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-rw-r--r--Kernel/DoubleBuffer.cpp45
1 files changed, 15 insertions, 30 deletions
diff --git a/Kernel/DoubleBuffer.cpp b/Kernel/DoubleBuffer.cpp
index 512c506407..d4015f12e5 100644
--- a/Kernel/DoubleBuffer.cpp
+++ b/Kernel/DoubleBuffer.cpp
@@ -1,32 +1,20 @@
#include <Kernel/DoubleBuffer.h>
-inline void DoubleBuffer::compute_lockfree_metadata()
+inline void DoubleBuffer::compute_emptiness()
{
- InterruptDisabler disabler;
- m_empty = m_read_buffer_index >= m_read_buffer->size && m_write_buffer->size == 0;
- m_space_for_writing = m_capacity - m_write_buffer->size;
-}
-
-DoubleBuffer::DoubleBuffer(size_t capacity)
- : m_write_buffer(&m_buffer1)
- , m_read_buffer(&m_buffer2)
- , m_storage(KBuffer::create_with_size(capacity * 2))
- , m_capacity(capacity)
-{
- m_buffer1.data = m_storage.data();
- m_buffer1.size = 0;
- m_buffer2.data = m_storage.data() + capacity;
- m_buffer2.size = 0;
- m_space_for_writing = capacity;
+ m_empty = m_read_buffer_index >= m_read_buffer->size() && m_write_buffer->is_empty();
}
void DoubleBuffer::flip()
{
- ASSERT(m_read_buffer_index == m_read_buffer->size);
+ ASSERT(m_read_buffer_index == m_read_buffer->size());
swap(m_read_buffer, m_write_buffer);
- m_write_buffer->size = 0;
+ if (m_write_buffer->capacity() < 32)
+ m_write_buffer->clear_with_capacity();
+ else
+ m_write_buffer->clear();
m_read_buffer_index = 0;
- compute_lockfree_metadata();
+ compute_emptiness();
}
ssize_t DoubleBuffer::write(const u8* data, ssize_t size)
@@ -34,11 +22,8 @@ ssize_t DoubleBuffer::write(const u8* data, ssize_t size)
if (!size)
return 0;
LOCKER(m_lock);
- ASSERT(size <= (ssize_t)space_for_writing());
- u8* write_ptr = m_write_buffer->data + m_write_buffer->size;
- m_write_buffer->size += size;
- compute_lockfree_metadata();
- memcpy(write_ptr, data, size);
+ m_write_buffer->append(data, size);
+ compute_emptiness();
return size;
}
@@ -47,13 +32,13 @@ ssize_t DoubleBuffer::read(u8* data, ssize_t size)
if (!size)
return 0;
LOCKER(m_lock);
- if (m_read_buffer_index >= m_read_buffer->size && m_write_buffer->size != 0)
+ if (m_read_buffer_index >= m_read_buffer->size() && !m_write_buffer->is_empty())
flip();
- if (m_read_buffer_index >= m_read_buffer->size)
+ if (m_read_buffer_index >= m_read_buffer->size())
return 0;
- ssize_t nread = min((ssize_t)m_read_buffer->size - (ssize_t)m_read_buffer_index, size);
- memcpy(data, m_read_buffer->data + m_read_buffer_index, nread);
+ ssize_t nread = min((ssize_t)m_read_buffer->size() - m_read_buffer_index, size);
+ memcpy(data, m_read_buffer->data() + m_read_buffer_index, nread);
m_read_buffer_index += nread;
- compute_lockfree_metadata();
+ compute_emptiness();
return nread;
}