Added test-ffi target, use it in CI (#9)

* Added test-ffi target, use it in CI

* Added clang-format config, fixed RETURN_STRING API mismatch

* Skip installing php and packages on the PHP docker images

* Removed al2 job that was never going to work, and compiler tests

* Fixed basic test for extension loading

* Cleaned up lib structure, fixed tests

* use test-ci target to conditionally test in GitHub

* Use v0.8.1 of builder

lib/AWS/CRT/IO/EventLoopGroup.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * Represents 1 or more event loops (1 per thread) for doing I/O and background tasks.
+ * Typically, every application has one EventLoopGroup.
+ *
+ * @param array options:
+ * - int num_threads - Number of worker threads in the EventLoopGroup. Defaults to 0/1 per logical core.
+ */
+final class EventLoopGroup extends NativeResource {
+
+    static function defaults() {
+        return array(
+            'num_threads' => 0,
+        );
+    }
+
+    function __construct(array $options = array()) {
+        parent::__construct();
+        if (count($options) == 0) {
+            $options = self::defaults();
+        }
+        $this->acquire(self::$crt->event_loop_group_new($options['num_threads']));
+    }
+
+    function __destruct() {
+        self::$crt->event_loop_group_release($this->native);
+        $this->release();
+        parent::__destruct();
+    }
+}

lib/AWS/CRT/NativeResource.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * Base class for all native resources, tracks all outstanding resources
+ * and provides basic leak checking
+ */
+abstract class NativeResource {
+    protected static $crt = null;
+    protected static $resources = [];
+    protected $native = null;
+
+    function __construct() {
+        if (is_null(self::$crt)) {
+            try {
+                self::$crt = new CRT();
+            } catch (Exception $e) {
+                echo 'Exception while loading CRT: ', $e->getMessage(), "\n";
+            }
+        }
+
+        self::$resources[spl_object_hash($this)] = 1;
+    }
+
+    protected function acquire($handle) {
+        $this->native = $handle;
+    }
+
+    protected function release() {
+        $this->native = null;
+    }
+
+    function __destruct() {
+        // Should have been destroyed and released by derived resource
+        assert($this->native == null);
+        unset(self::$resources[spl_object_hash($this)]);
+    }
+}