lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Linuxthreads - a simple clone()-based implementation of Posix */ |
| 2 | /* threads for Linux. */ |
| 3 | /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ |
| 4 | /* */ |
| 5 | /* This program is free software; you can redistribute it and/or */ |
| 6 | /* modify it under the terms of the GNU Library General Public License */ |
| 7 | /* as published by the Free Software Foundation; either version 2 */ |
| 8 | /* of the License, or (at your option) any later version. */ |
| 9 | /* */ |
| 10 | /* This program is distributed in the hope that it will be useful, */ |
| 11 | /* but WITHOUT ANY WARRANTY; without even the implied warranty of */ |
| 12 | /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ |
| 13 | /* GNU Library General Public License for more details. */ |
| 14 | |
| 15 | /* Thread creation, initialization, and basic low-level routines */ |
| 16 | |
| 17 | #define __FORCE_GLIBC |
| 18 | #include <features.h> |
| 19 | #include <errno.h> |
| 20 | #include <netdb.h> /* for h_errno */ |
| 21 | #include <stddef.h> |
| 22 | #include <stdio.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <unistd.h> |
| 26 | #include <fcntl.h> |
| 27 | #include <sys/wait.h> |
| 28 | #include <sys/resource.h> |
| 29 | #include "pthread.h" |
| 30 | #include "internals.h" |
| 31 | #include "spinlock.h" |
| 32 | #include "restart.h" |
| 33 | #include "debug.h" /* added to linuxthreads -StS */ |
| 34 | |
| 35 | |
| 36 | /* Mods for uClibc: Some includes */ |
| 37 | #include <signal.h> |
| 38 | #include <sys/types.h> |
| 39 | #include <sys/syscall.h> |
| 40 | |
| 41 | /* mods for uClibc: __libc_sigaction is not in any standard headers */ |
| 42 | extern __typeof(sigaction) __libc_sigaction; |
| 43 | libpthread_hidden_proto(waitpid) |
| 44 | libpthread_hidden_proto(raise) |
| 45 | |
| 46 | /* These variables are used by the setup code. */ |
| 47 | extern int _errno; |
| 48 | extern int _h_errno; |
| 49 | |
| 50 | |
| 51 | /* Descriptor of the initial thread */ |
| 52 | |
| 53 | struct _pthread_descr_struct __pthread_initial_thread = { |
| 54 | &__pthread_initial_thread, /* pthread_descr p_nextlive */ |
| 55 | &__pthread_initial_thread, /* pthread_descr p_prevlive */ |
| 56 | NULL, /* pthread_descr p_nextwaiting */ |
| 57 | NULL, /* pthread_descr p_nextlock */ |
| 58 | PTHREAD_THREADS_MAX, /* pthread_t p_tid */ |
| 59 | 0, /* int p_pid */ |
| 60 | 0, /* int p_priority */ |
| 61 | &__pthread_handles[0].h_lock, /* struct _pthread_fastlock * p_lock */ |
| 62 | 0, /* int p_signal */ |
| 63 | NULL, /* sigjmp_buf * p_signal_buf */ |
| 64 | NULL, /* sigjmp_buf * p_cancel_buf */ |
| 65 | 0, /* char p_terminated */ |
| 66 | 0, /* char p_detached */ |
| 67 | 0, /* char p_exited */ |
| 68 | NULL, /* void * p_retval */ |
| 69 | 0, /* int p_retval */ |
| 70 | NULL, /* pthread_descr p_joining */ |
| 71 | NULL, /* struct _pthread_cleanup_buffer * p_cleanup */ |
| 72 | 0, /* char p_cancelstate */ |
| 73 | 0, /* char p_canceltype */ |
| 74 | 0, /* char p_canceled */ |
| 75 | &_errno, /* int *p_errnop */ |
| 76 | 0, /* int p_errno */ |
| 77 | &_h_errno, /* int *p_h_errnop */ |
| 78 | 0, /* int p_h_errno */ |
| 79 | NULL, /* char * p_in_sighandler */ |
| 80 | 0, /* char p_sigwaiting */ |
| 81 | PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */ |
| 82 | {NULL}, /* void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE] */ |
| 83 | {NULL}, /* void * p_libc_specific[_LIBC_TSD_KEY_N] */ |
| 84 | 0, /* int p_userstack */ |
| 85 | NULL, /* void * p_guardaddr */ |
| 86 | 0, /* size_t p_guardsize */ |
| 87 | &__pthread_initial_thread, /* pthread_descr p_self */ |
| 88 | 0, /* Always index 0 */ |
| 89 | 0, /* int p_report_events */ |
| 90 | {{{0, }}, 0, NULL}, /* td_eventbuf_t p_eventbuf */ |
| 91 | __ATOMIC_INITIALIZER, /* struct pthread_atomic p_resume_count */ |
| 92 | 0, /* char p_woken_by_cancel */ |
| 93 | 0, /* char p_condvar_avail */ |
| 94 | 0, /* char p_sem_avail */ |
| 95 | NULL, /* struct pthread_extricate_if *p_extricate */ |
| 96 | NULL, /* pthread_readlock_info *p_readlock_list; */ |
| 97 | NULL, /* pthread_readlock_info *p_readlock_free; */ |
| 98 | 0 /* int p_untracked_readlock_count; */ |
| 99 | #ifdef __UCLIBC_HAS_XLOCALE__ |
| 100 | , |
| 101 | &__global_locale_data, /* __locale_t locale; */ |
| 102 | #endif /* __UCLIBC_HAS_XLOCALE__ */ |
| 103 | }; |
| 104 | |
| 105 | /* Descriptor of the manager thread; none of this is used but the error |
| 106 | variables, the p_pid and p_priority fields, |
| 107 | and the address for identification. */ |
| 108 | #define manager_thread (&__pthread_manager_thread) |
| 109 | struct _pthread_descr_struct __pthread_manager_thread = { |
| 110 | NULL, /* pthread_descr p_nextlive */ |
| 111 | NULL, /* pthread_descr p_prevlive */ |
| 112 | NULL, /* pthread_descr p_nextwaiting */ |
| 113 | NULL, /* pthread_descr p_nextlock */ |
| 114 | 0, /* int p_tid */ |
| 115 | 0, /* int p_pid */ |
| 116 | 0, /* int p_priority */ |
| 117 | &__pthread_handles[1].h_lock, /* struct _pthread_fastlock * p_lock */ |
| 118 | 0, /* int p_signal */ |
| 119 | NULL, /* sigjmp_buf * p_signal_buf */ |
| 120 | NULL, /* sigjmp_buf * p_cancel_buf */ |
| 121 | 0, /* char p_terminated */ |
| 122 | 0, /* char p_detached */ |
| 123 | 0, /* char p_exited */ |
| 124 | NULL, /* void * p_retval */ |
| 125 | 0, /* int p_retval */ |
| 126 | NULL, /* pthread_descr p_joining */ |
| 127 | NULL, /* struct _pthread_cleanup_buffer * p_cleanup */ |
| 128 | 0, /* char p_cancelstate */ |
| 129 | 0, /* char p_canceltype */ |
| 130 | 0, /* char p_canceled */ |
| 131 | &__pthread_manager_thread.p_errno, /* int *p_errnop */ |
| 132 | 0, /* int p_errno */ |
| 133 | NULL, /* int *p_h_errnop */ |
| 134 | 0, /* int p_h_errno */ |
| 135 | NULL, /* char * p_in_sighandler */ |
| 136 | 0, /* char p_sigwaiting */ |
| 137 | PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */ |
| 138 | {NULL}, /* void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE] */ |
| 139 | {NULL}, /* void * p_libc_specific[_LIBC_TSD_KEY_N] */ |
| 140 | 0, /* int p_userstack */ |
| 141 | NULL, /* void * p_guardaddr */ |
| 142 | 0, /* size_t p_guardsize */ |
| 143 | &__pthread_manager_thread, /* pthread_descr p_self */ |
| 144 | 1, /* Always index 1 */ |
