Merge remote-tracking branch 'upstream/master'

.travis.yml

@@ -25,7 +25,6 @@ env:
     - CONFIG=opt TEST=python
     - CONFIG=opt TEST=csharp
     - USE_GCC=4.4 CONFIG=opt TEST=build
-    - USE_GCC=4.5 CONFIG=opt TEST=build
 script:
   - rvm use $RUBY_VERSION
   - gem install bundler

gRPC.podspec

@@ -4,7 +4,7 @@ Pod::Spec.new do |s|
   s.summary  = 'Generic gRPC client library for iOS'
   s.homepage = 'https://www.grpc.io'
   s.license  = 'New BSD'
-  s.authors  = { 'Jorge Canizales' => 'jcanizales@google.com'
+  s.authors  = { 'Jorge Canizales' => 'jcanizales@google.com',
                  'Michael Lumish' => 'mlumish@google.com' }
 
   # s.source = { :git => 'https://github.com/grpc/grpc.git',  :tag => 'release-0_5_0' }

src/compiler/cpp_generator.cc

@@ -828,9 +828,7 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
           "    new ::grpc::RpcMethodHandler< $ns$$Service$::Service, "
           "$Request$, "
           "$Response$>(\n"
-          "        std::function< ::grpc::Status($ns$$Service$::Service*, "
+          "        std::mem_fn(&$ns$$Service$::Service::$Method$), this),\n"
-          "::grpc::ServerContext*, const $Request$*, $Response$*)>("
-          "&$ns$$Service$::Service::$Method$), this),\n"
           "    new $Request$, new $Response$));\n");
     } else if (ClientOnlyStreaming(method)) {
       printer->Print(
@@ -840,10 +838,7 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
           "    ::grpc::RpcMethod::CLIENT_STREAMING,\n"
           "    new ::grpc::ClientStreamingHandler< "
           "$ns$$Service$::Service, $Request$, $Response$>(\n"
-          "        std::function< ::grpc::Status($ns$$Service$::Service*, "
+          "        std::mem_fn(&$ns$$Service$::Service::$Method$), this),\n"
-          "::grpc::ServerContext*, "
-          "::grpc::ServerReader< $Request$>*, $Response$*)>("
-          "&$ns$$Service$::Service::$Method$), this),\n"
           "    new $Request$, new $Response$));\n");
     } else if (ServerOnlyStreaming(method)) {
       printer->Print(
@@ -853,10 +848,7 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
           "    ::grpc::RpcMethod::SERVER_STREAMING,\n"
           "    new ::grpc::ServerStreamingHandler< "
           "$ns$$Service$::Service, $Request$, $Response$>(\n"
-          "        std::function< ::grpc::Status($ns$$Service$::Service*, "
+          "        std::mem_fn(&$ns$$Service$::Service::$Method$), this),\n"
-          "::grpc::ServerContext*, "
-          "const $Request$*, ::grpc::ServerWriter< $Response$>*)>("
-          "&$ns$$Service$::Service::$Method$), this),\n"
           "    new $Request$, new $Response$));\n");
     } else if (BidiStreaming(method)) {
       printer->Print(
@@ -866,10 +858,7 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
           "    ::grpc::RpcMethod::BIDI_STREAMING,\n"
           "    new ::grpc::BidiStreamingHandler< "
           "$ns$$Service$::Service, $Request$, $Response$>(\n"
-          "        std::function< ::grpc::Status($ns$$Service$::Service*, "
+          "        std::mem_fn(&$ns$$Service$::Service::$Method$), this),\n"
-          "::grpc::ServerContext*, "
-          "::grpc::ServerReaderWriter< $Response$, $Request$>*)>("
-          "&$ns$$Service$::Service::$Method$), this),\n"
           "    new $Request$, new $Response$));\n");
     }
   }

src/core/iomgr/endpoint_pair_windows.c

@@ -50,7 +50,7 @@ static void create_sockets(SOCKET sv[2]) {
   SOCKET lst_sock = INVALID_SOCKET;
   SOCKET cli_sock = INVALID_SOCKET;
   SOCKADDR_IN addr;
-  int addr_len;
+  int addr_len = sizeof(addr);
 
   lst_sock = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);
   GPR_ASSERT(lst_sock != INVALID_SOCKET);

src/core/iomgr/iocp_windows.c

@@ -172,9 +172,15 @@ void grpc_iocp_add_socket(grpc_winsocket *socket) {
 }
 
 void grpc_iocp_socket_orphan(grpc_winsocket *socket) {
+  GPR_ASSERT(!socket->orphan);
   gpr_atm_full_fetch_add(&g_orphans, 1);
+  socket->orphan = 1;
 }
 
+/* Calling notify_on_read or write means either of two things:
+   -) The IOCP already completed in the background, and we need to call
+   the callback now.
+   -) The IOCP hasn't completed yet, and we're queuing it for later. */
 static void socket_notify_on_iocp(grpc_winsocket *socket,
                                   void(*cb)(void *, int), void *opaque,
                                   grpc_winsocket_callback_info *info) {

src/core/iomgr/iomgr_windows.c

@@ -43,6 +43,10 @@
 #include "src/core/iomgr/iocp_windows.h"
 #include "src/core/iomgr/iomgr.h"
 
+/* Windows' io manager is going to be fully designed using IO completion
+   ports. All of what we're doing here is basically make sure that
+   Windows sockets are initialized in and out. */
+
 static void winsock_init(void) {
   WSADATA wsaData;
   int status = WSAStartup(MAKEWORD(2, 0), &wsaData);

src/core/iomgr/pollset_kick_windows.h

@@ -36,6 +36,9 @@
 
 #include <grpc/support/sync.h>
 
+/* There isn't really any such thing as a pollset under Windows, due to the
+   nature of the IO completion ports. */
+
 struct grpc_kick_fd_info;
 
 typedef struct grpc_pollset_kick_state {

src/core/iomgr/pollset_windows.c

@@ -41,6 +41,11 @@
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/pollset_windows.h"
 
+/* There isn't really any such thing as a pollset under Windows, due to the
+   nature of the IO completion ports. We're still going to provide a minimal
+   set of features for the sake of the rest of grpc. But grpc_pollset_work
+   won't actually do any polling, and return as quickly as possible. */
+
 void grpc_pollset_init(grpc_pollset *pollset) {
   gpr_mu_init(&pollset->mu);
   gpr_cv_init(&pollset->cv);

src/core/iomgr/pollset_windows.h

@@ -40,10 +40,10 @@
 #include "src/core/iomgr/pollset_kick.h"
 #include "src/core/iomgr/socket_windows.h"
 
-/* forward declare only in this file to avoid leaking impl details via
+/* There isn't really any such thing as a pollset under Windows, due to the
-   pollset.h; real users of grpc_fd should always include 'fd_posix.h' and not
+   nature of the IO completion ports. A Windows "pollset" is merely a mutex
-   use the struct tag */
+   and a condition variable, as this is the minimal set of features we need
-struct grpc_fd;
+   implemented for the rest of grpc. But we won't use them directly. */
 
 typedef struct grpc_pollset {
   gpr_mu mu;

src/core/iomgr/socket_windows.c

@@ -32,17 +32,18 @@
  */
 
 #include <grpc/support/port_platform.h>
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
 
 #ifdef GPR_WINSOCK_SOCKET
 
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
 #include "src/core/iomgr/iocp_windows.h"
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/iomgr/iomgr_internal.h"
-#include "src/core/iomgr/socket_windows.h"
 #include "src/core/iomgr/pollset.h"
 #include "src/core/iomgr/pollset_windows.h"
+#include "src/core/iomgr/socket_windows.h"
 
 grpc_winsocket *grpc_winsocket_create(SOCKET socket) {
   grpc_winsocket *r = gpr_malloc(sizeof(grpc_winsocket));
@@ -54,26 +55,44 @@ grpc_winsocket *grpc_winsocket_create(SOCKET socket) {
   return r;
 }
 
-static void shutdown_op(grpc_winsocket_callback_info *info) {
+/* Schedule a shutdown of the socket operations. Will call the pending
-  if (!info->cb) return;
+   operations to abort them. We need to do that this way because of the
-  grpc_iomgr_add_delayed_callback(info->cb, info->opaque, 0);
+   various callsites of that function, which happens to be in various
-}
+   mutex hold states, and that'd be unsafe to call them directly. */
-
 void grpc_winsocket_shutdown(grpc_winsocket *socket) {
-  shutdown_op(&socket->read_info);
+  gpr_mu_lock(&socket->state_mu);
-  shutdown_op(&socket->write_info);
+  if (socket->read_info.cb) {
+    grpc_iomgr_add_delayed_callback(socket->read_info.cb,
+                                    socket->read_info.opaque, 0);
+  }
+  if (socket->write_info.cb) {
+    grpc_iomgr_add_delayed_callback(socket->write_info.cb,
+                                    socket->write_info.opaque, 0);
+  }
+  gpr_mu_unlock(&socket->state_mu);
 }
 
