diff options
Diffstat (limited to 'libpthread/linuxthreads/manager.c')
| -rw-r--r-- | libpthread/linuxthreads/manager.c | 905 |
1 files changed, 0 insertions, 905 deletions
diff --git a/libpthread/linuxthreads/manager.c b/libpthread/linuxthreads/manager.c deleted file mode 100644 index 204344aef..000000000 --- a/libpthread/linuxthreads/manager.c +++ /dev/null @@ -1,905 +0,0 @@ -/* 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. */ - -/* The "thread manager" thread: manages creation and termination of threads */ - -/* mods for uClibc: getpwd and getpagesize are the syscalls */ -#define __getpid getpid -#define __getpagesize getpagesize - -#include <features.h> -#define __USE_GNU -#include <errno.h> -#include <sched.h> -#include <stddef.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <sys/poll.h> /* for poll */ -#include <sys/mman.h> /* for mmap */ -#include <sys/param.h> -#include <sys/time.h> -#include <sys/wait.h> /* for waitpid macros */ - -#include "pthread.h" -#include "internals.h" -#include "spinlock.h" -#include "restart.h" -#include "semaphore.h" -#include "debug.h" /* PDEBUG, added by StS */ - - -/* poll() is not supported in kernel <= 2.0, therefore is __NR_poll is - * not available, we assume an old Linux kernel is in use and we will - * use select() instead. */ -#include <sys/syscall.h> -#ifndef __NR_poll -# define USE_SELECT -#endif - - -/* Array of active threads. Entry 0 is reserved for the initial thread. */ -struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX] = -{ { __LOCK_INITIALIZER, &__pthread_initial_thread, 0}, - { __LOCK_INITIALIZER, &__pthread_manager_thread, 0}, /* All NULLs */ }; - -/* For debugging purposes put the maximum number of threads in a variable. */ -const int __linuxthreads_pthread_threads_max = PTHREAD_THREADS_MAX; - -/* Indicate whether at least one thread has a user-defined stack (if 1), - or if all threads have stacks supplied by LinuxThreads (if 0). */ -int __pthread_nonstandard_stacks; - -/* Number of active entries in __pthread_handles (used by gdb) */ -volatile int __pthread_handles_num = 2; - -/* Whether to use debugger additional actions for thread creation - (set to 1 by gdb) */ -volatile int __pthread_threads_debug; - -/* Globally enabled events. */ -volatile td_thr_events_t __pthread_threads_events; - -/* Pointer to thread descriptor with last event. */ -volatile pthread_descr __pthread_last_event; - -/* Mapping from stack segment to thread descriptor. */ -/* Stack segment numbers are also indices into the __pthread_handles array. */ -/* Stack segment number 0 is reserved for the initial thread. */ - -static inline pthread_descr thread_segment(int seg) -{ - return (pthread_descr)(THREAD_STACK_START_ADDRESS - (seg - 1) * STACK_SIZE) - - 1; -} - -/* Flag set in signal handler to record child termination */ - -static volatile int terminated_children = 0; - -/* Flag set when the initial thread is blocked on pthread_exit waiting - for all other threads to terminate */ - -static int main_thread_exiting = 0; - -/* Counter used to generate unique thread identifier. - Thread identifier is pthread_threads_counter + segment. */ - -static pthread_t pthread_threads_counter = 0; - -/* Forward declarations */ - -static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr, - void * (*start_routine)(void *), void *arg, - sigset_t *mask, int father_pid, - int report_events, - td_thr_events_t *event_maskp); -static void pthread_handle_free(pthread_t th_id); -static void pthread_handle_exit(pthread_descr issuing_thread, int exitcode); -static void pthread_reap_children(void); -static void pthread_kill_all_threads(int sig, int main_thread_also); - -/* The server thread managing requests