xref: /linux/tools/perf/util/comm.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
1 #include "comm.h"
2 #include "util.h"
3 #include <errno.h>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <string.h>
7 #include <linux/refcount.h>
8 
9 struct comm_str {
10 	char *str;
11 	struct rb_node rb_node;
12 	refcount_t refcnt;
13 };
14 
15 /* Should perhaps be moved to struct machine */
16 static struct rb_root comm_str_root;
17 
18 static struct comm_str *comm_str__get(struct comm_str *cs)
19 {
20 	if (cs)
21 		refcount_inc(&cs->refcnt);
22 	return cs;
23 }
24 
25 static void comm_str__put(struct comm_str *cs)
26 {
27 	if (cs && refcount_dec_and_test(&cs->refcnt)) {
28 		rb_erase(&cs->rb_node, &comm_str_root);
29 		zfree(&cs->str);
30 		free(cs);
31 	}
32 }
33 
34 static struct comm_str *comm_str__alloc(const char *str)
35 {
36 	struct comm_str *cs;
37 
38 	cs = zalloc(sizeof(*cs));
39 	if (!cs)
40 		return NULL;
41 
42 	cs->str = strdup(str);
43 	if (!cs->str) {
44 		free(cs);
45 		return NULL;
46 	}
47 
48 	refcount_set(&cs->refcnt, 1);
49 
50 	return cs;
51 }
52 
53 static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root)
54 {
55 	struct rb_node **p = &root->rb_node;
56 	struct rb_node *parent = NULL;
57 	struct comm_str *iter, *new;
58 	int cmp;
59 
60 	while (*p != NULL) {
61 		parent = *p;
62 		iter = rb_entry(parent, struct comm_str, rb_node);
63 
64 		cmp = strcmp(str, iter->str);
65 		if (!cmp)
66 			return comm_str__get(iter);
67 
68 		if (cmp < 0)
69 			p = &(*p)->rb_left;
70 		else
71 			p = &(*p)->rb_right;
72 	}
73 
74 	new = comm_str__alloc(str);
75 	if (!new)
76 		return NULL;
77 
78 	rb_link_node(&new->rb_node, parent, p);
79 	rb_insert_color(&new->rb_node, root);
80 
81 	return new;
82 }
83 
84 struct comm *comm__new(const char *str, u64 timestamp, bool exec)
85 {
86 	struct comm *comm = zalloc(sizeof(*comm));
87 
88 	if (!comm)
89 		return NULL;
90 
91 	comm->start = timestamp;
92 	comm->exec = exec;
93 
94 	comm->comm_str = comm_str__findnew(str, &comm_str_root);
95 	if (!comm->comm_str) {
96 		free(comm);
97 		return NULL;
98 	}
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__put(old);
112 	comm->comm_str = new;
113 	comm->start = timestamp;
114 	if (exec)
115 		comm->exec = true;
116 
117 	return 0;
118 }
119 
120 void comm__free(struct comm *comm)
121 {
122 	comm_str__put(comm->comm_str);
123 	free(comm);
124 }
125 
126 const char *comm__str(const struct comm *comm)
127 {
128 	return comm->comm_str->str;
129 }
130