streamline and test transaction_manager

This commit is contained in:
Joe Thornber 2011-07-14 15:31:00 +01:00
parent a0cae447f6
commit a4b5718a78
4 changed files with 194 additions and 95 deletions

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@ -3,13 +3,21 @@ SOURCE=\
PROGRAM_SOURCE=\
block_t.cc \
space_map_t.cc
space_map_t.cc \
transaction_manager_t.cc
OBJECTS=$(subst .cc,.o,$(SOURCE))
CPPFLAGS=-Wall -std=c++0x
INCLUDES=
LIBS=-lstdc++
.PHONEY: unit-tests
unit-tests: block_t space_map_t transaction_manager_t
./block_t
./space_map_t
./transaction_manager_t
.SUFFIXES: .cc .o .d
%.d: %.cc
@ -21,13 +29,16 @@ LIBS=-lstdc++
g++ -c $(CPPFLAGS) $(INCLUDES) -o $@ $<
multisnap_display: $(OBJECTS) main.o
g++ -o $@ $+ $(LIBS)
g++ $(CPPFLAGS) -o $@ $+ $(LIBS)
block_t: block_t.o
g++ -o $@ $+ $(LIBS)
g++ $(CPPFLAGS) -o $@ $+ $(LIBS)
space_map_t: space_map_t.o
g++ -o $@ $+ $(LIBS)
g++ $(CPPFLAGS) -o $@ $+ $(LIBS)
transaction_manager_t: transaction_manager_t.o
g++ $(CPPFLAGS) -o $@ $+ $(LIBS)
include $(subst .cc,.d,$(SOURCE))
include $(subst .cc,.d,$(PROGRAM_SOURCE))

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@ -14,37 +14,41 @@ namespace persistent_data {
class transaction_manager : public boost::noncopyable {
public:
typedef boost::shared_ptr<transaction_manager<MetadataBlockSize> > ptr;
typedef typename block_manager<MetadataBlockSize>::read_ref read_ref;
typedef typename block_manager<MetadataBlockSize>::write_ref write_ref;
typedef typename block_manager<MetadataBlockSize>::validator::ptr validator;
// If the space map is persistent, then the caller should
// hold onto a reference and remember to call sm_->commit()
// and update the superblock before dropping the superblock
// reference.
transaction_manager(typename block_manager<MetadataBlockSize>::ptr bm,
space_map::ptr sm);
~transaction_manager();
typedef typename block_manager<MetadataBlockSize>::read_ref read_ref;
typedef typename block_manager<MetadataBlockSize>::write_ref write_ref;
typedef typename block_manager<MetadataBlockSize>::block_validator block_validator;
// Drop the superblock reference to commit
write_ref begin(block_address superblock);
write_ref begin(block_address superblock, validator v);
void reserve_block(block_address location);
void begin();
void pre_commit();
void commit(write_ref superblock);
block_address alloc_block();
write_ref new_block();
write_ref new_block(block_validator const &v);
write_ref new_block(validator v);
write_ref shadow(block_address orig, bool &inc_children);
write_ref shadow(block_address orig, block_validator const &v, bool &inc_children);
// shadowing returns a new write_ref, and a boolean which
// indicates whether the children should be incremented.
std::pair<write_ref, bool> shadow(block_address orig);
std::pair<write_ref, bool> shadow(block_address orig, validator v);
read_ref read_lock(block_address b);
read_ref read_lock(block_address b, block_validator const &v);
read_ref read_lock(block_address b, validator v);
void inc(block_address b);
void dec(block_address b);
uint32_t ref_count(block_address b) const;
space_map::ptr get_sm() {
return sm_;
}
private:
void add_shadow(block_address b);
bool is_shadow(block_address b);
void remove_shadow(block_address b);
bool is_shadow(block_address b) const;
void wipe_shadow_table();
typename block_manager<MetadataBlockSize>::ptr bm_;

