Merge pull request #4157 from nicolasnoble/paddywhack

Adding grpc_tcp_listener as an actual object being returned.

src/core/iomgr/tcp_server.h

@@ -39,6 +39,9 @@
 /* Forward decl of grpc_tcp_server */
 typedef struct grpc_tcp_server grpc_tcp_server;
 
+/* Forward decl of grpc_tcp_listener */
+typedef struct grpc_tcp_listener grpc_tcp_listener;
+
 /* Called for newly connected TCP connections. */
 typedef void (*grpc_tcp_server_cb)(grpc_exec_ctx *exec_ctx, void *arg,
                                    grpc_endpoint *ep);
@@ -51,19 +54,18 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *server,
                            grpc_pollset **pollsets, size_t pollset_count,
                            grpc_tcp_server_cb on_accept_cb, void *cb_arg);
 
-/* Add a port to the server, returning port number on success, or negative
-   on failure.
+/* Add a port to the server, returning the newly created listener on success,
+   or a null pointer on failure.
 
    The :: and 0.0.0.0 wildcard addresses are treated identically, accepting
    both IPv4 and IPv6 connections, but :: is the preferred style.  This usually
    creates one socket, but possibly two on systems which support IPv6,
-   but not dualstack sockets.
-
-   For raw access to the underlying sockets, see grpc_tcp_server_get_fd(). */
+   but not dualstack sockets. */
 /* TODO(ctiller): deprecate this, and make grpc_tcp_server_add_ports to handle
                   all of the multiple socket port matching logic in one place */
-int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                             size_t addr_len);
+grpc_tcp_listener *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                            const void *addr,
+                                            size_t addr_len);
 
 /* Returns the file descriptor of the Nth listening socket on this server,
    or -1 if the index is out of bounds.
@@ -75,4 +77,8 @@ int grpc_tcp_server_get_fd(grpc_tcp_server *s, unsigned index);
 void grpc_tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *server,
                              grpc_closure *closure);
 
+int grpc_tcp_listener_get_port(grpc_tcp_listener *listener);
+void grpc_tcp_listener_ref(grpc_tcp_listener *listener);
+void grpc_tcp_listener_unref(grpc_tcp_listener *listener);
+
 #endif /* GRPC_INTERNAL_CORE_IOMGR_TCP_SERVER_H */

src/core/iomgr/tcp_server_posix.c

@@ -67,14 +67,13 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
-#define INIT_PORT_CAP 2
 #define MIN_SAFE_ACCEPT_QUEUE_SIZE 100
 
 static gpr_once s_init_max_accept_queue_size;
 static int s_max_accept_queue_size;
 
 /* one listening port */
-typedef struct {
+struct grpc_tcp_listener {
   int fd;
   grpc_fd *emfd;
   grpc_tcp_server *server;
@@ -84,9 +83,18 @@ typedef struct {
     struct sockaddr_un un;
   } addr;
   size_t addr_len;
+  int port;
   grpc_closure read_closure;
   grpc_closure destroyed_closure;
-} server_port;
+  gpr_refcount refs;
+  struct grpc_tcp_listener *next;
+  /* When we add a listener, more than one can be created, mainly because of
+     IPv6. A sibling will still be in the normal list, but will be flagged
+     as such. Any action, such as ref or unref, will affect all of the
+     siblings in the list. */
+  struct grpc_tcp_listener *sibling;
+  int is_sibling;
+};
 
 static void unlink_if_unix_domain_socket(const struct sockaddr_un *un) {
   struct stat st;
@@ -112,10 +120,9 @@ struct grpc_tcp_server {
   /* is this server shutting down? (boolean) */
   int shutdown;
 
-  /* all listening ports */
-  server_port *ports;
-  size_t nports;
-  size_t port_capacity;
+  /* linked list of server ports */
+  grpc_tcp_listener *head;
+  unsigned nports;
 
   /* shutdown callback */
   grpc_closure *shutdown_complete;
@@ -134,9 +141,8 @@ grpc_tcp_server *grpc_tcp_server_create(void) {
   s->shutdown = 0;
   s->on_accept_cb = NULL;
   s->on_accept_cb_arg = NULL;
-  s->ports = gpr_malloc(sizeof(server_port) * INIT_PORT_CAP);
+  s->head = NULL;
   s->nports = 0;
-  s->port_capacity = INIT_PORT_CAP;
   return s;
 }
 
