]> sigrok.org Git - pulseview.git/blobdiff - pv/data/segment.cpp
Segment: Catch by reference
[pulseview.git] / pv / data / segment.cpp
index a2a213afcdcbca59a6c0bba9a66632bdc78af7d8..5022d6a900f7064c683c5f0d3ab9f80d5feeb100 100644 (file)
 #include <cassert>
 #include <cstdlib>
 #include <cstring>
-#include <vector>
 
+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),
        iterator_count_(0),
-       mem_optimization_requested_(false)
+       mem_optimization_requested_(false),
+       is_complete_(false)
 {
        lock_guard<recursive_mutex> 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_];
@@ -91,6 +92,21 @@ 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<recursive_mutex> lock(mutex_);
@@ -101,15 +117,17 @@ void Segment::free_unused_memory()
                return;
        }
 
-       // 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_);
+       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)
@@ -119,8 +137,7 @@ 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_--;
 
@@ -138,48 +155,70 @@ void Segment::append_samples(void* data, uint64_t samples)
 {
        lock_guard<recursive_mutex> 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<recursive_mutex> 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_;
@@ -188,7 +227,7 @@ 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);
@@ -199,8 +238,6 @@ 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)
@@ -222,16 +259,12 @@ SegmentRawDataIterator* Segment::begin_raw_sample_iteration(uint64_t start)
 
 void Segment::continue_raw_sample_iteration(SegmentRawDataIterator* it, uint64_t increase)
 {
-       lock_guard<recursive_mutex> lock(mutex_);
-
+       // Fail gracefully if we are asked to deliver data we don't have
        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++;
@@ -254,6 +287,5 @@ void Segment::end_raw_sample_iteration(SegmentRawDataIterator* it)
        }
 }
 
-
 } // namespace data
 } // namespace pv