| 145 | 0, /* int p_report_events */ |
| 146 | {{{0, }}, 0, NULL}, /* td_eventbuf_t p_eventbuf */ |
| 147 | __ATOMIC_INITIALIZER, /* struct pthread_atomic p_resume_count */ |
| 148 | 0, /* char p_woken_by_cancel */ |
| 149 | 0, /* char p_condvar_avail */ |
| 150 | 0, /* char p_sem_avail */ |
| 151 | NULL, /* struct pthread_extricate_if *p_extricate */ |
| 152 | NULL, /* pthread_readlock_info *p_readlock_list; */ |
| 153 | NULL, /* pthread_readlock_info *p_readlock_free; */ |
| 154 | 0 /* int p_untracked_readlock_count; */ |
| 155 | #ifdef __UCLIBC_HAS_XLOCALE__ |
| 156 | , |
| 157 | &__global_locale_data, /* __locale_t locale; */ |
| 158 | #endif /* __UCLIBC_HAS_XLOCALE__ */ |
| 159 | }; |
| 160 | |
| 161 | /* Pointer to the main thread (the father of the thread manager thread) */ |
| 162 | /* Originally, this is the initial thread, but this changes after fork() */ |
| 163 | |
| 164 | pthread_descr __pthread_main_thread = &__pthread_initial_thread; |
| 165 | |
| 166 | /* Limit between the stack of the initial thread (above) and the |
| 167 | stacks of other threads (below). Aligned on a STACK_SIZE boundary. */ |
| 168 | |
| 169 | char *__pthread_initial_thread_bos = NULL; |
| 170 | |
| 171 | #ifndef __ARCH_USE_MMU__ |
| 172 | /* See nommu notes in internals.h and pthread_initialize() below. */ |
| 173 | char *__pthread_initial_thread_tos = NULL; |
| 174 | char *__pthread_initial_thread_mid = NULL; |
| 175 | #endif /* __ARCH_USE_MMU__ */ |
| 176 | |
| 177 | /* File descriptor for sending requests to the thread manager. */ |
| 178 | /* Initially -1, meaning that the thread manager is not running. */ |
| 179 | |
| 180 | int __pthread_manager_request = -1; |
| 181 | |
| 182 | /* Other end of the pipe for sending requests to the thread manager. */ |
| 183 | |
| 184 | int __pthread_manager_reader; |
| 185 | |
| 186 | /* Limits of the thread manager stack */ |
| 187 | |
| 188 | char *__pthread_manager_thread_bos = NULL; |
| 189 | char *__pthread_manager_thread_tos = NULL; |
| 190 | |
| 191 | /* For process-wide exit() */ |
| 192 | |
| 193 | int __pthread_exit_requested = 0; |
| 194 | int __pthread_exit_code = 0; |
| 195 | |
| 196 | /* Communicate relevant LinuxThreads constants to gdb */ |
| 197 | |
| 198 | const int __pthread_threads_max = PTHREAD_THREADS_MAX; |
| 199 | const int __pthread_sizeof_handle = sizeof(struct pthread_handle_struct); |
| 200 | const int __pthread_offsetof_descr = offsetof(struct pthread_handle_struct, h_descr); |
| 201 | const int __pthread_offsetof_pid = offsetof(struct _pthread_descr_struct, |
| 202 | p_pid); |
| 203 | const int __linuxthreads_pthread_sizeof_descr |
| 204 | = sizeof(struct _pthread_descr_struct); |
| 205 | |
| 206 | const int __linuxthreads_initial_report_events; |
| 207 | |
| 208 | const char __linuxthreads_version[] = VERSION; |
| 209 | |
| 210 | /* Forward declarations */ |
| 211 | static void pthread_onexit_process(int retcode, void *arg); |
| 212 | static void pthread_handle_sigcancel(int sig); |
| 213 | static void pthread_handle_sigrestart(int sig); |
| 214 | static void pthread_handle_sigdebug(int sig); |
| 215 | int __pthread_timedsuspend_new(pthread_descr self, const struct timespec *abstime); |
| 216 | |
| 217 | /* Signal numbers used for the communication. |
| 218 | In these variables we keep track of the used variables. If the |
| 219 | platform does not support any real-time signals we will define the |
| 220 | values to some unreasonable value which will signal failing of all |
| 221 | the functions below. */ |
| 222 | #ifndef __NR_rt_sigaction |
| 223 | static int current_rtmin = -1; |
| 224 | static int current_rtmax = -1; |
| 225 | int __pthread_sig_restart = SIGUSR1; |
| 226 | int __pthread_sig_cancel = SIGUSR2; |
| 227 | int __pthread_sig_debug; |
| 228 | #else |
| 229 | |
| 230 | #if __SIGRTMAX - __SIGRTMIN >= 3 |
| 231 | static int current_rtmin = __SIGRTMIN + 3; |
| 232 | static int current_rtmax = __SIGRTMAX; |
| 233 | int __pthread_sig_restart = __SIGRTMIN; |
| 234 | int __pthread_sig_cancel = __SIGRTMIN + 1; |
| 235 | int __pthread_sig_debug = __SIGRTMIN + 2; |
| 236 | void (*__pthread_restart)(pthread_descr) = __pthread_restart_new; |
| 237 | void (*__pthread_suspend)(pthread_descr) = __pthread_wait_for_restart_signal; |
| 238 | int (*__pthread_timedsuspend)(pthread_descr, const struct timespec *) = __pthread_timedsuspend_new; |
| 239 | #else |
| 240 | static int current_rtmin = __SIGRTMIN; |
| 241 | static int current_rtmax = __SIGRTMAX; |
| 242 | int __pthread_sig_restart = SIGUSR1; |
| 243 | int __pthread_sig_cancel = SIGUSR2; |
| 244 | int __pthread_sig_debug; |
| 245 | void (*__pthread_restart)(pthread_descr) = __pthread_restart_old; |
| 246 | void (*__pthread_suspend)(pthread_descr) = __pthread_suspend_old; |
| 247 | int (*__pthread_timedsuspend)(pthread_descr, const struct timespec *) = __pthread_timedsuspend_old; |
| 248 | |
| 249 | #endif |
| 250 | |
| 251 | /* Return number of available real-time signal with highest priority. */ |
| 252 | int __libc_current_sigrtmin (void) |
| 253 | { |
| 254 | return current_rtmin; |
| 255 | } |
| 256 | |
| 257 | /* Return number of available real-time signal with lowest priority. */ |
| 258 | int __libc_current_sigrtmax (void) |
| 259 | { |
| 260 | return current_rtmax; |
| 261 | } |
| 262 | |
| 263 | /* Allocate real-time signal with highest/lowest available |
| 264 | priority. Please note that we don't use a lock since we assume |
| 265 | this function to be called at program start. */ |
| 266 | int __libc_allocate_rtsig (int high); |
| 267 | int __libc_allocate_rtsig (int high) |
| 268 | { |
| 269 | if (current_rtmin == -1 || current_rtmin > current_rtmax) |
| 270 | /* We don't have anymore signal available. */ |
| 271 | return -1; |
| 272 | return high ? current_rtmin++ : current_rtmax--; |
| 273 | } |
| 274 | #endif |
| 275 | |
| 276 | /* Initialize the pthread library. |
| 277 | Initialization is split in two functions: |
| 278 | - a constructor function that blocks the __pthread_sig_restart signal |
| 279 | (must do this very early, since the program could capture the signal |
| 280 | mask with e.g. sigsetjmp before creating the first thread); |
| 281 | - a regular function called from pthread_create when needed. */ |
