Cleanup + inter-process concurrency

Dependencies

• [2] PXF3R6SV Improving test coverage for btree::cursor
• [3] X3QVVQIS More debugging (del seems to work now)
• [4] YXKP4AIW New file locks, with multiple sets of free pages
• [5] EAAYH6BQ Debugging put
• [6] ONES3V46 reference counting works for put
• [7] OP6SVMOD Resetting history
• [8] WS4ZQM4R Debugging, tests, etc.
• [9] UAQX27N4 Tests
• [10] NQBEOCFO Tests cleanup

Change contents

• replacement in sanakirja-core/src/btree/put.rs at line 19
  [5.4230]→[5.4230:4259](∅→∅)
  − db: &mut Db<T, K, V, P>,
  [5.4230]

  [5.4259]
  + db: &mut Db_<T, K, V, P>,
• replacement in sanakirja-core/src/btree/mod.rs at line 250
  [5.52016]→[5.52016:52110](∅→∅)
  − pub struct Db<T: LoadPage, K: Representable<T>, V: Representable<T>, P: BTreePage<T, K, V>> {
  [5.52016]

  [5.31135]
  + pub struct Db_<T: LoadPage, K: Representable<T>, V: Representable<T>, P: BTreePage<T, K, V>> {
• replacement in sanakirja-core/src/btree/mod.rs at line 255
  [5.52188]→[5.52188:52206](∅→∅)
  − pub fn create_db<
  [5.52188]

  [5.52206]
  + pub type Db<T, K, V> = Db_<T, K, V, page::Page<K, V>>;

  +

  + pub fn create_db_<
• replacement in sanakirja-core/src/btree/mod.rs at line 264
  [5.52324]→[5.52324:52364](∅→∅)
  − ) -> Result<Db<T, K, V, P>, T::Error> {
  [5.52324]

  [5.31157]
  + ) -> Result<Db_<T, K, V, P>, T::Error> {
• replacement in sanakirja-core/src/btree/mod.rs at line 267
  [5.31219]→[5.52417:52429](∅→∅),[5.52417]→[5.52417:52429](∅→∅)
  − Ok(Db {
  [5.31219]

  [5.52429]
  + Ok(Db_ {
• replacement in sanakirja-core/src/btree/mod.rs at line 273
  [5.3887]→[5.3887:3903](∅→∅)
  − pub fn fork_db<
  [5.3887]

  [5.3903]
  + pub fn create_db<

  + T: AllocPage + core::fmt::Debug,

  + K: Representable<T> + core::fmt::Debug,

  + V: Representable<T> + core::fmt::Debug,

  + >(

  + txn: &mut T,

  + ) -> Result<Db_<T, K, V, page::Page<K, V>>, T::Error> {

  + create_db_(txn)

  + }

  +

  + pub fn fork_db_<
• replacement in sanakirja-core/src/btree/mod.rs at line 290
  [5.4021]→[5.4021:4086](∅→∅)
  − db: &Db<T, K, V, P>,

  − ) -> Result<Db<T, K, V, P>, T::Error> {
  [5.4021]

  [5.4086]
  + db: &Db_<T, K, V, P>,

  + ) -> Result<Db_<T, K, V, P>, T::Error> {
• replacement in sanakirja-core/src/btree/mod.rs at line 293
  [5.4118]→[5.4118:4130](∅→∅)
  − Ok(Db {
  [5.4118]

  [5.4130]
  + Ok(Db_ {
• edit in sanakirja-core/src/btree/mod.rs at line 297
  [5.4199]

  [5.404]
  + }

  +

  + pub fn fork_db<

  + T: AllocPage + core::fmt::Debug,

  + K: Representable<T> + core::fmt::Debug,

  + V: Representable<T> + core::fmt::Debug,

  + >(

  + txn: &mut T,

  + db: &Db<T, K, V>,

  + ) -> Result<Db<T, K, V>, T::Error> {

  + fork_db_(txn, db)
• replacement in sanakirja-core/src/btree/mod.rs at line 313
  [5.518]→[5.518:543](∅→∅)
  − db: &Db<T, K, V, P>,
  [5.518]

