thread-self.c (1740B)
1/* 2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16// Test that /proc/thread-self gives correct TGID/PID. 17#undef NDEBUG 18#include <assert.h> 19#include <sched.h> 20#include <stdio.h> 21#include <unistd.h> 22#include <sys/mman.h> 23#include <sys/wait.h> 24 25#include "proc.h" 26 27int f(void *arg) 28{ 29 char buf1[64], buf2[64]; 30 pid_t pid, tid; 31 ssize_t rv; 32 33 pid = sys_getpid(); 34 tid = sys_gettid(); 35 snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid); 36 37 rv = readlink("/proc/thread-self", buf2, sizeof(buf2)); 38 assert(rv == strlen(buf1)); 39 buf2[rv] = '\0'; 40 assert(streq(buf1, buf2)); 41 42 if (arg) 43 exit(0); 44 return 0; 45} 46 47int main(void) 48{ 49 const int PAGE_SIZE = sysconf(_SC_PAGESIZE); 50 pid_t pid; 51 void *stack; 52 53 /* main thread */ 54 f((void *)0); 55 56 stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 57 assert(stack != MAP_FAILED); 58 /* side thread */ 59 pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1); 60 assert(pid > 0); 61 pause(); 62 63 return 0; 64}