for thread creation and termination */ - -int __pthread_manager(void *arg) -{ - int reqfd = (int) (long int) arg; -#ifdef USE_SELECT - struct timeval tv; - fd_set fd; -#else - struct pollfd ufd; -#endif - sigset_t manager_mask; - int n; - struct pthread_request request; - - /* If we have special thread_self processing, initialize it. */ -#ifdef INIT_THREAD_SELF - INIT_THREAD_SELF(&__pthread_manager_thread, 1); -#endif - /* Set the error variable. */ - __pthread_manager_thread.p_errnop = &__pthread_manager_thread.p_errno; - __pthread_manager_thread.p_h_errnop = &__pthread_manager_thread.p_h_errno; - -#ifdef __UCLIBC_HAS_XLOCALE__ - /* Initialize thread's locale to the global locale. */ - __pthread_manager_thread.locale = __global_locale; -#endif /* __UCLIBC_HAS_XLOCALE__ */ - - /* Block all signals except __pthread_sig_cancel and SIGTRAP */ - sigfillset(&manager_mask); - sigdelset(&manager_mask, __pthread_sig_cancel); /* for thread termination */ - sigdelset(&manager_mask, SIGTRAP); /* for debugging purposes */ - if (__pthread_threads_debug && __pthread_sig_debug > 0) - sigdelset(&manager_mask, __pthread_sig_debug); - sigprocmask(SIG_SETMASK, &manager_mask, NULL); - /* Raise our priority to match that of main thread */ - __pthread_manager_adjust_prio(__pthread_main_thread->p_priority); - /* Synchronize debugging of the thread manager */ - n = TEMP_FAILURE_RETRY(__libc_read(reqfd, (char *)&request, - sizeof(request))); - ASSERT(n == sizeof(request) && request.req_kind == REQ_DEBUG); -#ifndef USE_SELECT - ufd.fd = reqfd; - ufd.events = POLLIN; -#endif - /* Enter server loop */ - while(1) { -#ifdef USE_SELECT - tv.tv_sec = 2; - tv.tv_usec = 0; - FD_ZERO (&fd); - FD_SET (reqfd, &fd); - n = select (reqfd + 1, &fd, NULL, NULL, &tv); -#else - PDEBUG("before poll\n"); - n = poll(&ufd, 1, 2000); - PDEBUG("after poll\n"); -#endif - /* Check for termination of the main thread */ - if (getppid() == 1) { - pthread_kill_all_threads(SIGKILL, 0); - _exit(0); - } - /* Check for dead children */ - if (terminated_children) { - terminated_children = 0; - pthread_reap_children(); - } - /* Read and execute request */ -#ifdef USE_SELECT - if (n == 1) -#else - if (n == 1 && (ufd.revents & POLLIN)) -#endif - { - - PDEBUG("before __libc_read\n"); - n = __libc_read(reqfd, (char *)&request, sizeof(request)); - PDEBUG("after __libc_read, n=%d\n", n); - ASSERT(n == sizeof(request)); - switch(request.req_kind) { - case REQ_CREATE: - PDEBUG("got REQ_CREATE\n"); - request.req_thread->p_retcode = - pthread_handle_create((pthread_t *) &request.req_thread->p_retval, - request.req_args.create.attr, - request.req_args.create.fn, - request.req_args.create.arg, - &request.req_args.create.mask, - request.req_thread->p_pid, - request.req_thread->p_report_events, - &request.req_thread->p_eventbuf.eventmask); - PDEBUG("restarting %d\n", request.req_thread); - restart(request.req_thread); - break; - case REQ_FREE: - PDEBUG("got REQ_FREE\n"); - pthread_handle_free(request.req_args.free.thread_id); - break; - case REQ_PROCESS_EXIT: - PDEBUG("got REQ_PROCESS_EXIT from %d, exit code = %d\n", - request.req_thread, request.req_args.exit.code); - pthread_handle_exit(request.req_thread, - request.req_args.exit.code); - break; - case REQ_MAIN_THREAD_EXIT: - PDEBUG("got REQ_MAIN_THREAD_EXIT\n"); - main_thread_exiting = 1; - /* Reap children in case all other threads died and the signal handler - went off before we set main_thread_exiting to 1, and therefore did - not do REQ_KICK. */ - pthread_reap_children(); - - if (__pthread_main_thread->p_nextlive == __pthread_main_thread) { - restart(__pthread_main_thread); - /* The main thread will now call exit() which will trigger an - __on_exit