-void grpc_winsocket_orphan(grpc_winsocket *socket) {
+/* Abandons a socket. Either we're going to queue it up for garbage collecting
-  grpc_iocp_socket_orphan(socket);
+   from the IO Completion Port thread, or destroy it immediately. Note that this
-  socket->orphan = 1;
+   mechanisms assumes that we're either always waiting for an operation, or we
+   explicitely know that we don't. If there is a future case where we can have
+   an "idle" socket which is neither trying to read or write, we'd start leaking
+   both memory and sockets. */
+void grpc_winsocket_orphan(grpc_winsocket *winsocket) {
+  SOCKET socket = winsocket->socket;
+  if (!winsocket->closed_early) {
+    grpc_iocp_socket_orphan(winsocket);
+  }
+  if (winsocket->closed_early) {
+    grpc_winsocket_destroy(winsocket);
+  }
+  closesocket(socket);
   grpc_iomgr_unref();
-  closesocket(socket->socket);
 }
 
-void grpc_winsocket_destroy(grpc_winsocket *socket) {
+void grpc_winsocket_destroy(grpc_winsocket *winsocket) {
-  gpr_mu_destroy(&socket->state_mu);
+  gpr_mu_destroy(&winsocket->state_mu);
-  gpr_free(socket);
+  gpr_free(winsocket);
 }
 
 #endif  /* GPR_WINSOCK_SOCKET */

src/core/iomgr/socket_windows.h

@@ -39,21 +39,43 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/atm.h>
 
+/* This holds the data for an outstanding read or write on a socket.
+   The mutex to protect the concurrent access to that data is the one
+   inside the winsocket wrapper. */
 typedef struct grpc_winsocket_callback_info {
   /* This is supposed to be a WSAOVERLAPPED, but in order to get that
-   * definition, we need to include ws2tcpip.h, which needs to be included
+     definition, we need to include ws2tcpip.h, which needs to be included
-   * from the top, otherwise it'll clash with a previous inclusion of
+     from the top, otherwise it'll clash with a previous inclusion of
-   * windows.h that in turns includes winsock.h. If anyone knows a way
+     windows.h that in turns includes winsock.h. If anyone knows a way
-   * to do it properly, feel free to send a patch.
+     to do it properly, feel free to send a patch. */
-   */
   OVERLAPPED overlapped;
+  /* The callback information for the pending operation. May be empty if the
+     caller hasn't registered a callback yet. */
   void(*cb)(void *opaque, int success);
   void *opaque;
+  /* A boolean to describe if the IO Completion Port got a notification for
+     that operation. This will happen if the operation completed before the
+     called had time to register a callback. We could avoid that behavior
+     altogether by forcing the caller to always register its callback before
+     proceeding queue an operation, but it is frequent for an IO Completion
+     Port to trigger quickly. This way we avoid a context switch for calling
+     the callback. We also simplify the read / write operations to avoid having
+     to hold a mutex for a long amount of time. */
   int has_pending_iocp;
+  /* The results of the overlapped operation. */
   DWORD bytes_transfered;
   int wsa_error;
 } grpc_winsocket_callback_info;
 
+/* This is a wrapper to a Windows socket. A socket can have one outstanding
+   read, and one outstanding write. Doing an asynchronous accept means waiting
+   for a read operation. Doing an asynchronous connect means waiting for a
+   write operation. These are completely abitrary ties between the operation
+   and the kind of event, because we can have one overlapped per pending
+   operation, whichever its nature is. So we could have more dedicated pending
+   operation callbacks for connect and listen. But given the scope of listen
+   and accept, we don't need to go to that extent and waste memory. Also, this
+   is closer to what happens in posix world. */
 typedef struct grpc_winsocket {
   SOCKET socket;
 
@@ -62,16 +84,35 @@ typedef struct grpc_winsocket {
 
   gpr_mu state_mu;
 
+  /* You can't add the same socket twice to the same IO Completion Port.
+     This prevents that. */
   int added_to_iocp;
+  /* A boolean to indicate that the caller has abandonned that socket, but
+     there is a pending operation that the IO Completion Port will have to
+     wait for. The socket will be collected at that time. */
   int orphan;
+  /* A boolean to indicate that the socket was already closed somehow, and
+     that no operation is going to be pending. Trying to abandon a socket in
+     that state won't result in an orphan, but will instead be destroyed
+     without further delay. We could avoid that boolean by adding one into
+     grpc_winsocket_callback_info describing that the operation is pending,
+     but that 1) waste memory more and 2) obfuscate the intent a bit more. */
+  int closed_early;
 } grpc_winsocket;
 
-/* Create a wrapped windows handle.
+/* Create a wrapped windows handle. This takes ownership of it, meaning that
-This takes ownership of closing it. */
+   it will be responsible for closing it. */
 grpc_winsocket *grpc_winsocket_create(SOCKET socket);
 
+/* Initiate an asynchronous shutdown of the socket. Will call off any pending
+   operation to cancel them. */
 void grpc_winsocket_shutdown(grpc_winsocket *socket);
+
+/* Abandon a socket. */
 void grpc_winsocket_orphan(grpc_winsocket *socket);
+
+/* Destroy a socket. Should only be called by the IO Completion Port thread,
+   or by grpc_winsocket_orphan if there's no pending operation. */
 void grpc_winsocket_destroy(grpc_winsocket *socket);
 
 #endif  /* GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H */

src/core/iomgr/tcp_client_windows.c

@@ -59,6 +59,7 @@ typedef struct {
   gpr_timespec deadline;
   grpc_alarm alarm;
   int refs;
+  int aborted;
 } async_connect;
 
 static void async_connect_cleanup(async_connect *ac) {
@@ -70,26 +71,31 @@ static void async_connect_cleanup(async_connect *ac) {
   }
 }
 
-static void on_alarm(void *acp, int success) {
+static void on_alarm(void *acp, int occured) {
   async_connect *ac = acp;
   gpr_mu_lock(&ac->mu);
-  if (ac->socket != NULL && success) {
+  /* If the alarm didn't occor, it got cancelled. */
+  if (ac->socket != NULL && occured) {
     grpc_winsocket_shutdown(ac->socket);
   }
   async_connect_cleanup(ac);
 }
 
-static void on_connect(void *acp, int success) {
+static void on_connect(void *acp, int from_iocp) {
   async_connect *ac = acp;
   SOCKET sock = ac->socket->socket;
   grpc_endpoint *ep = NULL;
   grpc_winsocket_callback_info *info = &ac->socket->write_info;
   void(*cb)(void *arg, grpc_endpoint *tcp) = ac->cb;
   void *cb_arg = ac->cb_arg;
+  int aborted;
 
   grpc_alarm_cancel(&ac->alarm);
 
-  if (success) {
+  gpr_mu_lock(&ac->mu);
+  aborted = ac->aborted;
+
+  if (from_iocp) {
     DWORD transfered_bytes = 0;
     DWORD flags;
     BOOL wsa_success = WSAGetOverlappedResult(sock, &info->overlapped,
@@ -107,20 +113,40 @@ static void on_connect(void *acp, int success) {
     }
   } else {
     gpr_log(GPR_ERROR, "on_connect is shutting down");
-    goto finish;
+    /* If the connection timeouts, we will still get a notification from
+       the IOCP whatever happens. So we're just going to flag that connection
+       as being in the process of being aborted, and wait for the IOCP. We
+       can't just orphan the socket now, because the IOCP might already have
+       gotten a successful connection, which is our worst-case scenario.
+       We need to call our callback now to respect the deadline. */
+    ac->aborted = 1;
+    gpr_mu_unlock(&ac->mu);
+    cb(cb_arg, NULL);
+    return;
   }
 
   abort();
 
 finish:
-  gpr_mu_lock(&ac->mu);
+  /* If we don't have an endpoint, it means the connection failed,
-  if (!ep) {
+     so it doesn't matter if it aborted or failed. We need to orphan
+     that socket. */
+  if (!ep || aborted) {
+    /* If the connection failed, it means we won't get an IOCP notification,
+       so let's flag it as already closed. But if the connection was aborted,
+       while we still got an endpoint, we have to wait for the IOCP to collect
+       that socket. So let's properly flag that. */
+    ac->socket->closed_early = !ep;
     grpc_winsocket_orphan(ac->socket);
   }
   async_connect_cleanup(ac);
-  cb(cb_arg, ep);
+  /* If the connection was aborted, the callback was already called when
+     the deadline was met. */
+  if (!aborted) cb(cb_arg, ep);
 }
 
+/* Tries to issue one async connection, then schedules both an IOCP
+   notification request for the connection, and one timeout alert. */
 void grpc_tcp_client_connect(void(*cb)(void *arg, grpc_endpoint *tcp),
                              void *arg, const struct sockaddr *addr,
                              int addr_len, gpr_timespec deadline) {
@@ -156,6 +182,8 @@ void grpc_tcp_client_connect(void(*cb)(void *arg, grpc_endpoint *tcp),
     goto failure;
   }
 
+  /* Grab the function pointer for ConnectEx for that specific socket.
+     It may change depending on the interface. */
   status = WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER,
                     &guid, sizeof(guid), &ConnectEx, sizeof(ConnectEx),
                     &ioctl_num_bytes, NULL, NULL);
@@ -178,6 +206,8 @@ void grpc_tcp_client_connect(void(*cb)(void *arg, grpc_endpoint *tcp),
   info = &socket->write_info;
   success = ConnectEx(sock, addr, addr_len, NULL, 0, NULL, &info->overlapped);
 
