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use crate::cell::{RootCell, RootObj}; use crate::result::Result; use crate::stm::{journal::*, Chaperon, Log}; use crate::{as_mut, PSafe, TxInSafe, TxOutSafe}; use std::collections::HashMap; use std::fs::OpenOptions; use std::ops::Range; use std::panic::UnwindSafe; use std::path::Path; use std::thread::ThreadId; use std::{alloc::Layout, mem, ptr}; /// Default pool memory size to be used while creating a new pool pub const DEFAULT_POOL_SIZE: u64 = 8 * 1024 * 1024; /// Open pool flags pub mod open_flags { /// Open Flag: Create the pool memory file pub const O_C: u32 = 0x00000001; /// Open Flag: Formats the pool memory file if file exists, otherwise error pub const O_F: u32 = 0x00000002; /// Open Flag: Creates pool memory file only if it does not exist pub const O_CNE: u32 = 0x00000004; /// Open Flag: Creates and formats a new file pub const O_CF: u32 = O_C | O_F; /// Open Flag: Creates and formats pool memory file only if it does not exist pub const O_CFNE: u32 = O_CNE | O_F; /// Open Flag: Creates a pool memory file of size 1GB pub const O_1GB: u32 = 0x00000010; /// Open Flag: Creates a pool memory file of size 2GB pub const O_2GB: u32 = 0x00000020; /// Open Flag: Creates a pool memory file of size 4GB pub const O_4GB: u32 = 0x00000040; /// Open Flag: Creates a pool memory file of size 8GB pub const O_8GB: u32 = 0x00000080; /// Open Flag: Creates a pool memory file of size 16GB pub const O_16GB: u32 = 0x00000100; /// Open Flag: Creates a pool memory file of size 32GB pub const O_32GB: u32 = 0x00000200; /// Open Flag: Creates a pool memory file of size 64GB pub const O_64GB: u32 = 0x00000400; /// Open Flag: Creates a pool memory file of size 128GB pub const O_128GB: u32 = 0x00000800; /// Open Flag: Creates a pool memory file of size 256GB pub const O_256GB: u32 = 0x00001000; /// Open Flag: Creates a pool memory file of size 512GB pub const O_512GB: u32 = 0x00002000; /// Open Flag: Creates a pool memory file of size 1TB pub const O_1TB: u32 = 0x00004000; /// Open Flag: Creates a pool memory file of size 2TB pub const O_2TB: u32 = 0x00008000; /// Open Flag: Creates a pool memory file of size 4TB pub const O_4TB: u32 = 0x00010000; /// Open Flag: Creates a pool memory file of size 8TB pub const O_8TB: u32 = 0x00020000; /// Open Flag: Creates a pool memory file of size 16TB pub const O_16TB: u32 = 0x00040000; /// Open Flag: Creates a pool memory file of size 32TB pub const O_32TB: u32 = 0x00080000; /// Open Flag: Creates a pool memory file of size 64TB pub const O_64TB: u32 = 0x00100000; } pub use open_flags::*; /// Shows that the pool has a root object pub const FLAG_HAS_ROOT: u64 = 0x0000_0001; /// This macro can be used to declare a static struct for the inner data of an /// arbitrary allocator. #[macro_export] macro_rules! static_inner_object { ($id:ident, $ty:ty) => { static mut $id: Option<&'static mut $ty> = None; }; } /// This macro can be used to access static data of an arbitrary allocator #[macro_export] macro_rules! static_inner { ($id:ident, $inner:ident, $body:block) => { unsafe { if let Some($inner) = &mut $id { $body } else { panic!("No memory pool is open"); } } }; } /// Persistent Memory Pool /// /// This trait can be used to define a persistent memory pool type. The /// methods of `MemPool` trait do not have a reference to self in order to make /// sure that all information that it works with, including the virtual address /// boundaries, are static. Therefore, all objects with the same memory /// allocator will share a unique memory pool type. Having a strong set of type /// checking rules, Rust prevents referencing from one memory pool to another. /// /// To implement a new memory pool, you should define a new type with static /// values, that implements `MemPool`. You may use [`static_inner_object!()`] /// to statically define allocator's inner data, and [`static_inner!()`] to /// access it. You may also use the default allocator using [`pool!