glibc-linuxthreads-2.3.4.tar.gz

/* Linuxthreads - a simple clone()-based implementation of Posix */ /* threads for Linux. */ /* Copyright (C) 1996 Xavier Leroy ([email protected]) */ /* */ /* This program is free software; you can redistribute it and/or */ /* modify it under the terms of the GNU Library General Public License */ /* as published by the Free Software Foundation; either version 2 */ /* of the License, or (at your option) any later version. */ /* */ /* This program is distributed in the hope that it will be useful, */ /* but WITHOUT ANY WARRANTY; without even the implied warranty of */ /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ /* GNU Library General Public License for more details. */ /* Thread creation, initialization, and basic low-level routines */ #include <errno.h> #include <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/wait.h> #include <sys/resource.h> #include <sys/time.h> #include <shlib-compat.h> #include "pthread.h" #include "internals.h" #include "spinlock.h" #include "restart.h" #include "smp.h" #include <ldsodefs.h> #include <tls.h> #include <version.h> #include <not-cancel.h> /* Sanity check. */ #if !defined __SIGRTMIN || (__SIGRTMAX - __SIGRTMIN) < 3 # error "This must not happen" #endif #if !(USE_TLS && HAVE___THREAD) /* These variables are used by the setup code. */ extern int _errno; extern int _h_errno; /* We need the global/static resolver state here. */ # include <resolv.h> # undef _res extern struct __res_state _res; #endif #ifdef USE_TLS /* We need only a few variables. */ #define manager_thread __pthread_manager_threadp pthread_descr __pthread_manager_threadp attribute_hidden; #else /* Descriptor of the initial thread */ struct _pthread_descr_struct __pthread_initial_thread = { .p_header.data.self = &__pthread_initial_thread, .p_nextlive = &__pthread_initial_thread, .p_prevlive = &__pthread_initial_thread, .p_tid = PTHREAD_THREADS_MAX, .p_lock = &__pthread_handles[0].h_lock, .p_start_args = PTHREAD_START_ARGS_INITIALIZER(NULL), #if !(USE_TLS && HAVE___THREAD) .p_errnop = &_errno, .p_h_errnop = &_h_errno, .p_resp = &_res, #endif .p_userstack = 1, .p_resume_count = __ATOMIC_INITIALIZER, .p_alloca_cutoff = __MAX_ALLOCA_CUTOFF }; /* Descriptor of the manager thread; none of this is used but the error variables, the p_pid and p_priority fields, and the address for identification. */ #define manager_thread (&__pthread_manager_thread) struct _pthread_descr_struct __pthread_manager_thread = { .p_header.data.self = &__pthread_manager_thread, .p_header.data.multiple_threads = 1, .p_lock = &__pthread_handles[1].h_lock, .p_start_args = PTHREAD_START_ARGS_INITIALIZER(__pthread_manager), #if !(USE_TLS && HAVE___THREAD) .p_errnop = &__pthread_manager_thread.p_errno, #endif .p_nr = 1, .p_resume_count = __ATOMIC_INITIALIZER, .p_alloca_cutoff = PTHREAD_STACK_MIN / 4 }; #endif /* Pointer to the main thread (the father of the thread manager thread) */ /* Originally, this is the initial thread, but this changes after fork() */ #ifdef USE_TLS pthread_descr __pthread_main_thread; #else pthread_descr __pthread_main_thread = &__pthread_initial_thread; #endif /* Limit between the stack of the initial thread (above) and the stacks of other threads (below). Aligned on a STACK_SIZE boundary. */ char *__pthread_initial_thread_bos; /* File descriptor for sending requests to the thread manager. */ /* Initially -1, meaning that the thread manager is not running. */ int __pthread_manager_request = -1; int __pthread_multiple_threads attribute_hidden; /* Other end of the pipe for sending requests to the thread manager. */ int __pthread_manager_reader; /* Limits of the thread manager stack */ char *__pthread_manager_thread_bos; char *__pthread_manager_thread_tos; /* For process-wide exit() */ int __pthread_exit_requested; int __pthread_exit_code; /* Maximum stack size. */ size_t __pthread_max_stacksize; /* Nozero if the machine has more than one processor. */ int __pthread_smp_kernel; #if !__ASSUME_REALTIME_SIGNALS /* Pointers that select new or old suspend/resume functions based on availability of rt signals. */ void (*__pthread_restart)(pthread_descr) = __pthread_restart_old; void (*__pthread_suspend)(pthread_descr) = __pthread_suspend_old; int (*__pthread_timedsuspend)(pthread_descr, const struct timespec *) = __pthread_timedsuspend_old; #endif /* __ASSUME_REALTIME_SIGNALS */ /* Communicate relevant LinuxThreads constants to gdb */ const int __pthread_threads_max = PTHREAD_THREADS_MAX; const int __pthread_sizeof_handle = sizeof(struct pthread_handle_struct); const int __pthread_offsetof_descr = offsetof(struct pthread_handle_struct, h_descr); const int __pthread_offsetof_pid = offsetof(struct _pthread_descr_struct, p_pid); const int __linuxthreads_pthread_sizeof_descr = sizeof(struct _pthread_descr_struct); const int __linuxthreads_initial_report_events; const char __linuxthreads_version[] = VERSION; /* Forward declarations */ static void pthread_onexit_process(int retcode, void *arg); #ifndef HAVE_Z_NODELETE static void pthread_atexit_process(void *arg, int retcode); static void pthread_atexit_retcode(void *arg, int retcode); #endif static void pthread_handle_sigcancel(int sig); static void pthread_handle_sigrestart(int sig); static void pthread_handle_sigdebug(int sig); /* Signal numbers used for the communication. In these variables we keep track of the used variables. If the platform does not support any real-time signals we will define the values to some unreasonable value which will signal failing of all the functions below. */ int __pthread_sig_restart = __SIGRTMIN; int __pthread_sig_cancel = __SIGRTMIN + 1; int __pthread_sig_debug = __SIGRTMIN + 2; extern int __libc_current_sigrtmin_private (void); #if !__ASSUME_REALTIME_SIGNALS static int rtsigs_initialized; static void init_rtsigs (void) { if (rtsigs_initialized) return; if (__libc_current_sigrtmin_private () == -1) { __pthread_sig_restart = SIGUSR1; __pthread_sig_cancel = SIGUSR2; __pthread_sig_debug = 0; } else { __pthread_restart = __pthread_restart_new; __pthread_suspend = __pthread_wait_for_restart_signal; __pthread_timedsuspend = __pthread_timedsuspend_new; } rtsigs_initialized = 1; } #endif /* Initialize the pthread library. Initialization is split in two functions: - a constructor function that blocks the __pthread_sig_restart signal (must do this very early, since the program could capture the signal mask with e.g. sigsetjmp before creating the first thread); - a regular function called from pthread_create when needed. */ static void pthread_initialize(void) __attribute__((constructor)); #ifndef HAVE_Z_NODELETE extern void *__dso_handle __attribute__ ((weak)); #endif #if defined USE_TLS && !defined SHARED extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign); #endif struct pthread_functions __pthread_functions = { #if !(USE_TLS && HAVE___THREAD) .ptr_pthread_internal_tsd_set = __pthread_internal_tsd_set, .ptr_pthread_internal_tsd_get = __pthread_internal_tsd_get, .ptr_pthread_internal_tsd_address = __pthread_internal_tsd_address, #endif .ptr_pthread_fork = __pthread_fork, .ptr_pthread_attr_destroy = __pthread_attr_destroy, #if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1) .ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0, #endif .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1, .ptr_pthread_a