@@ -145,7 +151,12 @@ static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 
   gpr_mu_destroy(&s->mu);
 
-  gpr_free(s->ports);
+  while (s->head) {
+    grpc_tcp_listener *sp = s->head;
+    s->head = sp->next;
+    grpc_tcp_listener_unref(sp);
+  }
+
   gpr_free(s);
 }
 
@@ -166,8 +177,6 @@ static void destroyed_port(grpc_exec_ctx *exec_ctx, void *server, int success) {
    events will be received on them - at this point it's safe to destroy
    things */
 static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
-  size_t i;
-
   /* delete ALL the things */
   gpr_mu_lock(&s->mu);
 
@@ -176,9 +185,9 @@ static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
     return;
   }
 
-  if (s->nports) {
-    for (i = 0; i < s->nports; i++) {
-      server_port *sp = &s->ports[i];
+  if (s->head) {
+    grpc_tcp_listener *sp;
+    for (sp = s->head; sp; sp = sp->next) {
       if (sp->addr.sockaddr.sa_family == AF_UNIX) {
         unlink_if_unix_domain_socket(&sp->addr.un);
       }
@@ -196,7 +205,6 @@ static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 
 void grpc_tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
                              grpc_closure *closure) {
-  size_t i;
   gpr_mu_lock(&s->mu);
 
   GPR_ASSERT(!s->shutdown);
@@ -206,8 +214,9 @@ void grpc_tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 
   /* shutdown all fd's */
   if (s->active_ports) {
-    for (i = 0; i < s->nports; i++) {
-      grpc_fd_shutdown(exec_ctx, s->ports[i].emfd);
+    grpc_tcp_listener *sp;
+    for (sp = s->head; sp; sp = sp->next) {
+      grpc_fd_shutdown(exec_ctx, sp->emfd);
     }
     gpr_mu_unlock(&s->mu);
   } else {
@@ -298,7 +307,7 @@ error:
 
 /* event manager callback when reads are ready */
 static void on_read(grpc_exec_ctx *exec_ctx, void *arg, int success) {
-  server_port *sp = arg;
+  grpc_tcp_listener *sp = arg;
   grpc_fd *fdobj;
   size_t i;
 
@@ -364,9 +373,10 @@ error:
   }
 }
 
-static int add_socket_to_server(grpc_tcp_server *s, int fd,
-                                const struct sockaddr *addr, size_t addr_len) {
-  server_port *sp;
+static grpc_tcp_listener *add_socket_to_server(grpc_tcp_server *s, int fd,
+                                         const struct sockaddr *addr,
+                                         size_t addr_len) {
+  grpc_tcp_listener *sp = NULL;
   int port;
   char *addr_str;
   char *name;
@@ -376,32 +386,35 @@ static int add_socket_to_server(grpc_tcp_server *s, int fd,
     grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
     gpr_asprintf(&name, "tcp-server-listener:%s", addr_str);
     gpr_mu_lock(&s->mu);
+    s->nports++;
     GPR_ASSERT(!s->on_accept_cb && "must add ports before starting server");
-    /* append it to the list under a lock */
-    if (s->nports == s->port_capacity) {
-      s->port_capacity *= 2;
-      s->ports = gpr_realloc(s->ports, sizeof(server_port) * s->port_capacity);
-    }
-    sp = &s->ports[s->nports++];
+    sp = gpr_malloc(sizeof(grpc_tcp_listener));
+    sp->next = s->head;
+    s->head = sp;
     sp->server = s;
     sp->fd = fd;
     sp->emfd = grpc_fd_create(fd, name);
     memcpy(sp->addr.untyped, addr, addr_len);
     sp->addr_len = addr_len;
+    sp->port = port;
+    sp->is_sibling = 0;
+    sp->sibling = NULL;
+    gpr_ref_init(&sp->refs, 1);
     GPR_ASSERT(sp->emfd);
     gpr_mu_unlock(&s->mu);
     gpr_free(addr_str);
     gpr_free(name);
   }
 
