| #pragma once |
| |
| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <cerrno> |
| #include <cstring> |
| |
| #include "common/vsoc/lib/region_signaling_interface.h" |
| #include "common/vsoc/shm/circqueue.h" |
| |
| // Increases the given index until it is naturally aligned for T. |
| template <typename T> |
| uintptr_t align(uintptr_t index) { |
| return (index + sizeof(T) - 1) & ~(sizeof(T) - 1); |
| } |
| |
| namespace vsoc { |
| class RegionSignalingInterface; |
| namespace layout { |
| |
| template <uint32_t SizeLog2> |
| void CircularQueueBase<SizeLog2>::CopyInRange(const char* buffer_in, |
| const Range& t) { |
| size_t bytes = t.end_idx - t.start_idx; |
| uint32_t index = t.start_idx & (BufferSize - 1); |
| if (index + bytes <= BufferSize) { |
| std::memcpy(buffer_ + index, buffer_in, bytes); |
| } else { |
| size_t part1_size = BufferSize - index; |
| size_t part2_size = bytes - part1_size; |
| std::memcpy(buffer_ + index, buffer_in, part1_size); |
| std::memcpy(buffer_, buffer_in + part1_size, part2_size); |
| } |
| } |
| |
| template <uint32_t SizeLog2> |
| void CircularQueueBase<SizeLog2>::CopyOutRange(const Range& t, |
| char* buffer_out) { |
| uint32_t index = t.start_idx & (BufferSize - 1); |
| size_t total_size = t.end_idx - t.start_idx; |
| if (index + total_size <= BufferSize) { |
| std::memcpy(buffer_out, buffer_ + index, total_size); |
| } else { |
| uint32_t part1_size = BufferSize - index; |
| uint32_t part2_size = total_size - part1_size; |
| std::memcpy(buffer_out, buffer_ + index, part1_size); |
| std::memcpy(buffer_out + part1_size, buffer_, part2_size); |
| } |
| } |
| |
| template <uint32_t SizeLog2> |
| void CircularQueueBase<SizeLog2>::WaitForDataLocked( |
| RegionSignalingInterface* r) { |
| while (1) { |
| uint32_t o_w_pub = w_pub_; |
| // We don't have data. Wait until some appears and try again |
| if (r_released_ != o_w_pub) { |
| return; |
| } |
| lock_.Unlock(); |
| r->WaitForSignal(&w_pub_, o_w_pub); |
| lock_.Lock(); |
| } |
| } |
| |
| template <uint32_t SizeLog2> |
| intptr_t CircularQueueBase<SizeLog2>::WriteReserveLocked( |
| RegionSignalingInterface* r, size_t bytes, Range* t, bool non_blocking) { |
| // Can't write more than the buffer will hold |
| if (bytes > BufferSize) { |
| return -ENOSPC; |
| } |
| while (true) { |
| uint32_t o_w_pub = w_pub_; |
| uint32_t o_r_release = r_released_; |
| uint32_t bytes_in_use = o_w_pub - o_r_release; |
| size_t available = BufferSize - bytes_in_use; |
| if (available >= bytes) { |
| t->start_idx = o_w_pub; |
| t->end_idx = o_w_pub + bytes; |
| break; |
| } |
| if (non_blocking) { |
| return -EWOULDBLOCK; |
| } |
| // If we can't write at the moment wait for a reader to release |
| // some bytes. |
| lock_.Unlock(); |
| r->WaitForSignal(&r_released_, o_r_release); |
| lock_.Lock(); |
| } |
| return t->end_idx - t->start_idx; |
| } |
| |
| template <uint32_t SizeLog2> |
| intptr_t CircularByteQueue<SizeLog2>::Read(RegionSignalingInterface* r, |
| char* buffer_out, size_t max_size) { |
| this->lock_.Lock(); |
| this->WaitForDataLocked(r); |
| Range t; |
| t.start_idx = this->r_released_; |
| t.end_idx = this->w_pub_; |
| // The lock is still held here... |
| // Trim the range if we got more than the reader wanted |
