Merge pull request #1495 from inolen/websocket_tests

more websocket test updates

20 files changed, 823 insertions, 1063 deletions

diff --git a/tests/runner.py b/tests/runner.py
index d6ec37a3..f7a0fa26 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -12528,11 +12528,10 @@ elif 'browser' in str(sys.argv):
     i = sys.argv.index('browser')
     sys.argv = sys.argv[:i] + sys.argv[i+1:]
     sys.argv += [
-      'browser.test_sockets_bi',
-      'browser.test_sockets_gethostbyname',
-      'browser.test_sockets_bi_bigdata',
-      'browser.test_sockets_select_server_down',
-      'browser.test_sockets_select_server_closes_connection',
+      'browser.test_sockets_echo',
+      'browser.test_sockets_echo_bigdata',
+      'browser.test_sockets_partial',
+      'browser.test_sockets_select_server_no_accept',
       'browser.test_sockets_select_server_closes_connection_rw',
       'browser.test_enet'
     ]
@@ -13784,15 +13783,17 @@ Press any key to continue.'''
         self.btest(program,
             reference=book_path(basename.replace('.bc', '.png')), args=args)
 
-    def btest(self, filename, expected=None, reference=None, reference_slack=0,
+    def btest(self, filename, expected=None, reference=None, force_c=False, reference_slack=0,
         args=[], outfile='test.html', message='.'): # TODO: use in all other tests
-      filepath = path_from_root('tests', filename)
-      temp_filepath = os.path.join(self.get_dir(), os.path.basename(filename))
+      # if we are provided the source and not a path, use that
+      filename_is_src = '\n' in filename
+      src = filename if filename_is_src else ''
+      filepath = path_from_root('tests', filename) if not filename_is_src else ('main.c' if force_c else 'main.cpp')
+      temp_filepath = os.path.join(self.get_dir(), os.path.basename(filepath))
+      if filename_is_src:
+        with open(temp_filepath, 'w') as f: f.write(src)
       if not reference:
-        if '\n' in filename: # if we are provided the source and not a path, use that
-          src = filename
-          filename = 'main.cpp'
-        else:
+        if not src:
           with open(filepath) as f: src = f.read()
         with open(temp_filepath, 'w') as f: f.write(self.with_report_result(src))
       else:
@@ -14068,16 +14069,16 @@ Press any key to continue.'''
 
     def test_emscripten_async_wget2(self):
       self.btest('http.cpp', expected='0', args=['-I' + path_from_root('tests')])
-
-    pids_to_clean = []
-    def clean_pids(self):
+  
+    @staticmethod
+    def clean_pids(pids):
       import signal, errno
       def pid_exists(pid):
         try:
-            # NOTE: may just kill the process in Windows
-            os.kill(pid, 0)
+          # NOTE: may just kill the process in Windows
+          os.kill(pid, 0)
         except OSError, e:
-            return e.errno == errno.EPERM
+          return e.errno == errno.EPERM
         else:
             return True
       def kill_pids(pids, sig):
@@ -14091,198 +14092,143 @@ Press any key to continue.'''
           except:
             print '[kill fail]'
       # ask nicely (to try and catch the children)
-      kill_pids(browser.pids_to_clean, signal.SIGTERM)
+      kill_pids(pids, signal.SIGTERM)
       time.sleep(1)
       # extreme prejudice, may leave children
-      kill_pids(browser.pids_to_clean, signal.SIGKILL)
-      browser.pids_to_clean = []
+      kill_pids(pids, signal.SIGKILL)
 
-    # Runs a websocket server at a specific port. port is the true tcp socket we forward to, port+1 is the websocket one
-    class WebsockHarness:
-      def __init__(self, port, server_func=None, no_server=False):
-        self.port = port
-        self.server_func = server_func
-        self.no_server = no_server
+    class WebsockifyServerHarness:
+      def __init__(self, filename, args, listen_port, target_port):
+        self.pids = []
+        self.filename = filename
+        self.target_port = target_port
+        self.listen_port = listen_port
+        self.args = args or []
 
       def __enter__(self):
         import socket, websockify
-        if not self.no_server:
-          def server_func(q):
-            q.put(None) # No sub-process to start
-            ssock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            ssock.bind(("127.0.0.1", self.port))
-            ssock.listen(2)
-            while True:
-              csock, addr = ssock.accept()
-              print "Connection from %s" % repr(addr)
-              csock.send("te\x01\xff\x79st\x02")
-
-          server_func = self.server_func or server_func
-
-          server_queue = multiprocessing.Queue()
-          self.server = multiprocessing.Process(target=server_func, args=(server_queue,))
-          self.server.start()
-          browser.pids_to_clean.append(self.server.pid)
-          while True:
-            if not server_queue.empty():
-              spid = server_queue.get()
-              if spid:
-                browser.pids_to_clean.append(spid)
-              break
-            time.sleep(0.1)
-          print '[Socket server on processes %s]' % str(browser.pids_to_clean[-2:])
-
-        def websockify_func(wsp): wsp.start_server()
 
-        print >> sys.stderr, 'running websockify on %d, forward to tcp %d' % (self.port+1, self.port)
-        wsp = websockify.WebSocketProxy(verbose=True, listen_port=self.port+1, target_host="127.0.0.1", target_port=self.port, run_once=True)
-        self.websockify = multiprocessing.Process(target=websockify_func, args=(wsp,))
+        # compile the server
+        # NOTE empty filename support is a hack to support
+        # the current test_enet
+        if self.filename:
+          Popen([CLANG_CC, path_from_root('tests', self.filename), '-o', 'server'] + self.args).communicate()
+          process = Popen([os.path.abspath('server')])
+          self.pids.append(process.pid)
+
+        # start the websocket proxy
+        print >> sys.stderr, 'running websockify on %d, forward to tcp %d' % (self.listen_port, self.target_port)
+        wsp = websockify.WebSocketProxy(verbose=True, listen_port=self.listen_port, target_host="127.0.0.1", target_port=self.target_port, run_once=True)
+        self.websockify = multiprocessing.Process(target=wsp.start_server)
         self.websockify.start()
-        browser.pids_to_clean.append(self.websockify.pid)
-        print '[Websockify on processes %s]' % str(browser.pids_to_clean[-2:])
+        self.pids.append(self.websockify.pid)
+        print '[Websockify on process %s]' % str(self.pids[-2:])
 
       def __exit__(self, *args, **kwargs):
+        # try to kill the websockify proxy gracefully
         if self.websockify.is_alive():
           self.websockify.terminate()
         self.websockify.join()
 
+        # clean up any processes we started
+        browser.clean_pids(self.pids)
+
+
+    class CompiledServerHarness:
+      def __init__(self, filename, args):
+        self.pids = browser.PidContainer()
+        self.filename = filename
+        self.args = args or []
+
+      def __enter__(self):
+        import socket, websockify
+
+        # compile the server
+        Popen([PYTHON, EMCC, path_from_root('tests', self.filename), '-o', 'server.js'] + self.args).communicate()
+        process = Popen([NODE_JS, 'server.js'])
+        self.pids.append(process.pid)
+
+      def __exit__(self, *args, **kwargs):
+        # clean up any processes we started
+        self.pids.kill_all()
+
+    def make_relay_server(self, port1, port2):
+      print >> sys.stderr, 'creating relay server on ports %d,%d' % (port1, port2)
+      proc = Popen([PYTHON, path_from_root('tests', 'sockets', 'socket_relay.py'), str(port1), str(port2)])
+      return proc
+
     # always run these tests last
     # make sure to use different ports in each one because it takes a while for the processes to be cleaned up
-    def test_sockets(self):
-      try:
-        with self.WebsockHarness(8990):
-          self.btest('sockets/test_sockets.c', expected='571', args=['-DSOCKK=8991'])
-      finally:
-        self.clean_pids()
 
-    def test_sockets_partial(self):
-      def partial(q):
-        import socket
-
-        q.put(None) # No sub-process to start
-        ssock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        ssock.bind(("127.0.0.1", 8990))
-        ssock.listen(2)
-        while True:
-          csock, addr = ssock.accept()
-          print "Connection from %s" % repr(addr)
-          csock.send("\x09\x01\x02\x03\x04\x05\x06\x07\x08\x09")
-          csock.send("\x08\x01\x02\x03\x04\x05\x06\x07\x08")
-          csock.send("\x07\x01\x02\x03\x04\x05\x06\x07")
-          csock.send("\x06\x01\x02\x03\x04\x05\x06")
-          csock.send("\x05\x01\x02\x03\x04\x05")
-          csock.send("\x04\x01\x02\x03\x04")
-          csock.send("\x03\x01\x02\x03")
-          csock.send("\x02\x01\x02")
-          csock.send("\x01\x01")
+    # NOTE all datagram tests are temporarily disabled, as
+    # we can't truly test datagram sockets until we have
+    # proper listen server support.
 