  [5.543]
  + db: &Db_<T, K, V, P>,
• replacement in sanakirja-core/src/btree/del.rs at line 26
  [5.53416]→[5.53416:53445](∅→∅)
  − db: &mut Db<T, K, V, P>,
  [5.53416]

  [5.53445]
  + db: &mut Db_<T, K, V, P>,
• replacement in sanakirja-core/src/btree/del.rs at line 45
  [5.53873]→[5.53873:53902](∅→∅)
  − db: &mut Db<T, K, V, P>,
  [5.53873]

  [5.53902]
  + db: &mut Db_<T, K, V, P>,
• replacement in sanakirja-core/src/btree/cursor.rs at line 50
  [5.65307]→[5.65307:65353](∅→∅)
  − pub fn new(db: &Db<T, K, V, P>) -> Self {
  [5.65307]

  [5.65353]
  + pub fn new(db: &Db_<T, K, V, P>) -> Self {
• edit in sanakirja/src/tests.rs at line 10
  [5.205]→[5.205:262](∅→∅)
  − use crate::*;

  −

  − type B<T> = btree::page::Page<u64, A<T>>;
• replacement in sanakirja/src/tests.rs at line 37
  [5.979]→[5.979:1024](∅→∅)
  − type T<'a> = MutTxn<&'a Env<Exclusive>, ()>;
  [5.979]

  [5.1024]
  + type T<'a> = MutTxn<&'a Env, ()>;
• replacement in sanakirja/src/tests.rs at line 42
  [5.1091]→[5.1091:1140](∅→∅)
  − let env = Env::new_anon(409600000).unwrap();
  [5.1091]

  [5.1140]
  + let env = Env::new_anon(409600000, 1).unwrap();
• replacement in sanakirja/src/tests.rs at line 44
  [5.1193]→[5.1193:1288](∅→∅)
  − let mut db = create_db::<MutTxn<&Env<Exclusive>, ()>, u64, A<T>, B<T>>(&mut txn).unwrap();
  [5.1193]

  [5.1288]
  + let mut db = create_db::<MutTxn<&Env, ()>, u64, A<T>>(&mut txn).unwrap();
• replacement in sanakirja/src/tests.rs at line 69
  [5.2242]→[5.2242:2289](∅→∅)
  − let db2 = fork_db(&mut txn, &db).unwrap();
  [5.2242]

  [5.2289]
  + let _db2 = fork_db(&mut txn, &db).unwrap();
• edit in sanakirja/src/tests.rs at line 97
  [5.4293]→[5.4293:4334](∅→∅)
  − type B = btree::page::Page<u64, ()>;
• replacement in sanakirja/src/tests.rs at line 98
  [5.4376]→[5.4376:4425](∅→∅)
  − let env = Env::new_anon(409600000).unwrap();
  [5.4376]

  [5.4425]
  + let env = Env::new_anon(409600000, 1).unwrap();
• replacement in sanakirja/src/tests.rs at line 100
  [5.4478]→[5.4478:4544](∅→∅)
  − let mut db: Db<_, u64, (), B> = create_db(&mut txn).unwrap();
  [5.4478]

  [5.4544]
  + let mut db: Db<_, u64, ()> = create_db(&mut txn).unwrap();
• edit in sanakirja/src/tests.rs at line 102
  [5.4572]→[5.4572:4616](∅→∅)
  − let now = std::time::SystemTime::now();
• edit in sanakirja/src/tests.rs at line 114
  [5.4977]→[5.4977:5018](∅→∅)
  − type B = btree::page::Page<u64, ()>;
• replacement in sanakirja/src/tests.rs at line 115
  [5.5060]→[5.5060:5109](∅→∅)
  − let env = Env::new_anon(409600000).unwrap();
  [5.5060]

  [5.5109]
  + let env = Env::new_anon(409600000, 1).unwrap();
• replacement in sanakirja/src/tests.rs at line 117
  [5.5162]→[5.5162:5228](∅→∅)
  − let mut db: Db<_, u64, (), B> = create_db(&mut txn).unwrap();
  [5.5162]

