libsysprof: add a SysprofTracefdConsumer

This is meant to simplify the proxying of data from a tracefd into the
destination capture.

src/libsysprof/meson.build

@@ -57,6 +57,7 @@ libsysprof_public_sources = [
   'sysprof-system-logs.c',
   'sysprof-thread-info.c',
   'sysprof-time-span.c',
+  'sysprof-tracefd-consumer.c',
   'sysprof-tracer.c',
 ]
 
@@ -118,6 +119,7 @@ libsysprof_public_headers = [
   'sysprof-system-logs.h',
   'sysprof-thread-info.h',
   'sysprof-time-span.h',
+  'sysprof-tracefd-consumer.h',
   'sysprof-tracer.h',
 ]
 

src/libsysprof/sysprof-tracefd-consumer.c

@@ -0,0 +1,116 @@
+/* sysprof-tracefd-consumer.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <glib/gstdio.h>
+
+#include "sysprof-instrument-private.h"
+#include "sysprof-recording-private.h"
+#include "sysprof-tracefd-consumer.h"
+
+struct _SysprofTracefdConsumer
+{
+  SysprofInstrument parent_instance;
+  int trace_fd;
+};
+
+struct _SysprofTracefdConsumerClass
+{
+  SysprofInstrumentClass parent_class;
+};
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofCaptureReader, sysprof_capture_reader_unref)
+
+G_DEFINE_FINAL_TYPE (SysprofTracefdConsumer, sysprof_tracefd_consumer, SYSPROF_TYPE_INSTRUMENT)
+
+static DexFuture *
+sysprof_tracefd_consumer_augment (SysprofInstrument *instrument,
+                                  SysprofRecording  *recording)
+{
+  SysprofTracefdConsumer *self = (SysprofTracefdConsumer *)instrument;
+  g_autoptr(SysprofCaptureReader) reader = NULL;
+  SysprofCaptureWriter *writer;
+
+  g_assert (SYSPROF_IS_TRACEFD_CONSUMER (self));
+  g_assert (SYSPROF_IS_RECORDING (recording));
+
+  if (self->trace_fd == -1)
+    return dex_future_new_for_boolean (TRUE);
+
+  writer = _sysprof_recording_writer (recording);
+
+  lseek (self->trace_fd, 0, SEEK_SET);
+
+  if ((reader = sysprof_capture_reader_new_from_fd (g_steal_fd (&self->trace_fd))))
+    sysprof_capture_writer_cat (writer, reader);
+
+  return dex_future_new_for_boolean (TRUE);
+}
+
+static void
+sysprof_tracefd_consumer_finalize (GObject *object)
+{
+  SysprofTracefdConsumer *self = (SysprofTracefdConsumer *)object;
+
+  g_clear_fd (&self->trace_fd, NULL);
+
+  G_OBJECT_CLASS (sysprof_tracefd_consumer_parent_class)->finalize (object);
+}
+
+static void
+sysprof_tracefd_consumer_class_init (SysprofTracefdConsumerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  SysprofInstrumentClass *instrument_class = SYSPROF_INSTRUMENT_CLASS (klass);
+
+  object_class->finalize = sysprof_tracefd_consumer_finalize;
+
+  instrument_class->augment = sysprof_tracefd_consumer_augment;
+}
+
+static void
+sysprof_tracefd_consumer_init (SysprofTracefdConsumer *self)
+{
+  self->trace_fd = -1;
+}
+
+/**
+ * sysprof_tracefd_consumer_new:
+ * @trace_fd: a file-descriptor to read from
+ *
+ * This function will take ownership of @trace_fd, If you need to keep a
+ * copy of your FD then it is suggested you use `dup()` to copy the file
+ * descriptor.
+ *
+ * Returns: (transfer full): a #SysprofInstrument
+ */
+SysprofInstrument *
+sysprof_tracefd_consumer_new (int trace_fd)
+{
+  SysprofTracefdConsumer *self;
+
+  g_return_val_if_fail (trace_fd >= -1, NULL);
+
+  self = g_object_new (SYSPROF_TYPE_TRACEFD_CONSUMER, NULL);
+  self->trace_fd = trace_fd;
+
+  return SYSPROF_INSTRUMENT (self);
+}