-      try:
-        with self.WebsockHarness(8990, partial):
-          self.btest('sockets/test_sockets_partial.c', expected='165', args=['-DSOCKK=8991'])
-      finally:
-        self.clean_pids()
+    def test_sockets_echo(self):
+      sockets_include = '-I'+path_from_root('tests', 'sockets')
 
-    def make_relay_server(self, port1, port2):
-      def relay_server(q):
-        print >> sys.stderr, 'creating relay server on ports %d,%d' % (port1, port2)
-        proc = Popen([PYTHON, path_from_root('tests', 'socket_relay.py'), str(port1), str(port2)])
-        q.put(proc.pid)
-        proc.communicate()
-      return relay_server
-
-    def test_sockets_bi(self):
-      for datagram in [0,1]:
-        for fileops in [0,1]:
-          try:
-            print >> sys.stderr, 'test_websocket_bi datagram %d, fileops %d' % (datagram, fileops)
-            with self.WebsockHarness(6992, self.make_relay_server(6992, 6994)):
-              with self.WebsockHarness(6994, no_server=True):
-                Popen([PYTHON, EMCC, path_from_root('tests', 'sockets/test_sockets_bi_side.c'), '-o', 'side.html', '-DSOCKK=6995', '-DTEST_DGRAM=%d' % datagram]).communicate()
-                self.btest('sockets/test_sockets_bi.c', expected='2499', args=['-DSOCKK=6993', '-DTEST_DGRAM=%d' % datagram, '-DTEST_FILE_OPS=%s' % fileops])
-          finally:
-            self.clean_pids()
+      for datagram in [0]:
+        dgram_define = '-DTEST_DGRAM=%d' % datagram
 
-    def test_sockets_gethostbyname(self):
-      try:
-        with self.WebsockHarness(7000):
-          self.btest('sockets/test_sockets_gethostbyname.c', expected='571', args=['-O2', '-DSOCKK=7001'])
-      finally:
-        self.clean_pids()
+        for harness in [
+          self.WebsockifyServerHarness(os.path.join('sockets', 'test_sockets_echo_server.c'), ['-DSOCKK=8990', dgram_define, sockets_include], 8991, 8990)
+          # self.CompiledServerHarness(os.path.join('sockets', 'test_sockets_echo_server.c'), ['-DSOCKK=8990', dgram_define, sockets_include])
+        ]:
+          with harness:
+            self.btest(os.path.join('sockets', 'test_sockets_echo_client.c'), expected='0', args=['-DSOCKK=8991', dgram_define, sockets_include])
 
-    def test_sockets_bi_bigdata(self):
-      try:
-        with self.WebsockHarness(3992, self.make_relay_server(3992, 3994)):
-          with self.WebsockHarness(3994, no_server=True):
-            Popen([PYTHON, EMCC, path_from_root('tests', 'sockets/test_sockets_bi_side_bigdata.c'), '-o', 'side.html', '-DSOCKK=3995', '-s', 'SOCKET_DEBUG=0', '-I' + path_from_root('tests/sockets')]).communicate()
-            self.btest('sockets/test_sockets_bi_bigdata.c', expected='0', args=['-DSOCKK=3993', '-s', 'SOCKET_DEBUG=0', '-I' + path_from_root('tests/sockets')])
-      finally:
-        self.clean_pids()
+    def test_sockets_echo_bigdata(self):
+      sockets_include = '-I'+path_from_root('tests', 'sockets')
 
-    def test_sockets_select_server_down(self):
-      def closedServer(q):
-        import socket
+      for datagram in [0]:
+        dgram_define = '-DTEST_DGRAM=%d' % datagram
 
-        q.put(None) # No sub-process to start
-        ssock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        ssock.bind(("127.0.0.1", 8994))
-      try:
-        with self.WebsockHarness(8994, closedServer):
-          self.btest('sockets/test_sockets_select.c', expected='266', args=['-DSOCKK=8995'])
-      finally:
-        self.clean_pids()
-
-    def test_sockets_select_server_closes_connection(self):
-      def closingServer(q):
-        import socket
-
-        q.put(None) # No sub-process to start
-        ssock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        ssock.bind(("127.0.0.1", 8994))
-        ssock.listen(2)
-        while True:
-          csock, addr = ssock.accept()
-          print "Connection from %s" % repr(addr)
-          csock.send("1234567")
-          csock.close()
+        # generate a large string literal to use as our message
+        message = ''
+        for i in range(256*256*2):
+            message += str(unichr(ord('a') + (i % 26)))
 
-      try:
-        with self.WebsockHarness(8994, closingServer):
-          self.btest('sockets/test_sockets_select_server_closes_connection.c', expected='266', args=['-DSOCKK=8995'])
-      finally:
-        self.clean_pids()
+        # re-write the client test with this literal (it's too big to pass via command line)
+        input_filename = path_from_root('tests', 'sockets', 'test_sockets_echo_client.c')
+        input = open(input_filename).read()
+        output = input.replace('#define MESSAGE "pingtothepong"', '#define MESSAGE "%s"' % message)
+
+        for harness in [
+          self.WebsockifyServerHarness(os.path.join('sockets', 'test_sockets_echo_server.c'), ['-DSOCKK=8992', dgram_define, sockets_include], 8993, 8992)
+        ]:
+          with harness:
+            self.btest(output, expected='0', args=['-DSOCKK=8993', dgram_define, sockets_include], force_c=True)
+
+    def test_sockets_partial(self):
+      for harness in [
+        self.WebsockifyServerHarness(os.path.join('sockets', 'test_sockets_partial_server.c'), ['-DSOCKK=8994'], 8995, 8994)
+      ]:
+        with harness:
+          self.btest(os.path.join('sockets', 'test_sockets_partial_client.c'), expected='165', args=['-DSOCKK=8995'])
+
+    # TODO add support for gethostbyaddr to re-enable this test
+    # def test_sockets_gethostbyname(self):
+    #   self.btest(os.path.join('sockets', 'test_sockets_gethostbyname.c'), expected='0', args=['-O2', '-DSOCKK=8997'])
+
+    def test_sockets_select_server_no_accept(self):
+      for harness in [
+        self.WebsockifyServerHarness(os.path.join('sockets', 'test_sockets_select_server_no_accept_server.c'), ['-DSOCKK=8995'], 8996, 8995)
+      ]:
+        self.btest(os.path.join('sockets', 'test_sockets_select_server_no_accept_client.c'), expected='266', args=['-DSOCKK=8996'])
 
     def test_sockets_select_server_closes_connection_rw(self):
-      def closingServer_rw(q):
-        import socket
-
-        q.put(None) # No sub-process to start
-        ssock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        ssock.bind(("127.0.0.1", 8998))
-        ssock.listen(2)
-        while True:
-          csock, addr = ssock.accept()
-          print "Connection from %s" % repr(addr)
-          readArray = bytearray(10)
-          #readBuffer = buffer(readArray)
-          bytesRead = 0
-          # Let the client start to write data
-          while (bytesRead < 10):
-            (readBytes, address) = csock.recvfrom_into( readArray, 10 )
-            bytesRead += readBytes
-          print "server: 10 bytes read"
-          # Now we write a message on our own ...
-          csock.send("0123456789")
-          print "server: 10 bytes written"
-          # And immediately close the connection
-          csock.close()
-          print "server: connection closed"
+      sockets_include = '-I'+path_from_root('tests', 'sockets')
 