| 282 | |
| 283 | static void pthread_initialize(void) __attribute__((constructor)); |
| 284 | |
| 285 | libpthread_hidden_proto(pthread_attr_destroy) |
| 286 | libpthread_hidden_proto(pthread_attr_init) |
| 287 | libpthread_hidden_proto(pthread_attr_getdetachstate) |
| 288 | libpthread_hidden_proto(pthread_attr_setdetachstate) |
| 289 | libpthread_hidden_proto(pthread_attr_getinheritsched) |
| 290 | libpthread_hidden_proto(pthread_attr_setinheritsched) |
| 291 | libpthread_hidden_proto(pthread_attr_setschedparam) |
| 292 | libpthread_hidden_proto(pthread_attr_getschedparam) |
| 293 | libpthread_hidden_proto(pthread_attr_getschedpolicy) |
| 294 | libpthread_hidden_proto(pthread_attr_setschedpolicy) |
| 295 | libpthread_hidden_proto(pthread_attr_getscope) |
| 296 | libpthread_hidden_proto(pthread_attr_setscope) |
| 297 | |
| 298 | libpthread_hidden_proto(pthread_exit) |
| 299 | |
| 300 | libpthread_hidden_proto(pthread_equal) |
| 301 | libpthread_hidden_proto(pthread_self) |
| 302 | libpthread_hidden_proto(pthread_getschedparam) |
| 303 | libpthread_hidden_proto(pthread_setschedparam) |
| 304 | |
| 305 | libpthread_hidden_proto(pthread_setcancelstate) |
| 306 | libpthread_hidden_proto(pthread_setcanceltype) |
| 307 | libpthread_hidden_proto(_pthread_cleanup_push_defer) |
| 308 | libpthread_hidden_proto(_pthread_cleanup_pop_restore) |
| 309 | |
| 310 | libpthread_hidden_proto(pthread_cond_broadcast) |
| 311 | libpthread_hidden_proto(pthread_cond_destroy) |
| 312 | libpthread_hidden_proto(pthread_cond_init) |
| 313 | libpthread_hidden_proto(pthread_cond_signal) |
| 314 | libpthread_hidden_proto(pthread_cond_wait) |
| 315 | libpthread_hidden_proto(pthread_cond_timedwait) |
| 316 | |
| 317 | libpthread_hidden_proto(pthread_condattr_destroy) |
| 318 | libpthread_hidden_proto(pthread_condattr_init) |
| 319 | |
| 320 | struct pthread_functions __pthread_functions = |
| 321 | { |
| 322 | #ifndef USE___THREAD |
| 323 | .ptr_pthread_internal_tsd_set = __pthread_internal_tsd_set, |
| 324 | .ptr_pthread_internal_tsd_get = __pthread_internal_tsd_get, |
| 325 | .ptr_pthread_internal_tsd_address = __pthread_internal_tsd_address, |
| 326 | #endif |
| 327 | /* |
| 328 | .ptr_pthread_fork = __pthread_fork, |
| 329 | */ |
| 330 | .ptr_pthread_attr_destroy = pthread_attr_destroy, |
| 331 | .ptr_pthread_attr_init = pthread_attr_init, |
| 332 | .ptr_pthread_attr_getdetachstate = pthread_attr_getdetachstate, |
| 333 | .ptr_pthread_attr_setdetachstate = pthread_attr_setdetachstate, |
| 334 | .ptr_pthread_attr_getinheritsched = pthread_attr_getinheritsched, |
| 335 | .ptr_pthread_attr_setinheritsched = pthread_attr_setinheritsched, |
| 336 | .ptr_pthread_attr_getschedparam = pthread_attr_getschedparam, |
| 337 | .ptr_pthread_attr_setschedparam = pthread_attr_setschedparam, |
| 338 | .ptr_pthread_attr_getschedpolicy = pthread_attr_getschedpolicy, |
| 339 | .ptr_pthread_attr_setschedpolicy = pthread_attr_setschedpolicy, |
| 340 | .ptr_pthread_attr_getscope = pthread_attr_getscope, |
| 341 | .ptr_pthread_attr_setscope = pthread_attr_setscope, |
| 342 | .ptr_pthread_condattr_destroy = pthread_condattr_destroy, |
| 343 | .ptr_pthread_condattr_init = pthread_condattr_init, |
| 344 | .ptr_pthread_cond_broadcast = pthread_cond_broadcast, |
| 345 | .ptr_pthread_cond_destroy = pthread_cond_destroy, |
| 346 | .ptr_pthread_cond_init = pthread_cond_init, |
| 347 | .ptr_pthread_cond_signal = pthread_cond_signal, |
| 348 | .ptr_pthread_cond_wait = pthread_cond_wait, |
| 349 | .ptr_pthread_cond_timedwait = pthread_cond_timedwait, |
| 350 | .ptr_pthread_equal = pthread_equal, |
| 351 | .ptr___pthread_exit = pthread_exit, |
| 352 | .ptr_pthread_getschedparam = pthread_getschedparam, |
| 353 | .ptr_pthread_setschedparam = pthread_setschedparam, |
| 354 | .ptr_pthread_mutex_destroy = __pthread_mutex_destroy, |
| 355 | .ptr_pthread_mutex_init = __pthread_mutex_init, |
| 356 | .ptr_pthread_mutex_lock = __pthread_mutex_lock, |
| 357 | .ptr_pthread_mutex_trylock = __pthread_mutex_trylock, |
| 358 | .ptr_pthread_mutex_unlock = __pthread_mutex_unlock, |
| 359 | .ptr_pthread_self = pthread_self, |
| 360 | .ptr_pthread_setcancelstate = pthread_setcancelstate, |
| 361 | .ptr_pthread_setcanceltype = pthread_setcanceltype, |
| 362 | /* |
| 363 | .ptr_pthread_do_exit = pthread_do_exit, |
| 364 | .ptr_pthread_thread_self = pthread_thread_self, |
| 365 | .ptr_pthread_cleanup_upto = pthread_cleanup_upto, |
| 366 | .ptr_pthread_sigaction = pthread_sigaction, |
| 367 | .ptr_pthread_sigwait = pthread_sigwait, |
| 368 | .ptr_pthread_raise = pthread_raise, |
| 369 | .ptr__pthread_cleanup_push = _pthread_cleanup_push, |
| 370 | .ptr__pthread_cleanup_pop = _pthread_cleanup_pop |
| 371 | */ |
| 372 | .ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer, |
| 373 | .ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore, |
| 374 | }; |
| 375 | #ifdef SHARED |
| 376 | # define ptr_pthread_functions &__pthread_functions |
| 377 | #else |
| 378 | # define ptr_pthread_functions NULL |
| 379 | #endif |
| 380 | |
| 381 | static int *__libc_multiple_threads_ptr; |
| 382 | |
| 383 | /* Do some minimal initialization which has to be done during the |
| 384 | startup of the C library. */ |
| 385 | void __pthread_initialize_minimal(void) |
| 386 | { |
| 387 | /* If we have special thread_self processing, initialize |
| 388 | * that for the main thread now. */ |
| 389 | #ifdef INIT_THREAD_SELF |
| 390 | INIT_THREAD_SELF(&__pthread_initial_thread, 0); |
| 391 | #endif |
| 392 | |
| 393 | __libc_multiple_threads_ptr = __libc_pthread_init (ptr_pthread_functions); |
| 394 | } |
| 395 | |
| 396 | |
| 397 | static void pthread_initialize(void) |
| 398 | { |
| 399 | struct sigaction sa; |
| 400 | sigset_t mask; |
| 401 | #ifdef __ARCH_USE_MMU__ |
| 402 | struct rlimit limit; |
| 403 | rlim_t max_stack; |
| 404 | #endif |
| 405 | |
| 406 | /* If already done (e.g. by a constructor called earlier!), bail out */ |
| 407 | if (__pthread_initial_thread_bos != NULL) return; |
| 408 | #ifdef TEST_FOR_COMPARE_AND_SWAP |
| 409 | /* Test if compare-and-swap is available */ |
| 410 | __pthread_has_cas = compare_and_swap_is_available(); |
| 411 | #endif |
| 412 | /* For the initial stack, reserve at least STACK_SIZE bytes of stack |