-  return port;
+  return sp;
 }
 
-int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                             size_t addr_len) {
-  int allocated_port1 = -1;
-  int allocated_port2 = -1;
-  unsigned i;
+grpc_tcp_listener *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                            const void *addr,
+                                            size_t addr_len) {
+  int allocated_port = -1;
+  grpc_tcp_listener *sp;
+  grpc_tcp_listener *sp2 = NULL;
   int fd;
   grpc_dualstack_mode dsmode;
   struct sockaddr_in6 addr6_v4mapped;
@@ -420,9 +433,9 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
   /* Check if this is a wildcard port, and if so, try to keep the port the same
      as some previously created listener. */
   if (grpc_sockaddr_get_port(addr) == 0) {
-    for (i = 0; i < s->nports; i++) {
+    for (sp = s->head; sp; sp = sp->next) {
       sockname_len = sizeof(sockname_temp);
-      if (0 == getsockname(s->ports[i].fd, (struct sockaddr *)&sockname_temp,
+      if (0 == getsockname(sp->fd, (struct sockaddr *)&sockname_temp,
                            &sockname_len)) {
         port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
         if (port > 0) {
@@ -436,6 +449,8 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     }
   }
 
+  sp = NULL;
+
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
     addr = (const struct sockaddr *)&addr6_v4mapped;
     addr_len = sizeof(addr6_v4mapped);
@@ -449,14 +464,16 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     addr = (struct sockaddr *)&wild6;
     addr_len = sizeof(wild6);
     fd = grpc_create_dualstack_socket(addr, SOCK_STREAM, 0, &dsmode);
-    allocated_port1 = add_socket_to_server(s, fd, addr, addr_len);
+    sp = add_socket_to_server(s, fd, addr, addr_len);
+    allocated_port = sp->port;
     if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
       goto done;
     }
 
     /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
-    if (port == 0 && allocated_port1 > 0) {
-      grpc_sockaddr_set_port((struct sockaddr *)&wild4, allocated_port1);
+    if (port == 0 && allocated_port > 0) {
+      grpc_sockaddr_set_port((struct sockaddr *)&wild4, allocated_port);
+      sp2 = sp;
     }
     addr = (struct sockaddr *)&wild4;
     addr_len = sizeof(wild4);
@@ -471,22 +488,31 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     addr = (struct sockaddr *)&addr4_copy;
     addr_len = sizeof(addr4_copy);
   }
-  allocated_port2 = add_socket_to_server(s, fd, addr, addr_len);
+  sp = add_socket_to_server(s, fd, addr, addr_len);
+  sp->sibling = sp2;
+  if (sp2) sp2->is_sibling = 1;
 
 done:
   gpr_free(allocated_addr);
-  return allocated_port1 >= 0 ? allocated_port1 : allocated_port2;
+  return sp;
 }
 
 int grpc_tcp_server_get_fd(grpc_tcp_server *s, unsigned port_index) {
-  return (port_index < s->nports) ? s->ports[port_index].fd : -1;
+  grpc_tcp_listener *sp;
+  for (sp = s->head; sp && port_index != 0; sp = sp->next, port_index--);
+  if (port_index == 0 && sp) {
+    return sp->fd;
+  } else {
+    return -1;
+  }
 }
 
 void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
                            grpc_pollset **pollsets, size_t pollset_count,
                            grpc_tcp_server_cb on_accept_cb,
                            void *on_accept_cb_arg) {
-  size_t i, j;
+  size_t i;
+  grpc_tcp_listener *sp;
   GPR_ASSERT(on_accept_cb);
   gpr_mu_lock(&s->mu);
   GPR_ASSERT(!s->on_accept_cb);
@@ -495,17 +521,41 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
   s->on_accept_cb_arg = on_accept_cb_arg;
   s->pollsets = pollsets;
   s->pollset_count = pollset_count;
-  for (i = 0; i < s->nports; i++) {
-    for (j = 0; j < pollset_count; j++) {
-      grpc_pollset_add_fd(exec_ctx, pollsets[j], s->ports[i].emfd);
+  for (sp = s->head; sp; sp = sp->next) {
+    for (i = 0; i < pollset_count; i++) {
+      grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
     }
-    s->ports[i].read_closure.cb = on_read;
-    s->ports[i].read_closure.cb_arg = &s->ports[i];
-    grpc_fd_notify_on_read(exec_ctx, s->ports[i].emfd,
-                           &s->ports[i].read_closure);
+    sp->read_closure.cb = on_read;
+    sp->read_closure.cb_arg = sp;
+    grpc_fd_notify_on_read(exec_ctx, sp->emfd,
+                           &sp->read_closure);
     s->active_ports++;
   }
   gpr_mu_unlock(&s->mu);
 }
 
