79 lines
1.7 KiB
C++
79 lines
1.7 KiB
C++
/*
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* \brief Stack-allocator implementation for the Genode Thread API
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* \author Norman Feske
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* \author Martin Stein
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* \date 2014-01-26
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*/
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/*
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* Copyright (C) 2010-2014 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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/* base-internal includes */
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#include <base/internal/stack_allocator.h>
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using namespace Genode;
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Stack *Stack_allocator::base_to_stack(addr_t base)
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{
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addr_t result = base + Native_config::stack_virtual_size()
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- sizeof(Stack);
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return reinterpret_cast<Stack *>(result);
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}
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addr_t Stack_allocator::addr_to_base(void *addr)
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{
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return ((addr_t)addr) & ~(Native_config::stack_virtual_size() - 1);
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}
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size_t Stack_allocator::base_to_idx(addr_t base)
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{
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return (base - Native_config::stack_area_virtual_base()) /
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Native_config::stack_virtual_size();
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}
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addr_t Stack_allocator::idx_to_base(size_t idx)
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{
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return Native_config::stack_area_virtual_base() +
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idx * Native_config::stack_virtual_size();
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}
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Stack *
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Stack_allocator::alloc(Thread_base *thread_base, bool main_thread)
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{
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if (main_thread)
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/* the main-thread stack is the first one */
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return base_to_stack(Native_config::stack_area_virtual_base());
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try {
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Lock::Guard _lock_guard(_threads_lock);
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return base_to_stack(idx_to_base(_alloc.alloc()));
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} catch(Bit_allocator<MAX_THREADS>::Out_of_indices) {
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return 0;
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}
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}
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void Stack_allocator::free(Stack *stack)
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{
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addr_t const base = addr_to_base(stack);
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Lock::Guard _lock_guard(_threads_lock);
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_alloc.free(base_to_idx(base));
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}
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Stack_allocator &Stack_allocator::stack_allocator()
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{
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static Stack_allocator inst;
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return inst;
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}
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