()`] which /// creates a pool module with a default allocator of type [`BuddyAlloc`]. /// /// # Examples /// The following example shows how to use `MemPool` to track allocations of a /// single numerical object of type `i32`. /// /// ``` /// # use crndm::alloc::MemPool; /// # use crndm::stm::Journal; /// # use crndm::result::Result; /// # use std::ops::Range; /// use std::alloc::{alloc,dealloc,realloc,Layout}; /// /// struct TrackAlloc {} /// /// unsafe impl MemPool for TrackAlloc { /// fn rng() -> Range<u64> { 0..u64::MAX } /// unsafe fn pre_alloc(size: usize) -> (*mut u8, u64, usize) { /// let p = alloc(Layout::from_size_align_unchecked(size, 4)); /// println!("A block of {} bytes is allocated at {}", size, p as u64); /// (p, p as u64, size) /// } /// unsafe fn pre_dealloc(p: *mut u8, size: usize) { /// println!("A block of {} bytes at {} is deallocated", size, p as u64); /// dealloc(p, Layout::from_size_align_unchecked(size, 1)); /// } /// unsafe fn pre_realloc(p: *mut *mut u8, old: usize, new: usize) -> bool { /// println!("A block of {} bytes at {} is reallocated to {}", old, *p as u64, new); /// *p = realloc(*p, Layout::from_size_align_unchecked(old, 1), new); /// true /// } /// } /// /// unsafe { /// let (p, _, _) = TrackAlloc::alloc(1); /// *p = 10; /// println!("loc {} contains {}", p as u64, *p); /// TrackAlloc::dealloc(p, 1); /// } /// ``` /// /// # Safety /// /// This is the developer's responsibility to manually drop allocated objects. /// One way for memory management is to use pointer wrappers that implement /// [`Drop`] trait and deallocate the object on drop. Unsafe /// methods does not guarantee persistent memory safety. /// /// `pmem` crate provides `Pbox`, `Prc`, and `Parc` for memory management using /// RAII. They internally use the unsafe methods. /// /// [`pool!()`]: ./default/macro.pool.html /// [`static_inner_object!()`]: ../macro.static_inner_object.html /// [`static_inner!()`]: ../macro.static_inner.html /// [`BuddyAlloc`]: ./default/struct.BuddyAlloc.html pub unsafe trait MemPool where Self: 'static + Sized, { /// Opens a new pool without any root object. This function is for testing /// and is not useful in real applications as none of the allocated /// objects in persistent region is durable. The reason is that they are not /// reachable from a root object as it doesn't exists. All objects can live /// only in the scope of a transaction. /// /// # Flags /// * O_C: create a memory pool file if not exists /// * O_F: format the memory pool file /// * O_CNE: create a memory pool file if not exists /// * O_CF: create and format a new memory pool file /// * O_CFNE: create and format a memory pool file only if not exists /// /// See [`open_flags`](./open_flags/index.html) for more options. fn open_no_root(_path: &str, _flags: u32) -> Result<Self> { unimplemented!() } /// Commits all changes and clears the logs for all threads /// /// This method should be called while dropping the `MemPool` object to /// make sure that all uncommitted changes outside transactions, such as /// reference counters, are persistent. unsafe fn close() -> Result<()> { unimplemented!() } /// Opens a pool and retrieves the root object /// /// The root type should implement [`RootObj`] trait in order to create a /// root object on its absence. This function [creates and] returns an /// immutable reference to the root object. The pool remains open as long as /// the root object is in the scope. Like other persistent objects, the root /// object is immutable and it is modifiable via interior mutability. /// /// # Flags /// * O_C: create a memory pool file if not exists /// * O_F: format the memory pool file /// * O_CNE: create a memory pool file if not exists /// * O_CF: create and format a new memory pool file /// * O_CFNE: create and format a memory pool file only if not exists /// /// See [`open_flags`](./open_flags/index.html) for more options. /// /// # Examples /// /// ``` /// use crndm::default::*; /// /// let root = BuddyAlloc::open::<i32>("foo.pool", O_CF).unwrap(); /// /// assert_eq!(*root, i32::default()); /// ``` /// /// ## Single-thread Shared Root Object /// /// [`Prc`]`<`[`PCell`]`<T>>` can be used in order to have a mutable shared /// root object, as follows. /// /// ``` /// use crndm::default::*; /// /// type Root = Prc<PCell<i32>>; /// /// let root = BuddyAlloc::open::<Root>("foo.pool", O_CF).unwrap(); /// /// let data = root.get(); /// /// if data == i32::default() { /// println!