| if ((t.end_idx - t.start_idx) > max_size) { |
| t.end_idx = t.start_idx + max_size; |
| } |
| this->CopyOutRange(t, buffer_out); |
| this->r_released_ = t.end_idx; |
| this->lock_.Unlock(); |
| layout::Sides side; |
| side.value_ = layout::Sides::Both; |
| r->SendSignal(side, &this->r_released_); |
| return t.end_idx - t.start_idx; |
| } |
| |
| template <uint32_t SizeLog2> |
| intptr_t CircularByteQueue<SizeLog2>::Write(RegionSignalingInterface* r, |
| const char* buffer_in, size_t bytes, |
| bool non_blocking) { |
| Range range; |
| this->lock_.Lock(); |
| intptr_t rval = this->WriteReserveLocked(r, bytes, &range, non_blocking); |
| if (rval < 0) { |
| this->lock_.Unlock(); |
| return rval; |
| } |
| this->CopyInRange(buffer_in, range); |
| // We can't publish until all of the previous write allocations where |
| // published. |
| this->w_pub_ = range.end_idx; |
| this->lock_.Unlock(); |
| layout::Sides side; |
| side.value_ = layout::Sides::Both; |
| r->SendSignal(side, &this->w_pub_); |
| return bytes; |
| } |
| |
| template <uint32_t SizeLog2, uint32_t MaxPacketSize> |
| intptr_t CircularPacketQueue<SizeLog2, MaxPacketSize>::CalculateBufferedSize( |
| size_t payload) { |
| return align<uint32_t>(sizeof(uint32_t) + payload); |
| } |
| |
| template <uint32_t SizeLog2, uint32_t MaxPacketSize> |
| intptr_t CircularPacketQueue<SizeLog2, MaxPacketSize>::Read( |
| RegionSignalingInterface* r, char* buffer_out, size_t max_size) { |
| this->lock_.Lock(); |
| this->WaitForDataLocked(r); |
| uint32_t packet_size = *reinterpret_cast<uint32_t*>( |
| this->buffer_ + (this->r_released_ & (this->BufferSize - 1))); |
| if (packet_size > max_size) { |
| this->lock_.Unlock(); |
| return -ENOSPC; |
| } |
| Range t; |
| t.start_idx = this->r_released_ + sizeof(uint32_t); |
| t.end_idx = t.start_idx + packet_size; |
| this->CopyOutRange(t, buffer_out); |
| this->r_released_ += this->CalculateBufferedSize(packet_size); |
| this->lock_.Unlock(); |
| layout::Sides side; |
| side.value_ = layout::Sides::Both; |
| r->SendSignal(side, &this->r_released_); |
| return packet_size; |
| } |
| |
| template <uint32_t SizeLog2, uint32_t MaxPacketSize> |
| intptr_t CircularPacketQueue<SizeLog2, MaxPacketSize>::Write( |
| RegionSignalingInterface* r, const char* buffer_in, uint32_t bytes, |
| bool non_blocking) { |
| if (bytes > MaxPacketSize) { |
| return -ENOSPC; |
| } |
| Range range; |
| size_t buffered_size = this->CalculateBufferedSize(bytes); |
| this->lock_.Lock(); |
| intptr_t rval = |
| this->WriteReserveLocked(r, buffered_size, &range, non_blocking); |
| if (rval < 0) { |
| this->lock_.Unlock(); |
| return rval; |
| } |
| Range header = range; |
| header.end_idx = header.start_idx + sizeof(uint32_t); |
| Range payload{ |
| static_cast<uint32_t>(range.start_idx + sizeof(uint32_t)), |
| static_cast<uint32_t>(range.start_idx + sizeof(uint32_t) + bytes)}; |
| this->CopyInRange(reinterpret_cast<const char*>(&bytes), header); |
| this->CopyInRange(buffer_in, payload); |
| this->w_pub_ = range.end_idx; |
| this->lock_.Unlock(); |
| layout::Sides side; |
| side.value_ = layout::Sides::Both; |
| r->SendSignal(side, &this->w_pub_); |
| return bytes; |
| } |
| |
| } // namespace layout |
| } // namespace vsoc |