src/libsysprof/sysprof-tracefd-consumer.h

@@ -0,0 +1,42 @@
+/* sysprof-tracefd-consumer.h
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include "sysprof-instrument.h"
+
+G_BEGIN_DECLS
+
+#define SYSPROF_TYPE_TRACEFD_CONSUMER         (sysprof_tracefd_consumer_get_type())
+#define SYSPROF_IS_TRACEFD_CONSUMER(obj)      G_TYPE_CHECK_INSTANCE_TYPE(obj, SYSPROF_TYPE_TRACEFD_CONSUMER)
+#define SYSPROF_TRACEFD_CONSUMER(obj)         G_TYPE_CHECK_INSTANCE_CAST(obj, SYSPROF_TYPE_TRACEFD_CONSUMER, SysprofTracefdConsumer)
+#define SYSPROF_TRACEFD_CONSUMER_CLASS(klass) G_TYPE_CHECK_CLASS_CAST(klass, SYSPROF_TYPE_TRACEFD_CONSUMER, SysprofTracefdConsumerClass)
+
+typedef struct _SysprofTracefdConsumer      SysprofTracefdConsumer;
+typedef struct _SysprofTracefdConsumerClass SysprofTracefdConsumerClass;
+
+SYSPROF_AVAILABLE_IN_ALL
+GType              sysprof_tracefd_consumer_get_type (void) G_GNUC_CONST;
+SYSPROF_AVAILABLE_IN_ALL
+SysprofInstrument *sysprof_tracefd_consumer_new      (int trace_fd);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofTracefdConsumer, g_object_unref)
+
+G_END_DECLS

src/libsysprof/sysprof.h

@@ -83,6 +83,7 @@ G_BEGIN_DECLS
 # include "sysprof-system-logs.h"
 # include "sysprof-thread-info.h"
 # include "sysprof-time-span.h"
+# include "sysprof-tracefd-consumer.h"
 # include "sysprof-tracer.h"
 #undef SYSPROF_INSIDE
 

src/libsysprof/tests/test-profiler.c

@@ -34,11 +34,13 @@ static gboolean gnome_shell;
 static gboolean bundle_symbols;
 static gboolean session_bus;
 static gboolean system_bus;
+static gboolean gjs;
 static char *power_profile;
 static const GOptionEntry entries[] = {
   { "capture", 'c', 0, G_OPTION_ARG_FILENAME, &capture_file, "The file to capture into", "CAPTURE" },
   { "memprof", 'm', 0, G_OPTION_ARG_NONE, &memprof, "Do memory allocation tracking on subprocess" },
   { "tracer", 't', 0, G_OPTION_ARG_NONE, &tracer, "Enable tracing with __cyg_profile_enter" },
+  { "gjs", 'g', 0, G_OPTION_ARG_NONE, &gjs, "export GJS_TRACE_FD" },
   { "gnome-shell", 's', 0, G_OPTION_ARG_NONE, &gnome_shell, "Request GNOME Shell to provide profiler data" },
   { "power-profile", 'p', 0, G_OPTION_ARG_STRING, &power_profile, "Use POWER_PROFILE for duration of recording", "power-saver|balanced|performance" },
   { "session-bus", 0, 0, G_OPTION_ARG_NONE, &session_bus, "Record D-Bus messages on the session bus" },
@@ -144,6 +146,7 @@ main (int   argc,
   SysprofCaptureWriter *writer = NULL;
   SysprofCaptureReader *reader = NULL;
   g_autofd int trace_fd = -1;
+  g_autofd int gjs_trace_fd = -1;
   int argv_copy_len = 0;
 
   sysprof_clock_init ();
@@ -224,10 +227,16 @@ main (int   argc,
 
           trace_fd = sysprof_spawnable_add_trace_fd (spawnable, NULL);
 
+          if (gjs)
+            gjs_trace_fd = sysprof_spawnable_add_trace_fd (spawnable, "GJS_TRACE_FD");
+
           break;
         }
     }
 
+  sysprof_profiler_add_instrument (profiler, sysprof_tracefd_consumer_new (g_steal_fd (&gjs_trace_fd)));
+  sysprof_profiler_add_instrument (profiler, sysprof_tracefd_consumer_new (g_steal_fd (&trace_fd)));
+
   sysprof_profiler_record_async (profiler, writer, NULL, record_cb, NULL);
 
   g_unix_signal_add (SIGINT, sigint_handler, main_loop);