+  /* It wouldn't be unusual to get a success immediately. But we'll still get
+     an IOCP notification, so let's ignore it. */
   if (!success) {
     int error = WSAGetLastError();
     if (error != ERROR_IO_PENDING) {
@@ -192,6 +222,7 @@ void grpc_tcp_client_connect(void(*cb)(void *arg, grpc_endpoint *tcp),
   ac->socket = socket;
   gpr_mu_init(&ac->mu);
   ac->refs = 2;
+  ac->aborted = 0;
 
   grpc_alarm_init(&ac->alarm, deadline, on_alarm, ac, gpr_now());
   grpc_socket_notify_on_write(socket, on_connect, ac);
@@ -202,6 +233,7 @@ failure:
   gpr_log(GPR_ERROR, message, utf8_message);
   gpr_free(utf8_message);
   if (socket) {
+    socket->closed_early = 1;
     grpc_winsocket_orphan(socket);
   } else if (sock != INVALID_SOCKET) {
     closesocket(sock);

src/core/iomgr/tcp_posix.c

@@ -258,6 +258,8 @@ typedef struct {
   grpc_endpoint base;
   grpc_fd *em_fd;
   int fd;
+  int iov_size;            /* Number of slices to allocate per read attempt */
+  int finished_edge;
   size_t slice_size;
   gpr_refcount refcount;
 
@@ -315,9 +317,7 @@ static void call_read_cb(grpc_tcp *tcp, gpr_slice *slices, size_t nslices,
 
 #define INLINE_SLICE_BUFFER_SIZE 8
 #define MAX_READ_IOVEC 4
-static void grpc_tcp_handle_read(void *arg /* grpc_tcp */, int success) {
+static void grpc_tcp_continue_read(grpc_tcp *tcp) {
-  grpc_tcp *tcp = (grpc_tcp *)arg;
-  int iov_size = 1;
   gpr_slice static_read_slices[INLINE_SLICE_BUFFER_SIZE];
   struct msghdr msg;
   struct iovec iov[MAX_READ_IOVEC];
@@ -327,88 +327,103 @@ static void grpc_tcp_handle_read(void *arg /* grpc_tcp */, int success) {
   gpr_slice *final_slices;
   size_t final_nslices;
 
+  GPR_ASSERT(!tcp->finished_edge);
   GRPC_TIMER_BEGIN(GRPC_PTAG_HANDLE_READ, 0);
   slice_state_init(&read_state, static_read_slices, INLINE_SLICE_BUFFER_SIZE,
                    0);
 
-  if (!success) {
+  allocated_bytes = slice_state_append_blocks_into_iovec(
-    call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_SHUTDOWN);
+      &read_state, iov, tcp->iov_size, tcp->slice_size);
-    grpc_tcp_unref(tcp);
+
-    return;
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+  msg.msg_iov = iov;
+  msg.msg_iovlen = tcp->iov_size;
+  msg.msg_control = NULL;
+  msg.msg_controllen = 0;
+  msg.msg_flags = 0;
+
+  GRPC_TIMER_MARK(RECVMSG_BEGIN, 0);
+  do {
+    read_bytes = recvmsg(tcp->fd, &msg, 0);
+  } while (read_bytes < 0 && errno == EINTR);
+  GRPC_TIMER_MARK(RECVMSG_END, 0);
+
+  if (read_bytes < allocated_bytes) {
+    /* TODO(klempner): Consider a second read first, in hopes of getting a
+     * quick EAGAIN and saving a bunch of allocations. */
+    slice_state_remove_last(&read_state, read_bytes < 0
+                                             ? allocated_bytes
+                                             : allocated_bytes - read_bytes);
   }
 
-  /* TODO(klempner): Limit the amount we read at once. */
+  if (read_bytes < 0) {
-  for (;;) {
+    /* NB: After calling the user_cb a parallel call of the read handler may
-    allocated_bytes = slice_state_append_blocks_into_iovec(
+     * be running. */
-        &read_state, iov, iov_size, tcp->slice_size);
+    if (errno == EAGAIN) {
-
+      if (tcp->iov_size > 1) {
-    msg.msg_name = NULL;
+        tcp->iov_size /= 2;
-    msg.msg_namelen = 0;
-    msg.msg_iov = iov;
-    msg.msg_iovlen = iov_size;
-    msg.msg_control = NULL;
-    msg.msg_controllen = 0;
-    msg.msg_flags = 0;
-
-    GRPC_TIMER_BEGIN(GRPC_PTAG_RECVMSG, 0);
-    do {
-      read_bytes = recvmsg(tcp->fd, &msg, 0);
-    } while (read_bytes < 0 && errno == EINTR);
-    GRPC_TIMER_END(GRPC_PTAG_RECVMSG, 0);
-
-    if (read_bytes < allocated_bytes) {
-      /* TODO(klempner): Consider a second read first, in hopes of getting a
-       * quick EAGAIN and saving a bunch of allocations. */
-      slice_state_remove_last(&read_state, read_bytes < 0
-                                               ? allocated_bytes
-                                               : allocated_bytes - read_bytes);
-    }
-
-    if (read_bytes < 0) {
-      /* NB: After calling the user_cb a parallel call of the read handler may
-       * be running. */
-      if (errno == EAGAIN) {
-        if (slice_state_has_available(&read_state)) {
-          /* TODO(klempner): We should probably do the call into the application
-             without all this junk on the stack */
-          /* FIXME(klempner): Refcount properly */
-          slice_state_transfer_ownership(&read_state, &final_slices,
-                                         &final_nslices);
-          call_read_cb(tcp, final_slices, final_nslices, GRPC_ENDPOINT_CB_OK);
-          slice_state_destroy(&read_state);
-          grpc_tcp_unref(tcp);
-        } else {
-          /* Spurious read event, consume it here */
-          slice_state_destroy(&read_state);
-          grpc_fd_notify_on_read(tcp->em_fd, &tcp->read_closure);
-        }
-      } else {
-        /* TODO(klempner): Log interesting errors */
-        call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_ERROR);
-        slice_state_destroy(&read_state);
-        grpc_tcp_unref(tcp);
       }
-      return;
-    } else if (read_bytes == 0) {
-      /* 0 read size ==> end of stream */
       if (slice_state_has_available(&read_state)) {
-        /* there were bytes already read: pass them up to the application */
+        /* TODO(klempner): We should probably do the call into the application
+           without all this junk on the stack */
+        /* FIXME(klempner): Refcount properly */
         slice_state_transfer_ownership(&read_state, &final_slices,
                                        &final_nslices);
-        call_read_cb(tcp, final_slices, final_nslices, GRPC_ENDPOINT_CB_EOF);
+        tcp->finished_edge = 1;
+        call_read_cb(tcp, final_slices, final_nslices, GRPC_ENDPOINT_CB_OK);
+        slice_state_destroy(&read_state);
+        grpc_tcp_unref(tcp);
       } else {
-        call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_EOF);
+        /* We've consumed the edge, request a new one */
+        slice_state_destroy(&read_state);
+        grpc_fd_notify_on_read(tcp->em_fd, &tcp->read_closure);
       }
+    } else {
+      /* TODO(klempner): Log interesting errors */
+      call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_ERROR);
       slice_state_destroy(&read_state);
       grpc_tcp_unref(tcp);
-      return;
-    } else if (iov_size < MAX_READ_IOVEC) {
-      ++iov_size;
     }
+  } else if (read_bytes == 0) {
+    /* 0 read size ==> end of stream */
+    if (slice_state_has_available(&read_state)) {
+      /* there were bytes already read: pass them up to the application */
+      slice_state_transfer_ownership(&read_state, &final_slices,
+                                     &final_nslices);
+      call_read_cb(tcp, final_slices, final_nslices, GRPC_ENDPOINT_CB_EOF);
+    } else {
+      call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_EOF);
+    }
+    slice_state_destroy(&read_state);
+    grpc_tcp_unref(tcp);
+  } else {
+    if (tcp->iov_size < MAX_READ_IOVEC) {
+      ++tcp->iov_size;
+    }
+    GPR_ASSERT(slice_state_has_available(&read_state));
+    slice_state_transfer_ownership(&read_state, &final_slices,
+                                   &final_nslices);
+    call_read_cb(tcp, final_slices, final_nslices, GRPC_ENDPOINT_CB_OK);
+    slice_state_destroy(&read_state);
+    grpc_tcp_unref(tcp);
   }
+
   GRPC_TIMER_END(GRPC_PTAG_HANDLE_READ, 0);
 }
 
