Merge branch 'lukas/erl_interface/send-inf-tmo-fix/OTP-17358' into maint-21

* lukas/erl_interface/send-inf-tmo-fix/OTP-17358:
  ei: Correctly check timeout value vs EI_SCLBK_INF_TMO

3 files changed, 34 insertions, 12 deletions

diff --git a/lib/erl_interface/doc/src/ei_connect.xml b/lib/erl_interface/doc/src/ei_connect.xml
index 2dd0a285fe..8402787c67 100644
--- a/lib/erl_interface/doc/src/ei_connect.xml
+++ b/lib/erl_interface/doc/src/ei_connect.xml
@@ -1073,7 +1073,7 @@ self->num = fd;
     </func>
 
     <func>
-      <name since=""><ret>int</ret><nametext>ei_send_reg_encoded_tmo(int fd, const erlang_pid *from, const char *to, const char *buf, int len)</nametext></name>
+      <name since=""><ret>int</ret><nametext>ei_send_reg_encoded_tmo(int fd, const erlang_pid *from, const char *to, const char *buf, int len, unsigned timeout_ms)</nametext></name>
       <fsummary>Obsolete function to send a message to a registered name with
         time-out.</fsummary>
       <desc>
diff --git a/lib/erl_interface/src/misc/ei_portio.c b/lib/erl_interface/src/misc/ei_portio.c
index bccc86c1b1..a076e1ef7d 100644
--- a/lib/erl_interface/src/misc/ei_portio.c
+++ b/lib/erl_interface/src/misc/ei_portio.c
@@ -404,6 +404,12 @@ static int writev_ctx_t__(ei_socket_callbacks *cbs, void *ctx,
     do {
         error = cbs->writev(ctx, (const void *) iov, iovcnt, len, ms);
     } while (error == EINTR);
+
+    /* It should not be possible for writev_ctx_t__ to return EAGAIN,
+       because when the fd is set in non-blocking we always do a select on
+       the fd before trying to write. And if we do not do the select the fd
+       is always in blocking mode. */
+
     return error;
 }
 
@@ -417,7 +423,8 @@ int ei_writev_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx,
     struct iovec *current_iov;
     int current_iovcnt;
     int fd, error;
-    int basic;
+    int non_blocking = !(cbs->flags & EI_SCLBK_FLG_FULL_IMPL) &&
+        ms != EI_SCLBK_INF_TMO;
 
     if (!cbs->writev)
         return ENOTSUP;
@@ -426,12 +433,10 @@ int ei_writev_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx,
     if (error)
         return error;
 
-    basic = !(cbs->flags & EI_SCLBK_FLG_FULL_IMPL);
-    
     for (sum = 0, i = 0; i < iovcnt; ++i) {
 	sum += iov[i].iov_len;
     }
-    if (basic && ms != 0U) {
+    if (non_blocking) {
 	SET_NONBLOCKING(fd);
     } 
     current_iovcnt = iovcnt;
@@ -442,7 +447,7 @@ int ei_writev_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx,
 	error = writev_ctx_t__(cbs, ctx, current_iov, current_iovcnt, &i, ms);
         if (error) {
             *len = done;
-	    if (ms != 0U) {
+	    if (non_blocking) {
 		SET_BLOCKING(fd);
 	    }    
 	    if (iov_base != NULL) {
@@ -478,7 +483,7 @@ int ei_writev_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx,
 	    break;
 	}
     } 
-    if (basic && ms != 0U) {
+    if (non_blocking) {
 	SET_BLOCKING(fd);
     }
     if (iov_base != NULL) {
@@ -752,9 +757,10 @@ int ei_read_fill_ctx__(ei_socket_callbacks *cbs, void *ctx, char* buf, ssize_t *
 int ei_write_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx, const char *buf, ssize_t *len, unsigned ms)
 {
     ssize_t tot = *len, done = 0;
-    int error, fd = -1, basic = !(cbs->flags & EI_SCLBK_FLG_FULL_IMPL);
+    int error, fd = -1, non_blocking = !(cbs->flags & EI_SCLBK_FLG_FULL_IMPL) &&
+        ms != EI_SCLBK_INF_TMO;
     
-    if (basic && ms != 0U) {
+    if (non_blocking) {
         error = EI_GET_FD__(cbs, ctx, &fd);
         if (error)
             return error;
@@ -765,14 +771,14 @@ int ei_write_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx, const char *buf,
 	error = write_ctx_t__(cbs, ctx, buf+done, &write_len, ms);
         if (error) {
             *len = done;
-	    if (basic && ms != 0U) {
+	    if (non_blocking) {
 		SET_BLOCKING(fd);
 	    }    
 	    return error;
 	}
 	done += write_len;
     } while (done < tot);
-    if (basic && ms != 0U) {
+    if (non_blocking) {
 	SET_BLOCKING(fd);
     }
     *len = done;
diff --git a/lib/erl_interface/test/ei_connect_SUITE.erl b/lib/erl_interface/test/ei_connect_SUITE.erl
index 75b6bf18da..a219d35ed6 100644
--- a/lib/erl_interface/test/ei_connect_SUITE.erl
+++ b/lib/erl_interface/test/ei_connect_SUITE.erl
@@ -28,6 +28,7 @@
          init_per_testcase/2,
          ei_send/1,
          ei_reg_send/1,
+         ei_reg_send_large/1,
          ei_format_pid/1,
          ei_rpc/1,
          rpc_test/1,
@@ -42,7 +43,7 @@ suite() ->
      {timetrap, {seconds, 30}}].
 
 all() -> 
-    [ei_send, ei_reg_send, ei_rpc, ei_format_pid, ei_send_funs,
+    [ei_send, ei_reg_send, ei_reg_send_large, ei_rpc, ei_format_pid, ei_send_funs,
      ei_threaded_send, ei_set_get_tracelevel].
 
 init_per_testcase(Case, Config) ->
@@ -105,6 +106,21 @@ ei_reg_send(Config) when is_list(Config) ->
     runner:recv_eot(P),
     ok.
 
+ei_reg_send_large(Config) when is_list(Config) ->
+    P = runner:start(Config, ?interpret),
+    0 = ei_connect_init(P, 42, erlang:get_cookie(), 0),
+    {ok,Fd} = ei_connect(P, node()),
+
+    ARegName = a_strange_registred_name,
+    register(ARegName, self()),
+    ok = ei_reg_send(P, Fd, ARegName, AMsg={another,[strange],message,
+                                            <<0:(32*1024*1024*8)>>}),
+    receive AMsg -> ok end,
+
+    runner:send_eot(P),
+    runner:recv_eot(P),
+    ok.
+
 ei_threaded_send(Config) when is_list(Config) ->
     Einode = filename:join(proplists:get_value(data_dir, Config), "einode"),
     N = 15,