("Initializing data"); /// // This block runs only once to initialize the root object /// transaction(|j| { /// root.set(10, j); /// }).unwrap(); /// } /// /// assert_eq!(root.get(), 10); /// ``` /// /// ## Thread-safe Root Object /// /// If you need a thread-safe root object, you may want to wrap the root object /// in [`Parc`]`<`[`PMutex`]`<T>>`, as shown in the example below: /// /// ``` /// use crndm::default::*; /// use std::thread; /// /// type Root = Parc<PMutex<i32>>; /// /// let root = BuddyAlloc::open::<Root>("foo.pool", O_CF).unwrap(); /// /// let mut threads = vec!(); /// /// for _ in 0..10 { /// let root = Parc::volatile(&root); /// threads.push(thread::spawn(move || { /// transaction(|j| { /// if let Some(root) = root.upgrade(j) { /// let mut root = root.lock(j); /// *root += 10; /// } /// }).unwrap(); /// })); /// } /// /// for thread in threads { /// thread.join().unwrap(); /// } /// /// transaction(|j| { /// let data = root.lock(j); /// assert_eq!(*data % 100, 0); /// }).unwrap(); /// ``` /// /// # Errors /// /// * A volatile memory pool (e.g. `Heap`) doesn't have a root object. /// * The pool should be open before accessing the root object. /// /// [`RootObj`]: ../stm/trait.RootObj.html /// [`Prc`]: ../prc/struct.Prc.html /// [`Parc`]: ../sync/parc/struct.Parc.html /// [`PCell`]: ./default/type.PCell.html /// [`PRefCell`]: ./default/type.PRefCell.html /// [`PMutex`]: ./default/type.PMutex.html fn open<'a, U: 'a + PSafe + RootObj<Self>>( _path: &str, _flags: u32, ) -> Result<RootCell<'a, U, Self>> { unimplemented!() } /// Formats the memory pool file unsafe fn format(_path: &str) -> Result<()> { unimplemented!() } /// Applies open pool flags unsafe fn apply_flags(path: &str, flags: u32) -> Result<()> { let mut size: u64 = flags as u64 >> 4; if size.count_ones() > 1 { return Err("Cannot have multiple size flags".to_string()); } else if size == 0 { size = DEFAULT_POOL_SIZE; } else { if flags & (O_C | O_CNE) == 0 { return Err("Cannot use size flag without a create flag".to_string()); } size <<= 30; } let mut format = !Path::new(path).exists() && ((flags & O_F) != 0); if ((flags & O_C) != 0) || ((flags & O_CNE != 0) && !Path::new(path).exists()) { create_file(path, size)?; format = (flags & O_F) != 0; } if format { Self::format(path)?; } Ok(()) } /// Indicates if the given offset is allocated #[inline] fn allocated(_off: u64, _len: usize) -> bool { true } /// Translates raw pointers to memory offsets /// /// # Safety /// /// The raw pointer should be in the valid range #[inline] unsafe fn off_unchecked<T: ?Sized>(x: *const T) -> u64 { (x as *const u8 as u64) - Self::start() } /// Acquires a reference pointer to the object /// /// # Safety /// /// The offset should be in the valid address range #[inline] unsafe fn get_unchecked<'a, T: 'a + ?Sized>(off: u64) -> &'a T { union U<'b, K: 'b + ?Sized> { off: u64, raw: &'b K, } #[cfg(any(feature = "access_violation_check", debug_assertions))] assert!( Self::allocated(off, 1), "Bad address (0x{:x})", off ); U { off: Self::start() + off }.raw } /// Acquires a mutable reference to the object /// /// # Safety /// /// The offset should be in the valid address range #[inline] #[track_caller] unsafe fn get_mut_unchecked<'a, T: 'a + ?Sized>(off: u64) -> &'a mut T { union U<'b, K: 'b + ?Sized> { off: u64, raw: &'b mut K, } #[cfg(any(feature = "access_violation_check", debug_assertions))] assert!( Self::allocated(off, 1), "Bad address (0x{:x})", off ); U { off: Self::start() + off }.raw } /// Acquires a reference to the slice /// /// # Safety /// /// The offset should be in the valid address range #[inline] unsafe fn deref_slice_unchecked<'a, T: 'a>(off: u64, len: usize) -> &'a [T] { if len == 0 { &[] } else { union U<'b, K: 'b> { off: u64, raw: &'b K, } let ptr = U { off: Self::start() + off, } .raw; let res = std::slice::from_raw_parts(ptr, len); #[cfg(any(feature = "access_violation_check", debug_assertions))] assert!