util/perfetto: Add one-time init

Various places around mesa which might want to register a data-source,
etc, should call util_perfetto_init() first to ensure we connect to the
tracing service.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Acked-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9901>

meson.build

@@ -1972,6 +1972,14 @@ else
   dep_lmsensors = null_dep
 endif
 
+with_perfetto = get_option('perfetto')
+with_datasources = get_option('datasources')
+with_any_datasource = with_datasources.length() != 0
+if with_perfetto
+  dep_perfetto = dependency('perfetto', fallback: ['perfetto', 'dep_perfetto'])
+  pre_args += '-DHAVE_PERFETTO'
+endif
+
 # If the compiler supports it, put function and data symbols in their
 # own sections and GC the sections after linking.  This lets drivers
 # drop shared code unused by that specific driver (particularly
@@ -2046,13 +2054,6 @@ endif
 # as GCC LTO drops them. See: https://bugs.freedesktop.org/show_bug.cgi?id=109391
 gcc_lto_quirk = (cc.get_id() == 'gcc') ? ['-fno-lto'] : []
 
-with_perfetto = get_option('perfetto')
-with_datasources = get_option('datasources')
-with_any_datasource = with_datasources.length() != 0
-if with_perfetto
-  dep_perfetto = dependency('perfetto', fallback: ['perfetto', 'dep_perfetto'])
-endif
-
 subdir('include')
 subdir('bin')
 subdir('src')

src/util/meson.build

@@ -202,6 +202,14 @@ if with_platform_haiku
   deps_for_libmesa_util += dep_network
 endif
 
+if with_perfetto
+  files_mesa_util += files(
+    'u_perfetto.cc',
+    'u_perfetto.h',
+  )
+  deps_for_libmesa_util += dep_perfetto
+endif
+
 _libmesa_util = static_library(
   'mesa_util',
   [files_mesa_util, files_debug_stack, format_srgb],

src/util/u_perfetto.cc

@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2021 Google, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <perfetto.h>
+
+#include "c11/threads.h"
+
+#include "u_perfetto.h"
+
+static void
+util_perfetto_init_once(void)
+{
+   // Connects to the system tracing service
+   perfetto::TracingInitArgs args;
+   args.backends = perfetto::kSystemBackend;
+   perfetto::Tracing::Initialize(args);
+}
+
+static once_flag perfetto_once_flag = ONCE_FLAG_INIT;
+
+void
+util_perfetto_init(void)
+{
+   call_once(&perfetto_once_flag, util_perfetto_init_once);
+}

src/util/u_perfetto.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2021 Google, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _UTIL_PERFETTO_H
+#define _UTIL_PERFETTO_H
+
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+void util_perfetto_init(void);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _UTIL_PERFETTO_H */