1 /* Copyright (C) 2003-2022 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library; see the file COPYING.LIB. If 16 not, see <https://www.gnu.org/licenses/>. */ 17 18 #include <pthread.h> 19 #include <setjmp.h> 20 #include <signal.h> 21 #include <sys/types.h> 22 23 24 /* Nonzero if the system calls are not available. */ 25 extern int __no_posix_timers attribute_hidden; 26 27 /* Callback to start helper thread. */ 28 extern void __timer_start_helper_thread (void) attribute_hidden; 29 30 /* Control variable for helper thread creation. */ 31 extern pthread_once_t __timer_helper_once attribute_hidden; 32 33 /* Called from fork so that the new subprocess re-creates the 34 notification thread if necessary. */ 35 void __timer_fork_subprocess (void) attribute_hidden; 36 37 /* TID of the helper thread. */ 38 extern pid_t __timer_helper_tid attribute_hidden; 39 40 /* List of active SIGEV_THREAD timers. */ 41 extern struct timer *__timer_active_sigev_thread attribute_hidden; 42 43 /* Lock for __timer_active_sigev_thread. */ 44 extern pthread_mutex_t __timer_active_sigev_thread_lock attribute_hidden; 45 46 extern __typeof (timer_create) __timer_create; 47 libc_hidden_proto (__timer_create) 48 extern __typeof (timer_delete) __timer_delete; 49 libc_hidden_proto (__timer_delete) 50 extern __typeof (timer_getoverrun) __timer_getoverrun; 51 libc_hidden_proto (__timer_getoverrun) 52 53 /* Type of timers in the kernel. */ 54 typedef int kernel_timer_t; 55 56 /* Internal representation of SIGEV_THREAD timer. */ 57 struct timer 58 { 59 kernel_timer_t ktimerid; 60 61 void (*thrfunc) (sigval_t); 62 sigval_t sival; 63 pthread_attr_t attr; 64 65 /* Next element in list of active SIGEV_THREAD timers. */ 66 struct timer *next; 67 }; 68 69 70 /* For !SIGEV_THREAD, the resulting 'timer_t' is the returned kernel timer 71 identifer (kernel_timer_t), while for SIGEV_THREAD it uses the fact malloc 72 returns at least _Alignof (max_align_t) pointers plus that valid 73 kernel_timer_t are always positive to set the MSB bit of the returned 74 'timer_t' to indicate the timer handles a SIGEV_THREAD. */ 75 76 static inline timer_t kernel_timer_to_timerid(kernel_timer_t ktimerid)77kernel_timer_to_timerid (kernel_timer_t ktimerid) 78 { 79 return (timer_t) ((intptr_t) ktimerid); 80 } 81 82 static inline timer_t timer_to_timerid(struct timer * ptr)83timer_to_timerid (struct timer *ptr) 84 { 85 return (timer_t) (INTPTR_MIN | (uintptr_t) ptr >> 1); 86 } 87 88 static inline bool timer_is_sigev_thread(timer_t timerid)89timer_is_sigev_thread (timer_t timerid) 90 { 91 return (intptr_t) timerid < 0; 92 } 93 94 static inline struct timer * timerid_to_timer(timer_t timerid)95timerid_to_timer (timer_t timerid) 96 { 97 return (struct timer *)((uintptr_t) timerid << 1); 98 } 99 100 static inline kernel_timer_t timerid_to_kernel_timer(timer_t timerid)101timerid_to_kernel_timer (timer_t timerid) 102 { 103 if (timer_is_sigev_thread (timerid)) 104 return timerid_to_timer (timerid)->ktimerid; 105 else 106 return (kernel_timer_t) ((uintptr_t) timerid); 107 } 108 109 /* New targets use int instead of timer_t. The difference only 110 matters on 64-bit targets. */ 111 #include <timer_t_was_int_compat.h> 112 113 #if TIMER_T_WAS_INT_COMPAT 114 # define OLD_TIMER_MAX 256 115 extern timer_t __timer_compat_list[OLD_TIMER_MAX]; 116 #endif 117