glibc-linuxthreads-2.0.6.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 <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/wait.h> #include "pthread.h" #include "internals.h" #include "spinlock.h" #include "restart.h" /* Descriptor of the initial thread */ struct _pthread_descr_struct __pthread_initial_thread = { &__pthread_initial_thread, /* pthread_descr p_nextlive */ &__pthread_initial_thread, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ PTHREAD_THREADS_MAX, /* pthread_t p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ &__pthread_handles[0].h_spinlock, /* int * p_spinlock */ 0, /* int p_signal */ NULL, /* sigjmp_buf * p_signal_buf */ NULL, /* sigjmp_buf * p_cancel_buf */ 0, /* char p_terminated */ 0, /* char p_detached */ 0, /* char p_exited */ NULL, /* void * p_retval */ 0, /* int p_retval */ NULL, /* pthread_descr p_joining */ NULL, /* struct _pthread_cleanup_buffer * p_cleanup */ 0, /* char p_cancelstate */ 0, /* char p_canceltype */ 0, /* char p_canceled */ 0, /* int p_errno */ 0, /* int p_h_errno */ PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */ {NULL}, /* void ** p_specific[PTHREAD_KEY_1STLEVEL] */ {NULL} /* void * p_libc_specific[_LIBC_TSD_KEY_N] */ }; /* Descriptor of the manager thread; none of this is used but the error variables and the address for identification. */ struct _pthread_descr_struct __pthread_manager_thread = { NULL, /* pthread_descr p_nextlive */ NULL, /* pthread_descr p_prevlive */ NULL, /* pthread_descr p_nextwaiting */ 0, /* int p_tid */ 0, /* int p_pid */ 0, /* int p_priority */ NULL, /* int * p_spinlock */ 0, /* int p_signal */ NULL, /* sigjmp_buf * p_signal_buf */ NULL, /* sigjmp_buf * p_cancel_buf */ 0, /* char p_terminated */ 0, /* char p_detached */ 0, /* char p_exited */ NULL, /* void * p_retval */ 0, /* int p_retval */ NULL, /* pthread_descr p_joining */ NULL, /* struct _pthread_cleanup_buffer * p_cleanup */ 0, /* char p_cancelstate */ 0, /* char p_canceltype */ 0, /* char p_canceled */ 0, /* int p_errno */ 0, /* int p_h_errno */ PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */ {NULL}, /* void ** p_specific[PTHREAD_KEYS_MAX] */ {NULL} /* void * p_libc_specific[_LIBC_TSD_KEY_N] */ }; /* Pointer to the main thread (the father of the thread manager thread) */ /* Originally, this is the initial thread, but this changes after fork() */ pthread_descr __pthread_main_thread = &__pthread_initial_thread; /* 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 = NULL; /* File descriptor for sending requests to the thread manager. */ /* Initially -1, meaning that the thread manager is not running. */ int __pthread_manager_request = -1; /* Other end of the pipe for sending requests to the thread manager. */ int __pthread_manager_reader; /* PID of thread manager */ static int __pthread_manager_pid; /* Limits of the thread manager stack */ char *__pthread_manager_thread_bos = NULL; char *__pthread_manager_thread_tos = NULL; /* For process-wide exit() */ int __pthread_exit_requested = 0; int __pthread_exit_code = 0; /* Forward declarations */ static void pthread_exit_process(int retcode, void *arg); static void pthread_handle_sigcancel(int sig); /* 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)); static void pthread_initialize(void) { struct sigaction sa; sigset_t mask; /* If already done (e.g. by a constructor called earlier!), bail out */ if (__pthread_initial_thread_bos != NULL) return; /* For the initial stack, reserve at least STACK_SIZE bytes of stack below the current stack address, and align that on a STACK_SIZE boundary. */ __pthread_initial_thread_bos = (char *)(((long)CURRENT_STACK_FRAME - 2 * STACK_SIZE) & ~(STACK_SIZE - 1)); /* Update the descriptor for the initial thread. */ __pthread_initial_thread.p_pid = __getpid(); /* If we have special thread_self processing, initialize that for the main thread now. */ #ifdef INIT_THREAD_SELF INIT_THREAD_SELF(&__pthread_initial_thread); #endif /* Setup signal handlers for the initial thread. Since signal handlers are shared between threads, these settings will be inherited by all other threads. */ sa.sa_handler = __pthread_sighandler; sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART; /* does not matter for regular threads, but better for the thread manager */ sigaction(PTHREAD_SIG_RESTART, &sa, NULL); sa.sa_handler = pthread_handle_sigcancel; sa.sa_flags = 0; sigaction(PTHREAD_SIG_CANCEL, &sa, NULL); /* Initially, block PTHREAD_SIG_RESTART. Will be unblocked on demand. */ sigemptyset(&mask); sigaddset(&mask, PTHREAD_SIG_RESTART); sigprocmask(SIG_BLOCK, &mask, NULL); /* Register an exit function to kill all other threads. */ /* Do it early so that user-registered atexit functions are called before pthread_exit_process. */ __on_exit(pthread_exit_process, NULL); } static int pthread_initialize_manager(void) { int manager_pipe[2]; /* If basic initialization not done yet (e.g. we're called from a constructor run before our constructor), do it now */ if (__pthread_initial_thread_bos == NULL) pthread_initialize(); /* Setup stack for thread manager */ __pthread_manager_thread_bos = malloc(THREAD_MAN