From ae1ecec85aa090b90c09cc126a32b8dfa810c94d Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Mon, 8 Oct 2018 22:39:36 -0700 Subject: systemc: Fix accounting in the sc_fifo class. Reads shouldn't free up space until an update happens. Change-Id: I18e1601c27b44643f103c86f04b1fa2c23baf1e8 Reviewed-on: https://gem5-review.googlesource.com/c/13333 Reviewed-by: Gabe Black Maintainer: Gabe Black --- src/systemc/ext/channel/sc_fifo.hh | 39 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 21 deletions(-) (limited to 'src/systemc') diff --git a/src/systemc/ext/channel/sc_fifo.hh b/src/systemc/ext/channel/sc_fifo.hh index 0c83f6692..ee7872a26 100644 --- a/src/systemc/ext/channel/sc_fifo.hh +++ b/src/systemc/ext/channel/sc_fifo.hh @@ -55,11 +55,14 @@ class sc_fifo : public sc_fifo_in_if, explicit sc_fifo(int size=16) : sc_fifo_in_if(), sc_fifo_out_if(), sc_prim_channel(sc_gen_unique_name("fifo")), - _size(size), _readsHappened(false), _reader(NULL), _writer(NULL) + _size(size), _num_free(size), _num_available(0), + _readsHappened(false), _writesHappened(false), + _reader(NULL), _writer(NULL) {} explicit sc_fifo(const char *name, int size=16) : sc_fifo_in_if(), sc_fifo_out_if(), - sc_prim_channel(name), _size(size), _readsHappened(false), + sc_prim_channel(name), _size(size), _num_free(size), + _num_available(0), _readsHappened(false), _writesHappened(false), _reader(NULL), _writer(NULL) {} virtual ~sc_fifo() {} @@ -92,6 +95,7 @@ class sc_fifo : public sc_fifo_in_if, _readsHappened = true; t = _entries.front(); _entries.pop_front(); + _num_available--; request_update(); } virtual T @@ -118,7 +122,9 @@ class sc_fifo : public sc_fifo_in_if, { while (num_free() == 0) sc_core::wait(_dataReadEvent); - _pending.emplace_back(t); + _writesHappened = true; + _entries.emplace_back(t); + _num_free--; request_update(); } virtual bool @@ -149,20 +155,12 @@ class sc_fifo : public sc_fifo_in_if, return _dataReadEvent; } - virtual int num_available() const { return _entries.size(); } - virtual int - num_free() const - { - return _size - _entries.size() - _pending.size(); - } + virtual int num_available() const { return _num_available; } + virtual int num_free() const { return _num_free; } virtual void print(std::ostream &os=std::cout) const { - for (typename ::std::list::iterator pos = _pending.begin(); - pos != _pending.end(); pos++) { - os << *pos << ::std::endl; - } for (typename ::std::list::iterator pos = _entries.begin(); pos != _entries.end(); pos++) { os << *pos << ::std::endl; @@ -173,10 +171,6 @@ class sc_fifo : public sc_fifo_in_if, { os << "name = " << name() << std::endl; int idx = 0; - for (typename ::std::list::iterator pos = _pending.begin(); - pos != _pending.end(); pos++) { - os << "value[" << idx++ << "] = " << *pos << ::std::endl; - } for (typename ::std::list::iterator pos = _entries.begin(); pos != _entries.end(); pos++) { os << "value[" << idx++ << "] = " << *pos << ::std::endl; @@ -188,10 +182,11 @@ class sc_fifo : public sc_fifo_in_if, virtual void update() { - if (!_pending.empty()) { + _num_available = _entries.size(); + _num_free = _size - _num_available; + if (_writesHappened) { + _writesHappened = false; _dataWriteEvent.notify(SC_ZERO_TIME); - _entries.insert(_entries.end(), _pending.begin(), _pending.end()); - _pending.clear(); } if (_readsHappened) { _readsHappened = false; @@ -213,9 +208,11 @@ class sc_fifo : public sc_fifo_in_if, sc_port_base *_writer; int _size; + int _num_free; + int _num_available; mutable std::list _entries; - mutable std::list _pending; bool _readsHappened; + bool _writesHappened; }; template -- cgit v1.2.3