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 int __lwp_setname(lwpid_t tid, const char *name); 54 55 static int fast_setname_count; 56 static __thread int fast_setname_state TLS_ATTRIBUTE; 57 static __thread char *thread_title TLS_ATTRIBUTE; 58 static __thread lwpid_t *thread_tid TLS_ATTRIBUTE; 59 60 /* 61 * Optimize lwp_setname() if it is called a lot by using the lpmap to 62 * directly copy the name without making a system call. The optimization 63 * only operates when setting the name for the calling thread. 64 */ 65 int 66 __lwp_setname(lwpid_t tid, const char *name) 67 { 68 if (fast_setname_state == 0 && fast_setname_count++ >= 10) { 69 __lpmap_map(&thread_title, &fast_setname_state, 70 LPTYPE_THREAD_TITLE); 71 __lpmap_map(&thread_tid, &fast_setname_state, 72 LPTYPE_THREAD_TID); 73 __lpmap_map(NULL, &fast_setname_state, 0); 74 } 75 if (fast_setname_state > 0 && tid == *thread_tid) { 76 size_t len = strlen(name); 77 78 if (len >= LPMAP_MAXTHREADTITLE) 79 len = LPMAP_MAXTHREADTITLE - 1; 80 thread_title[len] = 0; 81 bcopy(name, thread_title, len); 82 return 0; 83 } else { 84 return(__sys_lwp_setname(tid, name)); 85 } 86 } 87 88 __weak_reference(__lwp_setname, lwp_setname); 89