+int grpc_tcp_listener_get_port(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  return sp->port;
+}
+
+void grpc_tcp_listener_ref(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  gpr_ref(&sp->refs);
+}
+
+void grpc_tcp_listener_unref(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  if (sp->is_sibling) return;
+  if (gpr_unref(&sp->refs)) {
+    grpc_tcp_listener *sibling = sp->sibling;
+    while (sibling) {
+      sp = sibling;
+      sibling = sp->sibling;
+      gpr_free(sp);
+    }
+    gpr_free(listener);
+  }
+}
+
 #endif

src/core/iomgr/tcp_server_windows.c

@@ -35,7 +35,8 @@
 
 #ifdef GPR_WINSOCK_SOCKET
 
-#define _GNU_SOURCE
+#include <io.h>
+
 #include "src/core/iomgr/sockaddr_utils.h"
 
 #include <grpc/support/alloc.h>
@@ -51,25 +52,29 @@
 #include "src/core/iomgr/tcp_server.h"
 #include "src/core/iomgr/tcp_windows.h"
 
-#define INIT_PORT_CAP 2
 #define MIN_SAFE_ACCEPT_QUEUE_SIZE 100
 
 /* one listening port */
-typedef struct server_port {
+struct grpc_tcp_listener {
   /* This seemingly magic number comes from AcceptEx's documentation. each
      address buffer needs to have at least 16 more bytes at their end. */
   gpr_uint8 addresses[(sizeof(struct sockaddr_in6) + 16) * 2];
   /* This will hold the socket for the next accept. */
   SOCKET new_socket;
-  /* The listener winsocked. */
+  /* The listener winsocket. */
   grpc_winsocket *socket;
+  /* The actual TCP port number. */
+  int port;
   grpc_tcp_server *server;
   /* The cached AcceptEx for that port. */
   LPFN_ACCEPTEX AcceptEx;
   int shutting_down;
   /* closure for socket notification of accept being ready */
   grpc_closure on_accept;
-} server_port;
+  gpr_refcount refs;
+  /* linked list */
+  struct grpc_tcp_listener *next;
+};
 
 /* the overall server */
 struct grpc_tcp_server {
@@ -82,10 +87,8 @@ struct grpc_tcp_server {
   /* active port count: how many ports are actually still listening */
   int active_ports;
 
-  /* all listening ports */
-  server_port *ports;
-  size_t nports;
-  size_t port_capacity;
+  /* linked list of server ports */
+  grpc_tcp_listener *head;
 
   /* shutdown callback */
   grpc_closure *shutdown_complete;
@@ -99,9 +102,7 @@ grpc_tcp_server *grpc_tcp_server_create(void) {
   s->active_ports = 0;
   s->on_accept_cb = NULL;
   s->on_accept_cb_arg = NULL;
-  s->ports = gpr_malloc(sizeof(server_port) * INIT_PORT_CAP);
-  s->nports = 0;
-  s->port_capacity = INIT_PORT_CAP;
+  s->head = NULL;
   s->shutdown_complete = NULL;
   return s;
 }
@@ -109,26 +110,26 @@ grpc_tcp_server *grpc_tcp_server_create(void) {
 static void dont_care_about_shutdown_completion(void *arg) {}
 
 static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
-  size_t i;
-
   grpc_exec_ctx_enqueue(exec_ctx, s->shutdown_complete, 1);
 
   /* Now that the accepts have been aborted, we can destroy the sockets.
      The IOCP won't get notified on these, so we can flag them as already
      closed by the system. */
-  for (i = 0; i < s->nports; i++) {
-    server_port *sp = &s->ports[i];
+  while (s->head) {
+    grpc_tcp_listener *sp = s->head;
+    s->head = sp->next;
+    sp->next = NULL;
     grpc_winsocket_destroy(sp->socket);
+    grpc_tcp_listener_unref(sp);
   }
-  gpr_free(s->ports);
   gpr_free(s);
 }
 
