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Diffstat (limited to 'linuxthreads/pthread.c')
| -rw-r--r-- | linuxthreads/pthread.c | 1407 |
1 files changed, 1407 insertions, 0 deletions
diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c new file mode 100644 index 0000000000..24f0eb02b0 --- /dev/null +++ b/linuxthreads/pthread.c @@ -0,0 +1,1407 @@ + +/* Linuxthreads - a simple clone()-based implementation of Posix */ +/* threads for Linux. */ +/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ +/* */ +/* 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_attr_getdetachstate = __pthread_attr_getdetachstate, + .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate, + .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched, + .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched, + .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam, + .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam, + .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy, + .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy, + .ptr_pthread_attr_getscope = __pthread_attr_getscope, + .ptr_pthread_attr_setscope = __pthread_attr_setscope, + .ptr_pthread_condattr_destroy = __pthread_condattr_destroy, + .ptr_pthread_condattr_init = __pthread_condattr_init, + .ptr___pthread_cond_broadcast = __pthread_cond_broadcast, + .ptr___pthread_cond_destroy = __pthread_cond_destroy, + .ptr___pthread_cond_init = __pthread_cond_init, + .ptr___pthread_cond_signal = __pthread_cond_signal, + .ptr___pthread_cond_wait = __pthread_cond_wait, + .ptr___pthread_cond_timedwait = __pthread_cond_timedwait, + .ptr_pthread_equal = __pthread_equal, + .ptr___pthread_exit = __pthread_exit, + .ptr_pthread_getschedparam = __pthread_getschedparam, + .ptr_pthread_setschedparam = __pthread_setschedparam, + .ptr_pthread_mutex_destroy = __pthread_mutex_destroy, + .ptr_pthread_mutex_init = __pthread_mutex_init, + .ptr_pthread_mutex_lock = __pthread_mutex_lock, + .ptr_pthread_mutex_trylock = __pthread_mutex_trylock, + .ptr_pthread_mutex_unlock = __pthread_mutex_unlock, + .ptr_pthread_self = __pthread_self, + .ptr_pthread_setcancelstate = __pthread_setcancelstate, + .ptr_pthread_setcanceltype = __pthread_setcanceltype, + .ptr_pthread_do_exit = __pthread_do_exit, + .ptr_pthread_thread_self = __pthread_thread_self, + .ptr_pthread_cleanup_upto = __pthread_cleanup_upto, + .ptr_pthread_sigaction = __pthread_sigaction, + .ptr_pthread_sigwait = __pthread_sigwait, + .ptr_pthread_raise = __pthread_raise, + .ptr__pthread_cleanup_push = _pthread_cleanup_push, + .ptr__pthread_cleanup_pop = _pthread_cleanup_pop + }; +#ifdef SHARED +# define ptr_pthread_functions &__pthread_functions +#else +# define ptr_pthread_functions NULL +#endif + +static int *__libc_multiple_threads_ptr; + +/* Do some minimal initialization which has to be done during the + startup of the C library. */ +void +__pthread_initialize_minimal(void) +{ +#ifdef USE_TLS + pthread_descr self; + + /* First of all init __pthread_handles[0] and [1] if needed. */ +# if __LT_SPINLOCK_INIT != 0 + __pthread_handles[0].h_lock = __LOCK_INITIALIZER; + __pthread_handles[1].h_lock = __LOCK_INITIALIZER; +# endif +# ifndef SHARED + /* Unlike in the dynamically linked case the dynamic linker has not + taken care of initializing the TLS data structures. */ + __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN); +# elif !USE___THREAD + if (__builtin_expect (GL(dl_tls_dtv_slotinfo_list) == NULL, 0)) + { + tcbhead_t *tcbp; + + /* There is no actual TLS being used, so the thread register + was not initialized in the dynamic linker. */ + + /* We need to install special hooks so that the malloc and memalign + calls in _dl_tls_setup and _dl_allocate_tls won't cause full + malloc initialization that will try to set up its thread state. */ + + extern void __libc_malloc_pthread_startup (bool first_time); + __libc_malloc_pthread_startup (true); + + if (__builtin_expect (_dl_tls_setup (), 0) + || __builtin_expect ((tcbp = _dl_allocate_tls (NULL)) == NULL, 0)) + { + static const char msg[] = "\ +cannot allocate TLS data structures for initial thread\n"; + TEMP_FAILURE_RETRY (write_not_cancel (STDERR_FILENO, + msg, sizeof msg - 1)); + abort (); + } + const char *lossage = TLS_INIT_TP (tcbp, 0); + if (__builtin_expect (lossage != NULL, 0)) + { + static const char msg[] = "cannot set up thread-local storage: "; + const char nl = '\n'; + TEMP_FAILURE_RETRY (write_not_cancel (STDERR_FILENO, + msg, sizeof msg - 1)); + TEMP_FAILURE_RETRY (write_not_cancel (STDERR_FILENO, + lossage, strlen (lossage))); + TEMP_FAILURE_RETRY (write_not_cancel (STDERR_FILENO, &nl, 1)); + } + + /* Though