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@ -4,6 +4,7 @@
using namespace boost;
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------
@ -21,98 +22,104 @@ transaction_manager<BlockSize>::~transaction_manager()
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::reserve_block(block_address location)
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::begin(block_address superblock)
{
sm_->inc_block(location);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::begin()
{
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::pre_commit()
{
sm_->commit();
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::commit(write_ref superblock)
{
bm_->flush(superblock);
auto wr = bm_->superblock(superblock);
wipe_shadow_table();
return wr;
}
template <uint32_t BlockSize>
block_address
transaction_manager<BlockSize>::alloc_block()
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::begin(block_address superblock,
validator v)
{
return sm_->new_block();
auto wr = bm_->superblock(superblock, v);
wipe_shadow_table();
return wr;
}
// FIXME: these explicit try/catches are gross
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::new_block()
{
block_address b = sm_->new_block();
add_shadow(b);
return bm_->write_lock_zero(b);
try {
add_shadow(b);
try {
return bm_->write_lock_zero(b);
} catch (...) {
remove_shadow(b);
throw;
}
} catch (...) {
sm_->dec(b);
throw;
}
}
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::new_block(block_validator const &v)
transaction_manager<BlockSize>::new_block(validator v)
{
block_address b = sm_->new_block();
add_shadow(b);
return bm_->write_lock_zero(b, v);
try {
add_shadow(b);
try {
return bm_->write_lock_zero(b, v);
} catch (...) {
remove_shadow(b);
throw;
}
} catch (...) {
sm_->dec(b);
throw;
}
}
// FIXME: make exception safe
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::shadow(block_address orig, bool &inc_children)
pair<typename transaction_manager<BlockSize>::write_ref, bool>
transaction_manager<BlockSize>::shadow(block_address orig)
{
if (is_shadow(orig) &&
sm_->count_possibly_greater_than_one(orig)) {
inc_children = false;
return bm_->write_lock(orig);
}
!sm_->count_possibly_greater_than_one(orig))
return make_pair(bm_->write_lock(orig), false);
auto src = bm_->read_lock(orig);
auto dest = bm_->write_lock_zero(sm_->new_block());
::memcpy(dest->data_, src->data_, BlockSize);
::memcpy(dest.data(), src.data(), BlockSize);
ref_t count = sm_->get_count(orig);
sm_->dec_block(orig);
inc_children = count > 1;
add_shadow(dest->location_);
return dest;
if (count == 0)
throw runtime_error("shadowing free block");
sm_->dec(orig);
add_shadow(dest.get_location());
return make_pair(dest, count > 1);
}
// FIXME: duplicate code
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::write_ref
transaction_manager<BlockSize>::shadow(block_address orig, block_validator const &v, bool &inc_children)
pair<typename transaction_manager<BlockSize>::write_ref, bool>
transaction_manager<BlockSize>::shadow(block_address orig, validator v)
{
if (is_shadow(orig) &&
sm_->count_possibly_greater_than_one(orig)) {
inc_children = false;
return bm_->write_lock(orig);
}
sm_->count_possibly_greater_than_one(orig))
return make_pair(bm_->write_lock(orig), false);
auto src = bm_->read_lock(orig, v);
auto dest = bm_->write_lock_zero(sm_->new_block(), v);
::memcpy(dest->data_, src->data_, BlockSize);
ref_t count = sm_->get_count(orig);
sm_->dec_block(orig);
inc_children = count > 1;
if (count == 0)
throw runtime_error("shadowing free block");
sm_->dec(orig);
add_shadow(dest->location_);
return dest;
return make_pair(dest, count > 1);
}
template <uint32_t BlockSize>
@ -124,32 +131,11 @@ transaction_manager<BlockSize>::read_lock(block_address b)
template <uint32_t BlockSize>
typename transaction_manager<BlockSize>::read_ref
transaction_manager<BlockSize>::read_lock(block_address b, block_validator const &v)
transaction_manager<BlockSize>::read_lock(block_address b, validator v)
{
return bm_->read_lock(b, v);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::inc(block_address b)
{
sm_->inc_block(b);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::dec(block_address b)
{
sm_->dec_block(b);
}
template <uint32_t BlockSize>
uint32_t
transaction_manager<BlockSize>::ref_count(block_address b) const
{
return sm_->get_count(b);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::add_shadow(block_address b)
@ -157,9 +143,16 @@ transaction_manager<BlockSize>::add_shadow(block_address b)
shadows_.insert(b);
}
template <uint32_t BlockSize>
void
transaction_manager<BlockSize>::remove_shadow(block_address b)
{
shadows_.erase(b);
}
template <uint32_t BlockSize>
bool
transaction_manager<BlockSize>::is_shadow(block_address b)
transaction_manager<BlockSize>::is_shadow(block_address b) const
{
return shadows_.count(b) > 0;
}

91
transaction_manager_t.cc Normal file
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@ -0,0 +1,91 @@
#include "transaction_manager.h"
#include "core_map.h"
#define BOOST_TEST_MODULE TransactionManagerTests
#include <boost/test/included/unit_test.hpp>
using namespace std;
using namespace boost;
using namespace persistent_data;
//----------------------------------------------------------------
namespace {
block_address const NR_BLOCKS = 1024;
transaction_manager<4096>::ptr
create_tm() {
block_manager<4096>::ptr bm(new block_manager<4096>("./test.data", NR_BLOCKS));
space_map::ptr sm(new core_map(NR_BLOCKS));
transaction_manager<4096>::ptr tm(new transaction_manager<4096>(bm, sm));
return tm;
}
}
//----------------------------------------------------------------
BOOST_AUTO_TEST_CASE(commit_succeeds)
{
auto tm = create_tm();
tm->begin(0);
}
BOOST_AUTO_TEST_CASE(shadowing)
{
auto tm = create_tm();
auto superblock = tm->begin(0);
auto sm = tm->get_sm();
sm->inc(1);
auto p = tm->shadow(1);
auto b = p.first.get_location();
BOOST_CHECK(b != 1);
BOOST_CHECK(!p.second);
BOOST_CHECK(sm->get_count(1) == 0);
p = tm->shadow(b);
BOOST_CHECK(p.first.get_location() == b);
BOOST_CHECK(!p.second);
sm->inc(b);
p = tm->shadow(b);
BOOST_CHECK(p.first.get_location() != b);
BOOST_CHECK(p.second);
}
BOOST_AUTO_TEST_CASE(multiple_shadowing)
{
auto tm = create_tm();
auto superblock = tm->begin(0);
auto sm = tm->get_sm();
sm->set_count(1, 3);
auto p = tm->shadow(1);
auto b = p.first.get_location();
BOOST_CHECK(b != 1);
BOOST_CHECK(p.second);
p = tm->shadow(1);
auto b2 = p.first.get_location();
BOOST_CHECK(b2 != 1);
BOOST_CHECK(b2 != b);
BOOST_CHECK(p.second);
p = tm->shadow(1);
auto b3 = p.first.get_location();
BOOST_CHECK(b3 != b2);
BOOST_CHECK(b3 != b);
BOOST_CHECK(b3 != 1);
BOOST_CHECK(!p.second);
}
BOOST_AUTO_TEST_CASE(shadow_free_block_fails)
{
auto tm = create_tm();
auto superblock = tm->begin(0);
BOOST_CHECK_THROW(tm->shadow(1), runtime_error);
}
// First shadow in a transaction returns a different block
// Second shadow in a transaction rtu