| paul@93 | 1 | /* |
| paul@93 | 2 | * A pipe pager providing access to pipe content and navigation support. |
| paul@93 | 3 | * |
| paul@485 | 4 | * Copyright (C) 2021, 2022, 2023 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@65 | 22 | #include "pipe_pager.h" |
| paul@65 | 23 | #include "pipe_object_server.h" |
| paul@65 | 24 | |
| paul@72 | 25 | |
| paul@72 | 26 | |
| paul@65 | 27 | /* Initialise a pager for a pipe with a shared page mapper for moderating |
| paul@65 | 28 | access to loaded pages. At first, no mapper will be configured: this must be |
| paul@65 | 29 | done by requesting a region. */ |
| paul@65 | 30 | |
| paul@66 | 31 | PipePager::PipePager(PipePaging *paging, bool writing) |
| paul@87 | 32 | : Pager(NULL, writing ? L4RE_DS_MAP_FLAG_RW : L4RE_DS_MAP_FLAG_RO), |
| paul@66 | 33 | _paging(paging), _writing(writing) |
| paul@65 | 34 | { |
| paul@66 | 35 | /* Initialise the size of the paged region. */ |
| paul@65 | 36 | |
| paul@66 | 37 | _size = _paging->region_size(); |
| paul@166 | 38 | |
| paul@166 | 39 | /* Obtain any initial page mapper, this having been set up in the paging |
| paul@166 | 40 | coordinator. */ |
| paul@166 | 41 | |
| paul@166 | 42 | _mapper = _paging->current_region(_writing); |
| paul@65 | 43 | } |
| paul@65 | 44 | |
| paul@459 | 45 | ipc_server_default_config_type PipePager::config() |
| paul@65 | 46 | { |
| paul@459 | 47 | return config_PipeObject; |
| paul@65 | 48 | } |
| paul@65 | 49 | |
| paul@65 | 50 | |
| paul@65 | 51 | |
| paul@127 | 52 | /* Close the pager, detaching from the paging coordinator for the pipe. When |
| paul@127 | 53 | both pagers have detached, this will release all active page mappers and |
| paul@127 | 54 | related resources. */ |
| paul@67 | 55 | |
| paul@67 | 56 | void PipePager::close() |
| paul@67 | 57 | { |
| paul@199 | 58 | if (_paging == NULL) |
| paul@199 | 59 | return; |
| paul@199 | 60 | |
| paul@386 | 61 | /* Notify the other endpoint and unsubscribe. */ |
| paul@117 | 62 | |
| paul@484 | 63 | _paging->notify_others(_writing ? PipePaging::WRITER : PipePaging::READER, |
| paul@484 | 64 | NOTIFY_PEER_CLOSED, NOTIFY_VALUES_NULL); |
| paul@488 | 65 | unsubscribe(_notifier); |
| paul@199 | 66 | |
| paul@199 | 67 | /* Deallocate the paging coordinator if no other endpoints are active. */ |
| paul@199 | 68 | |
| paul@544 | 69 | if (!_paging->detach()) |
| paul@199 | 70 | { |
| paul@199 | 71 | delete _paging; |
| paul@199 | 72 | _paging = NULL; |
| paul@199 | 73 | } |
| paul@67 | 74 | } |
| paul@67 | 75 | |
| paul@65 | 76 | /* Support paging. */ |
| paul@65 | 77 | |
| paul@410 | 78 | long PipePager::map(offset_t offset, map_address_t hot_spot, map_flags_t flags, l4_snd_fpage_t *region) |
| paul@65 | 79 | { |
| paul@65 | 80 | return Pager::map(offset, hot_spot, flags, region); |
| paul@65 | 81 | } |
| paul@65 | 82 | |
| paul@65 | 83 | |
| paul@65 | 84 | |
| paul@117 | 85 | /* Return whether the pipe is closed or partly closed. */ |
| paul@117 | 86 | |
| paul@117 | 87 | long PipePager::closed(int *closed) |
| paul@117 | 88 | { |
| paul@117 | 89 | *closed = _paging->closed(); |
| paul@117 | 90 | return L4_EOK; |
| paul@117 | 91 | } |
| paul@117 | 92 | |
| paul@65 | 93 | /* Return details of the current region. */ |
| paul@65 | 94 | |
| paul@65 | 95 | long PipePager::current_region(offset_t *populated_size, offset_t *size) |
| paul@65 | 96 | { |
| paul@65 | 97 | if (_mapper != NULL) |
| paul@65 | 98 | { |
| paul@65 | 99 | *populated_size = _mapper->get_data_size(); |
| paul@65 | 100 | *size = _size; |
| paul@65 | 101 | return L4_EOK; |
| paul@65 | 102 | } |
| paul@65 | 103 | else |
| paul@114 | 104 | return pipe_error(); |
| paul@65 | 105 | } |
| paul@65 | 106 | |
| paul@65 | 107 | /* Obtain the next region and its details. */ |
| paul@65 | 108 | |
| paul@65 | 109 | long PipePager::next_region(offset_t *populated_size, offset_t *size) |
| paul@65 | 110 | { |
| paul@65 | 111 | /* Obtain a new region if writing. */ |