( Self::allocated(off, mem::size_of::<T>() * len), format!( "Bad address (0x{:x}..0x{:x})", off, off + (mem::size_of::<T>() * len) as u64 - 1 ) ); res } } /// Acquires a mutable reference to the slice /// /// # Safety /// /// The offset should be in the valid address range #[inline] unsafe fn deref_slice_unchecked_mut<'a, T: 'a>(off: u64, len: usize) -> &'a mut [T] { if len == 0 { &mut [] } else { union U<'b, K: 'b> { off: u64, raw: &'b mut K, } let ptr = U { off: Self::start() + off, } .raw; let res = std::slice::from_raw_parts_mut(ptr, len); #[cfg(any(feature = "access_violation_check", debug_assertions))] assert!( Self::allocated(off, mem::size_of::<T>() * len), format!( "Bad address (0x{:x}..0x{:x})", off, off + (mem::size_of::<T>() * len) as u64 - 1 ) ); res } } /// Acquires a reference to the object #[inline] unsafe fn deref<'a, T: 'a>(off: u64) -> Result<&'a T> { if Self::allocated(off, mem::size_of::<T>()) { Ok(Self::get_unchecked(off)) } else { Err(format!("Bad address (0x{:x})", off)) } } /// Acquires a mutable reference pointer to the object #[inline] unsafe fn deref_mut<'a, T: 'a>(off: u64) -> Result<&'a mut T> { if Self::allocated(off, mem::size_of::<T>()) { Ok(Self::get_mut_unchecked(off)) } else { Err(format!("Bad address (0x{:x})", off)) } } /// Translates raw pointers to memory offsets #[inline] fn off<T: ?Sized>(x: *const T) -> Result<u64> { if Self::valid(unsafe { &*x }) { Ok(x as *const u8 as u64 - Self::start()) } else { Err("out of valid range".to_string()) } } /// Valid Virtual Address Range fn rng() -> Range<u64> { Self::start()..Self::end() } /// Start of virtual address range #[inline] fn start() -> u64 { Self::rng().start } /// End of virtual address range #[inline] fn end() -> u64 { Self::rng().end } /// Total size of the memory pool fn size() -> usize { unimplemented!() } /// Available space in the pool fn available() -> usize { unimplemented!() } /// Total occupied space fn used() -> usize { Self::size() - Self::available() } /// Checks if the reference `p` belongs to this pool #[inline] fn valid<T: ?Sized>(p: &T) -> bool { let rng = Self::rng(); let start = p as *const T as *const u8 as u64; // let end = start + std::mem::size_of_val(p) as u64; start >= rng.start && start < rng.end // && end >= rng.start && end < rng.end } /// Checks if `addr` is in the valid address range if this allocator /// /// `addr` contains the scalar of a virtual address. If you have a raw /// fat pointer of type T, you can obtain its virtual address by converting /// it into a thin pointer and then `u64`. /// /// # Examples /// /// ``` /// let p = Box::new(1); /// println!("Address {:#x} contains value '{}'", p.as_ref() as *const _ as u64, *p); /// ``` #[inline] fn contains(addr: u64) -> bool { let rng = Self::rng(); addr >= rng.start && addr < rng.end } /// Allocate memory as described by the given `layout`. /// /// Returns a pointer to newly-allocated memory. /// /// # Safety /// /// This function is unsafe because undefined behavior can result /// if the caller does not ensure that `layout` has non-zero size. /// The allocated block of memory may or may not be initialized. #[inline] #[track_caller] unsafe fn alloc(size: usize) -> (*mut u8, u64, usize) { let (p, off, len) = Self::pre_alloc(size); Self::drop_on_failure(off, len); Self::perform(); (p, off, len) } /// Deallocate the block of memory at the given `ptr` pointer with the /// given `size`. /// /// # Safety /// /// This function is unsafe because undefined behavior can result if the /// caller does not ensure all of the following: /// /// * `ptr` must denote a block of memory currently allocated via this /// allocator, /// /// * `size` must be the same size that was used to allocate that block /// of memory. #[inline] #[track_caller] unsafe fn dealloc(ptr: *mut u8, size: usize) { Self::pre_dealloc(ptr, size); Self::perform(); } /// Prepares allocation without performing it /// /// This function is used internally for low-level atomicity in memory /// allocation. See [`Log::set()`] for more details. /// /// # Examples /// /// ``` /// # use crndm::default::*; /// # type P = BuddyAlloc; /// # let _=P::open_no_root("foo.pool", O_CF).unwrap(); /// unsafe { /// let (ptr, _, _) = P::pre_alloc(8); /// *ptr = 10; /// P::perform(); /// } /// ``` /// /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn pre_alloc(size: usize) -> (*mut u8, u64, usize); /// Prepares deallocation without performing it /// /// This function is used internally for low-level atomicity in memory /// allocation. See [`Log::set()`] for more details. /// /// # Examples /// /// ``` /// # use crndm::default::*; /// # type P = BuddyAlloc; /// # let _=P::open_no_root("foo.pool", O_CF).unwrap(); /// unsafe { /// let (ptr, _, _) = P::alloc(8); /// *ptr = 10; /// P::pre_dealloc(ptr, 8); /// assert_eq!(*ptr, 10); /// P::perform(); /// assert_ne!(*ptr, 10); /// } /// ``` /// /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn pre_dealloc(ptr: *mut u8, size: usize); /// Prepares reallocation without performing it, updating the pointer to /// a new one, if required, with a new size /// /// # Examples /// /// ``` /// # use crndm::default::*; /// # type P = BuddyAlloc; /// # let _=P::open_no_root("foo.pool", O_CF).unwrap(); /// unsafe { /// let (mut ptr, _, _) = P::alloc(8); /// P::pre_realloc(&mut ptr, 8, 16); /// P::perform(); /// P::dealloc(ptr, 16); /// } /// ``` /// /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn pre_realloc(ptr: *mut *mut u8, size: usize, new_size: usize) -> bool; /// Adds a low-level log to update as 64-bit `obj` to `val` when /// [`perform()`] is called. See [`Log::set()`] for more details. /// /// [`perform()`]: #method.perform /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn log64(_obj: *const u64, _val: u64) { unimplemented!() } /// Adds a low-level `DropOnFailure` log to perform inside the allocator. /// This is internally used to atomically allocate a new objects. Calling /// [`perform()`] drops these logs. /// /// # Examples /// /// ``` /// # use crndm::default::*; /// # type P = BuddyAlloc; /// # let _ = P::open_no_root("foo.pool", O_CF).unwrap(); /// unsafe { /// // Prepare an allocation. The allocation is not durable yet. In case /// // of a crash, the prepared allocated space is gone. It is fine /// // because it has not been used. The `pre_` and `perform` functions /// // form a low-level atomic section. /// let (obj, off, len) = P::pre_alloc(1); /// /// // Create a low-level DropOnFailure log. This log is going to be used /// // when a crash happens while performing the changes made by the /// // preparation functions. If a crash happens before that, these logs /// // will be discarded. /// P::drop_on_failure(off, len); /// /// // It is fine to work with the prepared raw pointer. All changes in /// // the low-level atomic section are considered as part of the /// // allocation and will be gone in case of a crash, as the allocation /// // will be dropped. /// *obj = 20; /// /// // Transaction ends here. The perform function sets the `operating` /// // flag to show that the prepared changes are being materialized. /// // This flag remains set until the end of materialization. In case /// // of a crash while operating, the recovery procedure first continues /// // the materialization, and then uses the `DropOnFailure` logs to /// // reclaim the allocation. /// P::perform(); /// } /// ``` /// /// [`perform()`]: #method.perform /// [`Journal`]: ../stm/journal/struct.Journal.html /// unsafe fn drop_on_failure(_off: u64, _len: usize) {} /// Performs the prepared operations /// /// Materializes the changes made by [`pre_alloc`](#method.pre_alloc), /// [`pre_dealloc`](#method.pre_dealloc), and /// [`pre_realloc`](#method.pre_realloc). See [`Log::set()`] for more /// details. /// /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn perform() { } /// Discards the prepared operations /// /// Discards the changes made by [`pre_alloc`](#method.pre_alloc), /// [`pre_dealloc`](#method.pre_dealloc), and /// [`pre_realloc`](#method.pre_realloc). See [`Log::set()`] for more /// details. /// /// [`Log::set()`]: ../stm/struct.Log.html#method.set /// unsafe fn discard() { } /// Behaves like `alloc`, but also ensures that the contents /// are set to zero before being returned. /// /// # Safety /// /// This function is unsafe for the same reasons that `alloc` is. /// However the allocated block of memory is guaranteed to be initialized. /// /// # Errors /// /// Returning a null pointer indicates that either memory is exhausted /// or `layout` does not meet allocator's size or alignment constraints, /// just as in `alloc`. /// /// Clients wishing to abort computation in response to an /// allocation error are encouraged to call the [`handle_alloc_error`] function, /// rather than directly invoking `panic!