Note about multiplexing.

[rsync/rsync.git] / io.c

diff --git a/io.c b/io.c
index 20fc2ba..eca02fa 100644 (file)
--- a/io.c
+++ b/io.c
@@ -1,5 +1,6 @@
-/* 
-   Copyright (C) Andrew Tridgell 1996
+/* -*- c-file-style: "linux" -*-
+   
+   Copyright (C) 1996-2001 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
    
    This program is free software; you can redistribute it and/or modify
@@ -39,16 +40,10 @@ extern int verbose;
 extern int io_timeout;
 extern struct stats stats;
 
-static int buffer_f_in = -1;
 static int io_error_fd = -1;
 
 static void read_loop(int fd, char *buf, int len);
 
-void setup_readbuffer(int f_in)
-{
-       buffer_f_in = f_in;
-}
-
 static void check_timeout(void)
 {
        extern int am_server, am_daemon;
@@ -65,7 +60,7 @@ static void check_timeout(void)
 
        if (last_io && io_timeout && (t-last_io) >= io_timeout) {
                if (!am_server && !am_daemon) {
-                       rprintf(FERROR,"io timeout after %d second - exiting\n", 
+                       rprintf(FERROR,"io timeout after %d seconds - exiting\n", 
                                (int)(t-last_io));
                }
                exit_cleanup(RERR_TIMEOUT);
@@ -109,9 +104,15 @@ static void read_error_fd(void)
 
 static int no_flush;
 
-/* read from a socket with IO timeout. return the number of
-   bytes read. If no bytes can be read then exit, never return
-   a number <= 0 */
+/*
+ * Read from a socket with IO timeout. return the number of bytes
+ * read. If no bytes can be read then exit, never return a number <= 0.
+ *
+ * TODO: If the remote shell connection fails, then current versions actually
+ * report an "unexpected EOF" error here.  Since it's a fairly common mistake
+ * to try to use rsh when ssh is required, we should trap that: if we fail
+ * to read any data at all, we should give a better explanation.
+ */
 static int read_timeout(int fd, char *buf, int len)
 {
        int n, ret=0;
@@ -323,11 +324,7 @@ unsigned char read_byte(int f)
        return c;
 }
 
-
-
-/* write len bytes to fd, possibly reading from buffer_f_in if set
-   in order to unclog the pipe. don't return until all len
-   bytes have been written */
+/* write len bytes to fd */
 static void writefd_unbuffered(int fd,char *buf,int len)
 {
        int total = 0;
@@ -382,11 +379,15 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 
                        if (ret == -1 && 
                            (errno == EWOULDBLOCK || errno == EAGAIN)) {
+                               msleep(1);
                                continue;
                        }
 
                        if (ret <= 0) {
-                               rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
+                               rprintf(FERROR,
+                                       "error writing %d unbuffered bytes"
+                                       " - exiting: %s\n", len,
+                                       strerror(errno));
                                exit_cleanup(RERR_STREAMIO);
                        }
 
@@ -464,6 +465,8 @@ void io_flush(void)
        io_buffer_count = 0;
 }
 
+
+/* XXX: fd is ignored, which seems a little strange. */
 void io_end_buffering(int fd)
 {
        io_flush();
@@ -473,6 +476,17 @@ void io_end_buffering(int fd)
        }
 }
 
+/* some OSes have a bug where an exit causes the pending writes on
+   a socket to be flushed. Do an explicit shutdown to try to prevent this */
+void io_shutdown(void)
+{
+       if (multiplex_out_fd != -1) close(multiplex_out_fd);
+       if (io_error_fd != -1) close(io_error_fd);
+       multiplex_out_fd = -1;
+       io_error_fd = -1;
+}
+
+
 static void writefd(int fd,char *buf,int len)
 {
        stats.total_written += len;
@@ -503,6 +517,11 @@ void write_int(int f,int32 x)
        writefd(f,b,4);
 }
 
+
+/*
+ * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
+ * 64-bit types on this platform.
+ */
 void write_longint(int f, int64 x)
 {
        extern int remote_version;
@@ -623,8 +642,3 @@ void io_multiplexing_close(void)
        io_multiplexing_out = 0;
 }
 
-void io_close_input(int fd)
-{
-       buffer_f_in = -1;
-}
-