From Jonathan L. Fix ser-unix.c timing out when there was no timeout.

2 files changed, 33 insertions, 39 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bc83460..24b1811 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+Tue Mar 28 18:19:50 2000  Andrew Cagney  <cagney@b1.cygnus.com>
+
+	From 2000-03-20 Jonathan Larmour <jlarmour@redhat.co.uk>:
+        * ser-unix.c (do_unix_readchar): Reorganise to be more robust,
+        particularly ensuring it can't return SERIAL_TIMEOUT when told
+        not to time out.
+
 2000-03-24  Daniel Berlin  <dan@cgsoftware.com>
 
 	* gdbtypes.c (_initialize_gdbtypes): Add "set debug overload",
diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index 919c9fd..47b6647 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -910,9 +910,9 @@ do_unix_readchar (serial_t scb, int timeout)
      each time through the loop.
 
      Also, timeout = 0 means to poll, so we just set the delta to 0, so we
-     will only go through the loop once. */
+     will only go through the loop once. timeout < 0 means to wait forever. */
 
-  delta = (timeout == 0 ? 0 : 1);
+  delta = (timeout <= 0 ? 0 : 1);
   while (1)
     {
 
@@ -928,51 +928,38 @@ do_unix_readchar (serial_t scb, int timeout)
 	    return SERIAL_TIMEOUT;
 	}
 
-      status = ser_unix_wait_for (scb, delta);
+      status = ser_unix_wait_for (scb, timeout < 0 ? timeout : delta);
       timeout -= delta;
 
-      /* If we got a character or an error back from wait_for, then we can 
-         break from the loop before the timeout is completed. */
+      /* If we got an error back from wait_for, then we can return */
 
-      if (status != SERIAL_TIMEOUT)
-	{
-	  break;
-	}
+      if (status == SERIAL_ERROR)
+        return status;
 
-      /* If we have exhausted the original timeout, then generate
-         a SERIAL_TIMEOUT, and pass it out of the loop. */
+      status = read (scb->fd, scb->buf, BUFSIZ);
 
-      else if (timeout == 0)
-	{
-	  status = SERIAL_TIMEOUT;
-	  break;
+      if (status <= 0)
+        {
+          if (status == 0)
+            {
+              if (timeout != 0)
+                continue;
+              else
+                return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
+					   distinguish between EOF & timeouts
+					   someday] */
+            }
+	  else if (errno == EINTR)
+            continue;
+          else
+	    return SERIAL_ERROR;	/* Got an error from read */
 	}
-    }
-
-  if (status < 0)
-    return status;
 
-  while (1)
-    {
-      status = read (scb->fd, scb->buf, BUFSIZ);
-      if (status != -1 || errno != EINTR)
-	break;
-    }
-
-  if (status <= 0)
-    {
-      if (status == 0)
-	return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
-				   distinguish between EOF & timeouts
-				   someday] */
-      else
-	return SERIAL_ERROR;	/* Got an error from read */
+      scb->bufcnt = status;
+      scb->bufcnt--;
+      scb->bufp = scb->buf;
+      return *scb->bufp++;
     }
-
-  scb->bufcnt = status;
-  scb->bufcnt--;
-  scb->bufp = scb->buf;
-  return *scb->bufp++;
 }
 
 /* Perform operations common to both old and new readchar. */