From: Julian Seward <jseward@acm.org>
Date: Sun, 3 Nov 2002 11:44:36 +0000 (+0000)
Subject: Robustification of logging to a socket.  If the listener process dies
X-Git-Tag: svn/VALGRIND_1_9_4~174
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=72edb7fc20d693b8395b7c4e3cea171cd44a6bb2;p=thirdparty%2Fvalgrind.git

Robustification of logging to a socket.  If the listener process dies
or for whatever reason hangs up the connection, don't let valgrind
get SIGPIPE; instead just switch back to spewing messages on stderr.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1273
---

diff --git a/coregrind/vg_include.h b/coregrind/vg_include.h
index 2793b9ada3..d9ff25bca5 100644
--- a/coregrind/vg_include.h
+++ b/coregrind/vg_include.h
@@ -875,11 +875,21 @@ extern Int VG_(select)( Int n,
 extern Int VG_(nanosleep)( const struct vki_timespec *req, 
                            struct vki_timespec *rem );
 
-extern Int  VG_(write_socket)( Int sd, void *msg, Int count );
+extern Int VG_(write_socket)( Int sd, void *msg, Int count );
 
 /* --- Connecting over the network --- */
 extern Int VG_(connect_via_socket)( UChar* str );
 
+
+/* ---------------------------------------------------------------------
+   Exports of vg_message.c
+   ------------------------------------------------------------------ */
+
+/* Low-level -- send bytes directly to the message sink.  Do not
+   use. */
+extern void VG_(send_bytes_to_logging_sink) ( Char* msg, Int nbytes );
+
+
 /* ---------------------------------------------------------------------
    Definitions for the JITter (vg_translate.c, vg_to_ucode.c,
    vg_from_ucode.c).
diff --git a/coregrind/vg_main.c b/coregrind/vg_main.c
index 30fcac7363..85eebc174e 100644
--- a/coregrind/vg_main.c
+++ b/coregrind/vg_main.c
@@ -1102,14 +1102,18 @@ static void process_cmd_line_options ( void )
 	 }
          if (eventually_logfile_fd == -2) {
             VG_(message)(Vg_UserMsg, 
-               "Failed to connect to logging server `%s'; giving up",
+               "valgrind: failed to connect to logging server `%s'.",
                VG_(clo_logfile_name) ); 
-            VG_(bad_option)(
-               "--logsocket= (timeout during connect)");
-	 }
-	 vg_assert(eventually_logfile_fd > 0);
-         VG_(clo_logfile_fd) = eventually_logfile_fd;
-         VG_(logging_to_filedes) = False;
+            VG_(message)(Vg_UserMsg, 
+                "Log messages will sent to stderr instead." );
+            VG_(message)(Vg_UserMsg, 
+                "" );
+            /* We don't change anything here. */
+	 } else {
+            vg_assert(eventually_logfile_fd > 0);
+            VG_(clo_logfile_fd) = eventually_logfile_fd;
+            VG_(logging_to_filedes) = False;
+         }
          break;
       }
 
diff --git a/coregrind/vg_messages.c b/coregrind/vg_messages.c
index 02e79c8e2c..5f1ba2bfc9 100644
--- a/coregrind/vg_messages.c
+++ b/coregrind/vg_messages.c
@@ -86,12 +86,28 @@ void VG_(end_msg) ( void )
 {
    if (VG_(clo_logfile_fd) >= 0) {
       add_to_buf('\n');
-      if (VG_(logging_to_filedes))
-         VG_(write)(
-            VG_(clo_logfile_fd), vg_mbuf, VG_(strlen)(vg_mbuf));
-      else
-         VG_(write_socket)(
-            VG_(clo_logfile_fd), vg_mbuf, VG_(strlen)(vg_mbuf));
+      VG_(send_bytes_to_logging_sink) ( 
+         vg_mbuf, VG_(strlen)(vg_mbuf) );
+   }
+}
+
+
+/* Do the low-level send of a message to the logging sink. */
+void VG_(send_bytes_to_logging_sink) ( Char* msg, Int nbytes )
+{
+   Int rc;
+   if (VG_(logging_to_filedes)) {
+      VG_(write)( VG_(clo_logfile_fd), msg, nbytes );
+   } else {
+      rc = VG_(write_socket)( VG_(clo_logfile_fd), msg, nbytes );
+      if (rc == -1) {
+         /* for example, the listener process died.  Switch back to
+            stderr. */
+         VG_(logging_to_filedes) = True;
+         VG_(clo_log_to) = VgLogTo_Fd;
+         VG_(clo_logfile_fd) = 2;
+         VG_(write)( VG_(clo_logfile_fd), msg, nbytes );
+      }
    }
 }
 
diff --git a/coregrind/vg_mylibc.c b/coregrind/vg_mylibc.c
index 1bcf0372c2..aea7c63385 100644
--- a/coregrind/vg_mylibc.c
+++ b/coregrind/vg_mylibc.c
@@ -631,12 +631,8 @@ static void add_to_myprintf_buf ( Char c )
 {
    if (n_myprintf_buf >= 100-10 /*paranoia*/ ) {
       if (VG_(clo_logfile_fd) >= 0) {
-         if (VG_(logging_to_filedes))
-            VG_(write)
-              (VG_(clo_logfile_fd), myprintf_buf, VG_(strlen)(myprintf_buf));
-         else
-            VG_(write_socket)
-              (VG_(clo_logfile_fd), myprintf_buf, VG_(strlen)(myprintf_buf));
+         VG_(send_bytes_to_logging_sink)( 
+            myprintf_buf, VG_(strlen)(myprintf_buf) );
       }
       n_myprintf_buf = 0;
       myprintf_buf[n_myprintf_buf] = 0;      
@@ -656,12 +652,7 @@ UInt VG_(printf) ( const char *format, ... )
    ret = VG_(vprintf) ( add_to_myprintf_buf, format, vargs );
 
    if (n_myprintf_buf > 0 && VG_(clo_logfile_fd) >= 0) {
-      if (VG_(logging_to_filedes))
-         VG_(write)
-            ( VG_(clo_logfile_fd), myprintf_buf, n_myprintf_buf);
-      else
-         VG_(write_socket)
-            ( VG_(clo_logfile_fd), myprintf_buf, n_myprintf_buf);
+      VG_(send_bytes_to_logging_sink)( myprintf_buf, n_myprintf_buf );
    }
 
    va_end(vargs);
@@ -1455,6 +1446,7 @@ struct vki_in_addr {
 /* kernel, include/linux/socket.h */
 typedef unsigned short  vki_sa_family_t;
 #define AF_INET                2       /* Internet IP Protocol        */
+#define MSG_NOSIGNAL           0x4000  /* Do not generate SIGPIPE */
 
 /* kernel, ./include/asm-i386/socket.h */
 #define SOCK_STREAM 1                  /* stream (connection) socket  */
@@ -1625,7 +1617,12 @@ Int my_connect ( Int sockfd, struct vki_sockaddr_in* serv_addr,
 Int VG_(write_socket)( Int sd, void *msg, Int count )
 {
    /* This is actually send(). */
-   Int flags = 0;
+
+   /* Requests not to send SIGPIPE on errors on stream oriented
+      sockets when the other end breaks the connection. The EPIPE
+      error is still returned. */
+   Int flags = MSG_NOSIGNAL;
+
    Int res;
    UInt args[4];
    args[0] = sd;