  [5.5228]
  + let mut db: Db<_, u64, ()> = create_db(&mut txn).unwrap();
• edit in sanakirja/src/tests.rs at line 120
  [5.5276]→[5.5276:5320](∅→∅)
  − let now = std::time::SystemTime::now();
• edit in sanakirja/src/tests.rs at line 135
  [3.8909]→[3.8909:8950](∅→∅)
  − type B = btree::page::Page<u64, ()>;
• replacement in sanakirja/src/tests.rs at line 136
  [3.8992]→[3.8992:9041](∅→∅)
  − let env = Env::new_anon(409600000).unwrap();
  [3.8992]

  [3.9041]
  + let env = Env::new_anon(409600000, 1).unwrap();
• replacement in sanakirja/src/tests.rs at line 138
  [3.9094]→[3.9094:9160](∅→∅)
  − let mut db: Db<_, u64, (), B> = create_db(&mut txn).unwrap();
  [3.9094]

  [3.9160]
  + let mut db: Db<_, u64, ()> = create_db(&mut txn).unwrap();
• edit in sanakirja/src/tests.rs at line 140
  [3.9186]→[3.9186:9230](∅→∅)
  − let now = std::time::SystemTime::now();
• replacement in sanakirja/src/tests.rs at line 155
  [5.5784]→[5.5784:5833](∅→∅)
  − let env = Env::new_anon(409600000).unwrap();
  [5.5784]

  [5.5833]
  + let env = Env::new_anon(409600000, 1).unwrap();
• replacement in sanakirja/src/tests.rs at line 157
  [5.5886]→[5.5886:5952](∅→∅)
  − let mut db: Db<_, u64, (), B> = create_db(&mut txn).unwrap();
  [5.5886]

  [3.9953]
  + let mut db: Db<_, u64, ()> = create_db(&mut txn).unwrap();
• edit in sanakirja/src/tests.rs at line 159
  [3.9979]→[5.5977:6021](∅→∅),[5.5977]→[5.5977:6021](∅→∅)
  − let now = std::time::SystemTime::now();
• replacement in sanakirja/src/tests.rs at line 224
  [5.7976]→[5.7976:8001](∅→∅)
  − db: &Db<T, K, V, P>,
  [5.7976]

  [5.8001]
  + db: &Db_<T, K, V, P>,
• edit in sanakirja/src/tests.rs at line 248
  [5.8740]
  +

  +

  + #[cfg(target_family="unix")]

  + #[test]

  + fn multi_txn() {

  + env_logger::try_init().unwrap_or(());

  + std::fs::remove_dir_all("/tmp/sanakirja0").unwrap_or(());

  + std::fs::create_dir_all("/tmp/sanakirja0").unwrap();

  + let env = Env::new("/tmp/sanakirja0", 4096 * 20, 2).unwrap();

  + let mut txn = Env::mut_txn_begin(&env).unwrap();

  + debug!("txn.root = {:?}", txn.env.root);

  + let mut db = create_db::<MutTxn<&Env, ()>, u64, ()>(&mut txn).unwrap();

  + debug!("db = {:?}", db.db.offset);

  + txn.set_root(0, db.db.offset);

  + txn.commit().unwrap();

  + debug!("1. commit done");

  + let mut txn = Env::mut_txn_begin(&env).unwrap();

  + debug!("txn.root = {:?}", txn.env.root);

  + let db: Db<_, u64, ()> = txn.root_db(0).unwrap().unwrap();

  + debug!("txn.root = {:?}", db);

  + txn.commit().unwrap();

  + debug!("2. commit done");

  + let mut txn = Env::mut_txn_begin(&env).unwrap();

  + debug!("txn.root = {:?}", txn.env.root);

  + txn.commit().unwrap();

  + debug!("commit done");

  + }
• replacement in sanakirja/src/environment/muttxn.rs at line 6
  [5.80263]→[4.0:58](∅→∅)
  − impl<E:Borrow<Env>, T> std::fmt::Debug for MutTxn<E, T> {
  [5.80263]