` or similar. /// /// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html unsafe fn alloc_zeroed(size: usize) -> *mut u8 { let (ptr, _, _) = Self::alloc(size); if !ptr.is_null() { std::ptr::write_bytes(ptr, 0, size); } ptr } /// Shrink or grow a block of memory to the given `new_size`. /// The block is described by the given `ptr` pointer and `layout`. /// /// If successful, it replaces the pointer location to a new value and /// returns true. /// /// # Safety /// /// This function is unsafe because undefined behavior can result /// if the caller does not ensure all of the following: /// /// * `ptr` must be currently allocated using this allocator, /// /// * `size` must be the same size that was used /// to allocate that block of memory, /// /// * `new_size` must be greater than zero. /// unsafe fn realloc(ptr: *mut *mut u8, size: usize, new_size: usize) -> bool{ let (new_ptr, _, _) = Self::alloc(new_size); if !new_ptr.is_null() { std::ptr::copy_nonoverlapping(*ptr, new_ptr, std::cmp::min(size, new_size)); Self::dealloc(*ptr, size); *ptr = new_ptr; true } else { false } } /// Allocates new memory and then places `x` into it with `DropOnFailure` log unsafe fn new<'a, T: PSafe + 'a>(x: T, j: &Journal<Self>) -> &'a mut T { debug_assert!(mem::size_of::<T>() != 0, "Cannot allocated ZST"); let mut log = Log::drop_on_failure(u64::MAX, 1, j); let (p, off, len) = Self::atomic_new(x); log.set(off, len); Self::perform(); p } /// Allocates a new slice and then places `x` into it with `DropOnAbort` log unsafe fn new_slice<'a, T: PSafe + 'a>(x: &'a [T], _journal: &Journal<Self>) -> &'a mut [T] { debug_assert!(mem::size_of::<T>() != 0, "Cannot allocate ZST"); debug_assert!(!x.is_empty(), "Cannot allocate empty slice"); let mut log = Log::drop_on_abort(u64::MAX, 1, _journal); let (p, off, size) = Self::atomic_new_slice(x); log.set(off, size); Self::perform(); p } /// Allocates new memory and then places `x` into it without realizing the allocation unsafe fn atomic_new<'a, T: 'a>(x: T) -> (&'a mut T, u64, usize) { union U<'b, K: 'b + ?Sized> { raw: *mut u8, rf: &'b mut K, } #[cfg(feature = "verbose")] println!(" ALLOC TYPE: {}", std::any::type_name::<T>()); let size = mem::size_of::<T>(); let (raw, off, len) = Self::pre_alloc(size); if raw.is_null() { panic!("Memory exhausted"); } Self::drop_on_failure(off, len); let p = U { raw }.rf; mem::forget(ptr::replace(p, x)); (p, off, size) } /// Allocates new memory and then places `x` into it without realizing the allocation unsafe fn atomic_new_slice<'a, T: 'a + PSafe>(x: &'a [T]) -> (&'a mut [T], u64, usize) { #[cfg(feature = "verbose")] println!( " ALLOC TYPE: [{}; {}]", std::any::type_name::<T>(), x.len() ); let (ptr, off, size) = Self::pre_alloc(Layout::for_value(x).size()); if ptr.is_null() { panic!("Memory exhausted"); } Self::drop_on_failure(off, size); ptr::copy_nonoverlapping( x as *const _ as *const u8, ptr, x.len() * mem::size_of::<T>(), ); ( std::slice::from_raw_parts_mut(ptr.cast(), x.len()), off, size, ) } /// Allocates new memory without copying data unsafe fn new_uninit<'a, T: PSafe + 'a>(j: &Journal<Self>) -> &'a mut T { let mut log = Log::drop_on_failure(u64::MAX, 1, j); let (p, off, size) = Self::atomic_new_uninit(); // Self::drop_on_failure(off, size); log.set(off, size); Self::perform(); p } /// Allocates new memory without copying data unsafe fn new_uninit_for_layout(size: usize, journal: &Journal<Self>) -> *mut u8 { #[cfg(feature = "verbose")] println!(" ALLOC {:?}", size); let mut log = Log::drop_on_abort(u64::MAX, 1, journal); let (p, off, len) = Self::pre_alloc(size); if p.is_null() { panic!