diff options
Diffstat (limited to 'lib/libc_r/uthread/uthread_stack.c')
| -rw-r--r-- | lib/libc_r/uthread/uthread_stack.c | 242 |
1 files changed, 0 insertions, 242 deletions
diff --git a/lib/libc_r/uthread/uthread_stack.c b/lib/libc_r/uthread/uthread_stack.c deleted file mode 100644 index 0b176ce..0000000 --- a/lib/libc_r/uthread/uthread_stack.c +++ /dev/null @@ -1,242 +0,0 @@ -/* - * Copyright (c) 2001 Daniel Eischen <deischen@freebsd.org> - * Copyright (c) 2000-2001 Jason Evans <jasone@freebsd.org> - * 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. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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 "namespace.h" -#include <sys/types.h> -#include <sys/mman.h> -#include <sys/param.h> -#include <sys/queue.h> -#include <stdlib.h> -#include <pthread.h> -#include "un-namespace.h" - -#include "pthread_private.h" - -/* Spare thread stack. */ -struct stack { - LIST_ENTRY(stack) qe; /* Stack queue linkage. */ - size_t stacksize; /* Stack size (rounded up). */ - size_t guardsize; /* Guard size. */ - void *stackaddr; /* Stack address. */ -}; - -/* - * Default sized (stack and guard) spare stack queue. Stacks are cached to - * avoid additional complexity managing mmap()ed stack regions. Spare stacks - * are used in LIFO order to increase cache locality. - */ -static LIST_HEAD(, stack) _dstackq = LIST_HEAD_INITIALIZER(_dstackq); - -/* - * Miscellaneous sized (non-default stack and/or guard) spare stack queue. - * Stacks are cached to avoid additional complexity managing mmap()ed stack - * regions. This list is unordered, since ordering on both stack size and guard - * size would be more trouble than it's worth. Stacks are allocated from this - * cache on a first size match basis. - */ -static LIST_HEAD(, stack) _mstackq = LIST_HEAD_INITIALIZER(_mstackq); - -/** - * Base address of the last stack allocated (including its red zone, if there is - * one). Stacks are allocated contiguously, starting beyond the top of the main - * stack. When a new stack is created, a red zone is typically created - * (actually, the red zone is simply left unmapped) above the top of the stack, - * such that the stack will not be able to grow all the way to the bottom of the - * next stack. This isn't fool-proof. It is possible for a stack to grow by a - * large amount, such that it grows into the next stack, and as long as the - * memory within the red zone is never accessed, nothing will prevent one thread - * stack from trouncing all over the next. - * - * low memory - * . . . . . . . . . . . . . . . . . . - * | | - * | stack 3 | start of 3rd thread stack - * +-----------------------------------+ - * | | - * | Red Zone (guard page) | red zone for 2nd thread - * | | - * +-----------------------------------+ - * | stack 2 - _pthread_stack_default | top of 2nd thread stack - * | | - * | | - * | | - * | | - * | stack 2 | - * +-----------------------------------+ <-- start of 2nd thread stack - * | | - * | Red Zone | red zone for 1st thread - * | | - * +-----------------------------------+ - * | stack 1 - _pthread_stack_default | top of 1st thread stack - * | | - * | | - * | | - * | | - * | stack 1 | - * +-----------------------------------+ <-- start of 1st thread stack - * | | (initial value of last_stack) - * | Red Zone | - * | | red zone for main thread - * +-----------------------------------+ - * | USRSTACK - _pthread_stack_initial | top of main thread stack - * | | ^ - * | | | - * | | | - * | | | stack growth - * | | - * +-----------------------------------+ <-- start of main thread stack - * (USRSTACK) - * high memory - * - */ -static void * last_stack; - -void * -_thread_stack_alloc(size_t stacksize, size_t guardsize) -{ - void *stack = NULL; - struct stack *spare_stack; - size_t stack_size; - - /* - * Round up stack size to nearest multiple of _pthread_page_size, - * so that mmap() * will work. If the stack size is not an even - * multiple, we end up initializing things such that there is unused - * space above the beginning of the stack, so the stack sits snugly - * against its guard. - */ - if (stacksize % _pthread_page_size != 0) - stack_size = ((stacksize / _pthread_page_size) + 1) * - _pthread_page_size; - else - stack_size = stacksize; - - /* - * If the stack and guard sizes are default, try to allocate a stack - * from the default-size stack cache: - */ - if (stack_size == _pthread_stack_default && - guardsize == _pthread_guard_default) { - /* - * Use the garbage collector mutex for synchronization of the - * spare stack list. - */ - if (_pthread_mutex_lock(&_gc_mutex) != 0) - PANIC("Cannot lock gc mutex"); - - if ((spare_stack = LIST_FIRST(&_dstackq)) != NULL) { - /* Use the spare stack. */ - LIST_REMOVE(spare_stack, qe); - stack = spare_stack->stackaddr; - } - - /* Unlock the garbage collector mutex. */ - if (_pthread_mutex_unlock(&_gc_mutex) != 0) - PANIC("Cannot unlock gc mutex"); - } - /* - * The user specified a non-default stack and/or guard size, so try to - * allocate a stack from the non-default size stack cache, using the - * rounded up stack size (stack_size) in the search: - */ - else { - /* - * Use the garbage collector mutex for synchronization of the - * spare stack list. - */ - if (_pthread_mutex_lock(&_gc_mutex) != 0) - PANIC("Cannot lock gc mutex"); - - LIST_FOREACH(spare_stack, &_mstackq, qe) { - if (spare_stack->stacksize == stack_size && - spare_stack->guardsize == guardsize) { - LIST_REMOVE(spare_stack, qe); - stack = spare_stack->stackaddr; - break; - } - } - - /* Unlock the garbage collector mutex. */ - if (_pthread_mutex_unlock(&_gc_mutex) != 0) - PANIC("Cannot unlock gc mutex"); - } - - /* Check if a stack was not allocated from a stack cache: */ - if (stack == NULL) { - - if (last_stack == NULL) - last_stack = _usrstack - _pthread_stack_initial - - _pthread_guard_default; - - /* Allocate a new stack. */ - stack = last_stack - stack_size; - - /* - * Even if stack allocation fails, we don't want to try to use - * this location again, so unconditionally decrement - * last_stack. Under normal operating conditions, the most - * likely reason for an mmap() error is a stack overflow of the - * adjacent thread stack. - */ - last_stack -= (stack_size + guardsize); - - /* Stack: */ - if (mmap(stack, stack_size, PROT_READ | PROT_WRITE, MAP_STACK, - -1, 0) == MAP_FAILED) - stack = NULL; - } - - return (stack); -} - -/* This function must be called with _gc_mutex held. */ -void -_thread_stack_free(void *stack, size_t stacksize, size_t guardsize) -{ - struct stack *spare_stack; - - spare_stack = (stack + stacksize - sizeof(struct stack)); - /* Round stacksize up to nearest multiple of _pthread_page_size. */ - if (stacksize % _pthread_page_size != 0) { - spare_stack->stacksize = - ((stacksize / _pthread_page_size) + 1) * - _pthread_page_size; - } else - spare_stack->stacksize = stacksize; - spare_stack->guardsize = guardsize; - spare_stack->stackaddr = stack; - - if (spare_stack->stacksize == _pthread_stack_default && - spare_stack->guardsize == _pthread_guard_default) { - /* Default stack/guard size. */ - LIST_INSERT_HEAD(&_dstackq, spare_stack, qe); - } else { - /* Non-default stack/guard size. */ - LIST_INSERT_HEAD(&_mstackq, spare_stack, qe); - } -} |
