Add initial infrastructure for Profiling

The EosProfileProbe API allows defining profiling probes that can be
used to efficiently measure the time spent in a critical section.

The Profiling API is meant to collect samples and generate a report
at the end of the lifetime of the process, either by printing out the
results once the process terminates; or by saving the raw data in a
binary file that can be loaded at a later date.

This profiling API is meant to be as close as possible to a zero cost
abstraction:

 - probes are only allocated if profiling is enabled
 - all profiling API is a no-op if profiling isn't enabled
 - the C API is meant to be easily tied to a scope, through the
   use of auto-cleanup macros provided by GLib

This allows projects using the Endless SDK to keep the profiling probes
in place, instead of conditionally compile them in.

https://phabricator.endlessm.com/T18514

1 files changed, 48 insertions, 0 deletions

diff --git a/endless/eosprofile.h b/endless/eosprofile.h
new file mode 100644
index 0000000..9dacb50
--- /dev/null
+++ b/endless/eosprofile.h
@@ -0,0 +1,48 @@
+/* Copyright 2017 Endless Mobile, Inc. */
+
+#pragma once
+
+#if !(defined(_EOS_SDK_INSIDE_ENDLESS_H) || defined(COMPILING_EOS_SDK))
+#error "Please do not include this header file directly."
+#endif
+
+#include "eostypes.h"
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+/**
+ * EosProfileProbe:
+ *
+ * An opaque identifier for a profiling probe.
+ *
+ * Since: 0.6
+ */
+typedef struct _EosProfileProbe         EosProfileProbe;
+
+/**
+ * EOS_PROFILE_PROBE:
+ * @name: the name of the profiling probe
+ *
+ * A convenience macro that creates a profiling probe at the given
+ * location.
+ *
+ * Since: 0.6
+ */
+#define EOS_PROFILE_PROBE(name) \
+  eos_profile_probe_start (__FILE__, __LINE__, G_STRFUNC, name)
+
+EOS_SDK_AVAILABLE_IN_0_6
+GType eos_profile_probe_get_type (void) G_GNUC_CONST;
+
+EOS_SDK_AVAILABLE_IN_0_6
+EosProfileProbe *       eos_profile_probe_start (const char      *file,
+                                                 gsize            line,
+                                                 const char      *function,
+                                                 const char      *name);
+EOS_SDK_AVAILABLE_IN_0_6
+void                    eos_profile_probe_stop  (EosProfileProbe *probe);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(EosProfileProbe, eos_profile_probe_stop)
+
+G_END_DECLS