(), threadname);
+        }
+#else
+        snprintfz(threadname, NETDATA_THREAD_NAME_MAX, "WEBRTC[%zu]", __atomic_fetch_add(&webrtc_id, 1, __ATOMIC_RELAXED));
+        pthread_setname_np(pthread_self(), threadname);
+#endif
+
+        thread_name_get(true);
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -173,6 +228,8 @@ void uv_thread_set_name_np(uv_thread_t ut, const char* name) {
     ret = pthread_setname_np(ut, threadname);
 #endif
 
+    thread_name_get(true);
+
     if (ret)
         info("cannot set libuv thread name to %s. Err: %d", threadname, ret);
 }
diff --git a/libnetdata/threads/threads.h b/libnetdata/threads/threads.h
index ccc18aff0a..ad31b88161 100644
--- a/libnetdata/threads/threads.h
+++ b/libnetdata/threads/threads.h
@@ -43,6 +43,8 @@ int netdata_thread_detach(pthread_t thread);
 void uv_thread_set_name_np(uv_thread_t ut, const char* name);
 void os_thread_get_current_name_np(char threadname[NETDATA_THREAD_NAME_MAX + 1]);
 
+void webrtc_set_thread_name(void);
+
 #define netdata_thread_self pthread_self
 #define netdata_thread_testcancel pthread_testcancel