| paul@65 | 112 | |
| paul@66 | 113 | if (_writing) |
| paul@65 | 114 | return next_region_for_writer(populated_size, size); |
| paul@65 | 115 | else |
| paul@65 | 116 | return next_region_for_reader(populated_size, size); |
| paul@65 | 117 | } |
| paul@65 | 118 | |
| paul@65 | 119 | long PipePager::next_region_for_reader(offset_t *populated_size, offset_t *size) |
| paul@65 | 120 | { |
| paul@72 | 121 | PageMapper *mapper = _paging->next_region(); |
| paul@65 | 122 | |
| paul@72 | 123 | if (mapper == NULL) |
| paul@114 | 124 | return pipe_error(); |
| paul@65 | 125 | |
| paul@72 | 126 | _mapper = mapper; |
| paul@65 | 127 | |
| paul@65 | 128 | return current_region(populated_size, size); |
| paul@65 | 129 | } |
| paul@65 | 130 | |
| paul@65 | 131 | long PipePager::next_region_for_writer(offset_t *populated_size, offset_t *size) |
| paul@65 | 132 | { |
| paul@65 | 133 | /* Set the populated size before moving on. */ |
| paul@65 | 134 | |
| paul@65 | 135 | if (_mapper != NULL) |
| paul@65 | 136 | _mapper->set_data_size(*populated_size); |
| paul@65 | 137 | |
| paul@72 | 138 | /* Obtain the page mapper for the region. */ |
| paul@66 | 139 | |
| paul@72 | 140 | PageMapper *mapper = _paging->add_region(); |
| paul@65 | 141 | |
| paul@72 | 142 | if (mapper == NULL) |
| paul@114 | 143 | return pipe_error(); |
| paul@65 | 144 | |
| paul@72 | 145 | _mapper = mapper; |
| paul@65 | 146 | |
| paul@72 | 147 | return current_region(populated_size, size); |
| paul@65 | 148 | } |
| paul@65 | 149 | |
| paul@114 | 150 | long PipePager::pipe_error() |
| paul@114 | 151 | { |
| paul@114 | 152 | if (_paging->closed()) |
| paul@114 | 153 | return -L4_EIO; |
| paul@114 | 154 | else |
| paul@114 | 155 | return -L4_EBUSY; |
| paul@114 | 156 | } |
| paul@114 | 157 | |
| paul@117 | 158 | |
| paul@117 | 159 | |
| paul@117 | 160 | /* Update the populated size of a pipe region and notify the other endpoint. */ |
| paul@117 | 161 | |
| paul@117 | 162 | long PipePager::flush(offset_t populated_size, offset_t *size) |
| paul@117 | 163 | { |
| paul@117 | 164 | if (_mapper != NULL) |
| paul@117 | 165 | _mapper->set_data_size(populated_size); |
| paul@117 | 166 | |
| paul@117 | 167 | *size = _size; |
| paul@117 | 168 | |
| paul@122 | 169 | // NOTE: Perhaps employ a distinct event type for metadata updates. |
| paul@122 | 170 | |
| paul@137 | 171 | _paging->notify_others(_writing ? PipePaging::WRITER : PipePaging::READER, |
| paul@484 | 172 | NOTIFY_CONTENT_AVAILABLE | NOTIFY_SPACE_AVAILABLE, |
| paul@484 | 173 | NOTIFY_VALUES_NULL); |
| paul@117 | 174 | return L4_EOK; |
| paul@117 | 175 | } |
| paul@117 | 176 | |
| paul@117 | 177 | |
| paul@117 | 178 | |
| paul@488 | 179 | /* Subscribe to notifications. |
| paul@488 | 180 | Readers can subscribe to new data (at end), and pipe closed events. |
| paul@488 | 181 | Writers can subscribe to new space and pipe closed events. */ |
| paul@117 | 182 | |
| paul@290 | 183 | long PipePager::subscribe(l4_cap_idx_t notifier, notify_flags_t flags) |
| paul@117 | 184 | { |
| paul@488 | 185 | /* A single notifier is recorded so that it may be unsubscribed when the |
| paul@488 | 186 | file is closed. */ |
| paul@488 | 187 | |
| paul@488 | 188 | if ((notifier != _notifier) && l4_is_valid_cap(_notifier)) |
| paul@488 | 189 | unsubscribe(_notifier); |
| paul@117 | 190 | |
| paul@485 | 191 | _notifier = notifier; |
| paul@485 | 192 | |
| paul@288 | 193 | return _paging->subscribe(_writing ? PipePaging::WRITER : PipePaging::READER, |
| paul@485 | 194 | notifier, flags); |
| paul@290 | 195 | } |
| paul@290 | 196 | |
| paul@290 | 197 | /* Unsubscribe from notifications. */ |
| paul@290 | 198 | |
| paul@488 | 199 | long PipePager::unsubscribe(l4_cap_idx_t notifier) |
| paul@290 | 200 | { |
| paul@488 | 201 | return _paging->unsubscribe(notifier); |
| paul@117 | 202 | } |
| paul@117 | 203 | |
| paul@65 | 204 | // vim: tabstop=4 expandtab shiftwidth=4 |