+static void grpc_tcp_handle_read(void *arg /* grpc_tcp */, int success) {
+  grpc_tcp *tcp = (grpc_tcp *)arg;
+  GPR_ASSERT(!tcp->finished_edge);
+
+  if (!success) {
+    call_read_cb(tcp, NULL, 0, GRPC_ENDPOINT_CB_SHUTDOWN);
+    grpc_tcp_unref(tcp);
+  } else {
+    grpc_tcp_continue_read(tcp);
+  }
+}
+
 static void grpc_tcp_notify_on_read(grpc_endpoint *ep, grpc_endpoint_read_cb cb,
                                     void *user_data) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
@@ -416,7 +431,12 @@ static void grpc_tcp_notify_on_read(grpc_endpoint *ep, grpc_endpoint_read_cb cb,
   tcp->read_cb = cb;
   tcp->read_user_data = user_data;
   gpr_ref(&tcp->refcount);
-  grpc_fd_notify_on_read(tcp->em_fd, &tcp->read_closure);
+  if (tcp->finished_edge) {
+    tcp->finished_edge = 0;
+    grpc_fd_notify_on_read(tcp->em_fd, &tcp->read_closure);
+  } else {
+    grpc_iomgr_add_callback(grpc_tcp_handle_read, tcp);
+  }
 }
 
 #define MAX_WRITE_IOVEC 16
@@ -554,6 +574,8 @@ grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd, size_t slice_size) {
   tcp->read_user_data = NULL;
   tcp->write_user_data = NULL;
   tcp->slice_size = slice_size;
+  tcp->iov_size = 1;
+  tcp->finished_edge = 1;
   slice_state_init(&tcp->write_state, NULL, 0, 0);
   /* paired with unref in grpc_tcp_destroy */
   gpr_ref_init(&tcp->refcount, 1);

src/core/iomgr/tcp_server_windows.c

@@ -55,11 +55,17 @@
 
 /* one listening port */
 typedef struct server_port {
-  gpr_uint8 addresses[sizeof(struct sockaddr_in6) * 2 + 32];
+  /* 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. */
   grpc_winsocket *socket;
   grpc_tcp_server *server;
+  /* The cached AcceptEx for that port. */
   LPFN_ACCEPTEX AcceptEx;
+  int shutting_down;
 } server_port;
 
 /* the overall server */
@@ -79,6 +85,8 @@ struct grpc_tcp_server {
   size_t port_capacity;
 };
 
+/* Public function. Allocates the proper data structures to hold a
+   grpc_tcp_server. */
 grpc_tcp_server *grpc_tcp_server_create(void) {
   grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
   gpr_mu_init(&s->mu);
@@ -92,24 +100,30 @@ grpc_tcp_server *grpc_tcp_server_create(void) {
   return s;
 }
 
+/* Public function. Stops and destroys a grpc_tcp_server. */
 void grpc_tcp_server_destroy(grpc_tcp_server *s,
                              void (*shutdown_done)(void *shutdown_done_arg),
                              void *shutdown_done_arg) {
   size_t i;
   gpr_mu_lock(&s->mu);
-  /* shutdown all fd's */
+  /* First, shutdown all fd's. This will queue abortion calls for all
+     of the pending accepts. */
   for (i = 0; i < s->nports; i++) {
-    grpc_winsocket_shutdown(s->ports[i].socket);
+    server_port *sp = &s->ports[i];
+    grpc_winsocket_shutdown(sp->socket);
   }
-  /* wait while that happens */
+  /* This happens asynchronously. Wait while that happens. */
   while (s->active_ports) {
     gpr_cv_wait(&s->cv, &s->mu, gpr_inf_future);
   }
   gpr_mu_unlock(&s->mu);
 
-  /* delete ALL the things */
+  /* 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];
+    sp->socket->closed_early = 1;
     grpc_winsocket_orphan(sp->socket);
   }
   gpr_free(s->ports);
@@ -120,7 +134,7 @@ void grpc_tcp_server_destroy(grpc_tcp_server *s,
   }
 }
 
-/* Prepare a recently-created socket for listening. */
+/* Prepare (bind) a recently-created socket for listening. */
 static int prepare_socket(SOCKET sock, const struct sockaddr *addr,
                           int addr_len) {
   struct sockaddr_storage sockname_temp;
@@ -168,8 +182,11 @@ error:
   return -1;
 }
 
-static void on_accept(void *arg, int success);
+/* start_accept will reference that for the IOCP notification request. */
+static void on_accept(void *arg, int from_iocp);
 
+/* 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(server_port *port) {
   SOCKET sock = INVALID_SOCKET;
   char *message;
@@ -191,12 +208,13 @@ static void start_accept(server_port *port) {
     goto failure;
   }
 
-  /* TODO(jtattermusch): probably a race here, we regularly get use-after-free on server shutdown */
+  /* Start the "accept" asynchronously. */
-  GPR_ASSERT(port->socket != (grpc_winsocket*)0xfeeefeee);
   success = port->AcceptEx(port->socket->socket, sock, port->addresses, 0,
                            addrlen, addrlen, &bytes_received,
                            &port->socket->read_info.overlapped);
 
+  /* It is possible to get an accept immediately without delay. However, we
+     will still get an IOCP notification for it. So let's just ignore it. */
   if (!success) {
     int error = WSAGetLastError();
     if (error != ERROR_IO_PENDING) {
@@ -205,6 +223,8 @@ static void start_accept(server_port *port) {
     }
   }
 
+  /* We're ready to do the accept. Calling grpc_socket_notify_on_read may
+     immediately process an accept that happened in the meantime. */
   port->new_socket = sock;
   grpc_socket_notify_on_read(port->socket, on_accept, port);
   return;
@@ -216,14 +236,30 @@ failure:
   if (sock != INVALID_SOCKET) closesocket(sock);
 }
 
-/* event manager callback when reads are ready */
+/* Event manager callback when reads are ready. */
-static void on_accept(void *arg, int success) {
+static void on_accept(void *arg, int from_iocp) {
   server_port *sp = arg;
   SOCKET sock = sp->new_socket;
   grpc_winsocket_callback_info *info = &sp->socket->read_info;
   grpc_endpoint *ep = NULL;
 
-  if (success) {
+  /* The shutdown sequence is done in two parts. This is the second
+     part here, acknowledging the IOCP notification, and doing nothing
+     else, especially not queuing a new accept. */
+  if (sp->shutting_down) {
+    GPR_ASSERT(from_iocp);
+    sp->shutting_down = 0;
+    gpr_mu_lock(&sp->server->mu);
+    if (0 == --sp->server->active_ports) {
+      gpr_cv_broadcast(&sp->server->cv);
+    }
+    gpr_mu_unlock(&sp->server->mu);
+    return;
+  }
+
+  if (from_iocp) {
+    /* The IOCP notified us of a completed operation. Let's grab the results,
+       and act accordingly. */
     DWORD transfered_bytes = 0;
     DWORD flags;
     BOOL wsa_success = WSAGetOverlappedResult(sock, &info->overlapped,
@@ -237,18 +273,31 @@ static void on_accept(void *arg, int success) {
       ep = grpc_tcp_create(grpc_winsocket_create(sock));
     }
   } else {
-    closesocket(sock);
+    /* If we're not notified from the IOCP, it means we are asked to shutdown.
-    gpr_mu_lock(&sp->server->mu);
+       This will initiate that shutdown. Calling closesocket will trigger an
-    if (0 == --sp->server->active_ports) {
+       IOCP notification, that will call this function a second time, from
-      gpr_cv_broadcast(&sp->server->cv);
+       the IOCP thread. Of course, this only works if the socket was, in fact,
+       listening. If that's not the case, we'd wait indefinitely. That's a bit
+       of a degenerate case, but it can happen if you create a server, but
+       don't start it. So let's support that by recursing once. */
+    sp->shutting_down = 1;
+    sp->new_socket = INVALID_SOCKET;
+    if (sock != INVALID_SOCKET) {
+      closesocket(sock);
+    } else {
+      on_accept(sp, 1);
     }
-    gpr_mu_unlock(&sp->server->mu);
+    return;
   }
 
+  /* The only time we should call our callback, is where we successfully
+     managed to accept a connection, and created an endpoint. */
   if (ep) sp->server->cb(sp->server->cb_arg, ep);
-  if (success) {
+  /* As we were notified from the IOCP of one and exactly one accept,
-    start_accept(sp);
+      the former socked we created has now either been destroy or assigned
-  }
+      to the new connection. We need to create a new one for the next
+      connection. */
+  start_accept(sp);
 }
 
 static int add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
@@ -262,6 +311,8 @@ static int add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
 
   if (sock == INVALID_SOCKET) return -1;
 
+  /* 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. */
   status =
       WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid, sizeof(guid),
                &AcceptEx, sizeof(AcceptEx), &ioctl_num_bytes, NULL, NULL);
@@ -286,7 +337,9 @@ static int add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
     sp = &s->ports[s->nports++];
     sp->server = s;
     sp->socket = grpc_winsocket_create(sock);
+    sp->shutting_down = 0;
     sp->AcceptEx = AcceptEx;
+    sp->new_socket = INVALID_SOCKET;
     GPR_ASSERT(sp->socket);
     gpr_mu_unlock(&s->mu);
   }

src/core/iomgr/tcp_windows.c

@@ -76,8 +76,11 @@ int grpc_tcp_prepare_socket(SOCKET sock) {
 }
 
 typedef struct grpc_tcp {
+  /* This is our C++ class derivation emulation. */
   grpc_endpoint base;
+  /* The one socket this endpoint is using. */
   grpc_winsocket *socket;
+  /* Refcounting how many operations are in progress. */
   gpr_refcount refcount;
 
   grpc_endpoint_read_cb read_cb;
@@ -90,6 +93,10 @@ typedef struct grpc_tcp {
   gpr_slice_buffer write_slices;
   int outstanding_write;
 
