Add Aws.empty_connection_pools! API

aws-sdk-core/lib/aws-sdk-core.rb

@@ -403,6 +403,21 @@ def use_bundled_cert!
       ))
     end
 
+    # Close any long-lived connections maintained by the SDK's internal
+    # connection pool.
+    #
+    # Applications that rely heavily on the `fork()` system call on POSIX systems
+    # should call this method in the child process directly after fork to ensure
+    # there are no race conditions between the parent process and its children
+    # for the pooled TCP connections.
+    #
+    # @return [nil]
+    def empty_connection_pools!
+      Seahorse::Client::NetHttp::ConnectionPool.pools.each do |pool|
+        pool.empty!
+      end
+    end
+
     # Loads modules that are normally loaded with Ruby's `autoload`.
     # This can avoid thread-safety issues that some Ruby versions have
     # with `autoload`.

aws-sdk-core/spec/aws_spec.rb

@@ -138,4 +138,19 @@ module Aws
     end
 
   end
+
+  describe '.empty_connection_pools!' do
+    it 'closes any existing sessions' do
+      endpoint = "http://example.com"
+      conn_pool = Seahorse::Client::NetHttp::ConnectionPool.for({})
+      session = conn_pool.send(:start_session, endpoint)
+      conn_pool.instance_variable_get(:@pool)[endpoint] = [session]
+
+      expect(conn_pool.size).to eq(1)
+
+      Aws.empty_connection_pools!
+
+      expect(conn_pool.size).to eq(0)
+    end
+  end
 end