-      try:
-        with self.WebsockHarness(8998, closingServer_rw):
-          self.btest('sockets/test_sockets_select_server_closes_connection_rw.c', expected='266', args=['-DSOCKK=8999'])
-      finally:
-        self.clean_pids()
+      for harness in [
+        self.WebsockifyServerHarness(os.path.join('sockets', 'test_sockets_echo_server.c'), ['-DSOCKK=9004', sockets_include], 9005, 9004)
+      ]:
+        with harness:
+          self.btest(os.path.join('sockets', 'test_sockets_select_server_closes_connection_client_rw.c'), expected='266', args=['-DSOCKK=9005', sockets_include])
 
+    # TODO remove this once we have proper listen server support built into emscripten.
+    # being that enet uses datagram sockets, we can't proxy to a native server with
+    # websockify, so we're emulating the listen server in the browser and relaying
+    # between two TCP servers.
     def test_enet(self):
       try_delete(self.in_dir('enet'))
       shutil.copytree(path_from_root('tests', 'enet'), self.in_dir('enet'))
@@ -14292,14 +14238,34 @@ Press any key to continue.'''
       Popen([PYTHON, path_from_root('emmake'), 'make']).communicate()
       enet = [self.in_dir('enet', '.libs', 'libenet.a'), '-I'+path_from_root('tests', 'enet', 'include')]
       os.chdir(pwd)
-      Popen([PYTHON, EMCC, path_from_root('tests', 'enet_server.c'), '-o', 'server.html'] + enet).communicate()
+      Popen([PYTHON, EMCC, path_from_root('tests', 'sockets', 'test_enet_server.c'), '-o', 'server.html', '-DSOCKK=2235'] + enet).communicate()
 
-      try:
-        with self.WebsockHarness(1234, self.make_relay_server(1234, 1236)):
-          with self.WebsockHarness(1236, no_server=True):
-            self.btest('enet_client.c', expected='0', args=enet)
-      finally:
-        self.clean_pids()
+      with self.WebsockifyServerHarness('', [], 2235, 2234):
+        with self.WebsockifyServerHarness('', [], 2237, 2236):
+          pids = []
+          try:
+            proc = self.make_relay_server(2234, 2236)
+            pids.append(proc.pid)
+            self.btest(os.path.join('sockets', 'test_enet_client.c'), expected='0', args=['-DSOCKK=2237'] + enet)
+          finally:
+            browser.clean_pids(pids);
+
+    # TODO use this once we have listen server support
+    # def test_enet(self):
+    #   try_delete(self.in_dir('enet'))
+    #   shutil.copytree(path_from_root('tests', 'enet'), self.in_dir('enet'))
+    #   pwd = os.getcwd()
+    #   os.chdir(self.in_dir('enet'))
+    #   Popen([PYTHON, path_from_root('emconfigure'), './configure']).communicate()
+    #   Popen([PYTHON, path_from_root('emmake'), 'make']).communicate()
+    #   enet = [self.in_dir('enet', '.libs', 'libenet.a'), '-I'+path_from_root('tests', 'enet', 'include')]
+    #   os.chdir(pwd)
+
+    #   for harness in [
+    #     self.CompiledServerHarness(os.path.join('sockets', 'test_enet_server.c'), ['-DSOCKK=9010'] + enet, 9011, 9010)
+    #   ]:
+    #     with harness:
+    #       self.btest(os.path.join('sockets', 'test_enet_client.c'), expected='0', args=['-DSOCKK=9011'] + enet)
 
 elif 'benchmark' in str(sys.argv):
   # Benchmarks. Run them with argument |benchmark|. To run a specific test, do
diff --git a/tests/socket_relay.py b/tests/sockets/socket_relay.py
index 5b6403f9..5b6403f9 100644
--- a/tests/socket_relay.py
+++ b/tests/sockets/socket_relay.py
diff --git a/tests/enet_client.c b/tests/sockets/test_enet_client.c
index 601b8769..bf14375c 100644
--- a/tests/enet_client.c
+++ b/tests/sockets/test_enet_client.c
@@ -1,20 +1,22 @@
 #include <stdio.h>
-#include <emscripten.h>
-
+#include <string.h>
 #include <enet/enet.h>
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
 
 ENetHost * host;
 
 void main_loop() {
-  static int counter = 0;
 #if EMSCRIPTEN
+  static int counter = 0;
   counter++;
-#endif
   if (counter == 100) {
     printf("stop!\n");
     emscripten_cancel_main_loop();
     return;
   }
+#endif
 
   ENetEvent event;
   if (enet_host_service (host, & event, 0) == 0) return;
@@ -32,7 +34,11 @@ void main_loop() {
               event.channelID);
 
       int result = strcmp("packetfoo", event.packet->data);
+#if EMSCRIPTEN
       REPORT_RESULT();
+#else
+      exit(EXIT_SUCCESS);
+#endif
 
       /* Clean up the packet now that we're done using it. */
       enet_packet_destroy (event.packet);
@@ -73,11 +79,7 @@ int main (int argc, char ** argv)
 
   ENetAddress address;
   enet_address_set_host (& address, "localhost");
-#if EMSCRIPTEN
-  address.port = 1237;
-#else
-  address.port = 1235;
-#endif
+  address.port = SOCKK;
 
   printf("connecting to server...\n");
 
@@ -100,7 +102,11 @@ int main (int argc, char ** argv)
                         "console.log('added.');");
 #endif
 
+#if EMSCRIPTEN
   emscripten_set_main_loop(main_loop, 3, 1);
+#else
+  while (1) main_loop();
+#endif
 
   return 1;
 }
diff --git a/tests/enet_server.c b/tests/sockets/test_enet_server.c
index a8167e16..9a4518ac 100644
--- a/tests/enet_server.c
+++ b/tests/sockets/test_enet_server.c
@@ -1,10 +1,13 @@
 // g++ -fpermissive ../enet_server.c -I/home/alon/Dev/emscripten/system/include/emscripten/ -Iinclude/ -fpermissive .libs/libenet.a -o enet_server ; g++ ../enet_client.c -I/home/alon/Dev/emscripten/system/include/emscripten/ -Iinclude/ -fpermissive .libs/libenet.a -o enet_client
 
 #include <stdio.h>
-#include <emscripten.h>
-
+#include <string.h>
 #include <enet/enet.h>
 
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
 ENetHost *host;
 
 void send_msg(ENetPeer *peer) {
@@ -31,7 +34,9 @@ void main_loop() {
 #endif
   if (counter == 100) {
     printf("stop!\n");
+#if EMSCRIPTEN
     emscripten_cancel_main_loop();
+#endif
     return;
   }
 
@@ -82,7 +87,7 @@ int main (int argc, char ** argv)
 
   ENetAddress address;
   address.host = ENET_HOST_ANY;
-  address.port = 1235;
+  address.port = SOCKK;
   printf("create!\n");
   host = enet_host_create (& address /* the address to bind the server host to */,
                              32 /* allow up to 32 clients and/or outgoing connections */,
@@ -96,7 +101,11 @@ int main (int argc, char ** argv)
     exit (EXIT_FAILURE);
   }
 
+#if EMSCRIPTEN
   emscripten_set_main_loop(main_loop, 3, 1);
+#else
+  while (1) main_loop();
+#endif
 