handler, which in turn will send REQ_PROCESS_EXIT - to the thread manager. In case you are wondering how the - manager terminates from its loop here. */ - } - break; - case REQ_POST: - PDEBUG("got REQ_POST\n"); - __new_sem_post(request.req_args.post); - break; - case REQ_DEBUG: - PDEBUG("got REQ_DEBUG\n"); - /* Make gdb aware of new thread and gdb will restart the - new thread when it is ready to handle the new thread. */ - if (__pthread_threads_debug && __pthread_sig_debug > 0) { - PDEBUG("about to call raise(__pthread_sig_debug)\n"); - raise(__pthread_sig_debug); - } - case REQ_KICK: - /* This is just a prod to get the manager to reap some - threads right away, avoiding a potential delay at shutdown. */ - break; - } - } - } -} - -int __pthread_manager_event(void *arg) -{ - /* If we have special thread_self processing, initialize it. */ -#ifdef INIT_THREAD_SELF - INIT_THREAD_SELF(&__pthread_manager_thread, 1); -#endif - - /* Get the lock the manager will free once all is correctly set up. */ - __pthread_lock (THREAD_GETMEM((&__pthread_manager_thread), p_lock), NULL); - /* Free it immediately. */ - __pthread_unlock (THREAD_GETMEM((&__pthread_manager_thread), p_lock)); - - return __pthread_manager(arg); -} - -/* Process creation */ -static int -__attribute__ ((noreturn)) -pthread_start_thread(void *arg) -{ - pthread_descr self = (pthread_descr) arg; - struct pthread_request request; - void * outcome; - /* Initialize special thread_self processing, if any. */ -#ifdef INIT_THREAD_SELF - INIT_THREAD_SELF(self, self->p_nr); -#endif - PDEBUG("\n"); - /* Make sure our pid field is initialized, just in case we get there - before our father has initialized it. */ - THREAD_SETMEM(self, p_pid, __getpid()); - /* Initial signal mask is that of the creating thread. (Otherwise, - we'd just inherit the mask of the thread manager.) */ - sigprocmask(SIG_SETMASK, &self->p_start_args.mask, NULL); - /* Set the scheduling policy and priority for the new thread, if needed */ - if (THREAD_GETMEM(self, p_start_args.schedpolicy) >= 0) - /* Explicit scheduling attributes were provided: apply them */ - sched_setscheduler(THREAD_GETMEM(self, p_pid), - THREAD_GETMEM(self, p_start_args.schedpolicy), - &self->p_start_args.schedparam); - else if (__pthread_manager_thread.p_priority > 0) - /* Default scheduling required, but thread manager runs in realtime - scheduling: switch new thread to SCHED_OTHER policy */ - { - struct sched_param default_params; - default_params.sched_priority = 0; - sched_setscheduler(THREAD_GETMEM(self, p_pid), - SCHED_OTHER, &default_params); - } - /* Make gdb aware of new thread */ - if (__pthread_threads_debug && __pthread_sig_debug > 0) { - request.req_thread = self; - request.req_kind = REQ_DEBUG; - TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request, - (char *) &request, sizeof(request))); - suspend(self); - } - /* Run the thread code */ - outcome = self->p_start_args.start_routine(THREAD_GETMEM(self, - p_start_args.arg)); - /* Exit with the given return value */ - pthread_exit(outcome); -} - -static int -__attribute__ ((noreturn)) -pthread_start_thread_event(void *arg) -{ - pthread_descr self = (pthread_descr) arg; - -#ifdef INIT_THREAD_SELF - INIT_THREAD_SELF(self, self->p_nr); -#endif - /* Make sure our pid field is initialized, just in case we get there - before our father has initialized it. */ - THREAD_SETMEM(self, p_pid, __getpid()); - /* Get the lock the manager will free once all is correctly set up. */ - __pthread_lock (THREAD_GETMEM(self, p_lock), NULL); - /* Free it immediately. */ - __pthread_unlock (THREAD_GETMEM(self, p_lock)); - - /* Continue with the real function. */ - pthread_start_thread (arg); -} - -static