Add GUESTFS_EVENT_ENTER event.

This event is generated whenever a libguestfs function is called.

diff --git a/generator/generator_c.ml b/generator/generator_c.ml
index 5460a35..bfdea33 100644 (file)
--- a/generator/generator_c.ml
+++ b/generator/generator_c.ml
@@ -758,6 +758,13 @@ trace_send_line (guestfs_h *g)
 
 ";
 
+  (* Generate code for enter events. *)
+  let enter_event shortname =
+    pr "  guestfs___call_callbacks_message (g, GUESTFS_EVENT_ENTER,\n";
+    pr "                                    \"%s\", %d);\n"
+      shortname (String.length shortname)
+  in
+
   (* Generate code to check String-like parameters are not passed in
    * as NULL (returning an error if they are).
    *)
@@ -1027,6 +1034,7 @@ trace_send_line (guestfs_h *g)
            pr "  struct guestfs_%s_list *r;\n" typ
       );
       pr "\n";
+      enter_event shortname;
       check_null_strings shortname style;
       reject_unknown_optargs shortname style;
       trace_call shortname style;
@@ -1119,6 +1127,7 @@ trace_send_line (guestfs_h *g)
         pr "  const uint64_t progress_hint = 0;\n";
 
       pr "\n";
+      enter_event shortname;
       check_null_strings shortname style;
       reject_unknown_optargs shortname style;
       trace_call shortname style;

diff --git a/generator/generator_events.ml b/generator/generator_events.ml
index 54557c3..df74af3 100644 (file)
--- a/generator/generator_events.ml
+++ b/generator/generator_events.ml
@@ -35,6 +35,8 @@ let events = [
                                            qemu / kernel / guestfsd / tools *)
   "library";                            (* log messages from library *)
   "trace";                              (* call trace messages *)
+
+  "enter";                              (* enter a function *)
 ]
 
 let events = mapi (fun i name -> name, 1 lsl i) events

diff --git a/src/events.c b/src/events.c
index aa30fd2..f707e0b 100644 (file)
--- a/src/events.c
+++ b/src/events.c
@@ -111,12 +111,14 @@ guestfs___call_callbacks_message (guestfs_h *g, uint64_t event,
       count++;
     }
 
-  /* If nothing was registered and we're verbose or tracing, then we
-   * print the message on stderr.  This essentially emulates the
-   * behaviour of the old-style handlers, while allowing callers to
-   * override print-on-stderr simply by registering a callback.
+  /* Emulate the old-style handlers.  Callers can override
+   * print-on-stderr simply by registering a callback.
    */
-  if (count == 0 && (g->verbose || event == GUESTFS_EVENT_TRACE)) {
+  if (count == 0 &&
+      (event == GUESTFS_EVENT_APPLIANCE ||
+       event == GUESTFS_EVENT_LIBRARY ||
+       event == GUESTFS_EVENT_TRACE) &&
+      (g->verbose || event == GUESTFS_EVENT_TRACE)) {
     int from_appliance = event == GUESTFS_EVENT_APPLIANCE;
     size_t i;
     char c;

diff --git a/src/guestfs.pod b/src/guestfs.pod
index 8cb1b86..6cceced 100644 (file)
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -1833,6 +1833,21 @@ If no callback is registered: the messages are sent to stderr.  You
 can override the printing of trace messages to stderr by setting up a
 callback.
 
+=item GUESTFS_EVENT_ENTER
+(payload type: function name)
+
+The callback function is called whenever a libguestfs function
+is entered.
+
+The payload is a string which contains the name of the function
+that we are entering (not including C<guestfs_> prefix).
+
+Note that libguestfs functions can call themselves, so you may
+see many events from a single call.  A few libguestfs functions
+do not generate this event.
+
+If no callback is registered: the event is ignored.
+
 =back
 
 =head3 guestfs_set_event_callback