[sysprof] capture: add sysprof_collector_is_active()

[Christian Hergert <chergert src gnome org>]

commit 361b29a4598556cb6db8fc7ca46618d70300b498
Author: Christian Hergert <chergert redhat com>
Date:   Wed Aug 19 15:12:19 2020 -0700

    capture: add sysprof_collector_is_active()
    
    This can be used to check if a collector is actively running.

 src/libsysprof-capture/sysprof-collector.c | 12 ++++++++++++
 src/libsysprof-capture/sysprof-collector.h |  2 ++
 2 files changed, 14 insertions(+)
---
diff --git a/src/libsysprof-capture/sysprof-collector.c b/src/libsysprof-capture/sysprof-collector.c
index 23a3c105..27794328 100644
--- a/src/libsysprof-capture/sysprof-collector.c
+++ b/src/libsysprof-capture/sysprof-collector.c
@@ -863,3 +863,15 @@ sysprof_collector_request_counter (unsigned int n_counters)
 
   return ret;
 }
+
+bool
+sysprof_collector_is_active (void)
+{
+  bool ret = false;
+
+  COLLECTOR_BEGIN {
+    ret = true;
+  } COLLECTOR_END;
+
+  return ret;
+}
diff --git a/src/libsysprof-capture/sysprof-collector.h b/src/libsysprof-capture/sysprof-collector.h
index f989f08f..849ac628 100644
--- a/src/libsysprof-capture/sysprof-collector.h
+++ b/src/libsysprof-capture/sysprof-collector.h
@@ -65,6 +65,8 @@ SYSPROF_BEGIN_DECLS
 
 SYSPROF_AVAILABLE_IN_3_36
 void         sysprof_collector_init            (void);
+SYSPROF_AVAILABLE_IN_3_38
+bool         sysprof_collector_is_active       (void);
 SYSPROF_AVAILABLE_IN_3_36
 void         sysprof_collector_allocate        (SysprofCaptureAddress             alloc_addr,
                                                 int64_t                           alloc_size,