int pthread_allocate_stack(const pthread_attr_t *attr, - pthread_descr default_new_thread, - int pagesize, - pthread_descr * out_new_thread, - char ** out_new_thread_bottom, - char ** out_guardaddr, - size_t * out_guardsize) -{ - pthread_descr new_thread; - char * new_thread_bottom; - char * guardaddr; - size_t stacksize, guardsize; - - if (attr != NULL && attr->__stackaddr_set) - { - /* The user provided a stack. */ - new_thread = - (pthread_descr) ((long)(attr->__stackaddr) & -sizeof(void *)) - 1; - new_thread_bottom = (char *) attr->__stackaddr - attr->__stacksize; - guardaddr = NULL; - guardsize = 0; - __pthread_nonstandard_stacks = 1; - } - else - { -#ifdef __ARCH_HAS_MMU__ - stacksize = STACK_SIZE - pagesize; - if (attr != NULL) - stacksize = MIN (stacksize, roundup(attr->__stacksize, pagesize)); - /* Allocate space for stack and thread descriptor at default address */ - new_thread = default_new_thread; - new_thread_bottom = (char *) (new_thread + 1) - stacksize; - if (mmap((caddr_t)((char *)(new_thread + 1) - INITIAL_STACK_SIZE), - INITIAL_STACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED | MAP_GROWSDOWN, - -1, 0) == MAP_FAILED) - /* Bad luck, this segment is already mapped. */ - return -1; - /* We manage to get a stack. Now see whether we need a guard - and allocate it if necessary. Notice that the default - attributes (stack_size = STACK_SIZE - pagesize) do not need - a guard page, since the RLIMIT_STACK soft limit prevents stacks - from running into one another. */ - if (stacksize == STACK_SIZE - pagesize) - { - /* We don't need a guard page. */ - guardaddr = NULL; - guardsize = 0; - } - else - { - /* Put a bad page at the bottom of the stack */ - guardsize = attr->__guardsize; - guardaddr = (void *)new_thread_bottom - guardsize; - if (mmap ((caddr_t) guardaddr, guardsize, 0, MAP_FIXED, -1, 0) - == MAP_FAILED) - { - /* We don't make this an error. */ - guardaddr = NULL; - guardsize = 0; - } - } -#else - /* We cannot mmap to this huge chunk of stack space when we don't have - * an MMU. Pretend we are using a user provided stack even if there was - * none provided by the user. Thus, we get around the mmap and reservation - * of a huge stack segment. -StS */ - - stacksize = INITIAL_STACK_SIZE; - /* The user may want to use a non-default stacksize */ - if (attr != NULL) - { - stacksize = attr->__stacksize; - } - - /* malloc a stack - memory from the bottom up */ - if ((new_thread_bottom = malloc(stacksize)) == NULL) - { - /* bad luck, we cannot malloc any more */ - return -1 ; - } - PDEBUG("malloced chunk: base=%p, size=0x%04x\n", new_thread_bottom, stacksize); - - /* Set up the pointers. new_thread marks the TOP of the stack frame and - * the address of the pthread_descr struct at the same time. Therefore we - * must account for its size and fit it in the malloc()'ed block. The - * value of `new_thread' is then passed to clone() as the stack argument. - * - * ^ +------------------------+ - * | | pthread_descr struct | - * | +------------------------+ <- new_thread - * malloc block | | | - * | | thread stack | - * | | | - * v +------------------------+ <- new_thread_bottom - * - * Note: The calculated value of new_thread must be word aligned otherwise - * the kernel chokes on a non-aligned stack frame. Choose the lower - * available word boundary. - */ - new_thread = ((pthread_descr) ((int)(new_thread_bottom + stacksize) & -sizeof(void*))) - 1; - guardaddr = NULL; - guardsize = 0; - - PDEBUG("thread stack: bos=%p, tos=%p\n", new_thread_bottom, new_thread); - - /* check the initial thread stack boundaries so they don't overlap */ - NOMMU_INITIAL_THREAD_BOUNDS((char *) new_thread, (char *) new_thread_bottom); - - PDEBUG("initial