   return 1;
 }
diff --git a/tests/sockets/test_sockets.c b/tests/sockets/test_sockets.c
deleted file mode 100644
index 8845ef43..00000000
--- a/tests/sockets/test_sockets.c
+++ /dev/null
@@ -1,143 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <assert.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#define EXPECTED_BYTES 5
-
-int sockfd;
-int not_always_data = 0;
-
-void finish(int result) {
-  close(sockfd);
-#if EMSCRIPTEN
-  REPORT_RESULT();
-#endif
-  exit(result);
-}
-
-unsigned int get_all_buf(int sock, char* output, unsigned int maxsize) {
-  // select check for IO
-  fd_set sett;
-  FD_ZERO(&sett);
-  assert(select(64, &sett, NULL, NULL, NULL) == 0); // empty set
-  FD_SET(sock, &sett);
-  assert(select(0, &sett, NULL, NULL, NULL) == 0); // max FD to check is 0
-  assert(FD_ISSET(sock, &sett) == 0);
-  FD_SET(sock, &sett);
-  int select_says_yes = select(64, &sett, NULL, NULL, NULL);
-
-  // ioctl check for IO
-  int bytes;
-  if (ioctl(sock, FIONREAD, &bytes) || bytes == 0) {
-    not_always_data = 1;
-    printf("ioctl says 0, FD_ISSET says %ld\n", FD_ISSET(sock, &sett));
-    assert(FD_ISSET(sock, &sett) == 0);
-    return 0;
-  }
-
-  assert(FD_ISSET(sock, &sett));
-  assert(select_says_yes); // ioctl must agree with select
-
-  char buffer[1024];
-  int n;
-  unsigned int offset = 0;
-  while((errno = 0, (n = recv(sock, buffer, sizeof(buffer), 0))>0) ||
-    errno == EINTR) {
-    if(n > 0) {
-      if (((unsigned int) n)+offset > maxsize) {
-        fprintf(stderr, "too much data!");
-        finish(EXIT_FAILURE);
-      }
-      memcpy(output+offset, buffer, n);
-      offset += n;
-    }
-  }
-
-  if (n < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
-    fprintf(stderr, "error in get_all_buf! %d", errno);
-    finish(EXIT_FAILURE);
-  }
-  return offset;
-}
-
-void iter(void *arg) {
-  static char out[1024*2];
-  static int pos = 0;
-  fd_set fdr;
-  int res;
-
-  // make sure that sockfd is ready to read
-  FD_ZERO(&fdr);
-  FD_SET(sockfd, &fdr);
-  res = select(64, &fdr, NULL, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-  } else if (!FD_ISSET(sockfd, &fdr)) {
-    return;
-  }
-
-  // perform read write operations ...
-  int n = get_all_buf(sockfd, out+pos, 1024-pos);
-  if (n) printf("read! %d\n", n);
-  pos += n;
-  if (pos >= EXPECTED_BYTES) {
-    int i, sum = 0;
-    for (i=0; i < pos; i++) {
-      printf("%x\n", out[i]);
-      sum += out[i];
-    }
-
-    shutdown(sockfd, SHUT_RDWR);
-
-    close(sockfd);
-
-    printf("sum: %d\n", sum);
-    finish(sum);
-  }
-}
-
-void main() {
-  struct sockaddr_in addr;
-  int res;
-
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-  
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-#if EMSCRIPTEN
-  emscripten_set_main_loop(iter, 0, 0);
-#else
-  while (1) iter(NULL);
-#endif
-}
-
diff --git a/tests/sockets/test_sockets_bi.c b/tests/sockets/test_sockets_bi.c
deleted file mode 100644
index 4266d20c..00000000
--- a/tests/sockets/test_sockets_bi.c
+++ /dev/null
@@ -1,138 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#define EXPECTED_BYTES 28
-
-int sockfd;
-
-void finish(int result) {
-  close(sockfd);
-#if EMSCRIPTEN
-  REPORT_RESULT();
-#endif
-  exit(result);
-}
-
-unsigned int get_all_buf(int sock, char* output, unsigned int maxsize) {
-  int bytes;
-  if (ioctl(sock, FIONREAD, &bytes)) return 0;
-  if (bytes == 0) return 0;
-
-  char buffer[1024];
-  int n;
-  unsigned int offset = 0;
-#if TEST_FILE_OPS
-  while((errno = 0, (n = read(sock, buffer, sizeof(buffer)))>0) ||
-#else
-  while((errno = 0, (n = recv(sock, buffer, sizeof(buffer), 0))>0) ||
-#endif
-    errno == EINTR) {
-    if(n > 0) {
-      if (((unsigned int) n)+offset > maxsize) {
-        fprintf(stderr, "too much data!");
-        finish(EXIT_FAILURE);
-      }
-      memcpy(output+offset, buffer, n);
-      offset += n;
-    }
-  }
-
-  if(n < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
-    fprintf(stderr, "error in get_all_buf!");
-    finish(EXIT_FAILURE);
-  }
-  return offset;
-}
-
-void iter(void *arg) {
-  static char out[1024*2];
-  static int pos = 0;
-  fd_set fdr;
-  int res;
-
-  // make sure that sockfd is ready to read
-  FD_ZERO(&fdr);
-  FD_SET(sockfd, &fdr);
-  res = select(64, &fdr, NULL, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-  } else if (!FD_ISSET(sockfd, &fdr)) {
-    return;
-  }
-
-  // perform read write operations ...
-  int n = get_all_buf(sockfd, out+pos, 1024-pos);
-  if (n) printf("read! %d\n", n);
-  pos += n;
-  if (pos >= EXPECTED_BYTES) {
-    int i, sum = 0;
-    for (i=0; i < pos; i++) {
-      printf("%x\n", out[i]);
-      sum += out[i];
-    }
-
-    shutdown(sockfd, SHUT_RDWR);
-    close(sockfd);
-
-    printf("sum: %d\n", sum);
-    finish(sum);
-  }
-}
-
-int main() {
-  struct sockaddr_in addr;
-  int res;
-
-  printf("hello from main page\n");
-
-#if !TEST_DGRAM
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-#else
-  sockfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
-#endif
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-  
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-#if EMSCRIPTEN
-  emscripten_run_script("console.log('adding iframe');"
-                        "var iframe = document.createElement('iframe');"
-                        "iframe.src = 'side.html';"
-                        "document.body.appendChild(iframe);"
-                        "console.log('added.');");
-  emscripten_set_main_loop(iter, 0, 0);
-#else
-  while (1) iter(NULL);
-#endif
-
-  return EXIT_SUCCESS;
-}
diff --git a/tests/sockets/test_sockets_bi_bigdata.c b/tests/sockets/test_sockets_bi_bigdata.c
deleted file mode 100644
index c1d8100e..00000000
--- a/tests/sockets/test_sockets_bi_bigdata.c
+++ /dev/null
@@ -1,138 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#include "test_sockets_bigdata.h"
-
-#define EXPECTED_BYTES DATA_SIZE
-
-int sockfd;
-
-void finish(int result) {
-  close(sockfd);
-#if EMSCRIPTEN
-  REPORT_RESULT();
-#endif
-  exit(result);
-}
-
-unsigned int get_all_buf(int sock, char* output, unsigned int maxsize) {
-  int bytes;
-  if (ioctl(sock, FIONREAD, &bytes)) return 0;
-  if (bytes == 0) return 0;
-
-  char buffer[EXPECTED_BYTES];
-  int n;
-  unsigned int offset = 0;
-  while((errno = 0, (n = recv(sock, buffer, sizeof(buffer), 0))>0) ||
-    errno == EINTR) {
-    if (n > 0) {
-      if (((unsigned int) n)+offset > maxsize) {
-        fprintf(stderr, "too much data!");
-        finish(EXIT_FAILURE);
-      }
-      memcpy(output+offset, buffer, n);
-      offset += n;
-    }
-  }
-
-  if (n < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
-    fprintf(stderr, "error in get_all_buf!");
-    finish(EXIT_FAILURE);
-  }
-  return offset;
-}
-
-void iter(void *arg) {
-  static char out[EXPECTED_BYTES];
-  static int pos = 0;
-  fd_set fdr;
-  int res;
-
-  // make sure that sockfd has finished connecting and is ready to read
-  FD_ZERO(&fdr);
-  FD_SET(sockfd, &fdr);
-  res = select(64, &fdr, NULL, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-    return;
-  } else if (!FD_ISSET(sockfd, &fdr)) {
-    return;
-  }
-
-  // perform read write operations ...
-  printf("so far %d, expecting up to %d\n", pos, EXPECTED_BYTES-pos);
-  res = get_all_buf(sockfd, out+pos, EXPECTED_BYTES-pos);
-  if (res) printf("read! %d\n", res);
-  pos += res;
-  if (pos >= EXPECTED_BYTES) {
-    shutdown(sockfd, SHUT_RDWR);
-
-    close(sockfd);
-
-    char *comp = generateData();
-    int result = strcmp(comp, out);
-    if (result != 0) {
-      for (int i = 0; i < DATA_SIZE; i++) {
-        printf("%d:%d\n", comp[i], out[i]);
-      }
-    }
-    finish(result);
-  }
-}
-
-int main() {
-  struct sockaddr_in addr;
-  int res;
-
-  printf("hello from main page\n");
-
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-#if EMSCRIPTEN
-  emscripten_run_script("console.log('adding iframe');"
-                        "var iframe = document.createElement('iframe');"
-                        "iframe.src = 'side.html';"
-                        "iframe.width = '100%';"
-                        "iframe.width = '40%';"
-                        "document.body.appendChild(iframe);"
-                        "console.log('added.');");
-  emscripten_set_main_loop(iter, 3, 0);
-#else
-  while (1) iter(NULL);
-#endif
-
-  return EXIT_SUCCESS;
-}
-
diff --git a/tests/sockets/test_sockets_bi_side.c b/tests/sockets/test_sockets_bi_side.c
deleted file mode 100644
index b8910632..00000000
--- a/tests/sockets/test_sockets_bi_side.c
+++ /dev/null
@@ -1,93 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#define EXPECTED_BYTES 5
-
-int sockfd = -1;
-
-void finish(int result) {
-  close(sockfd);
-  exit(result);
-}
-
-void loop() {
-  fd_set fdw;
-  int res;
-
-  // Make sure that sockfd has actually finished connecting
-  // and is ready to read.
-  FD_ZERO(&fdw);
-  FD_SET(sockfd, &fdw);
-  res = select(64, NULL, &fdw, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-  } else if (!FD_ISSET(sockfd, &fdw)) {
-    return;
-  }
-
-  char data[] = "hello from the other siide\n";
-
-  printf("send..\n");
-#if TEST_FILE_OPS
-  res = write(sockfd, data, sizeof(data));
-#else
-  res = send(sockfd, data, sizeof(data), 0);
-#endif
-  if (res == -1) {
-    if (errno != EAGAIN) {
-      perror("send error");
-      finish(EXIT_FAILURE);
-    }
-    return;
-  }
-
-  finish(EXIT_SUCCESS);
-}
-