| 413 | below the current stack address, and align that on a |
| 414 | STACK_SIZE boundary. */ |
| 415 | __pthread_initial_thread_bos = |
| 416 | (char *)(((long)CURRENT_STACK_FRAME - 2 * STACK_SIZE) & ~(STACK_SIZE - 1)); |
| 417 | /* Update the descriptor for the initial thread. */ |
| 418 | __pthread_initial_thread.p_pid = getpid(); |
| 419 | /* If we have special thread_self processing, initialize that for the |
| 420 | main thread now. */ |
| 421 | #ifdef INIT_THREAD_SELF |
| 422 | INIT_THREAD_SELF(&__pthread_initial_thread, 0); |
| 423 | #endif |
| 424 | /* The errno/h_errno variable of the main thread are the global ones. */ |
| 425 | __pthread_initial_thread.p_errnop = &_errno; |
| 426 | __pthread_initial_thread.p_h_errnop = &_h_errno; |
| 427 | |
| 428 | #ifdef __UCLIBC_HAS_XLOCALE__ |
| 429 | /* The locale of the main thread is the current locale in use. */ |
| 430 | __pthread_initial_thread.locale = __curlocale_var; |
| 431 | #endif /* __UCLIBC_HAS_XLOCALE__ */ |
| 432 | |
| 433 | { /* uClibc-specific stdio initialization for threads. */ |
| 434 | FILE *fp; |
| 435 | |
| 436 | _stdio_user_locking = 0; /* 2 if threading not initialized */ |
| 437 | for (fp = _stdio_openlist; fp != NULL; fp = fp->__nextopen) { |
| 438 | if (fp->__user_locking != 1) { |
| 439 | fp->__user_locking = 0; |
| 440 | } |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | /* Play with the stack size limit to make sure that no stack ever grows |
| 445 | beyond STACK_SIZE minus two pages (one page for the thread descriptor |
| 446 | immediately beyond, and one page to act as a guard page). */ |
| 447 | |
| 448 | #ifdef __ARCH_USE_MMU__ |
| 449 | /* We cannot allocate a huge chunk of memory to mmap all thread stacks later |
| 450 | * on a non-MMU system. Thus, we don't need the rlimit either. -StS */ |
| 451 | getrlimit(RLIMIT_STACK, &limit); |
| 452 | max_stack = STACK_SIZE - 2 * getpagesize(); |
| 453 | if (limit.rlim_cur > max_stack) { |
| 454 | limit.rlim_cur = max_stack; |
| 455 | setrlimit(RLIMIT_STACK, &limit); |
| 456 | } |
| 457 | #else |
| 458 | /* For non-MMU, the initial thread stack can reside anywhere in memory. |
| 459 | * We don't have a way of knowing where the kernel started things -- top |
| 460 | * or bottom (well, that isn't exactly true, but the solution is fairly |
| 461 | * complex and error prone). All we can determine here is an address |
| 462 | * that lies within that stack. Save that address as a reference so that |
| 463 | * as other thread stacks are created, we can adjust the estimated bounds |
| 464 | * of the initial thread's stack appropriately. |
| 465 | * |
| 466 | * This checking is handled in NOMMU_INITIAL_THREAD_BOUNDS(), so see that |
| 467 | * for a few more details. |
| 468 | */ |
| 469 | __pthread_initial_thread_mid = CURRENT_STACK_FRAME; |
| 470 | __pthread_initial_thread_tos = (char *) -1; |
| 471 | __pthread_initial_thread_bos = (char *) 1; /* set it non-zero so we know we have been here */ |
| 472 | PDEBUG("initial thread stack bounds: bos=%p, tos=%p\n", |
| 473 | __pthread_initial_thread_bos, __pthread_initial_thread_tos); |
| 474 | #endif /* __ARCH_USE_MMU__ */ |
| 475 | |
| 476 | /* Setup signal handlers for the initial thread. |
| 477 | Since signal handlers are shared between threads, these settings |
| 478 | will be inherited by all other threads. */ |
| 479 | memset(&sa, 0, sizeof(sa)); |
| 480 | sa.sa_handler = pthread_handle_sigrestart; |
| 481 | __libc_sigaction(__pthread_sig_restart, &sa, NULL); |
| 482 | sa.sa_handler = pthread_handle_sigcancel; |
| 483 | sigaddset(&sa.sa_mask, __pthread_sig_restart); |
| 484 | __libc_sigaction(__pthread_sig_cancel, &sa, NULL); |
| 485 | if (__pthread_sig_debug > 0) { |
| 486 | sa.sa_handler = pthread_handle_sigdebug; |
| 487 | __sigemptyset(&sa.sa_mask); |
| 488 | __libc_sigaction(__pthread_sig_debug, &sa, NULL); |
| 489 | } |
| 490 | /* Initially, block __pthread_sig_restart. Will be unblocked on demand. */ |
| 491 | __sigemptyset(&mask); |
| 492 | sigaddset(&mask, __pthread_sig_restart); |
| 493 | sigprocmask(SIG_BLOCK, &mask, NULL); |
| 494 | /* And unblock __pthread_sig_cancel if it has been blocked. */ |
| 495 | sigdelset(&mask, __pthread_sig_restart); |
| 496 | sigaddset(&mask, __pthread_sig_cancel); |
| 497 | sigprocmask(SIG_UNBLOCK, &mask, NULL); |
| 498 | /* Register an exit function to kill all other threads. */ |
| 499 | /* Do it early so that user-registered atexit functions are called |
| 500 | before pthread_onexit_process. */ |
| 501 | on_exit(pthread_onexit_process, NULL); |
| 502 | } |
| 503 | |
| 504 | void __pthread_initialize(void); |
| 505 | void __pthread_initialize(void) |
| 506 | { |
| 507 | pthread_initialize(); |
| 508 | } |
| 509 | |
| 510 | int __pthread_initialize_manager(void) |
| 511 | { |
| 512 | int manager_pipe[2]; |
| 513 | int pid; |
| 514 | int report_events; |
| 515 | struct pthread_request request; |
| 516 | |
| 517 | *__libc_multiple_threads_ptr = 1; |
| 518 | |
| 519 | /* If basic initialization not done yet (e.g. we're called from a |
| 520 | constructor run before our constructor), do it now */ |
| 521 | if (__pthread_initial_thread_bos == NULL) pthread_initialize(); |
| 522 | /* Setup stack for thread manager */ |
| 523 | __pthread_manager_thread_bos = malloc(THREAD_MANAGER_STACK_SIZE); |
| 524 | if (__pthread_manager_thread_bos == NULL) return -1; |
| 525 | __pthread_manager_thread_tos = |
| 526 | __pthread_manager_thread_bos + THREAD_MANAGER_STACK_SIZE; |
| 527 | |
| 528 | /* On non-MMU systems we make sure that the initial thread bounds don't overlap |
| 529 | * with the manager stack frame */ |
| 530 | NOMMU_INITIAL_THREAD_BOUNDS(__pthread_manager_thread_tos,__pthread_manager_thread_bos); |
| 531 | PDEBUG("manager stack: size=%d, bos=%p, tos=%p\n", THREAD_MANAGER_STACK_SIZE, |
| 532 | __pthread_manager_thread_bos, __pthread_manager_thread_tos); |
| 533 | #if 0 |
| 534 | PDEBUG("initial stack: estimate bos=%p, tos=%p\n", |
| 535 | __pthread_initial_thread_bos, __pthread_initial_thread_tos); |
| 536 | #endif |
| 537 | |
| 538 | /* Setup pipe to communicate with thread manager */ |
| 539 | if (pipe(manager_pipe) == -1) { |
| 540 | free(__pthread_manager_thread_bos); |
| 541 | return -1; |
| 542 | } |
| 543 | /* Start the thread manager */ |
