perf tools: Introduce event selectors

Out of ad-hoc code and global arrays with hard coded sizes.

This is the first step on having a library that will be first
used on regression tests in the 'perf test' tool.

[acme@felicio linux]$ size /tmp/perf.before
   text	   data	    bss	    dec	    hex	filename
1273776	  97384	5104416	6475576	 62cf38	/tmp/perf.before
[acme@felicio linux]$ size /tmp/perf.new
   text	   data	    bss	    dec	    hex	filename
1275422	  97416	1392416	2765254	 2a31c6	/tmp/perf.new

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
new file mode 100644
index 0000000..3eb3989
--- /dev/null
+++ b/tools/perf/util/evsel.h
@@ -0,0 +1,24 @@
+#ifndef __PERF_EVSEL_H
+#define __PERF_EVSEL_H 1
+
+#include <linux/list.h>
+#include <linux/perf_event.h>
+#include "types.h"
+#include "xyarray.h"
+
+struct perf_evsel {
+	struct list_head	node;
+	struct perf_event_attr	attr;
+	char			*filter;
+	struct xyarray		*fd;
+	int			idx;
+	void			*priv;
+};
+
+struct perf_evsel *perf_evsel__new(u32 type, u64 config, int idx);
+void perf_evsel__delete(struct perf_evsel *evsel);
+
+int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
+void perf_evsel__free_fd(struct perf_evsel *evsel);
+
+#endif /* __PERF_EVSEL_H */