Experiment: Win32 sockets in non-synchronous mode.

This is an attempt to address PR#4466, #5325, #6771.  Not tested yet.

1 files changed, 30 insertions, 34 deletions

diff --git a/byterun/io.c b/byterun/io.c
index 60504f5862..48c9c00542 100644
--- a/byterun/io.c
+++ b/byterun/io.c
@@ -33,6 +33,7 @@
 #include "caml/memory.h"
 #include "caml/misc.h"
 #include "caml/mlvalues.h"
+#include "caml/osdeps.h"
 #include "caml/signals.h"
 #include "caml/sys.h"
 
@@ -158,25 +159,12 @@ CAMLexport int caml_channel_binary_mode(struct channel *channel)
 #define EWOULDBLOCK (-1)
 #endif
 
-static int do_write(int fd, char *p, int n)
+static int do_write(int fd, int flags, char *p, int n)
 {
   int retcode;
-
-again:
   caml_enter_blocking_section();
-  retcode = write(fd, p, n);
+  retcode = caml_write_fd(fd, flags & CHANNEL_FLAG_FROM_SOCKET, p, n);
   caml_leave_blocking_section();
-  if (retcode == -1) {
-    if (errno == EINTR) goto again;
-    if ((errno == EAGAIN || errno == EWOULDBLOCK) && n > 1) {
-      /* We couldn't do a partial write here, probably because
-         n <= PIPE_BUF and POSIX says that writes of less than
-         PIPE_BUF characters must be atomic.
-         We first try again with a partial write of 1 character.
-         If that fails too, we'll raise Sys_blocked_io below. */
-      n = 1; goto again;
-    }
-  }
   if (retcode == -1) caml_sys_io_error(NO_ARG);
   CAMLassert (retcode > 0);
   return retcode;
@@ -194,7 +182,7 @@ CAMLexport int caml_flush_partial(struct channel *channel)
   towrite = channel->curr - channel->buff;
   CAMLassert (towrite >= 0);
   if (towrite > 0) {
-    written = do_write(channel->fd, channel->buff, towrite);
+    written = do_write(channel->fd, channel->flags, channel->buff, towrite);
     channel->offset += written;
     if (written < towrite)
       memmove(channel->buff, channel->buff + written, towrite - written);
@@ -238,7 +226,7 @@ CAMLexport int caml_putblock(struct channel *channel, char *p, intnat len)
        fits to buffer and write the buffer */
     memmove(channel->curr, p, free);
     towrite = channel->end - channel->buff;
-    written = do_write(channel->fd, channel->buff, towrite);
+    written = do_write(channel->fd, channel->flags, channel->buff, towrite);
     if (written < towrite)
       memmove(channel->buff, channel->buff + written, towrite - written);
     channel->offset += written;
@@ -277,30 +265,28 @@ CAMLexport file_offset caml_pos_out(struct channel *channel)
 
 /* Input */
 
-/* caml_do_read is exported for Cash */
-CAMLexport int caml_do_read(int fd, char *p, unsigned int n)
+static int do_read(int fd, int flags, char *p, unsigned int n)
 {
   int retcode;
 
-  do {
-    caml_enter_blocking_section();
-    retcode = read(fd, p, n);
-#if defined(_WIN32)
-    if (retcode == -1 && errno == ENOMEM && n > 16384){
-      retcode = read(fd, p, 16384);
-    }
-#endif
-    caml_leave_blocking_section();
-  } while (retcode == -1 && errno == EINTR);
+  caml_enter_blocking_section();
+  retcode = caml_read_fd(fd, flags & CHANNEL_FLAG_FROM_SOCKET, p, n);
   if (retcode == -1) caml_sys_io_error(NO_ARG);
   return retcode;
 }
 
+/* caml_do_read is exported for Cash */
+CAMLexport int caml_do_read(int fd, char *p, unsigned int n)
+{
+  return do_read(fd, 0, p, n);
+}
+
 CAMLexport unsigned char caml_refill(struct channel *channel)
 {
   int n;
 
-  n = caml_do_read(channel->fd, channel->buff, channel->end - channel->buff);
+  n = do_read(channel->fd, channel->flags, 
+              channel->buff, channel->end - channel->buff);
   if (n == 0) caml_raise_end_of_file();
   channel->offset += n;
   channel->max = channel->buff + n;
@@ -337,8 +323,8 @@ CAMLexport int caml_getblock(struct channel *channel, char *p, intnat len)
     channel->curr += avail;
     return avail;
   } else {
-    nread = caml_do_read(channel->fd, channel->buff,
-                         channel->end - channel->buff);
+    nread = do_read(channel->fd, channel->flags, channel->buff,
+                    channel->end - channel->buff);
     channel->offset += nread;
     channel->max = channel->buff + nread;
     if (n > nread) n = nread;
@@ -407,7 +393,8 @@ CAMLexport intnat caml_input_scan_line(struct channel *channel)
         return -(channel->max - channel->curr);
       }
       /* Fill the buffer as much as possible */
-      n = caml_do_read(channel->fd, channel->max, channel->end - channel->max);
+      n = do_read(channel->fd, channel->flags, 
+                  channel->max, channel->end - channel->max);
       if (n == 0) {
         /* End-of-file encountered. Return the number of characters in the
            buffer, with negative sign since we haven't encountered
@@ -603,6 +590,15 @@ CAMLprim value caml_ml_set_binary_mode(value vchannel, value mode)
 {
 #if defined(_WIN32) || defined(__CYGWIN__)
   struct channel * channel = Channel(vchannel);
+#if defined(_WIN32)
+  /* The implementation of [caml_read_fd] and [caml_write_fd] in win32.c
+     doesn't support socket I/O with CRLF conversion. */
+  if (channel->flags & CHANNEL_FLAG_FROM_SOCKET != 0
+      && ! Bool_val(mode)) {
+    errno = EINVAL;
+    caml_sys_error(NO_ARG);
+  }
+#endif
   if (setmode(channel->fd, Bool_val(mode) ? O_BINARY : O_TEXT) == -1)
     caml_sys_error(NO_ARG);
 #endif
@@ -778,7 +774,7 @@ CAMLprim value caml_ml_input(value vchannel, value buff, value vstart,
     channel->curr += avail;
     n = avail;
   } else {
-    nread = caml_do_read(channel->fd, channel->buff,
+    nread = do_read(channel->fd, channel->flags, channel->buff,
                          channel->end - channel->buff);
     channel->offset += nread;
     channel->max = channel->buff + nread;