| 544 | pid = 0; |
| 545 | #if defined(USE_TLS) && USE_TLS |
| 546 | if (__linuxthreads_initial_report_events != 0) |
| 547 | THREAD_SETMEM (((pthread_descr) NULL), p_report_events, |
| 548 | __linuxthreads_initial_report_events); |
| 549 | report_events = THREAD_GETMEM (((pthread_descr) NULL), p_report_events); |
| 550 | #else |
| 551 | if (__linuxthreads_initial_report_events != 0) |
| 552 | __pthread_initial_thread.p_report_events |
| 553 | = __linuxthreads_initial_report_events; |
| 554 | report_events = __pthread_initial_thread.p_report_events; |
| 555 | #endif |
| 556 | if (__builtin_expect (report_events, 0)) |
| 557 | { |
| 558 | /* It's a bit more complicated. We have to report the creation of |
| 559 | the manager thread. */ |
| 560 | int idx = __td_eventword (TD_CREATE); |
| 561 | uint32_t mask = __td_eventmask (TD_CREATE); |
| 562 | |
| 563 | if ((mask & (__pthread_threads_events.event_bits[idx] |
| 564 | | __pthread_initial_thread.p_eventbuf.eventmask.event_bits[idx])) |
| 565 | != 0) |
| 566 | { |
| 567 | |
| 568 | __pthread_lock(__pthread_manager_thread.p_lock, NULL); |
| 569 | |
| 570 | #ifdef __ia64__ |
| 571 | pid = __clone2(__pthread_manager_event, |
| 572 | (void **) __pthread_manager_thread_tos, |
| 573 | THREAD_MANAGER_STACK_SIZE, |
| 574 | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, |
| 575 | (void *)(long)manager_pipe[0]); |
| 576 | #else |
| 577 | pid = clone(__pthread_manager_event, |
| 578 | (void **) __pthread_manager_thread_tos, |
| 579 | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, |
| 580 | (void *)(long)manager_pipe[0]); |
| 581 | #endif |
| 582 | |
| 583 | if (pid != -1) |
| 584 | { |
| 585 | /* Now fill in the information about the new thread in |
| 586 | the newly created thread's data structure. We cannot let |
| 587 | the new thread do this since we don't know whether it was |
| 588 | already scheduled when we send the event. */ |
| 589 | __pthread_manager_thread.p_eventbuf.eventdata = |
| 590 | &__pthread_manager_thread; |
| 591 | __pthread_manager_thread.p_eventbuf.eventnum = TD_CREATE; |
| 592 | __pthread_last_event = &__pthread_manager_thread; |
| 593 | __pthread_manager_thread.p_tid = 2* PTHREAD_THREADS_MAX + 1; |
| 594 | __pthread_manager_thread.p_pid = pid; |
| 595 | |
| 596 | /* Now call the function which signals the event. */ |
| 597 | __linuxthreads_create_event (); |
| 598 | } |
| 599 | /* Now restart the thread. */ |
| 600 | __pthread_unlock(__pthread_manager_thread.p_lock); |
| 601 | } |
| 602 | } |
| 603 | |
| 604 | if (pid == 0) { |
| 605 | #ifdef __ia64__ |
| 606 | pid = __clone2(__pthread_manager, (void **) __pthread_manager_thread_tos, |
| 607 | THREAD_MANAGER_STACK_SIZE, |
| 608 | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, |
| 609 | (void *)(long)manager_pipe[0]); |
| 610 | #else |
| 611 | pid = clone(__pthread_manager, (void **) __pthread_manager_thread_tos, |
| 612 | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, |
| 613 | (void *)(long)manager_pipe[0]); |
| 614 | #endif |
| 615 | } |
| 616 | if (pid == -1) { |
| 617 | free(__pthread_manager_thread_bos); |
| 618 | close(manager_pipe[0]); |
| 619 | close(manager_pipe[1]); |
| 620 | return -1; |
| 621 | } |
| 622 | __pthread_manager_request = manager_pipe[1]; /* writing end */ |
| 623 | __pthread_manager_reader = manager_pipe[0]; /* reading end */ |
| 624 | __pthread_manager_thread.p_tid = 2* PTHREAD_THREADS_MAX + 1; |
| 625 | __pthread_manager_thread.p_pid = pid; |
| 626 | |
| 627 | /* Make gdb aware of new thread manager */ |
| 628 | if (__pthread_threads_debug && __pthread_sig_debug > 0) |
| 629 | { |
| 630 | raise(__pthread_sig_debug); |
| 631 | /* We suspend ourself and gdb will wake us up when it is |
| 632 | ready to handle us. */ |
| 633 | __pthread_wait_for_restart_signal(thread_self()); |
| 634 | } |
| 635 | /* Synchronize debugging of the thread manager */ |
| 636 | PDEBUG("send REQ_DEBUG to manager thread\n"); |
| 637 | request.req_kind = REQ_DEBUG; |
| 638 | TEMP_FAILURE_RETRY(write(__pthread_manager_request, |
| 639 | (char *) &request, sizeof(request))); |
| 640 | return 0; |
| 641 | } |
| 642 | |
| 643 | /* Thread creation */ |
| 644 | |
| 645 | int pthread_create(pthread_t *thread, const pthread_attr_t *attr, |
| 646 | void * (*start_routine)(void *), void *arg) |
| 647 | { |
| 648 | pthread_descr self = thread_self(); |
| 649 | struct pthread_request request; |
| 650 | if (__pthread_manager_request < 0) { |
| 651 | if (__pthread_initialize_manager() < 0) return EAGAIN; |
| 652 | } |
| 653 | request.req_thread = self; |
| 654 | request.req_kind = REQ_CREATE; |
| 655 | request.req_args.create.attr = attr; |
| 656 | request.req_args.create.fn = start_routine; |
| 657 | request.req_args.create.arg = arg; |
| 658 | sigprocmask(SIG_SETMASK, NULL, &request.req_args.create.mask); |
| 659 | PDEBUG("write REQ_CREATE to manager thread\n"); |
| 660 | TEMP_FAILURE_RETRY(write(__pthread_manager_request, |
| 661 | (char *) &request, sizeof(request))); |
| 662 | PDEBUG("before suspend(self)\n"); |
| 663 | suspend(self); |
| 664 | PDEBUG("after suspend(self)\n"); |
| 665 | if (THREAD_GETMEM(self, p_retcode) == 0) |
| 666 | *thread = (pthread_t) THREAD_GETMEM(self, p_retval); |
| 667 | return THREAD_GETMEM(self, p_retcode); |
| 668 | } |
| 669 | |
| 670 | /* Simple operations on thread identifiers */ |
| 671 | |
| 672 | pthread_t pthread_self(void) |
| 673 | { |
| 674 | pthread_descr self = thread_self(); |
| 675 | return THREAD_GETMEM(self, p_tid); |
| 676 | } |
| 677 | libpthread_hidden_def (pthread_self) |
| 678 | |
| 679 | int pthread_equal(pthread_t thread1, pthread_t thread2) |
| 680 | { |
| 681 | return thread1 == thread2; |
| 682 | } |
| 683 | libpthread_hidden_def (pthread_equal) |
| 684 | |
| 685 | /* Helper function for thread_self in the case of user-provided stacks */ |
| 686 | |
| 687 | #ifndef THREAD_SELF |
| 688 | |
| 689 | pthread_descr __pthread_find_self(void) |
| 690 | { |
| 691 | char * sp = CURRENT_STACK_FRAME; |
| 692 | pthread_handle h; |
| 693 | |
| 694 | /* __pthread_handles[0] is the initial thread, __pthread_handles[1] is |
| 695 | the manager threads handled specially in thread_self(), so start at 2 */ |
| 696 | h = __pthread_handles + 2; |