 /* Public function. Stops and destroys a grpc_tcp_server. */
 void grpc_tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
                              grpc_closure *shutdown_complete) {
-  size_t i;
   int immediately_done = 0;
+  grpc_tcp_listener *sp;
   gpr_mu_lock(&s->mu);
 
   s->shutdown_complete = shutdown_complete;
@@ -138,8 +139,7 @@ void grpc_tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
   if (s->active_ports == 0) {
     immediately_done = 1;
   }
-  for (i = 0; i < s->nports; i++) {
-    server_port *sp = &s->ports[i];
+  for (sp = s->head; sp; sp = sp->next) {
     sp->shutting_down = 1;
     grpc_winsocket_shutdown(sp->socket);
   }
@@ -199,7 +199,7 @@ error:
 }
 
 static void decrement_active_ports_and_notify(grpc_exec_ctx *exec_ctx,
-                                              server_port *sp) {
+                                              grpc_tcp_listener *sp) {
   int notify = 0;
   sp->shutting_down = 0;
   gpr_mu_lock(&sp->server->mu);
@@ -216,7 +216,7 @@ static void decrement_active_ports_and_notify(grpc_exec_ctx *exec_ctx,
 
 /* In order to do an async accept, we need to create a socket first which
    will be the one assigned to the new incoming connection. */
-static void start_accept(grpc_exec_ctx *exec_ctx, server_port *port) {
+static void start_accept(grpc_exec_ctx *exec_ctx, grpc_tcp_listener *port) {
   SOCKET sock = INVALID_SOCKET;
   char *message;
   char *utf8_message;
@@ -276,7 +276,7 @@ failure:
 
 /* Event manager callback when reads are ready. */
 static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, int from_iocp) {
-  server_port *sp = arg;
+  grpc_tcp_listener *sp = arg;
   SOCKET sock = sp->new_socket;
   grpc_winsocket_callback_info *info = &sp->socket->read_info;
   grpc_endpoint *ep = NULL;
@@ -351,16 +351,17 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, int from_iocp) {
   start_accept(exec_ctx, sp);
 }
 
-static int add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
-                                const struct sockaddr *addr, size_t addr_len) {
-  server_port *sp;
+static grpc_tcp_listener *add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
+                                         const struct sockaddr *addr,
+                                         size_t addr_len) {
+  grpc_tcp_listener *sp = NULL;
   int port;
   int status;
   GUID guid = WSAID_ACCEPTEX;
   DWORD ioctl_num_bytes;
   LPFN_ACCEPTEX AcceptEx;
 
-  if (sock == INVALID_SOCKET) return -1;
+  if (sock == INVALID_SOCKET) return NULL;
 
   /* We need to grab the AcceptEx pointer for that port, as it may be
      interface-dependent. We'll cache it to avoid doing that again. */
@@ -373,37 +374,35 @@ static int add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
     gpr_log(GPR_ERROR, "on_connect error: %s", utf8_message);
     gpr_free(utf8_message);
     closesocket(sock);
-    return -1;
+    return NULL;
   }
 
   port = prepare_socket(sock, addr, addr_len);
   if (port >= 0) {
     gpr_mu_lock(&s->mu);
     GPR_ASSERT(!s->on_accept_cb && "must add ports before starting server");
-    /* append it to the list under a lock */
-    if (s->nports == s->port_capacity) {
-      /* too many ports, and we need to store their address in a closure */
-      /* TODO(ctiller): make server_port a linked list */
-      abort();
-    }
-    sp = &s->ports[s->nports++];
+    sp = gpr_malloc(sizeof(grpc_tcp_listener));
+    sp->next = s->head;
+    s->head = sp;
     sp->server = s;
     sp->socket = grpc_winsocket_create(sock, "listener");
     sp->shutting_down = 0;
     sp->AcceptEx = AcceptEx;
     sp->new_socket = INVALID_SOCKET;
+    sp->port = port;
+    gpr_ref_init(&sp->refs, 1);
     grpc_closure_init(&sp->on_accept, on_accept, sp);
     GPR_ASSERT(sp->socket);
     gpr_mu_unlock(&s->mu);
   }
 
-  return port;
+  return sp;
 }
 
-int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                             size_t addr_len) {
-  int allocated_port = -1;
-  unsigned i;
+grpc_tcp_listener *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                            const void *addr,
+                                            size_t addr_len) {
+  grpc_tcp_listener *sp;
   SOCKET sock;
   struct sockaddr_in6 addr6_v4mapped;
   struct sockaddr_in6 wildcard;
@@ -415,9 +414,9 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
   /* Check if this is a wildcard port, and if so, try to keep the port the same
      as some previously created listener. */
   if (grpc_sockaddr_get_port(addr) == 0) {
-    for (i = 0; i < s->nports; i++) {
+    for (sp = s->head; sp; sp = sp->next) {
       sockname_len = sizeof(sockname_temp);
-      if (0 == getsockname(s->ports[i].socket->socket,
+      if (0 == getsockname(sp->socket->socket,
                            (struct sockaddr *)&sockname_temp, &sockname_len)) {
         port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
         if (port > 0) {
@@ -452,33 +451,55 @@ int grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     gpr_free(utf8_message);
   }
 