  [5.37172]
  + impl<E: Borrow<Env>, T> std::fmt::Debug for MutTxn<E, T> {
• replacement in sanakirja/src/environment/muttxn.rs at line 14
  [4.98]→[5.80340:80352](∅→∅),[5.80340]→[5.80340:80352](∅→∅)
  − env: E,
  [4.98]

  [5.80352]
  + pub(crate) env: E,
• replacement in sanakirja/src/environment/muttxn.rs at line 18
  [5.37308]→[5.80400:80470](∅→∅),[2.1320]→[5.80400:80470](∅→∅),[5.80400]→[5.80400:80470](∅→∅)
  − rc: Option<btree::Db<Self, u64, (), btree::page::Page<u64, ()>>>,
  [2.1320]

  [5.80470]
  + rc: Option<btree::Db<Self, u64, ()>>,
• replacement in sanakirja/src/environment/muttxn.rs at line 30
  [5.80877]→[5.80877:80900](∅→∅)
  − roots: [u64; 508],
  [5.80877]

  [5.80900]
  + roots: Vec<u64>,
• edit in sanakirja/src/environment/muttxn.rs at line 68
  [5.81918]

  [5.81918]
  + for (n, &r) in self.roots.iter().enumerate() {

  + if r > 0 {

  + if self.parent.roots.get(n).is_none() {

  + self.parent.roots.resize(n + 1, 0u64)

  + }

  + self.parent.roots[n] = r

  + }

  + }
• edit in sanakirja/src/environment/muttxn.rs at line 94
  [4.578]→[5.82455:82513](∅→∅),[5.82455]→[5.82455:82513](∅→∅)
  − debug!("{:?} {:?}", v, env_.roots.len());
• replacement in sanakirja/src/environment/muttxn.rs at line 95
  [4.623]→[4.623:660](∅→∅)
  − let v0 = *v + n - 1;
  [4.623]

  [5.82513]
  + let v0 = (*v + n - 1) % env_.roots.len();

  + debug!("v = {:?} v0 = {:?}", v, v0);
• replacement in sanakirja/src/environment/muttxn.rs at line 100
  [4.808]→[5.82745:82828](∅→∅),[5.82745]→[5.82745:82828](∅→∅)
  − std::ptr::copy_nonoverlapping(page_ptr, next_page_ptr, PAGE_SIZE);
  [4.808]

  [5.82828]
  + std::ptr::copy_nonoverlapping(page_ptr.add(8), next_page_ptr.add(8), PAGE_SIZE - 8);
• replacement in sanakirja/src/environment/muttxn.rs at line 133
  [5.83993]→[5.83993:84026](∅→∅)
  − roots: [0; 508],
  [5.83993]

  [5.84026]
  + roots: Vec::new(),
• replacement in sanakirja/src/environment/muttxn.rs at line 142
  [5.84183]→[5.84183:84279](∅→∅)
  − let mut free_db: btree::Db<Self, u64, (), btree::page::Page<u64, ()>> = btree::Db {
  [5.84183]

  [5.84279]
  + let mut free_db: btree::Db<Self, u64, ()> = btree::Db {
• replacement in sanakirja/src/environment/muttxn.rs at line 166
  [5.4489]→[5.85286:85383](∅→∅),[5.85286]→[5.85286:85383](∅→∅)
  − let globptr = maps[0].ptr.offset((PAGE_SIZE * *root) as isize) as *mut GlobalHeader;
  [5.4489]

  [5.85383]
  + let globptr = maps[0].ptr.add(*root * PAGE_SIZE) as *mut GlobalHeader;
• edit in sanakirja/src/environment/muttxn.rs at line 170
  [5.85507]

  [5.85507]
  + let root_dbs = std::slice::from_raw_parts_mut(

  + maps[0].ptr.add(*root * PAGE_SIZE + GLOBAL_HEADER_SIZE) as *mut u64,

  + N_ROOTS,

  + );

  + for (&r, rr) in self.roots.iter().zip(root_dbs.iter_mut()) {

  + debug!("root_db: {:?}", rr as *mut u64);

  + debug!("committing root: {:?} {:?}", r, rr);

  + *rr = r

  + }

  +
• edit in sanakirja/src/environment/muttxn.rs at line 200
  [5.86111]