stack: bos=%p, tos=%p\n", __pthread_initial_thread_bos, - __pthread_initial_thread_tos); - - /* on non-MMU systems we always have non-standard stack frames */ - __pthread_nonstandard_stacks = 1; - -#endif /* __ARCH_HAS_MMU__ */ - } - - /* Clear the thread data structure. */ - memset (new_thread, '\0', sizeof (*new_thread)); - *out_new_thread = new_thread; - *out_new_thread_bottom = new_thread_bottom; - *out_guardaddr = guardaddr; - *out_guardsize = guardsize; - return 0; -} - -static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr, - void * (*start_routine)(void *), void *arg, - sigset_t * mask, int father_pid, - int report_events, - td_thr_events_t *event_maskp) -{ - size_t sseg; - int pid; - pthread_descr new_thread; - char * new_thread_bottom; - pthread_t new_thread_id; - char *guardaddr = NULL; - size_t guardsize = 0; - int pagesize = __getpagesize(); - int saved_errno = 0; - - /* First check whether we have to change the policy and if yes, whether - we can do this. Normally this should be done by examining the - return value of the sched_setscheduler call in pthread_start_thread - but this is hard to implement. FIXME */ - if (attr != NULL && attr->__schedpolicy != SCHED_OTHER && geteuid () != 0) - return EPERM; - /* Find a free segment for the thread, and allocate a stack if needed */ - for (sseg = 2; ; sseg++) - { - if (sseg >= PTHREAD_THREADS_MAX) - return EAGAIN; - if (__pthread_handles[sseg].h_descr != NULL) - continue; - if (pthread_allocate_stack(attr, thread_segment(sseg), pagesize, - &new_thread, &new_thread_bottom, - &guardaddr, &guardsize) == 0) - break; - } - __pthread_handles_num++; - /* Allocate new thread identifier */ - pthread_threads_counter += PTHREAD_THREADS_MAX; - new_thread_id = sseg + pthread_threads_counter; - /* Initialize the thread descriptor. Elements which have to be - initialized to zero already have this value. */ - new_thread->p_tid = new_thread_id; - new_thread->p_lock = &(__pthread_handles[sseg].h_lock); - new_thread->p_cancelstate = PTHREAD_CANCEL_ENABLE; - new_thread->p_canceltype = PTHREAD_CANCEL_DEFERRED; - new_thread->p_errnop = &new_thread->p_errno; - new_thread->p_h_errnop = &new_thread->p_h_errno; -#ifdef __UCLIBC_HAS_XLOCALE__ - /* Initialize thread's locale to the global locale. */ - new_thread->locale = __global_locale; -#endif /* __UCLIBC_HAS_XLOCALE__ */ - new_thread->p_guardaddr = guardaddr; - new_thread->p_guardsize = guardsize; - new_thread->p_self = new_thread; - new_thread->p_nr = sseg; - /* Initialize the thread handle */ - __pthread_init_lock(&__pthread_handles[sseg].h_lock); - __pthread_handles[sseg].h_descr = new_thread; - __pthread_handles[sseg].h_bottom = new_thread_bottom; - /* Determine scheduling parameters for the thread */ - new_thread->p_start_args.schedpolicy = -1; - if (attr != NULL) { - new_thread->p_detached = attr->__detachstate; - new_thread->p_userstack = attr->__stackaddr_set; - - switch(attr->__inheritsched) { - case PTHREAD_EXPLICIT_SCHED: - new_thread->p_start_args.schedpolicy = attr->__schedpolicy; - memcpy (&new_thread->p_start_args.schedparam, &attr->__schedparam, - sizeof (struct sched_param)); - break; - case PTHREAD_INHERIT_SCHED: - new_thread->p_start_args.schedpolicy = sched_getscheduler(father_pid); - sched_getparam(father_pid, &new_thread->p_start_args.schedparam); - break; - } - new_thread->p_priority = - new_thread->p_start_args.schedparam.sched_priority; - } - /* Finish setting up arguments to pthread_start_thread */ - new_thread->p_start_args.start_routine = start_routine; - new_thread->p_start_args.arg = arg; - new_thread->p_start_args.mask = *mask; - /* Raise priority of thread manager if needed */ - __pthread_manager_adjust_prio(new_thread->p_priority); - /* Do the cloning. We have to use two different functions depending - on whether we are debugging or not. */ - pid = 0; /* Note that the thread never can have PID zero. */ - - - /* ******************************************************** */ - /* This code was moved from below to cope with running threads - * on uClinux systems. See comment below... - * Insert new thread in doubly linked list of active threads */ - new_thread->p_prevlive = __pthread_main_thread; - new_thread->p_nextlive = __pthread_main_thread->p_nextlive; - __pthread_main_thread->p_nextlive->p_prevlive = new_thread; - __pthread_main_thread->p_nextlive = new_thread; - /* ********************************************************* */ - - if (report_events) - { - /* See whether the TD_CREATE event bit is set in any of the - masks. */ - int idx = __td_eventword (TD_CREATE); - uint32_t mask = __td_eventmask (TD_CREATE); - - if ((mask & (__pthread_threads_events.event_bits[idx] - | event_maskp->event_bits[idx])) != 0) - { - /* Lock the mutex the child will use now so that it will stop. */ - __pthread_lock(new_thread->p_lock, NULL); - - /* We have to report this event. */ - pid = clone(pthread_start_thread_event, (void **) new_thread, - CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | - __pthread_sig_cancel, new_thread); - - saved_errno = errno; - 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. */ - new_thread->p_eventbuf.eventdata = new_thread; - new_thread->p_eventbuf.eventnum = TD_CREATE; - __pthread_last_event = new_thread; - - /* We have to set the PID here since the callback function - in the debug library will need it and we cannot guarantee - the child got scheduled before the debugger. */ - new_thread->p_pid = pid; - - /* Now call the function which signals the event. */ - __linuxthreads_create_event (); - - /* Now restart the thread. */ - __pthread_unlock(new_thread->p_lock); - } - } - } - if (pid == 0) - { - PDEBUG("cloning new_thread = %p\n", new_thread); - pid = clone(pthread_start_thread, (void **) new_thread, - CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | - __pthread_sig_cancel, new_thread); - saved_errno = errno; - } - /* Check if cloning succeeded */ - if (pid == -1) { - /******************************************************** - * Code inserted to remove the thread from our list of active - * threads in case of failure (needed to cope with uClinux), - * See comment below. */ - new_thread->p_nextlive->p_prevlive = new_thread->p_prevlive; - new_thread->p_prevlive->p_nextlive = new_thread->p_nextlive; - /********************************************************/ - - /* Free the stack if we allocated it */ - if (attr == NULL || !attr->__stackaddr_set) - { -#ifdef __ARCH_HAS_MMU__ - if (new_thread->p_guardsize != 0) - munmap(new_thread->p_guardaddr, new_thread->p_guardsize); - munmap((caddr_t)((char *)(new_thread+1) - INITIAL_STACK_SIZE), - INITIAL_STACK_SIZE); -#else - free(new_thread_bottom); -#endif /* __ARCH_HAS_MMU__ */ - } - __pthread_handles[sseg].h_descr = NULL; - __pthread_handles[sseg].h_bottom = NULL; - __pthread_handles_num--; - return errno; - } - PDEBUG("new thread pid = %d\n", pid); - -#if 0 - /* *********************************************************** - This code has been moved before the call to clone(). In uClinux, - the use of wait on a semaphore is dependant upon that the child so - the child must be in the active threads list. This list is used in - pthread_find_self() to get the pthread_descr of self. So, if the - child calls sem_wait before this code is executed , it will hang - forever and initial_thread will instead be posted by a sem_post - call. */ - - /* Insert new thread