-int main() {
-  struct sockaddr_in addr;
-  int res;
-#if !TEST_DGRAM
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-#else
-  sockfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
-#endif
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-  emscripten_set_main_loop(loop, 0, 0);
-
-  return EXIT_SUCCESS;
-}
-
diff --git a/tests/sockets/test_sockets_bi_side_bigdata.c b/tests/sockets/test_sockets_bi_side_bigdata.c
deleted file mode 100644
index e31029b6..00000000
--- a/tests/sockets/test_sockets_bi_side_bigdata.c
+++ /dev/null
@@ -1,90 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#include "test_sockets_bigdata.h"
-
-#define EXPECTED_BYTES 5
-
-int sockfd = -1;
-char *data = NULL;
-
-void finish(int result) {
-  close(sockfd);
-  exit(result);
-}
-
-void loop() {
-  fd_set fdw;
-  int res;
-
-  // make sure that sockfd has finished connecting and is ready to write
-  FD_ZERO(&fdw);
-  FD_SET(sockfd, &fdw);
-  res = select(64, NULL, &fdw, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-    return;
-  } else if (!FD_ISSET(sockfd, &fdw)) {
-    return;
-  }
-
-  printf("send..\n");
-
-  res = send(sockfd, data, DATA_SIZE, 0);
-  if (res == -1) {
-    if (errno != EAGAIN) {
-      perror("send error");
-      finish(EXIT_FAILURE);
-    }
-    return;
-  }
-
-  finish(EXIT_SUCCESS);
-}
-
-int main() {
-  struct sockaddr_in addr;
-  int res;
-  
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    exit(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-
-  printf("connect..\n");
-
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-  data = generateData();
-
-  emscripten_set_main_loop(loop, 1, 0);
-
-  return EXIT_SUCCESS;
-}
\ No newline at end of file
diff --git a/tests/sockets/test_sockets_bigdata.h b/tests/sockets/test_sockets_bigdata.h
deleted file mode 100644
index 17149ad6..00000000
--- a/tests/sockets/test_sockets_bigdata.h
+++ /dev/null
@@ -1,20 +0,0 @@
-
-#include <stdlib.h>
-
-#define DATA_SIZE (256*256*2)
-// 1500 fails
-
-char *generateData() {
-  char *ret = malloc(256*256*2);
-  char *curr = ret;
-  for (int i = 0; i < 256; i++) {
-    for (int j = 0; j < 256; j++) {
-      *curr = i;
-      curr++;
-      *curr = j;
-      curr++;
-    }
-  }
-  return ret;
-}
-
diff --git a/tests/sockets/test_sockets_echo_client.c b/tests/sockets/test_sockets_echo_client.c
new file mode 100644
index 00000000..6b3ccef3
--- /dev/null
+++ b/tests/sockets/test_sockets_echo_client.c
@@ -0,0 +1,148 @@
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <assert.h>
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
+#include "test_sockets_msg.h"
+
+// message to send to the server
+#ifndef MESSAGE
+#define MESSAGE "pingtothepong"
+#endif
+
+typedef enum {
+  MSG_READ,
+  MSG_WRITE
+} msg_state_t;
+
+typedef struct {
+  int fd;
+  msg_t msg;
+  msg_state_t state;
+} server_t;
+
+server_t server;
+msg_t echo_msg;
+int echo_read;
+int echo_wrote;
+
+void finish(int result) {
+  close(server.fd);
+#if EMSCRIPTEN
+  REPORT_RESULT();
+#endif
+  exit(result);
+}
+
+void main_loop(void *arg) {
+  static char out[1024*2];
+  static int pos = 0;
+  fd_set fdr;
+  fd_set fdw;
+  int res;
+
+  // make sure that server.fd is ready to read / write
+  FD_ZERO(&fdr);
+  FD_ZERO(&fdw);
+  FD_SET(server.fd, &fdr);
+  FD_SET(server.fd, &fdw);
+  res = select(64, &fdr, &fdw, NULL, NULL);
+  if (res == -1) {
+    perror("select failed");
+    finish(EXIT_FAILURE);
+  }
+
+  if (server.state == MSG_READ) {
+    if (!FD_ISSET(server.fd, &fdr)) {
+      return;
+    }
+
+    // as a test, confirm with ioctl that we have data available
+    // after selecting
+    int available;
+    res = ioctl(server.fd, FIONREAD, &available);
+    assert(res != -1);
+    assert(available);
+
+    res = do_msg_read(server.fd, &server.msg, echo_read, 0, NULL, NULL);
+    if (res != -1) echo_read += res;
+
+    // once we've read the entire message, validate it
+    if (echo_read >= server.msg.length) {
+      assert(!strcmp(server.msg.buffer, MESSAGE));
+      finish(EXIT_SUCCESS);
+    }
+  } else {
+    if (!FD_ISSET(server.fd, &fdw)) {
+      return;
+    }
+
+    res = do_msg_write(server.fd, &echo_msg, echo_wrote, 0, NULL, 0);
+    if (res != -1) echo_wrote += res;
+
+    // once we're done writing the message, read it back
+    if (echo_wrote >= echo_msg.length) {
+      server.state = MSG_READ;
+    }
+  }
+}
+
+int main() {
+  struct sockaddr_in addr;
+  int res;
+
+  memset(&server, 0, sizeof(server_t));
+  server.state = MSG_WRITE;
+
+  // setup the message we're going to echo
+  memset(&echo_msg, 0, sizeof(msg_t));
+  echo_msg.length = strlen(MESSAGE) + 1;
+  echo_msg.buffer = malloc(echo_msg.length);
+  strncpy(echo_msg.buffer, MESSAGE, echo_msg.length);
+
+  // create the socket and set to non-blocking
+#if !USE_UDP
+  server.fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+#else
+  server.fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+#endif
+  if (server.fd == -1) {
+    perror("cannot create socket");
+    finish(EXIT_FAILURE);
+  }
+  fcntl(server.fd, F_SETFL, O_NONBLOCK);
+
+  // connect the socket
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons(SOCKK);
+  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
+    perror("inet_pton failed");
+    finish(EXIT_FAILURE);
+  }
+  
+  res = connect(server.fd, (struct sockaddr *)&addr, sizeof(addr));
+  if (res == -1 && errno != EINPROGRESS) {
+    perror("connect failed");
+    finish(EXIT_FAILURE);
+  }
+
+#if EMSCRIPTEN
+  emscripten_set_main_loop(main_loop, 0, 0);
+#else
+  while (1) main_loop(NULL);
+#endif
+
+  return EXIT_SUCCESS;
+}
\ No newline at end of file
diff --git a/tests/sockets/test_sockets_echo_server.c b/tests/sockets/test_sockets_echo_server.c
new file mode 100644
index 00000000..8a48b878
--- /dev/null
+++ b/tests/sockets/test_sockets_echo_server.c
@@ -0,0 +1,152 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
+#include "test_sockets_msg.h"
+
+typedef enum {
+  MSG_READ,
+  MSG_WRITE
+} msg_state_t;
+
+typedef struct {
+  int fd;
+} server_t;
+
+typedef struct {
+  int fd;
+  struct sockaddr_in addr;
+  msg_t msg;
+  msg_state_t state;
+  int read;
+  int wrote;
+} client_t;
+
+server_t server;
+client_t client;
+
+void main_loop(void *arg) {
+  int res;
+  fd_set fdr;
+  fd_set fdw;
+
+  // see if there are any connections to accept or read / write from
+  FD_ZERO(&fdr);
+  FD_ZERO(&fdw);
+  FD_SET(server.fd, &fdr);
+  FD_SET(server.fd, &fdw);
+#if !USE_UDP
+  if (client.fd) FD_SET(client.fd, &fdr);
+  if (client.fd) FD_SET(client.fd, &fdw);
+#endif
+  res = select(64, &fdr, &fdw, NULL, NULL);
+  if (res == -1) {
+    perror("select failed");
+    exit(EXIT_SUCCESS);
+  }
+
+#if !USE_UDP
+  // for TCP sockets, we may need to accept a connection
+  if (FD_ISSET(server.fd, &fdr)) {
+    client.fd = accept(server.fd, NULL, NULL);
+    assert(client.fd != -1);
+  }
+#endif
+
+#if !USE_UDP
+    int fd = client.fd;
+#else
+    int fd = server.fd;
+#endif
+  if (client.state == MSG_READ) {
+    socklen_t addrlen;
+
+    if (!FD_ISSET(fd, &fdr)) {
+      return;
+    }
+
+    res = do_msg_read(fd, &client.msg, client.read, 0, (struct sockaddr *)&client.addr, &addrlen);
+    if (res != -1) client.read += res;
+
+    // once we've read the entire message, echo it back
+    if (client.read >= client.msg.length) {
+      client.read = 0;
+      client.state = MSG_WRITE;
+    }
+  } else {
+    if (!FD_ISSET(fd, &fdw)) {
+      return;
+    }
+
+    res = do_msg_write(fd, &client.msg, client.wrote, 0, (struct sockaddr *)&client.addr, sizeof(client.addr));
+    if (res != -1) client.wrote += res;
+
+    // close the client once we've echo'd back the entire message
+    if (client.wrote >= client.msg.length) {
+      close(client.fd);
+      memset(&client, 0, sizeof(client_t));
+    }
+  }
+}
+
+int main() {
+  struct sockaddr_in addr;
+  int res;
+
+  memset(&server, 0, sizeof(server_t));
+  memset(&client, 0, sizeof(client_t));
+
+  // create the socket and set to non-blocking
+#if !USE_UDP
+  server.fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+#else
+  server.fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+#endif
+  if (server.fd == -1) {
+    perror("cannot create socket");
+    exit(EXIT_FAILURE);
+  }
+  fcntl(server.fd, F_SETFL, O_NONBLOCK);
+
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons(SOCKK);
+  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
+    perror("inet_pton failed");
+    exit(EXIT_FAILURE);
+  }
+
+  res = bind(server.fd, (struct sockaddr *)&addr, sizeof(addr));
+  if (res == -1) {
+    perror("bind failed");
+    exit(EXIT_FAILURE);
+  }
+
+#if !USE_UDP
+  res = listen(server.fd, 50);
+  if (res == -1) {
+    perror("listen failed");
+    exit(EXIT_FAILURE);
+  }
+#endif
+
+#if EMSCRIPTEN
+  emscripten_set_main_loop(main_loop, 60, 0);
+#else
+  while (1) main_loop(NULL);
+#endif
+
+  return EXIT_SUCCESS;
+}
diff --git a/tests/sockets/test_sockets_gethostbyname.c b/tests/sockets/test_sockets_gethostbyname.c
index 59c55ba1..12fc6d9d 100644
--- a/tests/sockets/test_sockets_gethostbyname.c
+++ b/tests/sockets/test_sockets_gethostbyname.c
@@ -1,20 +1,16 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
 #include <arpa/inet.h>
+#include <sys/socket.h>
+#include <assert.h>
+#include <errno.h>
+#include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
 #if EMSCRIPTEN
 #include <emscripten.h>
 #endif
 