  [5.86111]
  + if self.roots.get(num).is_none() {

  + self.roots.resize(num + 1, 0u64);

  + }
• replacement in sanakirja/src/environment/muttxn.rs at line 219
  [5.86537]→[5.86537:86624](∅→∅)
  − let mut db: btree::Db<Self, u64, (), btree::page::Page<u64, ()>> = btree::Db {
  [5.86537]

  [5.86624]
  + let mut db: btree::Db<Self, u64, ()> = btree::Db {
• replacement in sanakirja/src/environment/muttxn.rs at line 259
  [5.38235]→[5.38235:38334](∅→∅),[5.38334]→[5.88311:88331](∅→∅),[5.88311]→[5.88311:88331](∅→∅),[5.88331]→[5.38335:38418](∅→∅)
  − let page = MutPage(CowPage {

  − data,

  − offset,

  − });

  − self.occupied_owned_pages.push(MutPage(CowPage { data, offset }));
  [5.38235]

  [5.88385]
  + let page = MutPage(CowPage { data, offset });

  + self.occupied_owned_pages

  + .push(MutPage(CowPage { data, offset }));
• replacement in sanakirja/src/environment/muttxn.rs at line 286
  [5.1934]→[5.38850:38880](∅→∅),[5.38850]→[5.38850:38880](∅→∅)
  − return Ok(())
  [5.1934]

  [5.1935]
  + return Ok(());
• replacement in sanakirja/src/environment/muttxn.rs at line 316
  [5.2243]→[5.39361:39391](∅→∅),[5.89846]→[5.39361:39391](∅→∅)
  − return Ok(())
  [5.2243]

  [5.2244]
  + return Ok(());
• replacement in sanakirja/src/environment/muttxn.rs at line 346
  [5.2408]→[5.2408:2463](∅→∅)
  − debug!("put in RC: {:?} {:?}", rc, off|2);
  [5.2408]

  [5.2463]
  + debug!("put in RC: {:?} {:?}", rc, off | 2);
• edit in sanakirja/src/environment/muttxn.rs at line 376
  [5.91588]

  [5.91588]
  + }

  + }

  +

  + impl<E: Borrow<Env>, T> RootDb for MutTxn<E, T> {

  + fn root_db<

  + K: Representable<Self>,

  + V: Representable<Self>,

  + >(

  + &self,

  + n: usize,

  + ) -> Result<Option<sanakirja_core::btree::Db<Self, K, V>>, Error> {

  + use sanakirja_core::LoadPage;

  + if let Some(db) = self.roots.get(n) {

  + Ok(Some(sanakirja_core::btree::Db {

  + db: self.load_page(*db)?,

  + marker: std::marker::PhantomData,

  + }))

  + } else {

  + unsafe {

  + let env = self.env.borrow();

  + let db = {

  + let root = env.root.lock();

  + let maps = env.mmaps.lock();

  + *(maps[0].ptr.add(*root * PAGE_SIZE + GLOBAL_HEADER_SIZE + 8 * n) as *mut u64)

  + };

  + if db != 0 {

  + Ok(Some(sanakirja_core::btree::Db {

  + db: self.load_page(db)?,

  + marker: std::marker::PhantomData,

  + }))

  + } else {

  + Ok(None)

  + }

  + }

  + }
• edit in sanakirja/src/environment/mod.rs at line 2
  [5.91625]→[5.91625:91687](∅→∅)
  − use parking_lot::lock_api::RawRwLock;

  − use parking_lot::Mutex;
• edit in sanakirja/src/environment/mod.rs at line 4
  [4.1299]

  [5.91733]
  + use parking_lot::lock_api::RawRwLock;

  + use parking_lot::Mutex;
• replacement in sanakirja/src/environment/mod.rs at line 7
  [5.91734]→[5.39915:39944](∅→∅)
  − use sanakirja_core::CowPage;
  [5.91734]

  [4.1300]
  + use sanakirja_core::{CowPage, Representable};
• edit in sanakirja/src/environment/mod.rs at line 10
  [4.1326]

  [4.1326]
  + #[cfg(feature = "mmap")]

  + use std::fs::OpenOptions;
• edit in sanakirja/src/environment/mod.rs at line 16
  [4.1434]→[4.1434:1485](∅→∅)
  − #[cfg(feature = "mmap")]

  − use std::fs::OpenOptions;
• edit in sanakirja/src/environment/mod.rs at line 49
  [5.92836]→[5.92836:93218](∅→∅)
  − // Lock order: first take thread locks, then process locks.

