1 files changed, 121 insertions, 0 deletions

diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c
new file mode 100644
index 000000000000..ee0df0e24cdb
--- /dev/null
+++ b/tools/perf/util/comm.c
@@ -0,0 +1,121 @@
+#include "comm.h"
+#include "util.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+struct comm_str {
+        char *str;
+        struct rb_node rb_node;
+        int ref;
+};
+
+/* Should perhaps be moved to struct machine */
+static struct rb_root comm_str_root;
+
+static void comm_str__get(struct comm_str *cs)
+{
+        cs->ref++;
+}
+
+static void comm_str__put(struct comm_str *cs)
+{
+        if (!--cs->ref) {
+                rb_erase(&cs->rb_node, &comm_str_root);
+                free(cs->str);
+                free(cs);
+        }
+}
+
+static struct comm_str *comm_str__alloc(const char *str)
+{
+        struct comm_str *cs;
+
+        cs = zalloc(sizeof(*cs));
+        if (!cs)
+                return NULL;
+
+        cs->str = strdup(str);
+        if (!cs->str) {
+                free(cs);
+                return NULL;
+        }
+
+        return cs;
+}
+
+static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root)
+{
+        struct rb_node **p = &root->rb_node;
+        struct rb_node *parent = NULL;
+        struct comm_str *iter, *new;
+        int cmp;
+
+        while (*p != NULL) {
+                parent = *p;
+                iter = rb_entry(parent, struct comm_str, rb_node);
+
+                cmp = strcmp(str, iter->str);
+                if (!cmp)
+                        return iter;
+
+                if (cmp < 0)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+
+        new = comm_str__alloc(str);
+        if (!new)
+                return NULL;
+
+        rb_link_node(&new->rb_node, parent, p);
+        rb_insert_color(&new->rb_node, root);
+
+        return new;
+}
+
+struct comm *comm__new(const char *str, u64 timestamp)
+{
+        struct comm *comm = zalloc(sizeof(*comm));
+
+        if (!comm)
+                return NULL;
+
+        comm->start = timestamp;
+
+        comm->comm_str = comm_str__findnew(str, &comm_str_root);
+        if (!comm->comm_str) {
+                free(comm);
+                return NULL;
+        }
+
+        comm_str__get(comm->comm_str);
+
+        return comm;
+}
+
+void comm__override(struct comm *comm, const char *str, u64 timestamp)
+{
+        struct comm_str *old = comm->comm_str;
+
+        comm->comm_str = comm_str__findnew(str, &comm_str_root);
+        if (!comm->comm_str) {
+                comm->comm_str = old;
+                return;
+        }
+
+        comm->start = timestamp;
+        comm_str__get(comm->comm_str);
+        comm_str__put(old);
+}
+
+void comm__free(struct comm *comm)
+{
+        comm_str__put(comm->comm_str);
+        free(comm);
+}
+
+const char *comm__str(const struct comm *comm)
+{
+        return comm->comm_str->str;
+}