it was allocated with libc's malloc, that was done without + the user's __malloc_hook installed. A later realloc that uses + the hooks might not work with that block from the plain malloc. + So we record this block as unfreeable just as the dynamic linker + does when it allocates the DTV before the libc malloc exists. */ + GL(dl_initial_dtv) = GET_DTV (tcbp); + + __libc_malloc_pthread_startup (false); + } +# endif + + self = THREAD_SELF; + + /* The memory for the thread descriptor was allocated elsewhere as + part of the TLS allocation. We have to initialize the data + structure by hand. This initialization must mirror the struct + definition above. */ + self->p_nextlive = self->p_prevlive = self; + self->p_tid = PTHREAD_THREADS_MAX; + self->p_lock = &__pthread_handles[0].h_lock; +# ifndef HAVE___THREAD + self->p_errnop = &_errno; + self->p_h_errnop = &_h_errno; +# endif + /* self->p_start_args need not be initialized, it's all zero. */ + self->p_userstack = 1; +# if __LT_SPINLOCK_INIT != 0 + self->p_resume_count = (struct pthread_atomic) __ATOMIC_INITIALIZER; +# endif + self->p_alloca_cutoff = __MAX_ALLOCA_CUTOFF; + + /* Another variable which points to the thread descriptor. */ + __pthread_main_thread = self; + + /* And fill in the pointer the the thread __pthread_handles array. */ + __pthread_handles[0].h_descr = self; + +#else /* USE_TLS */ + + /* First of all init __pthread_handles[0] and [1]. */ +# if __LT_SPINLOCK_INIT != 0 + __pthread_handles[0].h_lock = __LOCK_INITIALIZER; + __pthread_handles[1].h_lock = __LOCK_INITIALIZER; +# endif + __pthread_handles[0].h_descr = &__pthread_initial_thread; + __pthread_handles[1].h_descr = &__pthread_manager_thread; + + /* If we have special thread_self processing, initialize that for the + main thread now. */ +# ifdef INIT_THREAD_SELF + INIT_THREAD_SELF(&__pthread_initial_thread, 0); +# endif +#endif + +#if HP_TIMING_AVAIL +# ifdef USE_TLS + self->p_cpuclock_offset = GL(dl_cpuclock_offset); +# else + __pthread_initial_thread.p_cpuclock_offset = GL(dl_cpuclock_offset); +# endif +#endif + + __libc_multiple_threads_ptr = __libc_pthread_init (ptr_pthread_functions); +} + + +void +__pthread_init_max_stacksize(void) +{ + struct rlimit limit; + size_t max_stack; + + getrlimit(RLIMIT_STACK, &limit); +#ifdef FLOATING_STACKS + if (limit.rlim_cur == RLIM_INFINITY) + limit.rlim_cur = ARCH_STACK_MAX_SIZE; +# ifdef NEED_SEPARATE_REGISTER_STACK + max_stack = limit.rlim_cur / 2; +# else + max_stack = limit.rlim_cur; +# endif +#else + /* Play with the stack size limit to make sure that no stack ever grows + beyond STACK_SIZE minus one page (to act as a guard page). */ +# ifdef NEED_SEPARATE_REGISTER_STACK + /* STACK_SIZE bytes hold both the main stack and register backing + store. The rlimit value applies to each individually. */ + max_stack = STACK_SIZE/2 - __getpagesize (); +# else + max_stack = STACK_SIZE - __getpagesize(); +# endif + if (limit.rlim_cur > max_stack) { + limit.rlim_cur = max_stack; + setrlimit(RLIMIT_STACK, &limit); + } +#endif + __pthread_max_stacksize = max_stack; + if (max_stack / 4 < __MAX_ALLOCA_CUTOFF) + { +#ifdef USE_TLS + pthread_descr self = THREAD_SELF; + self->p_alloca_cutoff = max_stack / 4; +#else + __pthread_initial_thread.p_alloca_cutoff = max_stack / 4; +#endif + } +} + +#ifdef SHARED +# if USE___THREAD +/* When using __thread for this, we do it in libc so as not + to give libpthread its own TLS segment just for this. */ +extern void **__libc_dl_error_tsd (void) __attribute__ ((const)); +# else +static void ** __attribute__ ((const)) +__libc_dl_error_tsd (void) +{ + return &thread_self ()->p_libc_specific[_LIBC_TSD_KEY_DL_ERROR]; +} +# endif +#endif + +#ifdef USE_TLS +static inline void __attribute__((always_inline)) +init_one_static_tls (pthread_descr descr, struct link_map *map) +{ +# if TLS_TCB_AT_TP + dtv_t *dtv = GET_DTV (descr); + void *dest = (char *) descr - map->l_tls_offset; +# elif TLS_DTV_AT_TP + dtv_t *dtv = GET_DTV ((pthread_descr) ((char *) descr + TLS_PRE_TCB_SIZE)); + void *dest = (char *) descr + map->l_tls_offset + TLS_PRE_TCB_SIZE; +# else +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +# endif + + /* Fill in the DTV slot so that a later LD/GD access will find it. */ + dtv[map->l_tls_modid].pointer = dest; + + /* Initialize the memory. */ + memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size), + '\0', map->l_tls_blocksize - map->l_tls_initimage_size); +} + +static void +__pthread_init_static_tls (struct link_map *map) +{ + size_t i; + + for (i = 0; i < PTHREAD_THREADS_MAX; ++i) + if (__pthread_handles[i].h_descr != NULL && i != 1) + { + __pthread_lock (&__pthread_handles[i].h_lock, NULL); + if (__pthread_handles[i].h_descr != NULL) + init_one_static_tls (__pthread_handles[i].h_descr, map); + __pthread_unlock (&__pthread_handles[i].h_lock); + } +} +#endif + +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; +#ifdef TEST_FOR_COMPARE_AND_SWAP + /* Test if compare-and-swap is available */ + __pthread_has_cas = compare_and_swap_is_available(); +#endif +#ifdef FLOATING_STACKS + /* We don't need to know the bottom of the stack. Give the pointer some + value to signal that initialization happened. */ + __pthread_initial_thread_bos = (void *) -1l; +#else + /* Determine stack size limits . */ + __pthread_init_max_stacksize (); +# ifdef _STACK_GROWS_UP + /* The initial thread already has all the stack it needs */ + __pthread_initial_thread_bos = (char *) + ((long)CURRENT_STACK_FRAME &~ (STACK_SIZE - 1)); +# else + /* 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)); +# endif +#endif +#ifdef USE_TLS + /* Update the descriptor for the initial thread. */ + THREAD_SETMEM (((pthread_descr) NULL), p_pid, __getpid()); +# ifndef HAVE___THREAD + /* Likewise for the resolver state _res. */ + THREAD_SETMEM (((pthread_descr) NULL), p_resp, &_res); +# endif +#else + /* Update the descriptor for the initial thread. */ + __pthread_initial_thread.p_pid = __getpid(); + /* Likewise for the resolver state _res. */ + __pthread_initial_thread.p_resp = &_res; +#endif +#if !__ASSUME_REALTIME_SIGNALS + /* Initialize real-time signals. */ + init_rtsigs (); +#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_handle_sigrestart; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + __libc_sigaction(__pthread_sig_restart, &sa, NULL); + sa.sa_handler = pthread_handle_sigcancel; + sigaddset(&sa.sa_mask, __pthread_sig_restart); + // sa.sa_flags = 0; + __libc_sigaction(__pthread_sig_cancel, &sa, NULL); + if (__pthread_sig_debug > 0) { + sa.sa_handler = pthread_handle_sigdebug; + sigemptyset(&sa.sa_mask); + // sa.sa_flags = 0; + __libc_sigaction(__pthread_sig_debug, &sa, NULL); + } + /* Initially, block __pthread_sig_restart. Will be unblocked on demand. */ + sigemptyset(&mask); + sigaddset(&mask, __pthread_sig_restart); + sigprocmask(SIG_BLOCK, &mask, NULL); + /* And unblock __pthread_sig_cancel if it has been blocked. */ + sigdelset(&mask, __pthread_sig_restart); + sigaddset(&mask, __pthread_sig_cancel); + sigprocmask(SIG_UNBLOCK, &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. */ +#ifndef HAVE_Z_NODELETE + if (__builtin_expect (&__dso_handle != NULL, 1)) + __cxa_atexit ((void (*) (void *)) pthread_atexit_process, NULL, + __dso_handle); + else +#endif + __on_exit (pthread_onexit_process, NULL); + /* How many processors. */ + __pthread_smp_kernel = is_smp_system (); + +#ifdef SHARED + /* Transfer the old value from the dynamic linker's internal location. */ + *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) (); + GL(dl_error_catch_tsd) = &__libc_dl_error_tsd; + + /* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock, + keep the lock count from the ld.so implementation. */ + GL(dl_rtld_lock_recursive) = (void *) __pthread_mutex_lock; + GL(dl_rtld_unlock_recursive) = (void *) __pthread_mutex_unlock; + unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__m_count; + GL(dl_load_lock).mutex.__m_count = 0; + while (rtld_lock_count-- > 0) + __pthread_mutex_lock (&GL(dl_load_lock).mutex); +#endif + +#ifdef USE_TLS + GL(dl_init_static_tls) = &__pthread_init_static_tls; +#endif +} + +void __pthread_initialize(void) +{ + pthread_initialize(); +} + +int __pthread_initialize_manager(void) +{ + int manager_pipe[2]; + int pid; + struct pthread_request request; + int report_events; + pthread_descr mgr; +#ifdef USE_TLS + tcbhead_t *tcbp; +#endif + + __pthread_multiple_threads = 1; +#if TLS_MULTIPLE_THREADS_IN_TCB || !defined USE_TLS || !TLS_DTV_AT_TP + __pthread_main_thread->p_multiple_threads = 1; +#endif + *__libc_multiple_threads_ptr = 1; + +#ifndef HAVE_Z_NODELETE + if (__builtin_expect (&__dso_handle != NULL, 1)) + __cxa_atexit ((void (*) (void *)) pthread_atexit_retcode, NULL, + __dso_handle); +#endif + + if (__pthread_max_stacksize == 0) + __pthread_init_max_stacksize (); + /* 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_MANAGER_STACK_SIZE); + if (__pthread_manager_thread_bos == NULL) return -1; + __pthread_manager_thread_tos = + __pthread_manager_thread_bos + THREAD_MANAGER_STACK_SIZE; + /* Setup pipe to communicate with thread manager */ + if (pipe(manager_pipe) == -1) { + free(__pthread_manager_thread_bos); + return -1; + } + +#ifdef USE_TLS + /* Allocate memory for the thread descriptor and the dtv. */ + tcbp = _dl_allocate_tls (NULL); + if (tcbp == NULL) { + free(__pthread_manager_thread_bos); + close_not_cancel(manager_pipe[0]); + close_not_cancel(manager_pipe[1]); + return -1; + } + +# if TLS_TCB_AT_TP + mgr = (pthread_descr) tcbp; +# elif TLS_DTV_AT_TP + /* pthread_descr is located right below tcbhead_t which _dl_allocate_tls + returns. */ + mgr = (pthread_descr) ((char *) tcbp - TLS_PRE_TCB_SIZE); +# endif + __pthread_handles[1].h_descr = manager_thread = mgr; + + /* Initialize the descriptor. */ +#if !defined USE_TLS || !TLS_DTV_AT_TP + mgr->p_header.data.tcb = tcbp; + mgr->p_header.data.self = mgr; + mgr->p_header.data.multiple_threads = 1; +#elif TLS_MULTIPLE_THREADS_IN_TCB + mgr->p_multiple_threads = 1; +#endif + mgr->p_lock = &__pthread_handles[1].h_lock; +# ifndef HAVE___THREAD + mgr->p_errnop = &mgr->p_errno; +# endif + mgr->p_start_args = (struct pthread_start_args) PTHREAD_START_ARGS_INITIALIZER(__pthread_manager); + mgr->p_nr = 1; +# if __LT_SPINLOCK_INIT != 0 + self->p_resume_count = (struct pthread_atomic) __ATOMIC_INITIALIZER; +# endif + mgr->p_alloca_cutoff = PTHREAD_STACK_MIN / 4; +#else + mgr = &__pthread_manager_thread; +#endif + + __pthread_manager_request = manager_pipe[1]; /* writing end */ + __pthread_manager_reader = manager_pipe[0]; /* reading end */ + + /* Start the thread manager */ + pid = 0; +#ifdef USE_TLS + if (__linuxthreads_initial_report_events != 0) + THREAD_SETMEM (((pthread_descr) NULL), p_report_events, + __linuxthreads_initial_report_events); + report_events = THREAD_GETMEM (((pthread_descr) NULL), p_report_events); +#else + if (__linuxthreads_initial_report_events != 0) + __pthread_initial_thread.p_report_events + = __linuxthreads_initial_report_events; + report_events = __pthread_initial_thread.p_report_events; +#endif + if (__builtin_expect (report_events, 0)) + { + /* It's a bit more complicated. We have to report the creation of + the manager thread. */ + int idx = __td_eventword (TD_CREATE); + uint32_t mask = __td_eventmask (TD_CREATE); + uint32_t event_bits; + +#ifdef USE_TLS + event_bits = THREAD_GETMEM_NC (((pthread_descr) NULL), + p_eventbuf.eventmask.event_bits[idx]); +#else + event_bits = __pthread_initial_thread.p_eventbuf.eventmask.event_bits[idx]; +#endif + + if ((mask & (__pthread_threads_events.event_bits[idx] | event_bits)) + != 0) + { + __pthread_lock(mgr->p_lock, NULL); + +#ifdef NEED_SEPARATE_REGISTER_STACK + pid = __clone2(__pthread_manager_event, + (void **) __pthread_manager_thread_bos, + THREAD_MANAGER_STACK_SIZE, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, + mgr); +#elif _STACK_GROWS_UP + pid = __clone(__pthread_manager_event, + (void **) __pthread_manager_thread_bos, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, + mgr); +#else + pid = __clone(__pthread_manager_event, + (void **) __pthread_manager_thread_tos, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, + mgr); +#endif + + if (pid != -1) + { + /* Now fill in the information about the new thread in + the newly created thread's data structure. We cannot let + the new thread do this since we don't know whether it was + already scheduled when we send the event. */ + mgr->p_eventbuf.eventdata = mgr; + mgr->p_eventbuf.eventnum = TD_CREATE; + __pthread_last_event = mgr; + mgr->p_tid = 2* PTHREAD_THREADS_MAX + 1; + mgr->p_pid = pid; + + /* Now call the function which signals the event. */ + __linuxthreads_create_event (); + } + + /* Now restart the thread. */ + __pthread_unlock(mgr->p_lock); + } + } + + if (__builtin_expect (pid, 0) == 0) + { +#ifdef NEED_SEPARATE_REGISTER_STACK + pid = __clone2(__pthread_manager, (void **) __pthread_manager_thread_bos, + THREAD_MANAGER_STACK_SIZE, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, mgr); +#elif _STACK_GROWS_UP + pid = __clone(__pthread_manager, (void **) __pthread_manager_thread_bos, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, mgr); +#else + pid = __clone(__pthread_manager, (void **) __pthread_manager_thread_tos, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, mgr); +#endif + } + if (__builtin_expect (pid, 0) == -1) { +#ifdef USE_TLS + _dl_deallocate_tls (tcbp, true); +#endif + free(__pthread_manager_thread_bos); + close_not_cancel(manager_pipe[0]); + close_not_cancel(manager_pipe[1]); + return -1; + } + mgr->p_tid = 2* PTHREAD_THREADS_MAX + 1; + mgr->p_pid = pid; + /* Make gdb aware of new thread manager */ + if (__builtin_expect (__pthread_threads_debug, 0) && __pthread_sig_debug > 0) + { + raise(__pthread_sig_debug); + /* We suspend ourself and gdb will wake us up when it is + ready to handle us. */ + __pthread_wait_for_restart_signal(thread_self()); + } + /* Synchronize