1 /*
2 * Copyright (c) 2019 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 #include <sys/types.h>
37 #include <sys/syscall.h>
38 #include <sys/upmap.h>
39 #include <sys/time.h>
40 #include <sys/lwp.h>
41 #include <machine/cpufunc.h>
42 #include <machine/tls.h>
43 #include <errno.h>
44 #include <time.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <unistd.h>
48 /*#include "un-namespace.h"*/
49 #include "libc_private.h"
50 #include "upmap.h"
51
52 extern int __sys_lwp_setname(lwpid_t tid, const char *name);
53 extern int __sys_lwp_getname(lwpid_t tid, char *name, size_t len);
54 int __lwp_setname(lwpid_t tid, const char *name);
55 int __lwp_getname(lwpid_t tid, char *name, size_t len);
56
57 static int fast_setname_count;
58 static __thread int fast_setname_state TLS_ATTRIBUTE;
59 static __thread char *thread_title TLS_ATTRIBUTE;
60 static __thread lwpid_t *thread_tid TLS_ATTRIBUTE;
61
62 /*
63 * Optimize lwp_setname() if it is called a lot by using the lpmap to
64 * directly copy the name without making a system call. The optimization
65 * only operates when setting the name for the calling thread.
66 */
67 int
__lwp_setname(lwpid_t tid,const char * name)68 __lwp_setname(lwpid_t tid, const char *name)
69 {
70 if (fast_setname_state == 0 && fast_setname_count++ >= 10) {
71 __lpmap_map(&thread_title, &fast_setname_state,
72 LPTYPE_THREAD_TITLE);
73 __lpmap_map(&thread_tid, &fast_setname_state,
74 LPTYPE_THREAD_TID);
75 __lpmap_map(NULL, &fast_setname_state, 0);
76 }
77 if (fast_setname_state > 0 && tid == *thread_tid) {
78 size_t len = strlen(name);
79
80 if (len >= LPMAP_MAXTHREADTITLE)
81 len = LPMAP_MAXTHREADTITLE - 1;
82 thread_title[len] = 0;
83 bcopy(name, thread_title, len);
84 return 0;
85 } else {
86 return(__sys_lwp_setname(tid, name));
87 }
88 }
89
90 __weak_reference(__lwp_setname, lwp_setname);
91
92 /*
93 * Optimize lwp_getname() the same way, and as with lwp_setname() the
94 * optimization is only applicable for the current thread.
95 */
96 int
__lwp_getname(lwpid_t tid,char * name,size_t len)97 __lwp_getname(lwpid_t tid, char *name, size_t len)
98 {
99 if (fast_setname_state == 0 && fast_setname_count++ >= 10) {
100 __lpmap_map(&thread_title, &fast_setname_state,
101 LPTYPE_THREAD_TITLE);
102 __lpmap_map(&thread_tid, &fast_setname_state,
103 LPTYPE_THREAD_TID);
104 __lpmap_map(NULL, &fast_setname_state, 0);
105 }
106 if (fast_setname_state > 0 && tid == *thread_tid) {
107 snprintf(name, len, "%s", thread_title);
108 return 0;
109 } else {
110 return __sys_lwp_getname(tid, name, len);
111 }
112 }
113
114 __weak_reference(__lwp_getname, lwp_getname);
115