+  /* The IO Completion Port runs from another thread. We need some mechanism
+     to protect ourselves when requesting a shutdown. */
+  gpr_mu mu;
+  int shutting_down;
 } grpc_tcp;
 
 static void tcp_ref(grpc_tcp *tcp) {
@@ -100,11 +107,13 @@ static void tcp_unref(grpc_tcp *tcp) {
   if (gpr_unref(&tcp->refcount)) {
     gpr_slice_buffer_destroy(&tcp->write_slices);
     grpc_winsocket_orphan(tcp->socket);
+    gpr_mu_destroy(&tcp->mu);
     gpr_free(tcp);
   }
 }
 
-static void on_read(void *tcpp, int success) {
+/* Asynchronous callback from the IOCP, or the background thread. */
+static void on_read(void *tcpp, int from_iocp) {
   grpc_tcp *tcp = (grpc_tcp *) tcpp;
   grpc_winsocket *socket = tcp->socket;
   gpr_slice sub;
@@ -114,22 +123,32 @@ static void on_read(void *tcpp, int success) {
   grpc_endpoint_read_cb cb = tcp->read_cb;
   grpc_winsocket_callback_info *info = &socket->read_info;
   void *opaque = tcp->read_user_data;
+  int do_abort = 0;
+
+  gpr_mu_lock(&tcp->mu);
+  if (!from_iocp || tcp->shutting_down) {
+    /* If we are here with from_iocp set to true, it means we got raced to
+    shutting down the endpoint. No actual abort callback will happen
+    though, so we're going to do it from here. */
+    do_abort = 1;
+  }
+  gpr_mu_unlock(&tcp->mu);
 
-  GPR_ASSERT(tcp->outstanding_read);
+  if (do_abort) {
-
+    if (from_iocp) gpr_slice_unref(tcp->read_slice);
-  if (!success) {
     tcp_unref(tcp);
     cb(opaque, NULL, 0, GRPC_ENDPOINT_CB_SHUTDOWN);
     return;
   }
 
-  tcp->outstanding_read = 0;
+  GPR_ASSERT(tcp->outstanding_read);
 
   if (socket->read_info.wsa_error != 0) {
     char *utf8_message = gpr_format_message(info->wsa_error);
     gpr_log(GPR_ERROR, "ReadFile overlapped error: %s", utf8_message);
     gpr_free(utf8_message);
     status = GRPC_ENDPOINT_CB_ERROR;
+    socket->closed_early = 1;
   } else {
     if (info->bytes_transfered != 0) {
       sub = gpr_slice_sub(tcp->read_slice, 0, info->bytes_transfered);
@@ -141,6 +160,9 @@ static void on_read(void *tcpp, int success) {
       status = GRPC_ENDPOINT_CB_EOF;
     }
   }
+
+  tcp->outstanding_read = 0;
+
   tcp_unref(tcp);
   cb(opaque, slice, nslices, status);
 }
@@ -157,6 +179,7 @@ static void win_notify_on_read(grpc_endpoint *ep,
   WSABUF buffer;
 
   GPR_ASSERT(!tcp->outstanding_read);
+  GPR_ASSERT(!tcp->shutting_down);
   tcp_ref(tcp);
   tcp->outstanding_read = 1;
   tcp->read_cb = cb;
@@ -167,10 +190,12 @@ static void win_notify_on_read(grpc_endpoint *ep,
   buffer.len = GPR_SLICE_LENGTH(tcp->read_slice);
   buffer.buf = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
 
+  /* First let's try a synchronous, non-blocking read. */
   status = WSARecv(tcp->socket->socket, &buffer, 1, &bytes_read, &flags,
                    NULL, NULL);
   info->wsa_error = status == 0 ? 0 : WSAGetLastError();
 
+  /* Did we get data immediately ? Yay. */
   if (info->wsa_error != WSAEWOULDBLOCK) {
     info->bytes_transfered = bytes_read;
     /* This might heavily recurse. */
@@ -178,6 +203,7 @@ static void win_notify_on_read(grpc_endpoint *ep,
     return;
   }
 
+  /* Otherwise, let's retry, by queuing a read. */
   memset(&tcp->socket->read_info.overlapped, 0, sizeof(OVERLAPPED));
   status = WSARecv(tcp->socket->socket, &buffer, 1, &bytes_read, &flags,
                    &info->overlapped, NULL);
@@ -191,30 +217,53 @@ static void win_notify_on_read(grpc_endpoint *ep,
 
   if (error != WSA_IO_PENDING) {
     char *utf8_message = gpr_format_message(WSAGetLastError());
-    __debugbreak();
+    gpr_log(GPR_ERROR, "WSARecv error: %s - this means we're going to leak.",
-    gpr_log(GPR_ERROR, "WSARecv error: %s", utf8_message);
+            utf8_message);
     gpr_free(utf8_message);
-    /* would the IO completion port be called anyway... ? Let's assume not. */
+    /* I'm pretty sure this is a very bad situation there. Hence the log.
+       What will happen now is that the socket will neither wait for read
+       or write, unless the caller retry, which is unlikely, but I am not
+       sure if that's guaranteed. And there might also be a write pending.
+       This means that the future orphanage of that socket will be in limbo,
+       and we're going to leak it. I have no idea what could cause this
+       specific case however, aside from a parameter error from our call.
+       Normal read errors would actually happen during the overlapped
+       operation, which is the supported way to go for that. */
     tcp->outstanding_read = 0;
     tcp_unref(tcp);
     cb(arg, NULL, 0, GRPC_ENDPOINT_CB_ERROR);
+    /* Per the comment above, I'm going to treat that case as a hard failure
+       for now, and leave the option to catch that and debug. */
+    __debugbreak();
     return;
   }
 
   grpc_socket_notify_on_read(tcp->socket, on_read, tcp);
 }
 
-static void on_write(void *tcpp, int success) {
+/* Asynchronous callback from the IOCP, or the background thread. */
+static void on_write(void *tcpp, int from_iocp) {
   grpc_tcp *tcp = (grpc_tcp *) tcpp;
   grpc_winsocket *handle = tcp->socket;
   grpc_winsocket_callback_info *info = &handle->write_info;
   grpc_endpoint_cb_status status = GRPC_ENDPOINT_CB_OK;
   grpc_endpoint_write_cb cb = tcp->write_cb;
   void *opaque = tcp->write_user_data;
+  int do_abort = 0;
+
+  gpr_mu_lock(&tcp->mu);
+  if (!from_iocp || tcp->shutting_down) {
+    /* If we are here with from_iocp set to true, it means we got raced to
+        shutting down the endpoint. No actual abort callback will happen
+        though, so we're going to do it from here. */
+    do_abort = 1;
+  }
+  gpr_mu_unlock(&tcp->mu);
 
   GPR_ASSERT(tcp->outstanding_write);
 
-  if (!success) {
+  if (do_abort) {
+    if (from_iocp) gpr_slice_buffer_reset_and_unref(&tcp->write_slices);
     tcp_unref(tcp);
     cb(opaque, GRPC_ENDPOINT_CB_SHUTDOWN);
     return;
@@ -225,6 +274,7 @@ static void on_write(void *tcpp, int success) {
     gpr_log(GPR_ERROR, "WSASend overlapped error: %s", utf8_message);
     gpr_free(utf8_message);
     status = GRPC_ENDPOINT_CB_ERROR;
+    tcp->socket->closed_early = 1;
   } else {
     GPR_ASSERT(info->bytes_transfered == tcp->write_slices.length);
   }
@@ -236,6 +286,7 @@ static void on_write(void *tcpp, int success) {
   cb(opaque, status);
 }
 
+/* Initiates a write. */
 static grpc_endpoint_write_status win_write(grpc_endpoint *ep,
                                             gpr_slice *slices, size_t nslices,
                                             grpc_endpoint_write_cb cb,
@@ -251,11 +302,13 @@ static grpc_endpoint_write_status win_write(grpc_endpoint *ep,
   WSABUF *buffers = local_buffers;
 
   GPR_ASSERT(!tcp->outstanding_write);
+  GPR_ASSERT(!tcp->shutting_down);
   tcp_ref(tcp);
 
   tcp->outstanding_write = 1;
   tcp->write_cb = cb;
   tcp->write_user_data = arg;
+
   gpr_slice_buffer_addn(&tcp->write_slices, slices, nslices);
 
   if (tcp->write_slices.count > GPR_ARRAY_SIZE(local_buffers)) {
@@ -268,10 +321,14 @@ static grpc_endpoint_write_status win_write(grpc_endpoint *ep,
     buffers[i].buf = (char *)GPR_SLICE_START_PTR(tcp->write_slices.slices[i]);
   }
 
