| paul@93 | 1 | /* |
| paul@93 | 2 | * A memory pool providing regions from a preallocated amount of memory. |
| paul@93 | 3 | * |
| paul@93 | 4 | * Copyright (C) 2021 Paul Boddie <paul@boddie.org.uk> |
| paul@93 | 5 | * |
| paul@93 | 6 | * This program is free software; you can redistribute it and/or |
| paul@93 | 7 | * modify it under the terms of the GNU General Public License as |
| paul@93 | 8 | * published by the Free Software Foundation; either version 2 of |
| paul@93 | 9 | * the License, or (at your option) any later version. |
| paul@93 | 10 | * |
| paul@93 | 11 | * This program is distributed in the hope that it will be useful, |
| paul@93 | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| paul@93 | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| paul@93 | 14 | * GNU General Public License for more details. |
| paul@93 | 15 | * |
| paul@93 | 16 | * You should have received a copy of the GNU General Public License |
| paul@93 | 17 | * along with this program; if not, write to the Free Software |
| paul@93 | 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| paul@93 | 19 | * Boston, MA 02110-1301, USA |
| paul@93 | 20 | */ |
| paul@93 | 21 | |
| paul@72 | 22 | #include "memory_preallocated.h" |
| paul@72 | 23 | |
| paul@300 | 24 | #include <l4/cxx/exceptions> |
| paul@300 | 25 | |
| paul@72 | 26 | |
| paul@72 | 27 | |
| paul@72 | 28 | /* Initialise the memory pool with the given amount in bytes. */ |
| paul@72 | 29 | |
| paul@72 | 30 | MemoryPreallocated::MemoryPreallocated(Memory *memory, offset_t amount) |
| paul@72 | 31 | : _memory(memory), _amount(amount) |
| paul@72 | 32 | { |
| paul@72 | 33 | offset_t remaining = amount; |
| paul@72 | 34 | |
| paul@72 | 35 | while (remaining) |
| paul@72 | 36 | { |
| paul@300 | 37 | Region *region = memory->region(); |
| paul@72 | 38 | |
| paul@300 | 39 | if (region == NULL) |
| paul@300 | 40 | throw L4::Out_of_memory(); |
| paul@300 | 41 | |
| paul@300 | 42 | _regions.push_back(region); |
| paul@72 | 43 | |
| paul@72 | 44 | remaining -= memory->region_size(); |
| paul@72 | 45 | } |
| paul@72 | 46 | } |
| paul@72 | 47 | |
| paul@73 | 48 | /* Discard all unused regions. */ |
| paul@73 | 49 | |
| paul@73 | 50 | MemoryPreallocated::~MemoryPreallocated() |
| paul@73 | 51 | { |
| paul@73 | 52 | while (!_regions.empty()) |
| paul@73 | 53 | { |
| paul@73 | 54 | Region *region = _regions.front(); |
| paul@73 | 55 | |
| paul@73 | 56 | _regions.pop_front(); |
| paul@73 | 57 | _memory->release(region); |
| paul@73 | 58 | } |
| paul@73 | 59 | } |
| paul@73 | 60 | |
| paul@72 | 61 | /* Obtain an allocated region. */ |
| paul@72 | 62 | |
| paul@72 | 63 | Region *MemoryPreallocated::region() |
| paul@72 | 64 | { |
| paul@72 | 65 | std::lock_guard<std::mutex> guard(_lock); |
| paul@72 | 66 | |
| paul@107 | 67 | if (_regions.empty()) |
| paul@107 | 68 | return NULL; |
| paul@107 | 69 | |
| paul@72 | 70 | Region *region = _regions.front(); |
| paul@72 | 71 | |
| paul@72 | 72 | _regions.pop_front(); |
| paul@72 | 73 | return region; |
| paul@72 | 74 | } |
| paul@72 | 75 | |
| paul@72 | 76 | /* Release the allocated 'region'. */ |
| paul@72 | 77 | |
| paul@72 | 78 | void MemoryPreallocated::release(Region *region) |
| paul@72 | 79 | { |
| paul@72 | 80 | std::lock_guard<std::mutex> guard(_lock); |
| paul@72 | 81 | |
| paul@72 | 82 | _regions.push_back(region); |
| paul@72 | 83 | } |
| paul@72 | 84 | |
| paul@72 | 85 | // vim: tabstop=4 expandtab shiftwidth=4 |