| 697 | while (! (sp <= (char *) h->h_descr && sp >= h->h_bottom)) h++; |
| 698 | |
| 699 | #ifdef DEBUG_PT |
| 700 | if (h->h_descr == NULL) { |
| 701 | printf("*** %s ERROR descriptor is NULL!!!!! ***\n\n", __FUNCTION__); |
| 702 | _exit(1); |
| 703 | } |
| 704 | #endif |
| 705 | |
| 706 | return h->h_descr; |
| 707 | } |
| 708 | #else |
| 709 | |
| 710 | static pthread_descr thread_self_stack(void) |
| 711 | { |
| 712 | char *sp = CURRENT_STACK_FRAME; |
| 713 | pthread_handle h; |
| 714 | |
| 715 | if (sp >= __pthread_manager_thread_bos && sp < __pthread_manager_thread_tos) |
| 716 | return manager_thread; |
| 717 | h = __pthread_handles + 2; |
| 718 | # if defined(USE_TLS) && USE_TLS |
| 719 | while (h->h_descr == NULL |
| 720 | || ! (sp <= (char *) h->h_descr->p_stackaddr && sp >= h->h_bottom)) |
| 721 | h++; |
| 722 | # else |
| 723 | while (! (sp <= (char *) h->h_descr && sp >= h->h_bottom)) |
| 724 | h++; |
| 725 | # endif |
| 726 | return h->h_descr; |
| 727 | } |
| 728 | |
| 729 | #endif |
| 730 | |
| 731 | /* Thread scheduling */ |
| 732 | |
| 733 | int pthread_setschedparam(pthread_t thread, int policy, |
| 734 | const struct sched_param *param) |
| 735 | { |
| 736 | pthread_handle handle = thread_handle(thread); |
| 737 | pthread_descr th; |
| 738 | |
| 739 | __pthread_lock(&handle->h_lock, NULL); |
| 740 | if (invalid_handle(handle, thread)) { |
| 741 | __pthread_unlock(&handle->h_lock); |
| 742 | return ESRCH; |
| 743 | } |
| 744 | th = handle->h_descr; |
| 745 | if (sched_setscheduler(th->p_pid, policy, param) == -1) { |
| 746 | __pthread_unlock(&handle->h_lock); |
| 747 | return errno; |
| 748 | } |
| 749 | th->p_priority = policy == SCHED_OTHER ? 0 : param->sched_priority; |
| 750 | __pthread_unlock(&handle->h_lock); |
| 751 | if (__pthread_manager_request >= 0) |
| 752 | __pthread_manager_adjust_prio(th->p_priority); |
| 753 | return 0; |
| 754 | } |
| 755 | libpthread_hidden_def(pthread_setschedparam) |
| 756 | |
| 757 | int pthread_getschedparam(pthread_t thread, int *policy, |
| 758 | struct sched_param *param) |
| 759 | { |
| 760 | pthread_handle handle = thread_handle(thread); |
| 761 | int pid, pol; |
| 762 | |
| 763 | __pthread_lock(&handle->h_lock, NULL); |
| 764 | if (invalid_handle(handle, thread)) { |
| 765 | __pthread_unlock(&handle->h_lock); |
| 766 | return ESRCH; |
| 767 | } |
| 768 | pid = handle->h_descr->p_pid; |
| 769 | __pthread_unlock(&handle->h_lock); |
| 770 | pol = sched_getscheduler(pid); |
| 771 | if (pol == -1) return errno; |
| 772 | if (sched_getparam(pid, param) == -1) return errno; |
| 773 | *policy = pol; |
| 774 | return 0; |
| 775 | } |
| 776 | libpthread_hidden_def(pthread_getschedparam) |
| 777 | |
| 778 | /* Process-wide exit() request */ |
| 779 | |
| 780 | static void pthread_onexit_process(int retcode, void *arg attribute_unused) |
| 781 | { |
| 782 | struct pthread_request request; |
| 783 | pthread_descr self = thread_self(); |
| 784 | |
| 785 | if (__pthread_manager_request >= 0) { |
| 786 | request.req_thread = self; |
| 787 | request.req_kind = REQ_PROCESS_EXIT; |
| 788 | request.req_args.exit.code = retcode; |
| 789 | TEMP_FAILURE_RETRY(write(__pthread_manager_request, |
| 790 | (char *) &request, sizeof(request))); |
| 791 | suspend(self); |
| 792 | /* Main thread should accumulate times for thread manager and its |
| 793 | children, so that timings for main thread account for all threads. */ |
| 794 | if (self == __pthread_main_thread) { |
| 795 | waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); |
| 796 | /* Since all threads have been asynchronously terminated |
| 797 | * (possibly holding locks), free cannot be used any more. */ |
| 798 | __pthread_manager_thread_bos = __pthread_manager_thread_tos = NULL; |
| 799 | } |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | /* The handler for the RESTART signal just records the signal received |
| 804 | in the thread descriptor, and optionally performs a siglongjmp |
| 805 | (for pthread_cond_timedwait). */ |
| 806 | |
| 807 | static void pthread_handle_sigrestart(int sig) |
| 808 | { |
| 809 | pthread_descr self = thread_self(); |
| 810 | THREAD_SETMEM(self, p_signal, sig); |
| 811 | if (THREAD_GETMEM(self, p_signal_jmp) != NULL) |
| 812 | siglongjmp(*THREAD_GETMEM(self, p_signal_jmp), 1); |
| 813 | } |
| 814 | |
| 815 | /* The handler for the CANCEL signal checks for cancellation |
| 816 | (in asynchronous mode), for process-wide exit and exec requests. |
| 817 | For the thread manager thread, redirect the signal to |
| 818 | __pthread_manager_sighandler. */ |
| 819 | |
| 820 | static void pthread_handle_sigcancel(int sig) |
| 821 | { |
| 822 | pthread_descr self = thread_self(); |
| 823 | sigjmp_buf * jmpbuf; |
| 824 | |
| 825 | |
| 826 | if (self == &__pthread_manager_thread) |
| 827 | { |
| 828 | #ifdef THREAD_SELF |
| 829 | /* A new thread might get a cancel signal before it is fully |
| 830 | initialized, so that the thread register might still point to the |
| 831 | manager thread. Double check that this is really the manager |
| 832 | thread. */ |
| 833 | pthread_descr real_self = thread_self_stack(); |
| 834 | if (real_self == &__pthread_manager_thread) |
| 835 | { |
| 836 | __pthread_manager_sighandler(sig); |
| 837 | return; |
| 838 | } |
| 839 | /* Oops, thread_self() isn't working yet.. */ |
| 840 | self = real_self; |
| 841 | # ifdef INIT_THREAD_SELF |
| 842 | INIT_THREAD_SELF(self, self->p_nr); |
| 843 | # endif |
| 844 | #else |
| 845 | __pthread_manager_sighandler(sig); |
| 846 | return; |
| 847 | #endif |
| 848 | } |
| 849 | if (__builtin_expect (__pthread_exit_requested, 0)) { |
| 850 | /* Main thread should accumulate times for thread manager and its |
| 851 | children, so that timings for main thread account for all threads. */ |
| 852 | if (self == __pthread_main_thread) { |
| 853 | #if defined(USE_TLS) && USE_TLS |
| 854 | waitpid(__pthread_manager_thread->p_pid, NULL, __WCLONE); |
| 855 | #else |
| 856 | waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); |
| 857 | #endif |
| 858 | } |
| 859 | _exit(__pthread_exit_code); |
| 860 | } |
| 861 | if (__builtin_expect (THREAD_GETMEM(self, p_canceled), 0) |
| 862 | && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) { |
