libsysprof-profile: add some basic process information

This needs to get into the capture, and we still need to respond to the
discovery of new processes as well (which we lack API for).

src/libsysprof-profile/sysprof-linux-instrument.c

@@ -43,17 +43,121 @@ sysprof_linux_instrument_list_required_policy (SysprofInstrument *instrument)
   return g_strdupv ((char **)policy);
 }
 
+static void
+add_process_info (SysprofRecording *recording,
+                  GVariant         *process_info_reply)
+{
+  g_autoptr(GPtrArray) futures = NULL;
+  g_autoptr(GVariant) process_info = NULL;
+  SysprofCaptureWriter *writer;
+  GVariantIter iter;
+  GVariant *pidinfo;
+
+  g_assert (process_info_reply != NULL);
+  g_assert (g_variant_is_of_type (process_info_reply, G_VARIANT_TYPE ("(aa{sv})")));
+
+  writer = _sysprof_recording_writer (recording);
+
+  /* Loop through all the PIDs the server notified us about */
+  process_info = g_variant_get_child_value (process_info_reply, 0);
+  g_variant_iter_init (&iter, process_info);
+  while (g_variant_iter_loop (&iter, "@a{sv}", &pidinfo))
+    {
+      g_autofree char *mount_path = NULL;
+      GVariantDict dict;
+      const char *cmdline;
+      const char *comm;
+      const char *mountinfo;
+      const char *maps;
+      const char *cgroup;
+      gint32 pid;
+
+      g_variant_dict_init (&dict, pidinfo);
+
+      if (!g_variant_dict_lookup (&dict, "pid", "i", &pid))
+        goto skip;
+
+      if (!g_variant_dict_lookup (&dict, "cmdline", "&s", &cmdline))
+        cmdline = "";
+
+      if (!g_variant_dict_lookup (&dict, "comm", "&s", &comm))
+        comm = "";
+
+      if (!g_variant_dict_lookup (&dict, "mountinfo", "&s", &mountinfo))
+        mountinfo = "";
+
+      if (!g_variant_dict_lookup (&dict, "maps", "&s", &maps))
+        maps = "";
+
+      if (!g_variant_dict_lookup (&dict, "cgroup", "&s", &cgroup))
+        cgroup = "";
+
+      /* Notify the capture that a process was spawned */
+      sysprof_capture_writer_add_process (writer,
+                                          SYSPROF_CAPTURE_CURRENT_TIME,
+                                          -1,
+                                          pid,
+                                          *cmdline ? cmdline : comm);
+
+      /* Give the capture access to the mountinfo of that process to aid
+       * in resolving symbols later on.
+       */
+      mount_path = g_strdup_printf ("/proc/%u/mountinfo", pid);
+      _sysprof_recording_add_file_data (recording, mount_path, mountinfo, -1);
+
+      // TODO
+      //sysprof_proc_source_populate_maps (self, pid, maps, ignore_inode);
+      //sysprof_proc_source_populate_overlays (self, pid, cgroup);
+
+      skip:
+        g_variant_dict_clear (&dict);
+    }
+}
+
 static DexFuture *
 sysprof_linux_instrument_prepare_fiber (gpointer user_data)
 {
   SysprofRecording *recording = user_data;
+  g_autoptr(GDBusConnection) bus = NULL;
+  g_autoptr(GVariant) process_info_reply = NULL;
+  g_autoptr(GVariant) process_info = NULL;
+  g_autoptr(GError) error = NULL;
 
   g_assert (SYSPROF_IS_RECORDING (recording));
 
-  return dex_future_all (_sysprof_recording_add_file (recording, "/proc/kallsyms", TRUE),
-                         _sysprof_recording_add_file (recording, "/proc/cpuinfo", TRUE),
-                         _sysprof_recording_add_file (recording, "/proc/mounts", TRUE),
-                         NULL);
+  /* First get some basic information about the system into the capture. We can
+   * get the contents for all of these concurrently.
+   */
+  if (!dex_await (dex_future_all (_sysprof_recording_add_file (recording, "/proc/kallsyms", TRUE),
+                                  _sysprof_recording_add_file (recording, "/proc/cpuinfo", TRUE),
+                                  _sysprof_recording_add_file (recording, "/proc/mounts", TRUE),
+                                  NULL),
+                  &error))
+    return dex_future_new_for_error (g_steal_pointer (&error));
+
+  /* We need access to the bus to call various sysprofd API directly */
+  if (!(bus = dex_await_object (dex_bus_get (G_BUS_TYPE_SYSTEM), &error)))
+    return dex_future_new_for_error (g_steal_pointer (&error));
+
+  /* We also want to get a bunch of info on user processes so that we can add
+   * records about them to the recording.
+   */
+  if (!(process_info_reply = dex_await_variant (dex_dbus_connection_call (bus,
+                                                                          "org.gnome.Sysprof3",
+                                                                          "/org/gnome/Sysprof3",
+                                                                          "org.gnome.Sysprof3.Service",
+                                                                          "GetProcessInfo",
+                                                                          g_variant_new ("(s)", "pid,maps,mountinfo,cmdline,comm,cgroup"),
+                                                                          G_VARIANT_TYPE ("(aa{sv})"),
+                                                                          G_DBUS_CALL_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION,
+                                                                          G_MAXINT),
+                                                &error)))
+    return dex_future_new_for_error (g_steal_pointer (&error));
+
+  /* Add process records for each of the processes discovered */
+  add_process_info (recording, process_info_reply);
+
+  return dex_future_new_for_boolean (TRUE);
 }
 
 static DexFuture *