[PATCH 31/48] tools lib fd array: Introduce fdarray__add_clone function

[Jiri Olsa]

Adding fdarray__add_clone to be able to copy/clone
a specific entry from fdarray struct.

It will be useful when separating event maps for
specific threads.

Link: http://lkml.kernel.org/n/tip-0r9rtn1bii1iaggumlgkyxqk@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/lib/api/fd/array.c | 17 +++++++++++++++++
 tools/lib/api/fd/array.h |  1 +
 2 files changed, 18 insertions(+)

diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
index b0a035fc87b3..cd458b46f61b 100644
--- a/tools/lib/api/fd/array.c
+++ b/tools/lib/api/fd/array.c
@@ -84,6 +84,23 @@ int fdarray__add(struct fdarray *fda, int fd, short revents)
 	return pos;
 }
 
+int fdarray__add_clone(struct fdarray *fda, int pos, struct fdarray *base)
+{
+	struct pollfd *entry;
+	int npos;
+
+	if (pos >= base->nr)
+		return -EINVAL;
+
+	entry = &base->entries[pos];
+
+	npos = fdarray__add(fda, entry->fd, entry->events);
+	if (npos >= 0)
+		fda->priv[npos] = base->priv[pos];
+
+	return npos;
+}
+
 int fdarray__filter(struct fdarray *fda, short revents,
 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
 		    void *arg)
diff --git a/tools/lib/api/fd/array.h b/tools/lib/api/fd/array.h
index b39557d1a88f..06e89d099b1e 100644
--- a/tools/lib/api/fd/array.h
+++ b/tools/lib/api/fd/array.h
@@ -34,6 +34,7 @@ struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
 void fdarray__delete(struct fdarray *fda);
 
 int fdarray__add(struct fdarray *fda, int fd, short revents);
+int fdarray__add_clone(struct fdarray *fda, int pos, struct fdarray *base);
 int fdarray__poll(struct fdarray *fda, int timeout);
 int fdarray__filter(struct fdarray *fda, short revents,
 		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
-- 
2.17.1