+  /* First, let's try a synchronous, non-blocking write. */
   status = WSASend(socket->socket, buffers, tcp->write_slices.count,
                    &bytes_sent, 0, NULL, NULL);
   info->wsa_error = status == 0 ? 0 : WSAGetLastError();
 
+  /* We would kind of expect to get a WSAEWOULDBLOCK here, especially on a busy
+     connection that has its send queue filled up. But if we don't, then we can
+     avoid doing an async write operation at all. */
   if (info->wsa_error != WSAEWOULDBLOCK) {
     grpc_endpoint_write_status ret = GRPC_ENDPOINT_WRITE_ERROR;
     if (status == 0) {
@@ -289,25 +346,42 @@ static grpc_endpoint_write_status win_write(grpc_endpoint *ep,
     return ret;
   }
 
+  /* If we got a WSAEWOULDBLOCK earlier, then we need to re-do the same
+     operation, this time asynchronously. */
   memset(&socket->write_info.overlapped, 0, sizeof(OVERLAPPED));
   status = WSASend(socket->socket, buffers, tcp->write_slices.count,
                    &bytes_sent, 0, &socket->write_info.overlapped, NULL);
   if (allocated) gpr_free(allocated);
 
+  /* It is possible the operation completed then. But we'd still get an IOCP
+     notification. So let's ignore it and wait for the IOCP. */
   if (status != 0) {
     int error = WSAGetLastError();
     if (error != WSA_IO_PENDING) {
       char *utf8_message = gpr_format_message(WSAGetLastError());
-      __debugbreak();
+      gpr_log(GPR_ERROR, "WSASend error: %s - this means we're going to leak.",
-      gpr_log(GPR_ERROR, "WSASend error: %s", utf8_message);
+              utf8_message);
       gpr_free(utf8_message);
-      /* would the IO completion port be called anyway ? Let's assume not. */
+    /* I'm pretty sure this is a very bad situation there. Hence the log.
+       What will happen now is that the socket will neither wait for read
+       or write, unless the caller retry, which is unlikely, but I am not
+       sure if that's guaranteed. And there might also be a read pending.
+       This means that the future orphanage of that socket will be in limbo,
+       and we're going to leak it. I have no idea what could cause this
+       specific case however, aside from a parameter error from our call.
+       Normal read errors would actually happen during the overlapped
+       operation, which is the supported way to go for that. */
       tcp->outstanding_write = 0;
       tcp_unref(tcp);
+      /* Per the comment above, I'm going to treat that case as a hard failure
+         for now, and leave the option to catch that and debug. */
+      __debugbreak();
       return GRPC_ENDPOINT_WRITE_ERROR;
     }
   }
 
+  /* As all is now setup, we can now ask for the IOCP notification. It may
+     trigger the callback immediately however, but no matter. */
   grpc_socket_notify_on_write(socket, on_write, tcp);
   return GRPC_ENDPOINT_WRITE_PENDING;
 }
@@ -317,9 +391,20 @@ static void win_add_to_pollset(grpc_endpoint *ep, grpc_pollset *pollset) {
   grpc_iocp_add_socket(tcp->socket);
 }
 
+/* Initiates a shutdown of the TCP endpoint. This will queue abort callbacks
+   for the potential read and write operations. It is up to the caller to
+   guarantee this isn't called in parallel to a read or write request, so
+   we're not going to protect against these. However the IO Completion Port
+   callback will happen from another thread, so we need to protect against
+   concurrent access of the data structure in that regard. */
 static void win_shutdown(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *) ep;
+  gpr_mu_lock(&tcp->mu);
+  /* At that point, what may happen is that we're already inside the IOCP
+     callback. See the comments in on_read and on_write. */
+  tcp->shutting_down = 1;
   grpc_winsocket_shutdown(tcp->socket);
+  gpr_mu_unlock(&tcp->mu);
 }
 
 static void win_destroy(grpc_endpoint *ep) {
@@ -336,6 +421,7 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket) {
   memset(tcp, 0, sizeof(grpc_tcp));
   tcp->base.vtable = &vtable;
   tcp->socket = socket;
+  gpr_mu_init(&tcp->mu);
   gpr_slice_buffer_init(&tcp->write_slices);
   gpr_ref_init(&tcp->refcount, 1);
   return &tcp->base;

src/core/profiling/basic_timers.c

@@ -45,15 +45,10 @@
 #include <grpc/support/thd.h>
 #include <stdio.h>
 
-typedef enum {
+typedef enum { BEGIN = '{', END = '}', MARK = '.' } marker_type;
-  BEGIN = '{',
-  END = '}',
-  MARK = '.'
-} marker_type;
 
 typedef struct grpc_timer_entry {
   grpc_precise_clock tm;
-  gpr_thd_id thd;
   int tag;
   marker_type type;
   void* id;
@@ -61,71 +56,35 @@ typedef struct grpc_timer_entry {
   int line;
 } grpc_timer_entry;
 
-struct grpc_timers_log {
+#define MAX_COUNT (1024 * 1024 / sizeof(grpc_timer_entry))
-  gpr_mu mu;
-  grpc_timer_entry* log;
-  int num_entries;
-  int capacity;
-  int capacity_limit;
-  FILE* fp;
-};
 
-grpc_timers_log* grpc_timers_log_global = NULL;
+static __thread grpc_timer_entry log[MAX_COUNT];
+static __thread int count;
 
-static grpc_timers_log* grpc_timers_log_create(int capacity_limit, FILE* dump) {
+static void log_report() {
-  grpc_timers_log* log = gpr_malloc(sizeof(*log));
-
-  /* TODO (vpai): Allow allocation below limit */
-  log->log = gpr_malloc(capacity_limit * sizeof(*log->log));
-
-  /* TODO (vpai): Improve concurrency, do per-thread logging? */
-  gpr_mu_init(&log->mu);
-
-  log->num_entries = 0;
-  log->capacity = log->capacity_limit = capacity_limit;
-
-  log->fp = dump;
-
-  return log;
-}
-
-static void log_report_locked(grpc_timers_log* log) {
-  FILE* fp = log->fp;
   int i;
-  for (i = 0; i < log->num_entries; i++) {
+  for (i = 0; i < count; i++) {
-    grpc_timer_entry* entry = &(log->log[i]);
+    grpc_timer_entry* entry = &(log[i]);
-    fprintf(fp, "GRPC_LAT_PROF ");
+    printf("GRPC_LAT_PROF " GRPC_PRECISE_CLOCK_FORMAT " %p %c %d %p %s %d\n",
-    grpc_precise_clock_print(&entry->tm, fp);
+           GRPC_PRECISE_CLOCK_PRINTF_ARGS(&entry->tm),
-    fprintf(fp, " %p %c %d %p %s %d\n", (void*)(gpr_intptr)entry->thd, entry->type, entry->tag,
+           (void*)(gpr_intptr)gpr_thd_currentid(), entry->type, entry->tag,
-            entry->id, entry->file, entry->line);
+           entry->id, entry->file, entry->line);
   }
 
   /* Now clear out the log */
-  log->num_entries = 0;
+  count = 0;
 }
 
-static void grpc_timers_log_destroy(grpc_timers_log* log) {
+static void grpc_timers_log_add(int tag, marker_type type, void* id,
-  gpr_mu_lock(&log->mu);
-  log_report_locked(log);
-  gpr_mu_unlock(&log->mu);
-
-  gpr_free(log->log);
-  gpr_mu_destroy(&log->mu);
-
-  gpr_free(log);
-}
-
-static void grpc_timers_log_add(grpc_timers_log* log, int tag, marker_type type, void* id,
                                 const char* file, int line) {
   grpc_timer_entry* entry;
 
   /* TODO (vpai) : Improve concurrency */
-  gpr_mu_lock(&log->mu);
+  if (count == MAX_COUNT) {
-  if (log->num_entries == log->capacity_limit) {
+    log_report();
-    log_report_locked(log);
   }
 
-  entry = &log->log[log->num_entries++];
+  entry = &log[count++];
 
   grpc_precise_clock_now(&entry->tm);
   entry->tag = tag;
@@ -133,39 +92,31 @@ static void grpc_timers_log_add(grpc_timers_log* log, int tag, marker_type type,
   entry->id = id;
   entry->file = file;
   entry->line = line;
-  entry->thd = gpr_thd_currentid();
-
-  gpr_mu_unlock(&log->mu);
 }
 
 /* Latency profiler API implementation. */
 void grpc_timer_add_mark(int tag, void* id, const char* file, int line) {
   if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {
-    grpc_timers_log_add(grpc_timers_log_global, tag, MARK, id, file, line);
+    grpc_timers_log_add(tag, MARK, id, file, line);
   }
 }
 
-void grpc_timer_begin(int tag, void* id, const char *file, int line) {
+void grpc_timer_begin(int tag, void* id, const char* file, int line) {
   if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {
-    grpc_timers_log_add(grpc_timers_log_global, tag, BEGIN, id, file, line);
+    grpc_timers_log_add(tag, BEGIN, id, file, line);
   }
 }
 