debugging of the thread manager */ + request.req_kind = REQ_DEBUG; + TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request, + (char *) &request, sizeof(request))); + return 0; +} + +/* Thread creation */ + +int __pthread_create_2_1(pthread_t *thread, const pthread_attr_t *attr, + void * (*start_routine)(void *), void *arg) +{ + pthread_descr self = thread_self(); + struct pthread_request request; + int retval; + if (__builtin_expect (__pthread_manager_request, 0) < 0) { + if (__pthread_initialize_manager() < 0) return EAGAIN; + } + request.req_thread = self; + request.req_kind = REQ_CREATE; + request.req_args.create.attr = attr; + request.req_args.create.fn = start_routine; + request.req_args.create.arg = arg; + sigprocmask(SIG_SETMASK, (const sigset_t *) NULL, + &request.req_args.create.mask); + TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request, + (char *) &request, sizeof(request))); + suspend(self); + retval = THREAD_GETMEM(self, p_retcode); + if (__builtin_expect (retval, 0) == 0) + *thread = (pthread_t) THREAD_GETMEM(self, p_retval); + return retval; +} + +versioned_symbol (libpthread, __pthread_create_2_1, pthread_create, GLIBC_2_1); + +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) + +int __pthread_create_2_0(pthread_t *thread, const pthread_attr_t *attr, + void * (*start_routine)(void *), void *arg) +{ + /* The ATTR attribute is not really of type `pthread_attr_t *'. It has + the old size and access to the new members might crash the program. + We convert the struct now. */ + pthread_attr_t new_attr; + + if (attr != NULL) + { + size_t ps = __getpagesize (); + + memcpy (&new_attr, attr, + (size_t) &(((pthread_attr_t*)NULL)->__guardsize)); + new_attr.__guardsize = ps; + new_attr.__stackaddr_set = 0; + new_attr.__stackaddr = NULL; + new_attr.__stacksize = STACK_SIZE - ps; + attr = &new_attr; + } + return __pthread_create_2_1 (thread, attr, start_routine, arg); +} +compat_symbol (libpthread, __pthread_create_2_0, pthread_create, GLIBC_2_0); +#endif + +/* Simple operations on thread identifiers */ + +pthread_descr __pthread_thread_self(void) +{ + return thread_self(); +} + +pthread_t __pthread_self(void) +{ + pthread_descr self = thread_self(); + return THREAD_GETMEM(self, p_tid); +} +strong_alias (__pthread_self, pthread_self); + +int __pthread_equal(pthread_t thread1, pthread_t thread2) +{ + return thread1 == thread2; +} +strong_alias (__pthread_equal, pthread_equal); + +/* Helper function for thread_self in the case of user-provided stacks */ + +#ifndef THREAD_SELF + +pthread_descr __pthread_find_self(void) +{ + char * sp = CURRENT_STACK_FRAME; + pthread_handle h; + + /* __pthread_handles[0] is the initial thread, __pthread_handles[1] is + the manager threads handled specially in thread_self(), so start at 2 */ + h = __pthread_handles + 2; +# ifdef _STACK_GROWS_UP + while (! (sp >= (char *) h->h_descr && sp < h->h_descr->p_guardaddr)) h++; +# else + while (! (sp <= (char *) h->h_descr && sp >= h->h_bottom)) h++; +# endif + return h->h_descr; +} + +#else + +pthread_descr __pthread_self_stack(void) +{ + char *sp = CURRENT_STACK_FRAME; + pthread_handle h; + + if (sp >= __pthread_manager_thread_bos && sp < __pthread_manager_thread_tos) + return manager_thread; + h = __pthread_handles + 2; +# ifdef USE_TLS +# ifdef _STACK_GROWS_UP + while (h->h_descr == NULL + || ! (sp >= h->h_descr->p_stackaddr && sp < h->h_descr->p_guardaddr)) + h++; +# else + while (h->h_descr == NULL + || ! (sp <= (char *) h->h_descr->p_stackaddr && sp >= h->h_bottom)) + h++; +# endif +# else +# ifdef _STACK_GROWS_UP + while (! (sp >= (char *) h->h_descr && sp < h->h_descr->p_guardaddr)) + h++; +# else + while (! (sp <= (char *) h->h_descr && sp >= h->h_bottom)) + h++; +# endif +# endif + return h->h_descr; +} + +#endif + +/* Thread scheduling */ + +int __pthread_setschedparam(pthread_t thread, int policy, + const struct sched_param *param) +{ + pthread_handle handle = thread_handle(thread); + pthread_descr th; + + __pthread_lock(&handle->h_lock, NULL); + if (__builtin_expect (invalid_handle(handle, thread), 0)) { + __pthread_unlock(&handle->h_lock); + return ESRCH; + } + th = handle->h_descr; + if (__builtin_expect (__sched_setscheduler(th->p_pid, policy, param) == -1, + 0)) { + __pthread_unlock(&handle->h_lock); + return errno; + } + th->p_priority = policy == SCHED_OTHER ? 