in doubly linked list of active threads */ - new_thread->p_prevlive = __pthread_main_thread; - new_thread->p_nextlive = __pthread_main_thread->p_nextlive; - __pthread_main_thread->p_nextlive->p_prevlive = new_thread; - __pthread_main_thread->p_nextlive = new_thread; - /************************************************************/ -#endif - - /* Set pid field of the new thread, in case we get there before the - child starts. */ - new_thread->p_pid = pid; - /* We're all set */ - *thread = new_thread_id; - return 0; -} - - -/* Try to free the resources of a thread when requested by pthread_join - or pthread_detach on a terminated thread. */ - -static void pthread_free(pthread_descr th) -{ - pthread_handle handle; - pthread_readlock_info *iter, *next; - char *h_bottom_save; - - ASSERT(th->p_exited); - /* Make the handle invalid */ - handle = thread_handle(th->p_tid); - __pthread_lock(&handle->h_lock, NULL); - h_bottom_save = handle->h_bottom; - handle->h_descr = NULL; - handle->h_bottom = (char *)(-1L); - __pthread_unlock(&handle->h_lock); -#ifdef FREE_THREAD_SELF - FREE_THREAD_SELF(th, th->p_nr); -#endif - /* One fewer threads in __pthread_handles */ - __pthread_handles_num--; - - /* Destroy read lock list, and list of free read lock structures. - If the former is not empty, it means the thread exited while - holding read locks! */ - - for (iter = th->p_readlock_list; iter != NULL; iter = next) - { - next = iter->pr_next; - free(iter); - } - - for (iter = th->p_readlock_free; iter != NULL; iter = next) - { - next = iter->pr_next; - free(iter); - } - - /* If initial thread, nothing to free */ - if (th == &__pthread_initial_thread) return; -#ifdef __ARCH_HAS_MMU__ - if (!th->p_userstack) - { - /* Free the stack and thread descriptor area */ - if (th->p_guardsize != 0) - munmap(th->p_guardaddr, th->p_guardsize); - munmap((caddr_t) ((char *)(th+1) - STACK_SIZE), STACK_SIZE); - } -#else - /* For non-MMU systems we always malloc the stack, so free it here. -StS */ - if (!th->p_userstack) { - free(h_bottom_save); - } -#endif /* __ARCH_HAS_MMU__ */ -} - -/* Handle threads that have exited */ - -static void pthread_exited(pid_t pid) -{ - pthread_descr th; - int detached; - /* Find thread with that pid */ - for (th = __pthread_main_thread->p_nextlive; - th != __pthread_main_thread; - th = th->p_nextlive) { - if (th->p_pid == pid) { - /* Remove thread from list of active threads */ - th->p_nextlive->p_prevlive = th->p_prevlive; - th->p_prevlive->p_nextlive = th->p_nextlive; - /* Mark thread as exited, and if detached, free its resources */ - __pthread_lock(th->p_lock, NULL); - th->p_exited = 1; - /* If we have to signal this event do it now. */ - if (th->p_report_events) - { - /* See whether TD_REAP is in any of the mask. */ - int idx = __td_eventword (TD_REAP); - uint32_t mask = __td_eventmask (TD_REAP); - - if ((mask & (__pthread_threads_events.event_bits[idx] - | th->p_eventbuf.eventmask.event_bits[idx])) != 0) - { - /* Yep, we have to signal the reapage. */ - th->p_eventbuf.eventnum = TD_REAP; - th->p_eventbuf.eventdata = th; - __pthread_last_event = th; - - /* Now call the function to signal the event. */ - __linuxthreads_reap_event(); - } - } - detached = th->p_detached; - __pthread_unlock(th->p_lock); - if (detached) - pthread_free(th); - break; - } - } - /* If all threads have exited and the main thread is pending on a - pthread_exit, wake up the main thread and terminate ourselves. */ - if (main_thread_exiting && - __pthread_main_thread->p_nextlive == __pthread_main_thread) { - restart(__pthread_main_thread); - /* Same logic as REQ_MAIN_THREAD_EXIT. */ - } -} - -static void pthread_reap_children(void) -{ - pid_t pid; - int