-#define EXPECTED_BYTES 5
-
 int sockfd;
 
 void finish(int result) {
@@ -25,113 +21,28 @@ void finish(int result) {
   exit(result);
 }
 
-unsigned int get_all_buf(int sock, char* output, unsigned int maxsize) {
-  int bytes;
-  if (ioctl(sock, FIONREAD, &bytes)) return 0;
-  if (bytes == 0) return 0;
-
-  char buffer[1024];
-  int n;
-  unsigned int offset = 0;
-  while((errno = 0, (n = recv(sock, buffer, sizeof(buffer), 0))>0) ||
-    errno == EINTR) {
-    if (n > 0) {
-      if (((unsigned int) n)+offset > maxsize) {
-        fprintf(stderr, "too much data!");
-        finish(EXIT_FAILURE);
-      }
-      memcpy(output+offset, buffer, n);
-      offset += n;
-    }
-  }
-
-  if (n < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
-    perror("error in get_all_buf!");
-    finish(EXIT_FAILURE);
-  }
-  return offset;
-}
-
-void iter() {
-  static char out[1024*2];
-  static int pos = 0;
-  fd_set fdr;
-  int res;
-
-  // make sure that sockfd has finished connecting and is ready to read
-  FD_ZERO(&fdr);
-  FD_SET(sockfd, &fdr);
-  res = select(64, &fdr, NULL, NULL, NULL);
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-  } else if (!FD_ISSET(sockfd, &fdr)) {
-    return;
-  }
-
-  // perform read write operations ...
-  int n = get_all_buf(sockfd, out+pos, 1024-pos);
-  if (n) printf("read! %d\n", n);
-  pos += n;
-  if (pos >= EXPECTED_BYTES) {
-    int i, sum = 0;
-    for (i=0; i < pos; i++) {
-      printf("%x\n", out[i]);
-      sum += out[i];
-    }
-
-    shutdown(sockfd, SHUT_RDWR);
-
-    close(sockfd);
-
-    printf("sum: %d\n", sum);
-
-    finish(sum);
-  }
-}
-
 int main() {
-  struct sockaddr_in addr;
-  int res;
-
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  struct hostent *host0 = gethostbyname("test.com"); // increment hostname counter to check for possible but at 0,0 not differentiating low/high
-  struct hostent *host = gethostbyname("localhost");
+  char str[INET_ADDRSTRLEN];
+  struct in_addr addr;
+  const char *res;
+  int err;
+  
+  // resolve the hostname ot an actual address
+  struct hostent *host = gethostbyname("slashdot.org");
+
+  // convert the raw address to a string
   char **raw_addr_list = host->h_addr_list;
   int *raw_addr = (int*)*raw_addr_list;
-  printf("raw addr: %d\n", *raw_addr);
-  char name[INET_ADDRSTRLEN];
-  if (!inet_ntop(AF_INET, raw_addr, name, sizeof(name))) {
-    printf("could not figure out name\n");
-    finish(EXIT_FAILURE);
-  }
-  printf("localhost has 'ip' of %s\n", name);
-
-  if (inet_pton(AF_INET, name, &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
+  res = inet_ntop(host->h_addrtype, raw_addr, str, INET_ADDRSTRLEN);
+  assert(res);
 
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
+  // convert the string to an in_addr structure
+  err = inet_pton(AF_INET, str, &addr);
+  assert(err == 1);
 