("Memory exhausted"); } // Self::drop_on_failure(off, len); log.set(off, len); Self::perform(); p } /// Allocates new memory without copying data and realizing the allocation unsafe fn atomic_new_uninit<'a, T: 'a>() -> (&'a mut T, u64, usize) { union U<'b, K: 'b + ?Sized> { ptr: *mut u8, rf: &'b mut K, } let (ptr, off, len) = Self::pre_alloc(mem::size_of::<T>()); if ptr.is_null() { panic!("Memory exhausted"); } Self::drop_on_failure(off, len); (U { ptr }.rf, off, len) } /// Allocates new memory for value `x` unsafe fn alloc_for_value<'a, T: ?Sized>(x: &T) -> &'a mut T { union U<'b, K: 'b + ?Sized> { raw: *mut u8, rf: &'b mut K, } let raw = Self::alloc(mem::size_of_val(x)); if raw.0.is_null() { panic!("Memory exhausted"); } U { raw: raw.0 }.rf } /// Creates a `DropOnCommit` log for the value `x` unsafe fn free<'a, T: PSafe + ?Sized>(x: &mut T) { // std::ptr::drop_in_place(x); let off = Self::off_unchecked(x); let len = mem::size_of_val(x); if std::thread::panicking() { Log::drop_on_abort(off, len, &mut Journal::<Self>::current(true).unwrap().0); } else { Log::drop_on_commit(off, len, &mut Journal::<Self>::current(true).unwrap().0); } } /// Creates a `DropOnCommit` log for the value `x` unsafe fn free_slice<'a, T: PSafe>(x: &mut [T]) { // eprintln!("FREEING {} of size {}", x as *mut u8 as u64, len); if x.len() > 0 { let off = Self::off_unchecked(x); Log::drop_on_commit( off, x.len() * mem::size_of::<T>(), &mut Journal::<Self>::current(true).unwrap().0, ); } } /// Frees the allocation for value `x` unsafe fn free_nolog<'a, T: ?Sized>(x: &T) { Self::pre_dealloc(x as *const _ as *mut u8, mem::size_of_val(x)) } /// Executes a closure guarded by a global mutex unsafe fn guarded<T, F: FnOnce() -> T>(f: F) -> T { f() } /// Creates a new `Journal` object for the current thread unsafe fn new_journal(_tid: ThreadId) { } /// Drops a `journal` from memory unsafe fn drop_journal(_journal: &mut Journal<Self>) { } /// Returns the list of all journals unsafe fn journals() -> &'static mut HashMap<ThreadId, (&'static Journal<Self>, i32)> { unimplemented!() } /// Recovers from a crash unsafe fn recover() { unimplemented!() } /// Commits all changes and clears the logs for one thread /// /// If the transaction is nested, it postpones the commit to the top most /// transaction. /// /// # Safety /// /// This function is for internal use and should not be called elsewhere. /// #[inline] unsafe fn commit() { if let Some(journal) = Journal::<Self>::current(false) { journal.1 -= 1; if journal.1 == 0 { #[cfg(feature = "verbose")] println!("{:?}", journal.0); let journal = as_mut(journal.0); journal.commit(); journal.clear(); } } } #[inline] /// Commits all changes without clearing the logs /// /// If the transaction is nested, it postpones the commit to the top most /// transaction. /// /// # Safety /// /// This function is for internal use and should not be called elsewhere. /// unsafe fn commit_no_clear() { if let Some(journal) = Journal::<Self>::current(false) { if journal.1 == 1 { #[cfg(feature = "verbose")] println!("{:?}", journal.0); as_mut(journal.0).commit(); } } } #[inline] /// Clears the logs /// /// If the transaction is nested, it postpones the clear to the top most /// transaction. /// /// # Safety /// /// This function is for internal use and should not be called elsewhere. /// unsafe fn clear() { if let Some(journal) = Journal::<Self>::current(false) { journal.1 -= 1; if journal.1 == 0 { #[cfg(feature = "verbose")] println!("{:?}", journal.0); as_mut(journal.0).clear(); } } } #[inline] /// Discards all changes and clears the logs /// /// If the transaction is nested, it propagates the panic upto the top most /// transaction to make all of them tainted. /// /// # Safety /// /// This function is for internal use and should not be called elsewhere. /// unsafe fn rollback() { if let Some(journal) = Journal::<Self>::current(false) { journal.1 -= 1; if journal.1 == 0 { #[cfg(feature = "verbose")] println!("{:?}", journal.0); let journal = as_mut(journal.0); journal.rollback(); journal.clear(); } else { // Propagate the panic to the upper transactions panic!