-void grpc_timer_end(int tag, void* id, const char *file, int line) {
+void grpc_timer_end(int tag, void* id, const char* file, int line) {
   if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {
-    grpc_timers_log_add(grpc_timers_log_global, tag, END, id, file, line);
+    grpc_timers_log_add(tag, END, id, file, line);
   }
 }
 
 /* Basic profiler specific API functions. */
-void grpc_timers_global_init(void) {
+void grpc_timers_global_init(void) {}
-  grpc_timers_log_global = grpc_timers_log_create(100000, stdout);
-}
-
-void grpc_timers_global_destroy(void) {
-  grpc_timers_log_destroy(grpc_timers_log_global);
-}
 
+void grpc_timers_global_destroy(void) {}
 
 #else  /* !GRPC_BASIC_PROFILER */
 void grpc_timers_global_init(void) {}

src/core/profiling/timers.h

@@ -41,9 +41,9 @@ extern "C" {
 void grpc_timers_global_init(void);
 void grpc_timers_global_destroy(void);
 
-void grpc_timer_add_mark(int tag, void* id, const char *file, int line);
+void grpc_timer_add_mark(int tag, void *id, const char *file, int line);
-void grpc_timer_begin(int tag, void* id, const char *file, int line);
+void grpc_timer_begin(int tag, void *id, const char *file, int line);
-void grpc_timer_end(int tag, void* id, const char *file, int line);
+void grpc_timer_end(int tag, void *id, const char *file, int line);
 
 enum grpc_profiling_tags {
   /* Any GRPC_PTAG_* >= than the threshold won't generate any profiling mark. */
@@ -74,13 +74,16 @@ enum grpc_profiling_tags {
 #if !(defined(GRPC_STAP_PROFILER) + defined(GRPC_BASIC_PROFILER))
 /* No profiling. No-op all the things. */
 #define GRPC_TIMER_MARK(tag, id) \
-  do {} while(0)
+  do {                           \
+  } while (0)
 
 #define GRPC_TIMER_BEGIN(tag, id) \
-  do {} while(0)
+  do {                            \
+  } while (0)
 
 #define GRPC_TIMER_END(tag, id) \
-  do {} while(0)
+  do {                          \
+  } while (0)
 
 #else /* at least one profiler requested... */
 /* ... hopefully only one. */
@@ -94,14 +97,14 @@ enum grpc_profiling_tags {
     grpc_timer_add_mark(tag, ((void *)(gpr_intptr)(id)), __FILE__, __LINE__); \
   }
 
-#define GRPC_TIMER_BEGIN(tag, id)                                             \
+#define GRPC_TIMER_BEGIN(tag, id)                                          \
-  if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {                                     \
+  if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {                                  \
-    grpc_timer_begin(tag, ((void *)(gpr_intptr)(id)), __FILE__, __LINE__);    \
+    grpc_timer_begin(tag, ((void *)(gpr_intptr)(id)), __FILE__, __LINE__); \
   }
 
-#define GRPC_TIMER_END(tag, id)                                               \
+#define GRPC_TIMER_END(tag, id)                                          \
-  if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {                                     \
+  if (tag < GRPC_PTAG_IGNORE_THRESHOLD) {                                \
-    grpc_timer_end(tag, ((void *)(gpr_intptr)(id)), __FILE__, __LINE__);      \
+    grpc_timer_end(tag, ((void *)(gpr_intptr)(id)), __FILE__, __LINE__); \
   }
 
 #ifdef GRPC_STAP_PROFILER
@@ -109,9 +112,7 @@ enum grpc_profiling_tags {
 #endif /* GRPC_STAP_PROFILER */
 
 #ifdef GRPC_BASIC_PROFILER
-typedef struct grpc_timers_log grpc_timers_log;
+/* Empty placeholder for now. */
-
-extern grpc_timers_log *grpc_timers_log_global;
 #endif /* GRPC_BASIC_PROFILER */
 
 #endif /* at least one profiler requested. */

src/core/profiling/timers_preciseclock.h

@@ -43,7 +43,7 @@ typedef long long int grpc_precise_clock;
 #if defined(__i386__)
 static void grpc_precise_clock_now(grpc_precise_clock *clk) {
   grpc_precise_clock ret;
-  __asm__ volatile("rdtsc" : "=A" (ret) );
+  __asm__ volatile("rdtsc" : "=A"(ret));
   *clk = ret;
 }
 
@@ -51,7 +51,7 @@ static void grpc_precise_clock_now(grpc_precise_clock *clk) {
 #elif defined(__x86_64__) || defined(__amd64__)
 static void grpc_precise_clock_now(grpc_precise_clock *clk) {
   unsigned long long low, high;
-  __asm__ volatile("rdtsc" : "=a" (low), "=d" (high));
+  __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
   *clk = (high << 32) | low;
 }
 #endif
@@ -61,19 +61,21 @@ static void grpc_precise_clock_init() {
   time_t start = time(NULL);
   grpc_precise_clock start_time;
   grpc_precise_clock end_time;
-  while (time(NULL) == start);
+  while (time(NULL) == start)
+    ;
   grpc_precise_clock_now(&start_time);
-  while (time(NULL) == start+1);
+  while (time(NULL) == start + 1)
+    ;
   grpc_precise_clock_now(&end_time);
   cycles_per_second = end_time - start_time;
 }
 static double grpc_precise_clock_scaling_factor() {
-	gpr_once_init(&precise_clock_init, grpc_precise_clock_init);
+  gpr_once_init(&precise_clock_init, grpc_precise_clock_init);
-	return 1e6 / cycles_per_second;
+  return 1e6 / cycles_per_second;
-}
-static void grpc_precise_clock_print(const grpc_precise_clock* clk, FILE* fp) {
-  fprintf(fp, "%f", *clk * grpc_precise_clock_scaling_factor());
 }
+#define GRPC_PRECISE_CLOCK_FORMAT "%f"
+#define GRPC_PRECISE_CLOCK_PRINTF_ARGS(clk) \
+  (*(clk)*grpc_precise_clock_scaling_factor())
 #else
 typedef struct grpc_precise_clock grpc_precise_clock;
 struct grpc_precise_clock {
@@ -82,6 +84,9 @@ struct grpc_precise_clock {
 static void grpc_precise_clock_now(grpc_precise_clock* clk) {
   clk->clock = gpr_now();
 }
+#define GRPC_PRECISE_CLOCK_FORMAT "%ld.%09d"
+#define GRPC_PRECISE_CLOCK_PRINTF_ARGS(clk) \
+  (clk)->clock.tv_sec, (clk)->clock.tv_nsec
 static void grpc_precise_clock_print(const grpc_precise_clock* clk, FILE* fp) {
   fprintf(fp, "%ld.%09d", clk->clock.tv_sec, clk->clock.tv_nsec);
 }

src/core/surface/call.c

@@ -34,6 +34,7 @@
 #include "src/core/surface/call.h"
 #include "src/core/channel/channel_stack.h"
 #include "src/core/iomgr/alarm.h"
+#include "src/core/profiling/timers.h"
 #include "src/core/support/string.h"
 #include "src/core/surface/byte_buffer_queue.h"
 #include "src/core/surface/channel.h"
@@ -405,14 +406,14 @@ static void lock(grpc_call *call) { gpr_mu_lock(&call->mu); }
 
 static int need_more_data(grpc_call *call) {
   return is_op_live(call, GRPC_IOREQ_RECV_INITIAL_METADATA) ||
-         is_op_live(call, GRPC_IOREQ_RECV_MESSAGE) ||
+         (is_op_live(call, GRPC_IOREQ_RECV_MESSAGE) && grpc_bbq_empty(&call->incoming_queue)) ||
          is_op_live(call, GRPC_IOREQ_RECV_TRAILING_METADATA) ||
          is_op_live(call, GRPC_IOREQ_RECV_STATUS) ||
          is_op_live(call, GRPC_IOREQ_RECV_STATUS_DETAILS) ||
          (is_op_live(call, GRPC_IOREQ_RECV_CLOSE) &&
           grpc_bbq_empty(&call->incoming_queue)) ||
          (call->write_state == WRITE_STATE_INITIAL && !call->is_client &&
-          call->read_state != READ_STATE_STREAM_CLOSED);
+          call->read_state < READ_STATE_GOT_INITIAL_METADATA);
 }
 
 static void unlock(grpc_call *call) {
@@ -685,6 +686,7 @@ static int add_slice_to_message(grpc_call *call, gpr_slice slice) {
 static void call_on_done_recv(void *pc, int success) {
   grpc_call *call = pc;
   size_t i;
+  GRPC_TIMER_MARK(CALL_ON_DONE_RECV_BEGIN, 0);
   lock(call);
   call->receiving = 0;
   if (success) {
@@ -729,6 +731,7 @@ static void call_on_done_recv(void *pc, int success) {
   unlock(call);
 