0 : param->sched_priority; + __pthread_unlock(&handle->h_lock); + if (__pthread_manager_request >= 0) + __pthread_manager_adjust_prio(th->p_priority); + return 0; +} +strong_alias (__pthread_setschedparam, pthread_setschedparam); + +int __pthread_getschedparam(pthread_t thread, int *policy, + struct sched_param *param) +{ + pthread_handle handle = thread_handle(thread); + int pid, pol; + + __pthread_lock(&handle->h_lock, NULL); + if (__builtin_expect (invalid_handle(handle, thread), 0)) { + __pthread_unlock(&handle->h_lock); + return ESRCH; + } + pid = handle->h_descr->p_pid; + __pthread_unlock(&handle->h_lock); + pol = __sched_getscheduler(pid); + if (__builtin_expect (pol, 0) == -1) return errno; + if (__sched_getparam(pid, param) == -1) return errno; + *policy = pol; + return 0; +} +strong_alias (__pthread_getschedparam, pthread_getschedparam); + +int __pthread_yield (void) +{ + /* For now this is equivalent with the POSIX call. */ + return sched_yield (); +} +weak_alias (__pthread_yield, pthread_yield) + +/* Process-wide exit() request */ + +static void pthread_onexit_process(int retcode, void *arg) +{ + if (__builtin_expect (__pthread_manager_request, 0) >= 0) { + struct pthread_request request; + pthread_descr self = thread_self(); + + request.req_thread = self; + request.req_kind = REQ_PROCESS_EXIT; + request.req_args.exit.code = retcode; + TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request, + (char *) &request, sizeof(request))); + suspend(self); + /* Main thread should accumulate times for thread manager and its + children, so that timings for main thread account for all threads. */ + if (self == __pthread_main_thread) + { +#ifdef USE_TLS + waitpid(manager_thread->p_pid, NULL, __WCLONE); +#else + waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); +#endif + /* Since all threads have been asynchronously terminated + (possibly holding locks), free cannot be used any more. + For mtrace, we'd like to print something though. */ + /* #ifdef USE_TLS + tcbhead_t *tcbp = (tcbhead_t *) manager_thread; + # if TLS_DTV_AT_TP + tcbp = (tcbhead_t) ((char *) tcbp + TLS_PRE_TCB_SIZE); + # endif + _dl_deallocate_tls (tcbp, true); + #endif + free (__pthread_manager_thread_bos); */ + __pthread_manager_thread_bos = __pthread_manager_thread_tos = NULL; + } + } +} + +#ifndef HAVE_Z_NODELETE +static int __pthread_atexit_retcode; + +static void pthread_atexit_process(void *arg, int retcode) +{ + pthread_onexit_process (retcode ?: __pthread_atexit_retcode, arg); +} + +static void pthread_atexit_retcode(void *arg, int retcode) +{ + __pthread_atexit_retcode = retcode; +} +#endif + +/* The handler for the RESTART signal just records the signal received + in the thread descriptor, and optionally performs a siglongjmp + (for pthread_cond_timedwait). */ + +static void pthread_handle_sigrestart(int sig) +{ + pthread_descr self = check_thread_self(); + THREAD_SETMEM(self, p_signal, sig); + if (THREAD_GETMEM(self, p_signal_jmp) != NULL) + siglongjmp(*THREAD_GETMEM(self, p_signal_jmp), 1); +} + +/* The handler for the CANCEL signal checks for cancellation + (in asynchronous mode), for process-wide exit and exec requests. + For the thread manager thread, redirect the signal to + __pthread_manager_sighandler. */ + +static void pthread_handle_sigcancel(int sig) +{ + pthread_descr self = check_thread_self(); + sigjmp_buf * jmpbuf; + + if (self == manager_thread) + { + __pthread_manager_sighandler(sig); + return; + } + if (__builtin_expect (__pthread_exit_requested, 0)) { + /* Main thread should accumulate times for thread manager and its + children, so that timings for main thread account for all threads. */ + if (self == __pthread_main_thread) { +#ifdef USE_TLS + waitpid(manager_thread->p_pid, NULL, __WCLONE); +#else + waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); +#endif + } + _exit(__pthread_exit_code); + } + if (__builtin_expect (THREAD_GETMEM(self, p_canceled), 0) + && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) { + if (THREAD_GETMEM(self, p_canceltype) == PTHREAD_CANCEL_ASYNCHRONOUS) + __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME); + jmpbuf = THREAD_GETMEM(self, p_cancel_jmp); + if (jmpbuf != NULL) { + THREAD_SETMEM(self, p_cancel_jmp, NULL); + siglongjmp(*jmpbuf, 1); + } + } +} + +/* Handler for the DEBUG signal. + The debugging strategy is as follows: + On reception of a REQ_DEBUG request (sent by new threads created to + the thread manager under debugging mode), the thread manager throws + __pthread_sig_debug to itself. The debugger (if active) intercepts + this signal, takes into account new threads and continue execution + of the thread manager by propagating the signal because it doesn't + know what it is specifically done for. In the current implementation, + the thread manager simply discards it. */ + +static void pthread_handle_sigdebug(int sig) +{ + /* Nothing */ +} + +/* Reset the state of the