| 863 | if (THREAD_GETMEM(self, p_canceltype) == PTHREAD_CANCEL_ASYNCHRONOUS) |
| 864 | __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); |
| 865 | jmpbuf = THREAD_GETMEM(self, p_cancel_jmp); |
| 866 | if (jmpbuf != NULL) { |
| 867 | THREAD_SETMEM(self, p_cancel_jmp, NULL); |
| 868 | siglongjmp(*jmpbuf, 1); |
| 869 | } |
| 870 | } |
| 871 | } |
| 872 | |
| 873 | /* Handler for the DEBUG signal. |
| 874 | The debugging strategy is as follows: |
| 875 | On reception of a REQ_DEBUG request (sent by new threads created to |
| 876 | the thread manager under debugging mode), the thread manager throws |
| 877 | __pthread_sig_debug to itself. The debugger (if active) intercepts |
| 878 | this signal, takes into account new threads and continue execution |
| 879 | of the thread manager by propagating the signal because it doesn't |
| 880 | know what it is specifically done for. In the current implementation, |
| 881 | the thread manager simply discards it. */ |
| 882 | |
| 883 | static void pthread_handle_sigdebug(int sig attribute_unused) |
| 884 | { |
| 885 | /* Nothing */ |
| 886 | } |
| 887 | |
| 888 | /* Reset the state of the thread machinery after a fork(). |
| 889 | Close the pipe used for requests and set the main thread to the forked |
| 890 | thread. |
| 891 | Notice that we can't free the stack segments, as the forked thread |
| 892 | may hold pointers into them. */ |
| 893 | |
| 894 | void __pthread_reset_main_thread(void) |
| 895 | { |
| 896 | pthread_descr self = thread_self(); |
| 897 | |
| 898 | if (__pthread_manager_request != -1) { |
| 899 | /* Free the thread manager stack */ |
| 900 | free(__pthread_manager_thread_bos); |
| 901 | __pthread_manager_thread_bos = __pthread_manager_thread_tos = NULL; |
| 902 | /* Close the two ends of the pipe */ |
| 903 | close(__pthread_manager_request); |
| 904 | close(__pthread_manager_reader); |
| 905 | __pthread_manager_request = __pthread_manager_reader = -1; |
| 906 | } |
| 907 | |
| 908 | /* Update the pid of the main thread */ |
| 909 | THREAD_SETMEM(self, p_pid, getpid()); |
| 910 | /* Make the forked thread the main thread */ |
| 911 | __pthread_main_thread = self; |
| 912 | THREAD_SETMEM(self, p_nextlive, self); |
| 913 | THREAD_SETMEM(self, p_prevlive, self); |
| 914 | /* Now this thread modifies the global variables. */ |
| 915 | THREAD_SETMEM(self, p_errnop, &_errno); |
| 916 | THREAD_SETMEM(self, p_h_errnop, &_h_errno); |
| 917 | } |
| 918 | |
| 919 | /* Process-wide exec() request */ |
| 920 | |
| 921 | void __pthread_kill_other_threads_np(void) |
| 922 | { |
| 923 | struct sigaction sa; |
| 924 | /* Terminate all other threads and thread manager */ |
| 925 | pthread_onexit_process(0, NULL); |
| 926 | /* Make current thread the main thread in case the calling thread |
| 927 | changes its mind, does not exec(), and creates new threads instead. */ |
| 928 | __pthread_reset_main_thread(); |
| 929 | /* Reset the signal handlers behaviour for the signals the |
| 930 | implementation uses since this would be passed to the new |
| 931 | process. */ |
| 932 | memset(&sa, 0, sizeof(sa)); |
| 933 | if (SIG_DFL) /* if it's constant zero, it's already done */ |
| 934 | sa.sa_handler = SIG_DFL; |
| 935 | __libc_sigaction(__pthread_sig_restart, &sa, NULL); |
| 936 | __libc_sigaction(__pthread_sig_cancel, &sa, NULL); |
| 937 | if (__pthread_sig_debug > 0) |
| 938 | __libc_sigaction(__pthread_sig_debug, &sa, NULL); |
| 939 | } |
| 940 | weak_alias (__pthread_kill_other_threads_np, pthread_kill_other_threads_np) |
| 941 | |
| 942 | /* Concurrency symbol level. */ |
| 943 | static int current_level; |
| 944 | |
| 945 | int __pthread_setconcurrency(int level) |
| 946 | { |
| 947 | /* We don't do anything unless we have found a useful interpretation. */ |
| 948 | current_level = level; |
| 949 | return 0; |
| 950 | } |
| 951 | weak_alias (__pthread_setconcurrency, pthread_setconcurrency) |
| 952 | |
| 953 | int __pthread_getconcurrency(void) |
| 954 | { |
| 955 | return current_level; |
| 956 | } |
| 957 | weak_alias (__pthread_getconcurrency, pthread_getconcurrency) |
| 958 | |
| 959 | |
| 960 | /* Primitives for controlling thread execution */ |
| 961 | |
| 962 | void __pthread_wait_for_restart_signal(pthread_descr self) |
| 963 | { |
| 964 | sigset_t mask; |
| 965 | |
| 966 | sigprocmask(SIG_SETMASK, NULL, &mask); /* Get current signal mask */ |
| 967 | sigdelset(&mask, __pthread_sig_restart); /* Unblock the restart signal */ |
| 968 | THREAD_SETMEM(self, p_signal, 0); |
| 969 | do { |
| 970 | sigsuspend(&mask); /* Wait for signal */ |
| 971 | } while (THREAD_GETMEM(self, p_signal) !=__pthread_sig_restart); |
| 972 | |
| 973 | READ_MEMORY_BARRIER(); /* See comment in __pthread_restart_new */ |
| 974 | } |
| 975 | |
| 976 | #ifndef __NR_rt_sigaction |
| 977 | /* The _old variants are for 2.0 and early 2.1 kernels which don't have RT |
| 978 | signals. |
| 979 | On these kernels, we use SIGUSR1 and SIGUSR2 for restart and cancellation. |
| 980 | Since the restart signal does not queue, we use an atomic counter to create |
| 981 | queuing semantics. This is needed to resolve a rare race condition in |
| 982 | pthread_cond_timedwait_relative. */ |
| 983 | |
| 984 | void __pthread_restart_old(pthread_descr th) |
| 985 | { |
| 986 | if (atomic_increment(&th->p_resume_count) == -1) |
| 987 | kill(th->p_pid, __pthread_sig_restart); |
| 988 | } |
| 989 | |
| 990 | void __pthread_suspend_old(pthread_descr self) |
| 991 | { |
| 992 | if (atomic_decrement(&self->p_resume_count) <= 0) |
| 993 | __pthread_wait_for_restart_signal(self); |
| 994 | } |
| 995 | |
| 996 | int |
| 997 | __pthread_timedsuspend_old(pthread_descr self, const struct timespec *abstime) |
| 998 | { |
| 999 | sigset_t unblock, initial_mask; |
| 1000 | int was_signalled = 0; |
| 1001 | sigjmp_buf jmpbuf; |
| 1002 | |
| 1003 | if (atomic_decrement(&self->p_resume_count) == 0) { |
| 1004 | /* Set up a longjmp handler for the restart signal, unblock |
| 1005 | the signal and sleep. */ |
| 1006 | |
| 1007 | if (sigsetjmp(jmpbuf, 1) == 0) { |
| 1008 | THREAD_SETMEM(self, p_signal_jmp, &jmpbuf); |
| 1009 | THREAD_SETMEM(self, p_signal, 0); |
| 1010 | /* Unblock the restart signal */ |
| 1011 | __sigemptyset(&unblock); |
| 1012 | sigaddset(&unblock, __pthread_sig_restart); |