-#if EMSCRIPTEN
-  emscripten_set_main_loop(iter, 0, 0);
-#else
-  while (1) iter();
-#endif
+  // do a reverse lookup on the ip address
+  struct hostent *host1 = gethostbyaddr(&addr, sizeof(addr), host->h_addrtype);
+  assert(strstr(host1->h_name, "slashdot.org"));
 
   return EXIT_SUCCESS;
 }
diff --git a/tests/sockets/test_sockets_msg.h b/tests/sockets/test_sockets_msg.h
new file mode 100644
index 00000000..30094d65
--- /dev/null
+++ b/tests/sockets/test_sockets_msg.h
@@ -0,0 +1,78 @@
+#ifndef __TEST_SOCKETS_MSG_H__
+#define __TEST_SOCKETS_MSG_H__
+
+typedef struct {
+  char *buffer;
+  int length;
+} msg_t;
+
+int do_msg_read(int sockfd, msg_t *msg, int offset, int length, struct sockaddr *addr, socklen_t *addrlen) {
+  int res;
+
+  if (!msg->length) {
+    // read the message length
+    res = recvfrom(sockfd, &msg->length, sizeof(int), 0, (struct sockaddr *)addr, addrlen);
+    if (res == -1) {
+      assert(errno == EAGAIN);
+      return res;
+    }
+    assert(res != 0);
+    msg->buffer = malloc(msg->length);
+
+    printf("do_msg_read: allocating %d bytes for message\n", msg->length);
+  }
+
+  // read the actual message
+  int max = msg->length - offset;
+  if (length && max > length) {
+    max = length;
+  }
+  res = recvfrom(sockfd, msg->buffer + offset, max, 0, (struct sockaddr *)addr, addrlen);
+  if (res == -1) {
+    assert(errno == EAGAIN);
+    return res;
+  }
+
+  printf("do_msg_read: read %d bytes\n", res);
+
+  return res;
+}
+
+int do_msg_write(int sockfd, msg_t *msg, int offset, int length, struct sockaddr *addr, socklen_t addrlen) {
+  int res;
+
+  // send the message length first
+  if (!offset) {
+    if (addr) {
+      res = sendto(sockfd, &msg->length, sizeof(int), 0, addr, addrlen);
+    } else {
+      res = send(sockfd, &msg->length, sizeof(int), 0);
+    }
+    if (res == -1) {
+      assert(errno == EAGAIN);
+      return res;
+    }
+    assert(res == sizeof(int));
+  }
+
+  // then the actual message
+  int max = msg->length - offset;
+  if (length && max > length) {
+    max = length;
+  }
+  if (addr) {
+    res = sendto(sockfd, msg->buffer + offset, max, 0, addr, addrlen);
+  } else {
+    res = send(sockfd, msg->buffer + offset, max, 0);
+  }
+  if (res == -1) {
+    assert(errno == EAGAIN);
+    return res;
+  }
+
+  printf("do_msg_write: wrote %d bytes %d\n", res, msg->length);
+
+  return res;
+}
+
+#endif
\ No newline at end of file
diff --git a/tests/sockets/test_sockets_partial.c b/tests/sockets/test_sockets_partial_client.c
index 5fe34721..dcf90f19 100644
--- a/tests/sockets/test_sockets_partial.c
+++ b/tests/sockets/test_sockets_partial_client.c
@@ -111,7 +111,7 @@ int main() {
 #if EMSCRIPTEN
   emscripten_set_main_loop(iter, 0, 0);
 #else
-  while (!done) iter(NULL);
+  while (1) iter(NULL);
 #endif
 
   return EXIT_SUCCESS;
diff --git a/tests/sockets/test_sockets_partial_server.c b/tests/sockets/test_sockets_partial_server.c
new file mode 100644
index 00000000..57fae84b
--- /dev/null
+++ b/tests/sockets/test_sockets_partial_server.c
@@ -0,0 +1,130 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
+int serverfd = -1;
+int clientfd = -1;
+
+// csock.send("\x09\x01\x02\x03\x04\x05\x06\x07\x08\x09")
+// csock.send("\x08\x01\x02\x03\x04\x05\x06\x07\x08")
+// csock.send("\x07\x01\x02\x03\x04\x05\x06\x07")
+// csock.send("\x06\x01\x02\x03\x04\x05\x06")
+// csock.send("\x05\x01\x02\x03\x04\x05")
+// csock.send("\x04\x01\x02\x03\x04")
+// csock.send("\x03\x01\x02\x03")
+// csock.send("\x02\x01\x02")
+// csock.send("\x01\x01")
+
+void do_send(int sockfd) {
+  static char* buffers[] = {
+    "\x09\x01\x02\x03\x04\x05\x06\x07\x08\x09\0",
+    "\x08\x01\x02\x03\x04\x05\x06\x07\x08\0",
+    "\x07\x01\x02\x03\x04\x05\x06\x07\0",
+    "\x06\x01\x02\x03\x04\x05\x06\0",
+    "\x05\x01\x02\x03\x04\x05\0",
+    "\x04\x01\x02\x03\x04\0",
+    "\x03\x01\x02\x03\0",
+    "\x02\x01\x02\0",
+    "\x01\x01\0"
+  };
+
+  int i;
+  int res;
+  char *buffer;
+  struct sockaddr_in addr;
+  socklen_t addrlen;
+
+  for (i = 0; i < sizeof(buffers) / sizeof(char*); i++) {
+    buffer = buffers[i];
+
+    res = sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&addr, sizeof(addr));
+    if (res == -1) {
+      perror("send failed");
+      exit(EXIT_FAILURE);
+    }
+    printf("sent \"%s\" (%d bytes)\n", buffer, res);
+  }
+
+  exit(EXIT_SUCCESS);
+}
+
+void iter(void *arg) {
+  int res;
+  fd_set fdr;
+  fd_set fdw;
+
+  // see if there are any connections to accept / write to
+  FD_ZERO(&fdr);
+  FD_ZERO(&fdw);
+  FD_SET(serverfd, &fdr);
+  if (clientfd != -1) FD_SET(clientfd, &fdw);
+  res = select(64, &fdr, &fdw, NULL, NULL);
+  if (res == -1) {
+    perror("select failed");
+    exit(EXIT_SUCCESS);
+  }
+
+  if (FD_ISSET(serverfd, &fdr)) {
+    printf("accepted someone\n");
+    clientfd = accept(serverfd, NULL, NULL);
+    assert(clientfd != -1);
+  }
+
+  if (FD_ISSET(clientfd, &fdw)) {
+    do_send(clientfd);
+  }
+}
+
+int main() {
+  struct sockaddr_in addr;
+  int res;
+
+  // create the socket
+  serverfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+  if (serverfd == -1) {
+    perror("cannot create socket");
+    exit(EXIT_FAILURE);
+  }
+  fcntl(serverfd, F_SETFL, O_NONBLOCK);
+
+  // bind and listen to the supplied port
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons(SOCKK);
+  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
+    perror("inet_pton failed");
+    exit(EXIT_FAILURE);
+  }
+
+  res = bind(serverfd, (struct sockaddr *)&addr, sizeof(addr));
+  if (res == -1) {
+    perror("bind failed");
+    exit(EXIT_FAILURE);
+  }
+
+  res = listen(serverfd, 50);
+  if (res == -1) {
+    perror("listen failed");
+    exit(EXIT_FAILURE);
+  }
+
+#if EMSCRIPTEN
+  emscripten_set_main_loop(iter, 60, 0);
+#else
+  while (1) iter(NULL);
+#endif
+
+  return EXIT_SUCCESS;
+}
diff --git a/tests/sockets/test_sockets_select_server_closes_connection.c b/tests/sockets/test_sockets_select_server_closes_connection.c
deleted file mode 100644
index 4181b12b..00000000
--- a/tests/sockets/test_sockets_select_server_closes_connection.c
+++ /dev/null
@@ -1,112 +0,0 @@
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <assert.h>
-#if EMSCRIPTEN
-#include <emscripten.h>
-#endif
-
-#define EXPECTED_BYTES 5
-
-int sockfd = -1;
-
-void finish(int result) {
-  close(sockfd);
-#if EMSCRIPTEN
-  REPORT_RESULT();
-#endif
-  exit(result);
-}
-
-void iter(void *arg) {  
-  static char readbuf[1024];
-  static int readPos = 0;
-  
-  fd_set sett;
-  FD_ZERO(&sett);
-  FD_SET(sockfd, &sett);
-  
-  int res = select(64, &sett, NULL, NULL, NULL);
-  
-  if (res == -1) {
-    perror("select failed");
-    finish(EXIT_FAILURE);
-  } else if (res == 0) {
-    return;
-  } else if (res > 0) {
-    assert(FD_ISSET(sockfd, &sett));
-    
-    int bytesRead = recv(sockfd, readbuf+readPos, 7-readPos, 0);
-    if (bytesRead == -1) {
-      if (errno != EAGAIN) {
-        perror("recv error");
-        finish(EXIT_FAILURE);
-      }
-      // try again
-      return;
-    }
-
-    if (readPos < 7) {
-      readPos += bytesRead;
-    } else {
-      if (!bytesRead) {
-        perror("Connection to websocket server was closed as expected");
-        finish(266);
-      } else {
-        perror("Connection to websocket server was not closed");
-        finish(EXIT_FAILURE);
-      }
-    }
-  }
-  
-  return;
-}
-
-// Scenario: the server sends data and closes the connection after 7 bytes. 
-// This test should provoke the situation in which the underlying 
-// tcp connection has been torn down already but there is still data 
-// in the queue. The select call has to succeed as long the queue
-// still contains data and only then start to throw errors.
-int main() {
-  struct sockaddr_in addr;
-  int res;
-
-  sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
-  if (sockfd == -1) {
-    perror("cannot create socket");
-    finish(EXIT_FAILURE);
-  }
-  fcntl(sockfd, F_SETFL, O_NONBLOCK);
-
-  memset(&addr, 0, sizeof(addr));
-  addr.sin_family = AF_INET;
-  addr.sin_port = htons(SOCKK);
-  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
-    perror("inet_pton failed");
-    finish(EXIT_FAILURE);
-  }
-
-  // This call should succeed (even if the server port is closed)
-  res = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr));
-  if (res == -1 && errno != EINPROGRESS) {
-    perror("connect failed");
-    finish(EXIT_FAILURE);
-  }
-
-#if EMSCRIPTEN
-  emscripten_set_main_loop(iter, 0, 0);
-#else
-  while (1) iter(NULL);
-#endif
-
-  return EXIT_FAILURE;
-}
-
diff --git a/tests/sockets/test_sockets_select_server_closes_connection_rw.c b/tests/sockets/test_sockets_select_server_closes_connection_client_rw.c
index f7e19aca..198ad232 100644
--- a/tests/sockets/test_sockets_select_server_closes_connection_rw.c
+++ b/tests/sockets/test_sockets_select_server_closes_connection_client_rw.c
@@ -14,9 +14,13 @@
 #include <emscripten.h>
 #endif
 