thread machinery after a fork(). + Close the pipe used for requests and set the main thread to the forked + thread. + Notice that we can't free the stack segments, as the forked thread + may hold pointers into them. */ + +void __pthread_reset_main_thread(void) +{ + pthread_descr self = thread_self(); + + if (__pthread_manager_request != -1) { + /* Free the thread manager stack */ + free(__pthread_manager_thread_bos); + __pthread_manager_thread_bos = __pthread_manager_thread_tos = NULL; + /* Close the two ends of the pipe */ + close_not_cancel(__pthread_manager_request); + close_not_cancel(__pthread_manager_reader); + __pthread_manager_request = __pthread_manager_reader = -1; + } + + /* Update the pid of the main thread */ + THREAD_SETMEM(self, p_pid, __getpid()); + /* Make the forked thread the main thread */ + __pthread_main_thread = self; + THREAD_SETMEM(self, p_nextlive, self); + THREAD_SETMEM(self, p_prevlive, self); +#if !(USE_TLS && HAVE___THREAD) + /* Now this thread modifies the global variables. */ + THREAD_SETMEM(self, p_errnop, &_errno); + THREAD_SETMEM(self, p_h_errnop, &_h_errno); + THREAD_SETMEM(self, p_resp, &_res); +#endif + +#ifndef FLOATING_STACKS + /* This is to undo the setrlimit call in __pthread_init_max_stacksize. + XXX This can be wrong if the user set the limit during the run. */ + { + struct rlimit limit; + if (getrlimit (RLIMIT_STACK, &limit) == 0 + && limit.rlim_cur != limit.rlim_max) + { + limit.rlim_cur = limit.rlim_max; + setrlimit(RLIMIT_STACK, &limit); + } + } +#endif +} + +/* Process-wide exec() request */ + +void __pthread_kill_other_threads_np(void) +{ + struct sigaction sa; + /* Terminate all other threads and thread manager */ + pthread_onexit_process(0, NULL); + /* Make current thread the main thread in case the calling thread + changes its mind, does not exec(), and creates new threads instead. */ + __pthread_reset_main_thread(); + + /* Reset the signal handlers behaviour for the signals the + implementation uses since this would be passed to the new + process. */ + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + sa.sa_handler = SIG_DFL; + __libc_sigaction(__pthread_sig_restart, &sa, NULL); + __libc_sigaction(__pthread_sig_cancel, &sa, NULL); + if (__pthread_sig_debug > 0) + __libc_sigaction(__pthread_sig_debug, &sa, NULL); +} +weak_alias (__pthread_kill_other_threads_np, pthread_kill_other_threads_np) + +/* Concurrency symbol level. */ +static int current_level; + +int __pthread_setconcurrency(int level) +{ + /* We don't do anything unless we have found a useful interpretation. */ + current_level = level; + return 0; +} +weak_alias (__pthread_setconcurrency, pthread_setconcurrency) + +int __pthread_getconcurrency(void) +{ + return current_level; +} +weak_alias (__pthread_getconcurrency, pthread_getconcurrency) + +/* Primitives for controlling thread execution */ + +void __pthread_wait_for_restart_signal(pthread_descr self) +{ + sigset_t mask; + + sigprocmask(SIG_SETMASK, NULL, &mask); /* Get current signal mask */ + sigdelset(&mask, __pthread_sig_restart); /* Unblock the restart signal */ + THREAD_SETMEM(self, p_signal, 0); + do { + __pthread_sigsuspend(&mask); /* Wait for signal. Must not be a + cancellation point. */ + } while (THREAD_GETMEM(self, p_signal) !=__pthread_sig_restart); + + READ_MEMORY_BARRIER(); /* See comment in __pthread_restart_new */ +} + +#if !__ASSUME_REALTIME_SIGNALS +/* The _old variants are for 2.0 and early 2.1 kernels which don't have RT + signals. + On these kernels, we use SIGUSR1 and SIGUSR2 for restart and cancellation. + Since the restart signal does not queue, we use an atomic counter to create + queuing semantics. This is needed to resolve a rare race condition in + pthread_cond_timedwait_relative. */ + +void __pthread_restart_old(pthread_descr th) +{ + if (atomic_increment(&th->p_resume_count) == -1) + kill(th->p_pid, __pthread_sig_restart); +} + +void __pthread_suspend_old(pthread_descr self) +{ + if (atomic_decrement(&self->p_resume_count) <= 0) + __pthread_wait_for_restart_signal(self); +} + +int +__pthread_timedsuspend_old(pthread_descr self, const struct timespec *abstime) +{ + sigset_t unblock, initial_mask; + int was_signalled = 0; + sigjmp_buf jmpbuf; + + if (atomic_decrement(&self->p_resume_count) == 0) { + /* Set up a longjmp handler for the restart signal, unblock + the signal and sleep. */ + + if (sigsetjmp(jmpbuf, 1) == 0) { + THREAD_SETMEM(self, p_signal_jmp, &jmpbuf); + THREAD_SETMEM(self, p_signal, 0); + /* Unblock the restart signal */ + sigemptyset(&unblock); + sigaddset(&unblock, __pthread_sig_restart); + sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask); + + while (1) { + struct timeval now; + struct timespec reltime; + + /* Compute a time offset relative to now. */ + __gettimeofday (&now, NULL); + reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000; + reltime.tv_sec = abstime->tv_sec - now.tv_sec; + if (reltime.tv_nsec < 0) { + reltime.tv_nsec += 1000000000; + reltime.tv_sec -= 1; + } + + /* Sleep for the required duration. If woken by a signal, + resume waiting as required by Single Unix Specification. */ + if (reltime.tv_sec < 0 || __libc_nanosleep(&reltime, NULL) == 0) + break; + } + + /* Block the restart signal again */ + sigprocmask(SIG_SETMASK, &initial_mask, NULL); + was_signalled = 0; + } else { + was_signalled = 1; + } + THREAD_SETMEM(self, p_signal_jmp, NULL); + } + + /* Now was_signalled is true if we exited the above code + due to the delivery of a restart signal. In that case, + we know we have been dequeued and resumed and that the + resume count is balanced. Otherwise, there are some + cases to consider. First, try to bump up the resume count + back to zero. If it goes to 1, it means restart() was + invoked on this thread. The signal must be consumed + and the count bumped down and everything is cool. We + can return a 1 to the caller. + Otherwise, no restart was delivered yet, so a potential + race exists; we return a 0 to the caller which must deal + with this race in an appropriate way; for example by + atomically removing the thread from consideration for a + wakeup---if such a thing fails, it means a restart is + being delivered. */ + + if (!was_signalled) { + if (atomic_increment(&self->p_resume_count) != -1) { + __pthread_wait_for_restart_signal(self); + atomic_decrement(&self->p_resume_count); /* should be zero now! */ + /* woke spontaneously and consumed restart signal */ + return 1; + } + /* woke spontaneously but did not consume restart---caller must resolve */ + return 0; + } + /* woken due to restart signal */ + return 1; +} +#endif /* __ASSUME_REALTIME_SIGNALS */ + +void __pthread_restart_new(pthread_descr th) +{ + /* The barrier is proabably not needed, in which case it still documents + our assumptions. The intent is to commit previous writes to shared + memory so the woken thread will have a consistent view. Complementary + read barriers are present to the suspend functions. */ + WRITE_MEMORY_BARRIER(); + kill(th->p_pid, __pthread_sig_restart); +} + +/* There is no __pthread_suspend_new because it would just + be a wasteful wrapper for __pthread_wait_for_restart_signal */ + +int +__pthread_timedsuspend_new(pthread_descr self, const struct timespec *abstime) +{ + sigset_t unblock, initial_mask; + int was_signalled = 0; + sigjmp_buf jmpbuf; + + if (sigsetjmp(jmpbuf, 1) == 0) { + THREAD_SETMEM(self, p_signal_jmp, &jmpbuf); + THREAD_SETMEM(self, p_signal, 0); + /* Unblock the restart signal */ + sigemptyset(&unblock); + sigaddset(&unblock, __pthread_sig_restart); + sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask); + + while (1) { + struct timeval now; + struct timespec reltime; + + /* Compute a time offset relative to now. */ + __gettimeofday (&now, NULL); + reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000; + reltime.tv_sec = abstime->tv_sec - now.tv_sec; + if (reltime.tv_nsec < 0) { + reltime.tv_nsec += 1000000000; + reltime.tv_sec -= 1; + } + + /* Sleep for the required duration. If woken by a signal, + resume waiting as required by Single Unix Specification. */ + if (reltime.tv_sec < 0 || __libc_nanosleep(&reltime, NULL) == 0) + break; + } + + /* Block the restart signal again */ + sigprocmask(SIG_SETMASK, &initial_mask, NULL); + was_signalled = 0; + } else { + was_signalled = 1; + } + THREAD_SETMEM(self, p_signal_jmp, NULL); + + /* Now was_signalled is true if we exited the above code + due to the delivery of a restart signal. In that case, + everything is cool. We have been removed from whatever + we were waiting on by the other thread, and consumed its signal. + + Otherwise we this thread woke up spontaneously, or due to a signal other + than restart. This is an ambiguous case that must be resolved by + the caller; the thread is still eligible for a restart wakeup + so there is a race. */ + + READ_MEMORY_BARRIER(); /* See comment in __pthread_restart_new */ + return was_signalled; +} + + +/* Debugging aid */ + +#ifdef DEBUG +#include <stdarg.h> + +void __pthread_message(const char * fmt, ...) +{ + char buffer[1024]; + va_list args; + sprintf(buffer, "%05d : ", __getpid()); + va_start(args, fmt); + vsnprintf(buffer + 8, sizeof(buffer) - 8, fmt, args); + va_end(args); + TEMP_FAILURE_RETRY(write_not_cancel(2, buffer, strlen(buffer))); +} + +#endif |