From ee3a78433fb868a365c5db7b7bdd75248bc4fb2f Mon Sep 17 00:00:00 2001
From: Christian Hergert <chergert@redhat.com>
Date: Tue, 30 May 2023 17:12:19 -0700
Subject: [PATCH] libsysprof-profile: add processes during recording

We want to reduce the chances we miss things between prepare and record
virtual methods, so delay the adding of processes until the recording is
started. We may get duplicate records, but we can deal with that when
analyzing the capture.
---
 .../sysprof-linux-instrument.c                | 49 ++++++++++++++-----
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/src/libsysprof-profile/sysprof-linux-instrument.c b/src/libsysprof-profile/sysprof-linux-instrument.c
index b0300648..c970a092 100644
--- a/src/libsysprof-profile/sysprof-linux-instrument.c
+++ b/src/libsysprof-profile/sysprof-linux-instrument.c
@@ -45,21 +45,19 @@ sysprof_linux_instrument_list_required_policy (SysprofInstrument *instrument)
 
 static void
 add_process_info (SysprofRecording *recording,
-                  GVariant         *process_info_reply)
+                  GVariant         *process_info)
 {
   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})")));
+  g_assert (process_info != NULL);
+  g_assert (g_variant_is_of_type (process_info, 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))
     {
@@ -118,9 +116,6 @@ 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));
@@ -135,6 +130,33 @@ sysprof_linux_instrument_prepare_fiber (gpointer user_data)
                   &error))
     return dex_future_new_for_error (g_steal_pointer (&error));
 
+  return dex_future_new_for_boolean (TRUE);
+}
+
+static DexFuture *
+sysprof_linux_instrument_prepare (SysprofInstrument *instrument,
+                                  SysprofRecording  *recording)
+{
+  g_assert (SYSPROF_IS_INSTRUMENT (instrument));
+  g_assert (SYSPROF_IS_RECORDING (recording));
+
+  return dex_scheduler_spawn (NULL, 0,
+                              sysprof_linux_instrument_prepare_fiber,
+                              g_object_ref (recording),
+                              g_object_unref);
+}
+
+static DexFuture *
+sysprof_linux_instrument_record_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));
+
   /* 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));
@@ -155,20 +177,22 @@ sysprof_linux_instrument_prepare_fiber (gpointer user_data)
     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);
+  process_info = g_variant_get_child_value (process_info_reply, 0);
+  add_process_info (recording, process_info);
 
   return dex_future_new_for_boolean (TRUE);
 }
 
 static DexFuture *
-sysprof_linux_instrument_prepare (SysprofInstrument *instrument,
-                                  SysprofRecording  *recording)
+sysprof_linux_instrument_record (SysprofInstrument *instrument,
+                                 SysprofRecording  *recording,
+                                 GCancellable      *cancellable)
 {
   g_assert (SYSPROF_IS_INSTRUMENT (instrument));
   g_assert (SYSPROF_IS_RECORDING (recording));
 
   return dex_scheduler_spawn (NULL, 0,
-                              sysprof_linux_instrument_prepare_fiber,
+                              sysprof_linux_instrument_record_fiber,
                               g_object_ref (recording),
                               g_object_unref);
 }
@@ -189,6 +213,7 @@ sysprof_linux_instrument_class_init (SysprofLinuxInstrumentClass *klass)
 
   instrument_class->list_required_policy = sysprof_linux_instrument_list_required_policy;
   instrument_class->prepare = sysprof_linux_instrument_prepare;
+  instrument_class->record = sysprof_linux_instrument_record;
 }
 
 static void