status; - PDEBUG("\n"); - - while ((pid = __libc_waitpid(-1, &status, WNOHANG | __WCLONE)) > 0) { - pthread_exited(pid); - if (WIFSIGNALED(status)) { - /* If a thread died due to a signal, send the same signal to - all other threads, including the main thread. */ - pthread_kill_all_threads(WTERMSIG(status), 1); - _exit(0); - } - } -} - -/* Try to free the resources of a thread when requested by pthread_join - or pthread_detach on a terminated thread. */ - -static void pthread_handle_free(pthread_t th_id) -{ - pthread_handle handle = thread_handle(th_id); - pthread_descr th; - - __pthread_lock(&handle->h_lock, NULL); - if (invalid_handle(handle, th_id)) { - /* pthread_reap_children has deallocated the thread already, - nothing needs to be done */ - __pthread_unlock(&handle->h_lock); - return; - } - th = handle->h_descr; - if (th->p_exited) { - __pthread_unlock(&handle->h_lock); - pthread_free(th); - } else { - /* The Unix process of the thread is still running. - Mark the thread as detached so that the thread manager will - deallocate its resources when the Unix process exits. */ - th->p_detached = 1; - __pthread_unlock(&handle->h_lock); - } -} - -/* Send a signal to all running threads */ - -static void pthread_kill_all_threads(int sig, int main_thread_also) -{ - pthread_descr th; - for (th = __pthread_main_thread->p_nextlive; - th != __pthread_main_thread; - th = th->p_nextlive) { - kill(th->p_pid, sig); - } - if (main_thread_also) { - kill(__pthread_main_thread->p_pid, sig); - } -} - -/* Process-wide exit() */ - -static void pthread_handle_exit(pthread_descr issuing_thread, int exitcode) -{ - pthread_descr th; - __pthread_exit_requested = 1; - __pthread_exit_code = exitcode; - /* Send the CANCEL signal to all running threads, including the main - thread, but excluding the thread from which the exit request originated - (that thread must complete the exit, e.g. calling atexit functions - and flushing stdio buffers). */ - for (th = issuing_thread->p_nextlive; - th != issuing_thread; - th = th->p_nextlive) { - kill(th->p_pid, __pthread_sig_cancel); - } - /* Now, wait for all these threads, so that they don't become zombies - and their times are properly added to the thread manager's times. */ - for (th = issuing_thread->p_nextlive; - th != issuing_thread; - th = th->p_nextlive) { - waitpid(th->p_pid, NULL, __WCLONE); - } - restart(issuing_thread); - _exit(0); -} - -/* Handler for __pthread_sig_cancel in thread manager thread */ - -void __pthread_manager_sighandler(int sig) -{ - int kick_manager = terminated_children == 0 && main_thread_exiting; - terminated_children = 1; - - /* If the main thread is terminating, kick the thread manager loop - each time some threads terminate. This eliminates a two second - shutdown delay caused by the thread manager sleeping in the - call to __poll(). Instead, the thread manager is kicked into - action, reaps the outstanding threads and resumes the main thread - so that it can complete the shutdown. */ - - if (kick_manager) { - struct pthread_request request; - request.req_thread = 0; - request.req_kind = REQ_KICK; - TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request, - (char *) &request, sizeof(request))); - } -} - -/* Adjust priority of thread manager so that it always run at a priority - higher than all threads */ - -void __pthread_manager_adjust_prio(int thread_prio) -{ - struct sched_param param; - - if (thread_prio <= __pthread_manager_thread.p_priority) return; - param.sched_priority = - thread_prio < sched_get_priority_max(SCHED_FIFO) - ? thread_prio + 1 : thread_prio; - sched_setscheduler(__pthread_manager_thread.p_pid, SCHED_FIFO, ¶m); - __pthread_manager_thread.p_priority = thread_prio; -} |