| 1013 | sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask); |
| 1014 | |
| 1015 | while (1) { |
| 1016 | struct timeval now; |
| 1017 | struct timespec reltime; |
| 1018 | |
| 1019 | /* Compute a time offset relative to now. */ |
| 1020 | gettimeofday (&now, NULL); |
| 1021 | reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000; |
| 1022 | reltime.tv_sec = abstime->tv_sec - now.tv_sec; |
| 1023 | if (reltime.tv_nsec < 0) { |
| 1024 | reltime.tv_nsec += 1000000000; |
| 1025 | reltime.tv_sec -= 1; |
| 1026 | } |
| 1027 | |
| 1028 | /* Sleep for the required duration. If woken by a signal, |
| 1029 | resume waiting as required by Single Unix Specification. */ |
| 1030 | if (reltime.tv_sec < 0 || nanosleep(&reltime, NULL) == 0) |
| 1031 | break; |
| 1032 | } |
| 1033 | |
| 1034 | /* Block the restart signal again */ |
| 1035 | sigprocmask(SIG_SETMASK, &initial_mask, NULL); |
| 1036 | was_signalled = 0; |
| 1037 | } else { |
| 1038 | was_signalled = 1; |
| 1039 | } |
| 1040 | THREAD_SETMEM(self, p_signal_jmp, NULL); |
| 1041 | } |
| 1042 | |
| 1043 | /* Now was_signalled is true if we exited the above code |
| 1044 | due to the delivery of a restart signal. In that case, |
| 1045 | we know we have been dequeued and resumed and that the |
| 1046 | resume count is balanced. Otherwise, there are some |
| 1047 | cases to consider. First, try to bump up the resume count |
| 1048 | back to zero. If it goes to 1, it means restart() was |
| 1049 | invoked on this thread. The signal must be consumed |
| 1050 | and the count bumped down and everything is cool. We |
| 1051 | can return a 1 to the caller. |
| 1052 | Otherwise, no restart was delivered yet, so a potential |
| 1053 | race exists; we return a 0 to the caller which must deal |
| 1054 | with this race in an appropriate way; for example by |
| 1055 | atomically removing the thread from consideration for a |
| 1056 | wakeup---if such a thing fails, it means a restart is |
| 1057 | being delivered. */ |
| 1058 | |
| 1059 | if (!was_signalled) { |
| 1060 | if (atomic_increment(&self->p_resume_count) != -1) { |
| 1061 | __pthread_wait_for_restart_signal(self); |
| 1062 | atomic_decrement(&self->p_resume_count); /* should be zero now! */ |
| 1063 | /* woke spontaneously and consumed restart signal */ |
| 1064 | return 1; |
| 1065 | } |
| 1066 | /* woke spontaneously but did not consume restart---caller must resolve */ |
| 1067 | return 0; |
| 1068 | } |
| 1069 | /* woken due to restart signal */ |
| 1070 | return 1; |
| 1071 | } |
| 1072 | #endif /* __NR_rt_sigaction */ |
| 1073 | |
| 1074 | |
| 1075 | #ifdef __NR_rt_sigaction |
| 1076 | void __pthread_restart_new(pthread_descr th) |
| 1077 | { |
| 1078 | /* The barrier is proabably not needed, in which case it still documents |
| 1079 | our assumptions. The intent is to commit previous writes to shared |
| 1080 | memory so the woken thread will have a consistent view. Complementary |
| 1081 | read barriers are present to the suspend functions. */ |
| 1082 | WRITE_MEMORY_BARRIER(); |
| 1083 | kill(th->p_pid, __pthread_sig_restart); |
| 1084 | } |
| 1085 | |
| 1086 | int __pthread_timedsuspend_new(pthread_descr self, const struct timespec *abstime) |
| 1087 | { |
| 1088 | sigset_t unblock, initial_mask; |
| 1089 | int was_signalled = 0; |
| 1090 | sigjmp_buf jmpbuf; |
| 1091 | |
| 1092 | if (sigsetjmp(jmpbuf, 1) == 0) { |
| 1093 | THREAD_SETMEM(self, p_signal_jmp, &jmpbuf); |
| 1094 | THREAD_SETMEM(self, p_signal, 0); |
| 1095 | /* Unblock the restart signal */ |
| 1096 | __sigemptyset(&unblock); |
| 1097 | sigaddset(&unblock, __pthread_sig_restart); |
| 1098 | sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask); |
| 1099 | |
| 1100 | while (1) { |
| 1101 | struct timeval now; |
| 1102 | struct timespec reltime; |
| 1103 | |
| 1104 | /* Compute a time offset relative to now. */ |
| 1105 | gettimeofday (&now, NULL); |
| 1106 | reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000; |
| 1107 | reltime.tv_sec = abstime->tv_sec - now.tv_sec; |
| 1108 | if (reltime.tv_nsec < 0) { |
| 1109 | reltime.tv_nsec += 1000000000; |
| 1110 | reltime.tv_sec -= 1; |
| 1111 | } |
| 1112 | |
| 1113 | /* Sleep for the required duration. If woken by a signal, |
| 1114 | resume waiting as required by Single Unix Specification. */ |
| 1115 | if (reltime.tv_sec < 0 || nanosleep(&reltime, NULL) == 0) |
| 1116 | break; |
| 1117 | } |
| 1118 | |
| 1119 | /* Block the restart signal again */ |
| 1120 | sigprocmask(SIG_SETMASK, &initial_mask, NULL); |
| 1121 | was_signalled = 0; |
| 1122 | } else { |
| 1123 | was_signalled = 1; |
| 1124 | } |
| 1125 | THREAD_SETMEM(self, p_signal_jmp, NULL); |
| 1126 | |
| 1127 | /* Now was_signalled is true if we exited the above code |
| 1128 | due to the delivery of a restart signal. In that case, |
| 1129 | everything is cool. We have been removed from whatever |
| 1130 | we were waiting on by the other thread, and consumed its signal. |
| 1131 | |
| 1132 | Otherwise we this thread woke up spontaneously, or due to a signal other |
| 1133 | than restart. This is an ambiguous case that must be resolved by |
| 1134 | the caller; the thread is still eligible for a restart wakeup |
| 1135 | so there is a race. */ |
| 1136 | |
| 1137 | READ_MEMORY_BARRIER(); /* See comment in __pthread_restart_new */ |
| 1138 | return was_signalled; |
| 1139 | } |
| 1140 | #endif |
| 1141 | |
| 1142 | /* Debugging aid */ |
| 1143 | |
| 1144 | #ifdef DEBUG_PT |
| 1145 | #include <stdarg.h> |
| 1146 | |
| 1147 | void __pthread_message(char * fmt, ...) |
| 1148 | { |
| 1149 | char buffer[1024]; |
| 1150 | va_list args; |
| 1151 | sprintf(buffer, "%05d : ", getpid()); |
| 1152 | va_start(args, fmt); |
| 1153 | vsnprintf(buffer + 8, sizeof(buffer) - 8, fmt, args); |
| 1154 | va_end(args); |
| 1155 | TEMP_FAILURE_RETRY(write(2, buffer, strlen(buffer))); |
| 1156 | } |
| 1157 | |
| 1158 | #endif |
| 1159 | |
| 1160 | |
| 1161 | #ifndef __PIC__ |
| 1162 | /* We need a hook to force the cancellation wrappers to be linked in when |
| 1163 | static libpthread is used. */ |
| 1164 | extern const char __pthread_provide_wrappers; |
| 1165 | static const char *const __pthread_require_wrappers = |
| 1166 | &__pthread_provide_wrappers; |
| 1167 | #endif |