-  allocated_port = add_socket_to_server(s, sock, addr, addr_len);
+  sp = add_socket_to_server(s, sock, addr, addr_len);
   gpr_free(allocated_addr);
 
-  return allocated_port;
+  return sp;
 }
 
-SOCKET
-grpc_tcp_server_get_socket(grpc_tcp_server *s, unsigned index) {
-  return (index < s->nports) ? s->ports[index].socket->socket : INVALID_SOCKET;
+int grpc_tcp_server_get_fd(grpc_tcp_server *s, unsigned port_index) {
+  grpc_tcp_listener *sp;
+  for (sp = s->head; sp && port_index != 0; sp = sp->next, port_index--);
+  if (port_index == 0 && sp) {
+    return _open_osfhandle(sp->socket->socket, 0);
+  } else {
+    return -1;
+  }
 }
 
 void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
                            grpc_pollset **pollset, size_t pollset_count,
                            grpc_tcp_server_cb on_accept_cb,
                            void *on_accept_cb_arg) {
-  size_t i;
+  grpc_tcp_listener *sp;
   GPR_ASSERT(on_accept_cb);
   gpr_mu_lock(&s->mu);
   GPR_ASSERT(!s->on_accept_cb);
   GPR_ASSERT(s->active_ports == 0);
   s->on_accept_cb = on_accept_cb;
   s->on_accept_cb_arg = on_accept_cb_arg;
-  for (i = 0; i < s->nports; i++) {
-    start_accept(exec_ctx, s->ports + i);
+  for (sp = s->head; sp; sp = sp->next) {
+    start_accept(exec_ctx, sp);
     s->active_ports++;
   }
   gpr_mu_unlock(&s->mu);
 }
 
+int grpc_tcp_listener_get_port(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  return sp->port;
+}
+
+void grpc_tcp_listener_ref(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  gpr_ref(&sp->refs);
+}
+
+void grpc_tcp_listener_unref(grpc_tcp_listener *listener) {
+  grpc_tcp_listener *sp = listener;
+  if (gpr_unref(&sp->refs)) {
+    gpr_free(listener);
+  }
+}
+
 #endif /* GPR_WINSOCK_SOCKET */

src/core/security/server_secure_chttp2.c

@@ -249,9 +249,11 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   }
 
   for (i = 0; i < resolved->naddrs; i++) {
-    port_temp = grpc_tcp_server_add_port(
+    grpc_tcp_listener *listener;
+    listener = grpc_tcp_server_add_port(
         tcp, (struct sockaddr *)&resolved->addrs[i].addr,
         resolved->addrs[i].len);
+    port_temp = grpc_tcp_listener_get_port(listener);
     if (port_temp >= 0) {
       if (port_num == -1) {
         port_num = port_temp;

src/core/surface/server_chttp2.c

@@ -107,9 +107,11 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
   }
 
   for (i = 0; i < resolved->naddrs; i++) {
-    port_temp = grpc_tcp_server_add_port(
+    grpc_tcp_listener *listener;
+    listener = grpc_tcp_server_add_port(
         tcp, (struct sockaddr *)&resolved->addrs[i].addr,
         resolved->addrs[i].len);
+    port_temp = grpc_tcp_listener_get_port(listener);
     if (port_temp >= 0) {
       if (port_num == -1) {
         port_num = port_temp;

test/core/util/reconnect_server.c

@@ -113,6 +113,7 @@ void reconnect_server_init(reconnect_server *server) {
 
 void reconnect_server_start(reconnect_server *server, int port) {
   struct sockaddr_in addr;
+  grpc_tcp_listener *listener;
   int port_added;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
@@ -121,8 +122,9 @@ void reconnect_server_start(reconnect_server *server, int port) {
   memset(&addr.sin_addr, 0, sizeof(addr.sin_addr));
 
   server->tcp_server = grpc_tcp_server_create();
-  port_added =
+  listener = 
       grpc_tcp_server_add_port(server->tcp_server, &addr, sizeof(addr));
+  port_added = grpc_tcp_listener_get_port(listener);
   GPR_ASSERT(port_added == port);
 
   grpc_tcp_server_start(&exec_ctx, server->tcp_server, server->pollsets, 1,