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Diffstat (limited to 'lib/libpthread/thread/thr_create.c')
| -rw-r--r-- | lib/libpthread/thread/thr_create.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c new file mode 100644 index 0000000..74cb134 --- /dev/null +++ b/lib/libpthread/thread/thr_create.c @@ -0,0 +1,312 @@ +/* + * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com> + * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by John Birrell. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.h> +#include <stddef.h> +#include <sys/time.h> +#include <machine/reg.h> +#include <pthread.h> +#include "thr_private.h" +#include "libc_private.h" + +static u_int64_t next_uniqueid = 1; + +#define OFF(f) offsetof(struct pthread, f) +int _thread_next_offset = OFF(tle.tqe_next); +int _thread_uniqueid_offset = OFF(uniqueid); +int _thread_state_offset = OFF(state); +int _thread_name_offset = OFF(name); +int _thread_ctx_offset = OFF(tmbx.tm_context); +#undef OFF + +int _thread_PS_RUNNING_value = PS_RUNNING; +int _thread_PS_DEAD_value = PS_DEAD; + +static int create_stack(struct pthread_attr *pattr); +static void thread_start(struct pthread *curthread, + void *(*start_routine) (void *), void *arg); + +__weak_reference(_pthread_create, pthread_create); + +/* + * Some notes on new thread creation and first time initializion + * to enable multi-threading. + * + * There are basically two things that need to be done. + * + * 1) The internal library variables must be initialized. + * 2) Upcalls need to be enabled to allow multiple threads + * to be run. + * + * The first may be done as a result of other pthread functions + * being called. When _thr_initial is null, _libpthread_init is + * called to initialize the internal variables; this also creates + * or sets the initial thread. It'd be nice to automatically + * have _libpthread_init called on program execution so we don't + * have to have checks throughout the library. + * + * The second part is only triggered by the creation of the first + * thread (other than the initial/main thread). If the thread + * being created is a scope system thread, then a new KSE/KSEG + * pair needs to be allocated. Also, if upcalls haven't been + * enabled on the initial thread's KSE, they must be now that + * there is more than one thread; this could be delayed until + * the initial KSEG has more than one thread. + */ +int +_pthread_create(pthread_t * thread, const pthread_attr_t * attr, + void *(*start_routine) (void *), void *arg) +{ + struct kse *curkse; + struct pthread *curthread, *new_thread; + struct kse *kse = NULL; + struct kse_group *kseg = NULL; + kse_critical_t crit; + int i; + int ret = 0; + + if (_thr_initial == NULL) + _libpthread_init(NULL); + + crit = _kse_critical_enter(); + curthread = _get_curthread(); + curkse = curthread->kse; + + /* Allocate memory for the thread structure: */ + if ((new_thread = _thr_alloc(curthread)) == NULL) { + /* Insufficient memory to create a thread: */ + ret = EAGAIN; + } else { + /* Initialize the thread structure: */ + memset(new_thread, 0, sizeof(struct pthread)); + + /* Check if default thread attributes are required: */ + if (attr == NULL || *attr == NULL) + /* Use the default thread attributes: */ + new_thread->attr = _pthread_attr_default; + else + new_thread->attr = *(*attr); + + if (create_stack(&new_thread->attr) != 0) { + /* Insufficient memory to create a stack: */ + ret = EAGAIN; + _thr_free(curthread, new_thread); + } + else if (((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && + (((kse = _kse_alloc(curthread)) == NULL) + || ((kseg = _kseg_alloc(curthread)) == NULL))) { + /* Insufficient memory to create a new KSE/KSEG: */ + ret = EAGAIN; + if (kse != NULL) + _kse_free(curthread, kse); + if ((new_thread->attr.flags & THR_STACK_USER) == 0) { + KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); + _thr_stack_free(&new_thread->attr); + KSE_LOCK_RELEASE(curkse, &_thread_list_lock); + } + _thr_free(curthread, new_thread); + } + else { + if (kseg != NULL) { + /* Add the KSE to the KSEG's list of KSEs. */ + TAILQ_INSERT_HEAD(&kseg->kg_kseq, kse, k_qe); + kse->k_kseg = kseg; + kse->k_schedq = &kseg->kg_schedq; + } + /* + * Write a magic value to the thread structure + * to help identify valid ones: + */ + new_thread->magic = THR_MAGIC; + + new_thread->slice_usec = -1; + new_thread->start_routine = start_routine; + new_thread->arg = arg; + new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | + PTHREAD_CANCEL_DEFERRED; + + /* Initialize the thread for signals: */ + new_thread->sigmask = curthread->sigmask; + + /* No thread is wanting to join to this one: */ + new_thread->joiner = NULL; + + /* Initialize the signal frame: */ + new_thread->curframe = NULL; + + /* Initialize the machine context: */ + THR_GETCONTEXT(&new_thread->tmbx.tm_context); + new_thread->tmbx.tm_udata = new_thread; + new_thread->tmbx.tm_context.uc_sigmask = + new_thread->sigmask; + new_thread->tmbx.tm_context.uc_stack.ss_size = + new_thread->attr.stacksize_attr; + new_thread->tmbx.tm_context.uc_stack.ss_sp = + new_thread->attr.stackaddr_attr; + + makecontext(&new_thread->tmbx.tm_context, + (void (*)(void))thread_start, 4, new_thread, + start_routine, arg); + + /* + * Check if this thread is to inherit the scheduling + * attributes from its parent: + */ + if ((new_thread->attr.flags & PTHREAD_INHERIT_SCHED) != 0) { + /* Copy the scheduling attributes: */ + new_thread->base_priority = + curthread->base_priority & + ~THR_SIGNAL_PRIORITY; + new_thread->attr.prio = + curthread->base_priority & + ~THR_SIGNAL_PRIORITY; + new_thread->attr.sched_policy = + curthread->attr.sched_policy; + } else { + /* + * Use just the thread priority, leaving the + * other scheduling attributes as their + * default values: + */ + new_thread->base_priority = + new_thread->attr.prio; + } + new_thread->active_priority = new_thread->base_priority; + new_thread->inherited_priority = 0; + + /* Initialize the mutex queue: */ + TAILQ_INIT(&new_thread->mutexq); + + /* Initialize thread locking. */ + if (_lock_init(&new_thread->lock, LCK_ADAPTIVE, + _thr_lock_wait, _thr_lock_wakeup) != 0) + PANIC("Cannot initialize thread lock"); + for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { + _lockuser_init(&new_thread->lockusers[i], + (void *)new_thread); + _LCK_SET_PRIVATE2(&new_thread->lockusers[i], + (void *)new_thread); + } + + /* Initialise hooks in the thread structure: */ + new_thread->specific = NULL; + new_thread->cleanup = NULL; + new_thread->flags = 0; + new_thread->continuation = NULL; + + if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) + new_thread->state = PS_SUSPENDED; + else + new_thread->state = PS_RUNNING; + + /* + * System scope threads have their own kse and + * kseg. Process scope threads are all hung + * off the main process kseg. + */ + if ((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) { + new_thread->kseg = _kse_initial->k_kseg; + new_thread->kse = _kse_initial; + } + else { + kse->k_curthread = NULL; + kse->k_kseg->kg_flags |= KGF_SINGLE_THREAD; + new_thread->kse = kse; + new_thread->kseg = kse->k_kseg; + kse->k_mbx.km_udata = kse; + kse->k_mbx.km_curthread = NULL; + } + KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); + + /* + * Initialise the unique id which GDB uses to + * track threads. + */ + new_thread->uniqueid = next_uniqueid++; + + /* Add the thread to the linked list of all threads: */ + THR_LIST_ADD(new_thread); + + KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); + + /* + * Schedule the new thread starting a new KSEG/KSE + * pair if necessary. + */ + _thr_schedule_add(curthread, new_thread); + + /* Return a pointer to the thread structure: */ + (*thread) = new_thread; + } + } + _kse_critical_leave(crit); + + if ((ret == 0) && (_kse_isthreaded() == 0)) + _kse_setthreaded(1); + + /* Return the status: */ + return (ret); +} + +static int +create_stack(struct pthread_attr *pattr) +{ + int ret; + + /* Check if a stack was specified in the thread attributes: */ + if ((pattr->stackaddr_attr) != NULL) { + pattr->guardsize_attr = 0; + pattr->flags = THR_STACK_USER; + ret = 0; + } + else + ret = _thr_stack_alloc(pattr); + return (ret); +} + + +static void +thread_start(struct pthread *curthread, void *(*start_routine) (void *), + void *arg) +{ + /* Run the current thread's start routine with argument: */ + pthread_exit(start_routine(arg)); + + /* This point should never be reached. */ + PANIC("Thread has resumed after exit"); +} |