("Unsuccessful nested transaction"); } } } #[inline] /// Discards all changes without clearing the logs /// /// If the transaction is nested, it propagates the panic upto the top most /// transaction to make all of them tainted. /// /// # Safety /// /// This function is for internal use and should not be called elsewhere. /// unsafe fn rollback_no_clear() { if let Some(journal) = Journal::<Self>::current(false) { if journal.1 == 1 { #[cfg(feature = "verbose")] println!("{:?}", journal.0); as_mut(journal.0).rollback(); } else { // Propagate the panic to the upper transactions panic!("Unsuccessful nested transaction"); } } } /// Executes commands atomically /// /// The `transaction` function takes a closure with one argument of type /// `&Journal<Self>`. Before running the closure, it atomically creates a /// [`Journal`] object, if required, and prepares an immutable reference to /// it. Since there is no other safe way to create a `Journal` object, it /// ensures that every function taking an argument of type `&Journal<P>` is /// enforced to be invoked from a transaction. /// /// The captured types are bounded to be [`TxInSafe`], unless explicitly /// asserted otherwise using [`AssertTxInSafe`] type wrapper. This /// guarantees the volatile state consistency, as well as the persistent /// state. /// /// The returned type should be [`TxOutSafe`]. This prevents sending out /// unreachable persistent objects. The only way out of a transaction for /// a persistent object is to be reachable by the root object. /// /// # Examples /// /// ``` /// use crndm::default::*; /// /// type P = BuddyAlloc; /// /// let root = P::open::<PCell<i32>>("foo.pool", O_CF).unwrap(); /// /// let old = root.get(); /// let new = BuddyAlloc::transaction(|j| { /// root.set(root.get() + 1, j); /// root.get() /// }).unwrap(); /// /// assert_eq!(new, old + 1); /// ``` /// /// [`Journal`]: ../stm/journal/struct.Journal.html /// [`TxInSafe`]: ../trait.TxInSafe.html /// [`TxOutSafe`]: ../trait.TxOutSafe.html /// [`AssertTxInSafe`]: ../struct.AssertTxInSafe.html /// #[inline] fn transaction<T, F: FnOnce(&Journal<Self>) -> T>(body: F) -> Result<T> where F: TxInSafe + UnwindSafe, T: TxOutSafe, { let mut chaperoned = false; let cptr = &mut chaperoned as *mut bool; let res = std::panic::catch_unwind(move || { let chaperon = Chaperon::current(); if let Some(ptr) = chaperon { // FIXME: Chaperone session is corrupted. fix it. unsafe { *cptr = true; let mut chaperon = &mut *ptr; chaperon.postpone( &|| Self::commit_no_clear(), &|| Self::rollback_no_clear(), &|| Self::clear(), ); body({ let j = Journal::<Self>::current(true).unwrap(); j.1 += 1; let journal = as_mut(j.0); journal.start_session(&mut chaperon); journal.reset(JOURNAL_COMMITTED); journal }) } } else { body({ let j = Journal::<Self>::current(true).unwrap(); j.1 += 1; as_mut(j.0).reset(JOURNAL_COMMITTED); j.0 }) } }); unsafe { if let Ok(res) = res { if !chaperoned { Self::commit(); } Ok(res) } else { if !chaperoned { Self::rollback(); Err("Unsuccessful transaction".to_string()) } else { // Propagates the panic to the top level in enforce rollback panic!("Unsuccessful chaperoned transaction"); } } } } fn gen() -> u32 { 0 } /// Prints memory information fn print_info() {} #[cfg(feature = "capture_footprint")] fn footprint() -> usize { 0 } } pub(crate) fn create_file(filename: &str, size: u64) -> Result<()> { let file = OpenOptions::new().write(true).create(true).open(filename); if file.is_err() { Err(format!("{}", file.err().unwrap())) } else { if let Some(e) = file.unwrap().set_len(size).err() { Err(format!("{}", e)) } else { Ok(()) } } } #[cfg(test)] mod test { use crate::default::*; #[test] #[ignore] fn nested_transactions() { let _image = BuddyAlloc::open_no_root("nosb.pool", O_CFNE); if let Err(e) = BuddyAlloc::transaction(|_| { let _ = BuddyAlloc::transaction(|_| { let _ = BuddyAlloc::transaction(|_| { let _ = BuddyAlloc::transaction(|_| { println!("should print"); panic!("intentional"); }); println!("should not print"); }); println!("should not print"); }); println!("should not print"); }) { println!("Error: '{}'", e); } } }