[PATCH v2 9/10] perf tools: Introduce pstack_peek()

From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Jiri Olsa <jolsa@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
	David Ahern <dsahern@gmail.com>
Subject: [PATCH v2 9/10] perf tools: Introduce pstack_peek()
Date: Fri, 24 Apr 2015 10:15:32 +0900	[thread overview]
Message-ID: <1429838133-14001-1-git-send-email-namhyung@kernel.org> (raw)
In-Reply-To: <20150423223058.GJ7881@kernel.org>

The pstack_peek() is to get the topmost entry without removing it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
I also pushed to perf/tui-cleanup-v4.

 tools/perf/util/pstack.c | 7 +++++++
 tools/perf/util/pstack.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/tools/perf/util/pstack.c b/tools/perf/util/pstack.c
index a126e6cc6e73..b234a6e3d0d4 100644
--- a/tools/perf/util/pstack.c
+++ b/tools/perf/util/pstack.c
@@ -74,3 +74,10 @@ void *pstack__pop(struct pstack *pstack)
 	pstack->entries[pstack->top] = NULL;
 	return ret;
 }
+
+void *pstack__peek(struct pstack *pstack)
+{
+	if (pstack->top == 0)
+		return NULL;
+	return pstack->entries[pstack->top - 1];
+}
diff --git a/tools/perf/util/pstack.h b/tools/perf/util/pstack.h
index c3cb6584d527..ded7f2e36624 100644
--- a/tools/perf/util/pstack.h
+++ b/tools/perf/util/pstack.h
@@ -10,5 +10,6 @@ bool pstack__empty(const struct pstack *pstack);
 void pstack__remove(struct pstack *pstack, void *key);
 void pstack__push(struct pstack *pstack, void *key);
 void *pstack__pop(struct pstack *pstack);
+void *pstack__peek(struct pstack *pstack);
 
 #endif /* _PERF_PSTACK_ */
-- 
2.3.4