-#define EXPECTED_BYTES 5
+#include "test_sockets_msg.h"
 
-int sockfd = -1;
+#define MESSAGE "0123456789"
+
+int sockfd;
+msg_t readmsg;
+msg_t writemsg;
 
 void finish(int result) {
   close(sockfd);
@@ -26,12 +30,10 @@ void finish(int result) {
   exit(result);
 }
 
-void iter(void *arg) {
+void main_loop(void *arg) {
   static int state = 0;
-  static char writebuf[] = "01234567890123456789";
-  static int writePos = 0;
-  static char readbuf[1024];
   static int readPos = 0;
+  static int writePos = 0;
   int selectRes;
   ssize_t transferAmount;
   fd_set sett;  
@@ -63,11 +65,11 @@ void iter(void *arg) {
       }
       
       // send a single byte
-      transferAmount = send(sockfd, writebuf+writePos, 1, 0);
-      writePos += transferAmount;
+      transferAmount = do_msg_write(sockfd, &writemsg, writePos, 1, NULL, 0);
+      if (transferAmount != -1) writePos += transferAmount;
    
       // after 10 bytes switch to next state
-      if (writePos >= 10) {
+      if (writePos >= writemsg.length) {
         state = 1;
       }
       break;
@@ -86,8 +88,8 @@ void iter(void *arg) {
       }
 
       // read a single byte
-      transferAmount = recv(sockfd, readbuf+readPos, 1, 0);
-      readPos += transferAmount;
+      transferAmount = do_msg_read(sockfd, &readmsg, readPos, 1, NULL, NULL);
+      if (transferAmount != -1) readPos += transferAmount;
    
       // if successfully reading 1 byte, switch to next state
       if (readPos >= 1) {
@@ -119,11 +121,11 @@ void iter(void *arg) {
       }
       
       // read a single byte
-      transferAmount = recv(sockfd, readbuf+readPos, 1, 0);
-      readPos += transferAmount;
+      transferAmount = do_msg_read(sockfd, &readmsg, readPos, 1, NULL, NULL);
+      if (transferAmount != -1) readPos += transferAmount;
       
       // with 10 bytes read the inQueue is empty => switch state
-      if (readPos >= 10) {
+      if (readPos >= readmsg.length) {
         state = 3;
       }
       break;
@@ -141,7 +143,7 @@ void iter(void *arg) {
 
       // but recv should return 0 signaling the remote
       // end has closed the connection.
-      transferAmount = recv(sockfd, readbuf, 1, 0);
+      transferAmount = do_msg_read(sockfd, &readmsg, readPos, 0, NULL, NULL);
       if (transferAmount) {
         printf("case 3: read != 0\n");
         finish(EXIT_FAILURE);
@@ -176,6 +178,12 @@ int main() {
   struct sockaddr_in addr;
   int res;
 
+  memset(&readmsg, 0, sizeof(msg_t));
+  memset(&writemsg, 0, sizeof(msg_t));
+  writemsg.length = strlen(MESSAGE) + 1;
+  writemsg.buffer = malloc(writemsg.length);
+  strncpy(writemsg.buffer, MESSAGE, writemsg.length);
+
   sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
   if (sockfd == -1) {
     perror("cannot create socket");
@@ -199,9 +207,9 @@ int main() {
   }
 
 #if EMSCRIPTEN
-  emscripten_set_main_loop(iter, 0, 0);
+  emscripten_set_main_loop(main_loop, 0, 0);
 #else
-  while (1) iter(NULL);
+  while (1) main_loop(NULL);
 #endif
 
   return EXIT_SUCCESS;
diff --git a/tests/sockets/test_sockets_select.c b/tests/sockets/test_sockets_select_server_no_accept_client.c
index e05bd4c8..e05bd4c8 100644
--- a/tests/sockets/test_sockets_select.c
+++ b/tests/sockets/test_sockets_select_server_no_accept_client.c
diff --git a/tests/sockets/test_sockets_select_server_no_accept_server.c b/tests/sockets/test_sockets_select_server_no_accept_server.c
new file mode 100644
index 00000000..4a399ed1
--- /dev/null
+++ b/tests/sockets/test_sockets_select_server_no_accept_server.c
@@ -0,0 +1,86 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#if EMSCRIPTEN
+#include <emscripten.h>
+#endif
+
+int serverfd = -1;
+
+void iter(void *arg) {
+  int res;
+  fd_set fdr;
+  fd_set fdw;
+
+  // see if there are any connections to accept / write to
+  FD_ZERO(&fdr);
+  FD_ZERO(&fdw);
+  FD_SET(serverfd, &fdr);
+  if (clientfd != -1) FD_SET(clientfd, &fdw);
+  res = select(64, &fdr, &fdw, NULL, NULL);
+  if (res == -1) {
+    perror("select failed");
+    exit(EXIT_SUCCESS);
+  }
+
+  if (FD_ISSET(serverfd, &fdr)) {
+    printf("accepted someone\n");
+    clientfd = accept(serverfd, NULL, NULL);
+    assert(clientfd != -1);
+  }
+
+  if (FD_ISSET(clientfd, &fdw)) {
+    do_send(clientfd);
+  }
+}
+
+int main() {
+  struct sockaddr_in addr;
+  int res;
+
+  // create the socket
+  serverfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+  if (serverfd == -1) {
+    perror("cannot create socket");
+    exit(EXIT_FAILURE);
+  }
+  fcntl(serverfd, F_SETFL, O_NONBLOCK);
+
+  // bind and listen to the supplied port
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons(SOCKK);
+  if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1) {
+    perror("inet_pton failed");
+    exit(EXIT_FAILURE);
+  }
+
+  res = bind(serverfd, (struct sockaddr *)&addr, sizeof(addr));
+  if (res == -1) {
+    perror("bind failed");
+    exit(EXIT_FAILURE);
+  }
+
+  res = listen(serverfd, 50);
+  if (res == -1) {
+    perror("listen failed");
+    exit(EXIT_FAILURE);
+  }
+
+#if EMSCRIPTEN
+  emscripten_set_main_loop(iter, 60, 0);
+#else
+  while (1) iter(NULL);
+#endif
+
+  return EXIT_SUCCESS;
+}