X-Git-Url: https://sigrok.org/gitweb/?p=pulseview.git;a=blobdiff_plain;f=pv%2Fdata%2Fsegment.cpp;h=a71d49ca6d27b9f2098a844b4c425c9fdfe765f3;hp=cfe9aafa0385b7935e9e67fda9d026bedf4256f3;hb=65c92359634f672e5f472a5214719dabc7e20883;hpb=dd3f9a41a6b4debf5ad7aa8226bebd13504f2295 diff --git a/pv/data/segment.cpp b/pv/data/segment.cpp index cfe9aafa..a71d49ca 100644 --- a/pv/data/segment.cpp +++ b/pv/data/segment.cpp @@ -20,34 +20,38 @@ #include "segment.hpp" -#include -#include -#include +#include +#include +#include -#include +#include +using std::bad_alloc; using std::lock_guard; +using std::min; using std::recursive_mutex; -using std::vector; namespace pv { namespace data { -const uint64_t Segment::MaxChunkSize = 10*1024*1024; /* 10MiB */ +const uint64_t Segment::MaxChunkSize = 10 * 1024 * 1024; /* 10MiB */ -Segment::Segment(uint64_t samplerate, unsigned int unit_size) : +Segment::Segment(uint32_t segment_id, uint64_t samplerate, unsigned int unit_size) : + segment_id_(segment_id), sample_count_(0), start_time_(0), samplerate_(samplerate), - unit_size_(unit_size) + unit_size_(unit_size), + iterator_count_(0), + mem_optimization_requested_(false), + is_complete_(false) { lock_guard lock(mutex_); assert(unit_size_ > 0); // Determine the number of samples we can fit in one chunk // without exceeding MaxChunkSize - chunk_size_ = std::min(MaxChunkSize, - (MaxChunkSize / unit_size_) * unit_size_); + chunk_size_ = min(MaxChunkSize, (MaxChunkSize / unit_size_) * unit_size_); // Create the initial chunk current_chunk_ = new uint8_t[chunk_size_]; @@ -90,19 +94,42 @@ unsigned int Segment::unit_size() const return unit_size_; } +uint32_t Segment::segment_id() const +{ + return segment_id_; +} + +void Segment::set_complete() +{ + is_complete_ = true; +} + +bool Segment::is_complete() const +{ + return is_complete_; +} + void Segment::free_unused_memory() { lock_guard lock(mutex_); - // No more data will come in, so re-create the last chunk accordingly - uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_]; - memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_); + // Do not mess with the data chunks if we have iterators pointing at them + if (iterator_count_ > 0) { + mem_optimization_requested_ = true; + return; + } + + if (current_chunk_) { + // No more data will come in, so re-create the last chunk accordingly + uint8_t* resized_chunk = new uint8_t[used_samples_ * unit_size_]; + memcpy(resized_chunk, current_chunk_, used_samples_ * unit_size_); - delete[] current_chunk_; - current_chunk_ = resized_chunk; + delete[] current_chunk_; + current_chunk_ = resized_chunk; - data_chunks_.pop_back(); - data_chunks_.push_back(resized_chunk); + data_chunks_.pop_back(); + data_chunks_.push_back(resized_chunk); + } } void Segment::append_single_sample(void *data) @@ -112,8 +139,7 @@ void Segment::append_single_sample(void *data) // There will always be space for at least one sample in // the current chunk, so we do not need to test for space - memcpy(current_chunk_ + (used_samples_ * unit_size_), - data, unit_size_); + memcpy(current_chunk_ + (used_samples_ * unit_size_), data, unit_size_); used_samples_++; unused_samples_--; @@ -131,48 +157,70 @@ void Segment::append_samples(void* data, uint64_t samples) { lock_guard lock(mutex_); - if (unused_samples_ >= samples) { - // All samples fit into the current chunk - memcpy(current_chunk_ + (used_samples_ * unit_size_), - data, (samples * unit_size_)); - used_samples_ += samples; - unused_samples_ -= samples; - } else { - // Only a part of the samples fit, split data up between chunks - memcpy(current_chunk_ + (used_samples_ * unit_size_), - data, (unused_samples_ * unit_size_)); - const uint64_t remaining_samples = samples - unused_samples_; - - // If we're out of memory, this will throw std::bad_alloc - current_chunk_ = new uint8_t[chunk_size_]; - data_chunks_.push_back(current_chunk_); - memcpy(current_chunk_, (uint8_t*)data + (unused_samples_ * unit_size_), - (remaining_samples * unit_size_)); - - used_samples_ = remaining_samples; - unused_samples_ = (chunk_size_ / unit_size_) - remaining_samples; - } - - if (unused_samples_ == 0) { - // If we're out of memory, this will throw std::bad_alloc - current_chunk_ = new uint8_t[chunk_size_]; - data_chunks_.push_back(current_chunk_); - used_samples_ = 0; - unused_samples_ = chunk_size_ / unit_size_; - } + const uint8_t* data_byte_ptr = (uint8_t*)data; + uint64_t remaining_samples = samples; + uint64_t data_offset = 0; + + do { + uint64_t copy_count = 0; + + if (remaining_samples <= unused_samples_) { + // All samples fit into the current chunk + copy_count = remaining_samples; + } else { + // Only a part of the samples fit, fill up current chunk + copy_count = unused_samples_; + } + + const uint8_t* dest = &(current_chunk_[used_samples_ * unit_size_]); + const uint8_t* src = &(data_byte_ptr[data_offset]); + memcpy((void*)dest, (void*)src, (copy_count * unit_size_)); + + used_samples_ += copy_count; + unused_samples_ -= copy_count; + remaining_samples -= copy_count; + data_offset += (copy_count * unit_size_); + + if (unused_samples_ == 0) { + try { + // If we're out of memory, allocating a chunk will throw + // std::bad_alloc. To give the application some usable memory + // to work with in case chunk allocation fails, we allocate + // extra memory and throw it away if it all succeeded. + // This way, memory allocation will fail early enough to let + // PV remain alive. Otherwise, PV will crash in a random + // memory-allocating part of the application. + current_chunk_ = new uint8_t[chunk_size_]; + + const int dummy_size = 2 * chunk_size_; + auto dummy_chunk = new uint8_t[dummy_size]; + memset(dummy_chunk, 0xFF, dummy_size); + delete[] dummy_chunk; + } catch (bad_alloc&) { + delete[] current_chunk_; // The new may have succeeded + current_chunk_ = nullptr; + throw; + } + + data_chunks_.push_back(current_chunk_); + used_samples_ = 0; + unused_samples_ = chunk_size_ / unit_size_; + } + } while (remaining_samples > 0); sample_count_ += samples; } -uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const +void Segment::get_raw_samples(uint64_t start, uint64_t count, + uint8_t* dest) const { assert(start < sample_count_); assert(start + count <= sample_count_); assert(count > 0); + assert(dest != nullptr); lock_guard lock(mutex_); - uint8_t* dest = new uint8_t[count * unit_size_]; uint8_t* dest_ptr = dest; uint64_t chunk_num = (start * unit_size_) / chunk_size_; @@ -181,7 +229,7 @@ uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const while (count > 0) { const uint8_t* chunk = data_chunks_[chunk_num]; - uint64_t copy_size = std::min(count * unit_size_, + uint64_t copy_size = min(count * unit_size_, chunk_size_ - chunk_offs); memcpy(dest_ptr, chunk + chunk_offs, copy_size); @@ -192,52 +240,54 @@ uint8_t* Segment::get_raw_samples(uint64_t start, uint64_t count) const chunk_num++; chunk_offs = 0; } - - return dest; } -SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start) const +SegmentDataIterator* Segment::begin_sample_iteration(uint64_t start) { - SegmentRawDataIterator* it = new SegmentRawDataIterator; + SegmentDataIterator* it = new SegmentDataIterator; assert(start < sample_count_); + iterator_count_++; + it->sample_index = start; it->chunk_num = (start * unit_size_) / chunk_size_; it->chunk_offs = (start * unit_size_) % chunk_size_; it->chunk = data_chunks_[it->chunk_num]; - it->value = it->chunk + it->chunk_offs; return it; } -void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase) const +void Segment::continue_sample_iteration(SegmentDataIterator* it, uint64_t increase) { - lock_guard lock(mutex_); - - if (it->sample_index > sample_count_) - { - // Fail gracefully if we are asked to deliver data we don't have - return; - } else { - it->sample_index += increase; - it->chunk_offs += (increase * unit_size_); - } + it->sample_index += increase; + it->chunk_offs += (increase * unit_size_); if (it->chunk_offs > (chunk_size_ - 1)) { it->chunk_num++; it->chunk_offs -= chunk_size_; it->chunk = data_chunks_[it->chunk_num]; } - - it->value = it->chunk + it->chunk_offs; } -void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it) const +void Segment::end_sample_iteration(SegmentDataIterator* it) { delete it; + + iterator_count_--; + + if ((iterator_count_ == 0) && mem_optimization_requested_) { + mem_optimization_requested_ = false; + free_unused_memory(); + } } +uint8_t* Segment::get_iterator_value(SegmentDataIterator* it) +{ + assert(it->sample_index <= (sample_count_ - 1)); + + return (it->chunk + it->chunk_offs); +} } // namespace data } // namespace pv