  −

  − // Why are there two synchronization mechanisms?

  − // Because we would need to upgrade the read lock into a write lock,

  − // and there is no real way to do this with standard mechanisms.

  − // So, we take a mutex to make sure no other mutable transaction can start,

  − // and then at the time of writing, we also take the RwLock.

  −
• replacement in sanakirja/src/environment/mod.rs at line 61
  [4.1617]→[5.93775:93799](∅→∅),[5.93775]→[5.93775:93799](∅→∅)
  − root: Mutex<usize>,
  [4.1617]

  [5.93799]
  + pub(crate) root: Mutex<usize>,
• replacement in sanakirja/src/environment/mod.rs at line 121
  [5.95236]→[4.2029:2137](∅→∅)
  − pub unsafe fn new_nolock<P: AsRef<Path>>(path: P, length: u64, n_roots: usize) -> Result<Self, Error> {
  [5.95236]

  [5.95328]
  + pub unsafe fn new_nolock<P: AsRef<Path>>(

  + path: P,

  + length: u64,

  + n_roots: usize,

  + ) -> Result<Self, Error> {
• replacement in sanakirja/src/environment/mod.rs at line 134
  [5.95677]→[4.2138:2184](∅→∅)
  − let length = (length + 4095) & !4096;
  [5.95677]

  [5.95726]
  + let length = (length + 4095) & !4095;
• edit in sanakirja/src/environment/mod.rs at line 238
  [4.3259]→[5.99664:99665](∅→∅),[5.99664]→[5.99664:99665](∅→∅)
  −
• replacement in sanakirja/src/environment/mod.rs at line 257
  [4.4049]→[4.4049:4131](∅→∅)
  − .open(path.join("db").with_extension(&format!("lock{}", n)))?
  [4.4049]

  [4.4131]
  + .open(path.join("db").with_extension(&format!("lock{}", n)))?,
• replacement in sanakirja/src/environment/mod.rs at line 267
  [4.4230]→[4.4230:4297](∅→∅)
  − let length = (std::cmp::max(length, 4096) + 4095) & !4096;
  [4.4230]

  [5.102110]
  + let length = (std::cmp::max(length, 4096) + 4095) & !4095;
• replacement in sanakirja/src/environment/mod.rs at line 276
  [4.4432]→[5.102472:102542](∅→∅),[5.102472]→[5.102472:102542](∅→∅)
  − let length = std::cmp::max(length, 4096).next_power_of_two();
  [4.4432]

  [5.102542]
  + let length = (std::cmp::max(length, 4096) + 4095) & !4095;
• edit in sanakirja/src/environment/mod.rs at line 422
  [5.106701]

  [5.106701]
  + pub trait RootDb: Sized + sanakirja_core::LoadPage {

  + fn root_db<

  + K: Representable<Self>,

  + V: Representable<Self>,

  + >(

  + &self,

  + n: usize,

  + ) -> Result<Option<sanakirja_core::btree::Db<Self, K, V>>, Self::Error>;

  + }

  +
• edit in sanakirja/src/environment/global_header.rs at line 1
  [5.107218]

  [5.107219]
  + pub const GLOBAL_HEADER_SIZE: usize = 32;

  + pub const N_ROOTS: usize = 508;

  +
• edit in sanakirja/src/environment/global_header.rs at line 34
  [5.108041]→[5.108041:108379](∅→∅)
  − }

  − }

  − pub fn to_le(&self) -> Self {

  − GlobalHeader {

  − version: self.version.to_le(),

  − root: self.root,

  − n_roots: self.n_roots,

  − crc: self.crc.to_le(),

  − free_db: self.free_db.to_le(),

  − length: self.length.to_le(),

  − rc_db: self.rc_db.to_le(),