xref: /openbmc/linux/tools/perf/util/comm.c (revision a06c488d)
1 #include "comm.h"
2 #include "util.h"
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <linux/atomic.h>
6 
7 struct comm_str {
8 	char *str;
9 	struct rb_node rb_node;
10 	atomic_t refcnt;
11 };
12 
13 /* Should perhaps be moved to struct machine */
14 static struct rb_root comm_str_root;
15 
16 static struct comm_str *comm_str__get(struct comm_str *cs)
17 {
18 	if (cs)
19 		atomic_inc(&cs->refcnt);
20 	return cs;
21 }
22 
23 static void comm_str__put(struct comm_str *cs)
24 {
25 	if (cs && atomic_dec_and_test(&cs->refcnt)) {
26 		rb_erase(&cs->rb_node, &comm_str_root);
27 		zfree(&cs->str);
28 		free(cs);
29 	}
30 }
31 
32 static struct comm_str *comm_str__alloc(const char *str)
33 {
34 	struct comm_str *cs;
35 
36 	cs = zalloc(sizeof(*cs));
37 	if (!cs)
38 		return NULL;
39 
40 	cs->str = strdup(str);
41 	if (!cs->str) {
42 		free(cs);
43 		return NULL;
44 	}
45 
46 	atomic_set(&cs->refcnt, 0);
47 
48 	return cs;
49 }
50 
51 static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root)
52 {
53 	struct rb_node **p = &root->rb_node;
54 	struct rb_node *parent = NULL;
55 	struct comm_str *iter, *new;
56 	int cmp;
57 
58 	while (*p != NULL) {
59 		parent = *p;
60 		iter = rb_entry(parent, struct comm_str, rb_node);
61 
62 		cmp = strcmp(str, iter->str);
63 		if (!cmp)
64 			return iter;
65 
66 		if (cmp < 0)
67 			p = &(*p)->rb_left;
68 		else
69 			p = &(*p)->rb_right;
70 	}
71 
72 	new = comm_str__alloc(str);
73 	if (!new)
74 		return NULL;
75 
76 	rb_link_node(&new->rb_node, parent, p);
77 	rb_insert_color(&new->rb_node, root);
78 
79 	return new;
80 }
81 
82 struct comm *comm__new(const char *str, u64 timestamp, bool exec)
83 {
84 	struct comm *comm = zalloc(sizeof(*comm));
85 
86 	if (!comm)
87 		return NULL;
88 
89 	comm->start = timestamp;
90 	comm->exec = exec;
91 
92 	comm->comm_str = comm_str__findnew(str, &comm_str_root);
93 	if (!comm->comm_str) {
94 		free(comm);
95 		return NULL;
96 	}
97 
98 	comm_str__get(comm->comm_str);
99 
100 	return comm;
101 }
102 
103 int comm__override(struct comm *comm, const char *str, u64 timestamp, bool exec)
104 {
105 	struct comm_str *new, *old = comm->comm_str;
106 
107 	new = comm_str__findnew(str, &comm_str_root);
108 	if (!new)
109 		return -ENOMEM;
110 
111 	comm_str__get(new);
112 	comm_str__put(old);
113 	comm->comm_str = new;
114 	comm->start = timestamp;
115 	if (exec)
116 		comm->exec = true;
117 
118 	return 0;
119 }
120 
121 void comm__free(struct comm *comm)
122 {
123 	comm_str__put(comm->comm_str);
124 	free(comm);
125 }
126 
127 const char *comm__str(const struct comm *comm)
128 {
129 	return comm->comm_str->str;
130 }
131