modularized all source code (#4391)

* modularized all external plugins

* added README.md in plugins

* fixed title

* fixed typo

* relative link to external plugins

* external plugins configuration README

* added plugins link

* remove plugins link

* plugin names are links

* added links to external plugins

* removed unecessary spacing

* list to table

* added language

* fixed typo

* list to table on internal plugins

* added more documentation to internal plugins

* moved python, node, and bash code and configs into the external plugins

* added statsd README

* fix bug with corrupting config.h every 2nd compilation

* moved all config files together with their code

* more documentation

* diskspace info

* fixed broken links in apps.plugin

* added backends docs

* updated plugins readme

* move nc-backend.sh to backends

* created daemon directory

* moved all code outside src/

* fixed readme identation

* renamed plugins.d.plugin to plugins.d

* updated readme

* removed linux- from linux plugins

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* fixed README.md links

* fixed netdata tree links

* updated codacy, codeclimate and lgtm excluded paths

* update CMakeLists.txt

* updated automake options at top directory

* libnetdata slit into directories

* updated READMEs

* updated READMEs

* updated ARL docs

* updated ARL docs

* moved /plugins to /collectors

* moved all external plugins outside plugins.d

* updated codacy, codeclimate, lgtm

* updated README

* updated url

* updated readme

* updated readme

* updated readme

* updated readme

* moved api and web into webserver

* web/api web/gui web/server

* modularized webserver

* removed web/gui/version.txt

1 files changed, 92 insertions, 0 deletions

diff --git a/collectors/idlejitter.plugin/plugin_idlejitter.c b/collectors/idlejitter.plugin/plugin_idlejitter.c
new file mode 100644
index 0000000000..3fe3b0306e
--- /dev/null
+++ b/collectors/idlejitter.plugin/plugin_idlejitter.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "plugin_idlejitter.h"
+
+#define CPU_IDLEJITTER_SLEEP_TIME_MS 20
+
+static void cpuidlejitter_main_cleanup(void *ptr) {
+    struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITING;
+
+    info("cleaning up...");
+
+    static_thread->enabled = NETDATA_MAIN_THREAD_EXITED;
+}
+
+void *cpuidlejitter_main(void *ptr) {
+    netdata_thread_cleanup_push(cpuidlejitter_main_cleanup, ptr);
+
+    usec_t sleep_ut = config_get_number("plugin:idlejitter", "loop time in ms", CPU_IDLEJITTER_SLEEP_TIME_MS) * USEC_PER_MS;
+    if(sleep_ut <= 0) {
+        config_set_number("plugin:idlejitter", "loop time in ms", CPU_IDLEJITTER_SLEEP_TIME_MS);
+        sleep_ut = CPU_IDLEJITTER_SLEEP_TIME_MS * USEC_PER_MS;
+    }
+
+    RRDSET *st = rrdset_create_localhost(
+            "system"
+            , "idlejitter"
+            , NULL
+            , "idlejitter"
+            , NULL
+            , "CPU Idle Jitter"
+            , "microseconds lost/s"
+            , "idlejitter.plugin"
+            , NULL
+            , NETDATA_CHART_PRIO_SYSTEM_IDLEJITTER
+            , localhost->rrd_update_every
+            , RRDSET_TYPE_AREA
+    );
+    RRDDIM *rd_min = rrddim_add(st, "min", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+    RRDDIM *rd_max = rrddim_add(st, "max", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+    RRDDIM *rd_avg = rrddim_add(st, "average", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+
+    usec_t update_every_ut = localhost->rrd_update_every * USEC_PER_SEC;
+    struct timeval before, after;
+    unsigned long long counter;
+
+    for(counter = 0; 1 ;counter++) {
+        int iterations = 0;
+        usec_t error_total = 0,
+                error_min = 0,
+                error_max = 0,
+                elapsed = 0;
+
+        if(netdata_exit) break;
+
+        while(elapsed < update_every_ut) {
+            now_monotonic_timeval(&before);
+            sleep_usec(sleep_ut);
+            now_monotonic_timeval(&after);
+
+            usec_t dt = dt_usec(&after, &before);
+            elapsed += dt;
+
+            usec_t error = dt - sleep_ut;
+            error_total += error;
+
+            if(unlikely(!iterations))
+                error_min = error;
+            else if(error < error_min)
+                error_min = error;
+
+            if(error > error_max)
+                error_max = error;
+
+            iterations++;
+        }
+
+        if(netdata_exit) break;
+
+        if(iterations) {
+            if (likely(counter)) rrdset_next(st);
+            rrddim_set_by_pointer(st, rd_min, error_min);
+            rrddim_set_by_pointer(st, rd_max, error_max);
+            rrddim_set_by_pointer(st, rd_avg, error_total / iterations);
+            rrdset_done(st);
+        }
+    }
+
+    netdata_thread_cleanup_pop(1);
+    return NULL;
+}
+