   GRPC_CALL_INTERNAL_UNREF(call, "receiving", 0);
+  GRPC_TIMER_MARK(CALL_ON_DONE_RECV_END, 0);
 }
 
 static grpc_mdelem_list chain_metadata_from_app(grpc_call *call, size_t count,

src/core/surface/init.c

@@ -59,6 +59,7 @@ void grpc_init(void) {
     grpc_register_tracer("channel", &grpc_trace_channel);
     grpc_register_tracer("surface", &grpc_surface_trace);
     grpc_register_tracer("http", &grpc_http_trace);
+    grpc_register_tracer("flowctl", &grpc_flowctl_trace);
     grpc_register_tracer("batch", &grpc_trace_batch);
     grpc_security_pre_init();
     grpc_iomgr_init();

src/core/transport/chttp2_transport.c

@@ -37,6 +37,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "src/core/profiling/timers.h"
 #include "src/core/support/string.h"
 #include "src/core/transport/chttp2/frame_data.h"
 #include "src/core/transport/chttp2/frame_goaway.h"
@@ -64,6 +65,7 @@
 #define CLIENT_CONNECT_STRLEN 24
 
 int grpc_http_trace = 0;
+int grpc_flowctl_trace = 0;
 
 typedef struct transport transport;
 typedef struct stream stream;
@@ -74,6 +76,12 @@ typedef struct stream stream;
   else                    \
   stmt
 
+#define FLOWCTL_TRACE(t, obj, dir, id, delta) \
+  if (!grpc_flowctl_trace)                    \
+    ;                                         \
+  else                                        \
+  flowctl_trace(t, #dir, obj->dir##_window, id, delta)
+
 /* streams are kept in various linked lists depending on what things need to
    happen to them... this enum labels each list */
 typedef enum {
@@ -382,6 +390,12 @@ static void add_to_pollset_locked(transport *t, grpc_pollset *pollset);
 static void perform_op_locked(transport *t, stream *s, grpc_transport_op *op);
 static void add_metadata_batch(transport *t, stream *s);
 
+static void flowctl_trace(transport *t, const char *flow, gpr_int32 window,
+                          gpr_uint32 id, gpr_int32 delta) {
+  gpr_log(GPR_DEBUG, "HTTP:FLOW:%p:%d:%s: %d + %d = %d", t, id, flow, window,
+          delta, window + delta);
+}
+
 /*
  * CONSTRUCTION/DESTRUCTION/REFCOUNTING
  */
@@ -772,6 +786,8 @@ static void unlock(transport *t) {
   grpc_stream_op_buffer nuke_now;
   const grpc_transport_callbacks *cb = t->cb;
 
+  GRPC_TIMER_MARK(HTTP2_UNLOCK_BEGIN, 0);
+
   grpc_sopb_init(&nuke_now);
   if (t->nuke_later_sopb.nops) {
     grpc_sopb_swap(&nuke_now, &t->nuke_later_sopb);
@@ -820,6 +836,8 @@ static void unlock(transport *t) {
   /* finally unlock */
   gpr_mu_unlock(&t->mu);
 
+  GRPC_TIMER_MARK(HTTP2_UNLOCK_CLEANUP, 0);
+
   /* perform some callbacks if necessary */
   for (i = 0; i < num_goaways; i++) {
     cb->goaway(t->cb_user_data, &t->base, goaways[i].status, goaways[i].debug);
@@ -850,6 +868,8 @@ static void unlock(transport *t) {
   grpc_sopb_destroy(&nuke_now);
 
   gpr_free(goaways);
+
+  GRPC_TIMER_MARK(HTTP2_UNLOCK_END, 0);
 }
 
 /*
@@ -896,6 +916,8 @@ static int prepare_write(transport *t) {
     window_delta = grpc_chttp2_preencode(
         s->outgoing_sopb->ops, &s->outgoing_sopb->nops,
         GPR_MIN(t->outgoing_window, s->outgoing_window), &s->writing_sopb);
+    FLOWCTL_TRACE(t, t, outgoing, 0, -(gpr_int64)window_delta);
+    FLOWCTL_TRACE(t, s, outgoing, s->id, -(gpr_int64)window_delta);
     t->outgoing_window -= window_delta;
     s->outgoing_window -= window_delta;
 
@@ -924,6 +946,7 @@ static int prepare_write(transport *t) {
     if (!s->read_closed && window_delta) {
       gpr_slice_buffer_add(
           &t->outbuf, grpc_chttp2_window_update_create(s->id, window_delta));
+      FLOWCTL_TRACE(t, s, incoming, s->id, window_delta);
       s->incoming_window += window_delta;
     }
   }
@@ -933,6 +956,7 @@ static int prepare_write(transport *t) {
     window_delta = t->connection_window_target - t->incoming_window;
     gpr_slice_buffer_add(&t->outbuf,
                          grpc_chttp2_window_update_create(0, window_delta));
+    FLOWCTL_TRACE(t, t, incoming, 0, window_delta);
     t->incoming_window += window_delta;
   }
 
@@ -1259,6 +1283,8 @@ static grpc_chttp2_parse_error update_incoming_window(transport *t, stream *s) {
     return GRPC_CHTTP2_CONNECTION_ERROR;
   }
 
+  FLOWCTL_TRACE(t, t, incoming, 0, -(gpr_int64)t->incoming_frame_size);
+  FLOWCTL_TRACE(t, s, incoming, s->id, -(gpr_int64)t->incoming_frame_size);
   t->incoming_window -= t->incoming_frame_size;
   s->incoming_window -= t->incoming_frame_size;
 
@@ -1608,6 +1634,7 @@ static int parse_frame_slice(transport *t, gpr_slice slice, int is_last) {
         for (i = 0; i < t->stream_map.count; i++) {
           stream *s = (stream *)(t->stream_map.values[i]);
           int was_window_empty = s->outgoing_window <= 0;
+          FLOWCTL_TRACE(t, s, outgoing, s->id, st.initial_window_update);
           s->outgoing_window += st.initial_window_update;
           if (was_window_empty && s->outgoing_window > 0 && s->outgoing_sopb &&
               s->outgoing_sopb->nops > 0) {
@@ -1626,6 +1653,7 @@ static int parse_frame_slice(transport *t, gpr_slice slice, int is_last) {
                                       GRPC_CHTTP2_FLOW_CONTROL_ERROR),
                             GRPC_CHTTP2_FLOW_CONTROL_ERROR, NULL, 1);
             } else {
+              FLOWCTL_TRACE(t, s, outgoing, s->id, st.window_update);
               s->outgoing_window += st.window_update;
               /* if this window update makes outgoing ops writable again,
                  flag that */
@@ -1640,6 +1668,7 @@ static int parse_frame_slice(transport *t, gpr_slice slice, int is_last) {
           if (!is_window_update_legal(st.window_update, t->outgoing_window)) {
             drop_connection(t);
           } else {
+            FLOWCTL_TRACE(t, t, outgoing, 0, st.window_update);
             t->outgoing_window += st.window_update;
           }
         }

src/core/transport/chttp2_transport.h

@@ -38,6 +38,7 @@
 #include "src/core/transport/transport.h"
 
 extern int grpc_http_trace;
+extern int grpc_flowctl_trace;
 
 void grpc_create_chttp2_transport(grpc_transport_setup_callback setup,
                                   void *arg,

tools/gce_setup/cloud_prod_runner.sh

@@ -38,7 +38,7 @@ main() {
   source grpc_docker.sh
   test_cases=(large_unary empty_unary ping_pong client_streaming server_streaming cancel_after_begin cancel_after_first_response)
   auth_test_cases=(service_account_creds compute_engine_creds jwt_token_creds)
-  clients=(cxx java go ruby node csharp_mono python)
+  clients=(cxx java go ruby node csharp_mono python php)
   for test_case in "${test_cases[@]}"
   do
     for client in "${clients[@]}"

tools/run_tests/run_sanity.sh

@@ -37,3 +37,14 @@ export TEST=true
 cd `dirname $0`/../..
 
 ./tools/buildgen/generate_projects.sh
+
+submodules=`mktemp`
+
+git submodule > $submodules
+
+diff -u $submodules - << EOF
+ 05b155ff59114735ec8cd089f669c4c3d8f59029 third_party/gflags (v2.1.0-45-g05b155f)
+ 3df69d3aefde7671053d4e3c242b228e5d79c83f third_party/openssl (OpenSSL_1_0_2a)
+ 644a6a1da71385e9d7a7a26b3476c93fdd71788c third_party/protobuf (v3.0.0-alpha-1-35-g644a6a1)
+ 50893291621658f355bc5b4d450a8d06a563053d third_party/zlib (v1.2.8)
+EOF

vsprojects/openssl.props

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ImportGroup Label="PropertySheets" />
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup />
+  <ItemDefinitionGroup>
+    <Link>
+      <AdditionalDependencies>ssleay32.lib;libeay32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(MSBuildProjectDirectory)\..\packages\grpc.dependencies.openssl.1.0.2.2\build\native\lib\$(PlatformToolset)\$(Platform)\$(Configuration)\static;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup />
+</Project>

vsprojects/zlib.props

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ImportGroup Label="PropertySheets" />
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup />
+  <ItemDefinitionGroup>
+    <Link>
+      <AdditionalDependencies>zlib.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalLibraryDirectories>$(MSBuildProjectDirectory)\..\packages\grpc.dependencies.zlib.1.2.8.9\build\native\lib\$(PlatformToolset)\$(Platform)\$(Configuration)\static\cdecl;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup />
+</Project>