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tanya/middle/tanya/memory/allocator.d

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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* This module contains the interface for implementing custom allocators.
*
* Allocators are classes encapsulating memory allocation strategy. This allows
* to decouple memory management from the algorithms and the data.
*
* Copyright: Eugene Wissner 2016-2020.
* License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
* Mozilla Public License, v. 2.0).
* Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
* Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/middle/tanya/memory/allocator.d,
* tanya/memory/allocator.d)
*/
module tanya.memory.allocator;
import tanya.memory.lifetime;
import tanya.meta.trait;
/**
* Abstract class implementing a basic allocator.
*/
interface Allocator
{
/**
* Returns: Alignment offered.
*/
@property uint alignment() const shared pure nothrow @safe @nogc;
/**
* Allocates $(D_PARAM size) bytes of memory.
*
* Params:
* size = Amount of memory to allocate.
*
* Returns: Pointer to the new allocated memory.
*/
void[] allocate(size_t size) shared pure nothrow @nogc;
/**
* Deallocates a memory block.
*
* Params:
* p = A pointer to the memory block to be freed.
*
* Returns: Whether the deallocation was successful.
*/
bool deallocate(void[] p) shared pure nothrow @nogc;
/**
* Increases or decreases the size of a memory block.
*
* Params:
* p = A pointer to the memory block.
* size = Size of the reallocated block.
*
* Returns: Pointer to the allocated memory.
*/
bool reallocate(ref void[] p, size_t size) shared pure nothrow @nogc;
/**
* Reallocates a memory block in place if possible or returns
* $(D_KEYWORD false). This function cannot be used to allocate or
* deallocate memory, so if $(D_PARAM p) is $(D_KEYWORD null) or
* $(D_PARAM size) is `0`, it should return $(D_KEYWORD false).
*
* Params:
* p = A pointer to the memory block.
* size = Size of the reallocated block.
*
* Returns: $(D_KEYWORD true) if successful, $(D_KEYWORD false) otherwise.
*/
bool reallocateInPlace(ref void[] p, size_t size)
shared pure nothrow @nogc;
}
package template GetPureInstance(T : Allocator)
{
alias GetPureInstance = shared(T) function()
pure nothrow @nogc;
}
/**
* The mixin generates common methods for classes and structs using
* allocators. It provides a protected member, constructor and a read-only property,
* that checks if an allocator was already set and sets it to the default
* one, if not (useful for structs which don't have a default constructor).
*/
mixin template DefaultAllocator()
{
/// Allocator.
protected shared Allocator allocator_;
/**
* Params:
* allocator = The allocator should be used.
*
* Precondition: $(D_INLINECODE allocator_ !is null)
*/
this(shared Allocator allocator) @nogc nothrow pure @safe
in
{
assert(allocator !is null);
}
do
{
this.allocator_ = allocator;
}
/**
* This property checks if the allocator was set in the constructor
* and sets it to the default one, if not.
*
* Returns: Used allocator.
*
* Postcondition: $(D_INLINECODE allocator !is null)
*/
@property shared(Allocator) allocator() @nogc nothrow pure @safe
out (allocator)
{
assert(allocator !is null);
}
do
{
if (allocator_ is null)
{
allocator_ = defaultAllocator;
}
return allocator_;
}
/// ditto
@property shared(Allocator) allocator() const @nogc nothrow pure @trusted
out (allocator)
{
assert(allocator !is null);
}
do
{
if (allocator_ is null)
{
return defaultAllocator;
}
return cast(shared Allocator) allocator_;
}
}
shared Allocator allocator;
private shared(Allocator) getAllocatorInstance() @nogc nothrow
{
if (allocator is null)
{
version (TanyaNative)
{
import tanya.memory.mmappool : MmapPool;
defaultAllocator = MmapPool.instance;
}
else
{
import tanya.memory.mallocator : Mallocator;
defaultAllocator = Mallocator.instance;
}
}
return allocator;
}
/**
* Returns: Default allocator.
*
* Postcondition: $(D_INLINECODE allocator !is null).
*/
@property shared(Allocator) defaultAllocator() @nogc nothrow pure @trusted
out (allocator)
{
assert(allocator !is null);
}
do
{
return (cast(GetPureInstance!Allocator) &getAllocatorInstance)();
}
/**
* Sets the default allocator.
*
* Params:
* allocator = $(D_PSYMBOL Allocator) instance.
*
* Precondition: $(D_INLINECODE allocator !is null).
*/
@property void defaultAllocator(shared(Allocator) allocator) @nogc nothrow @safe
in
{
assert(allocator !is null);
}
do
{
.allocator = allocator;
}
/**
* Params:
* size = Raw size.
* alignment = Alignment.
*
* Returns: Aligned size.
*/
size_t alignedSize(const size_t size, const size_t alignment = 8)
pure nothrow @safe @nogc
{
return (size - 1) / alignment * alignment + alignment;
}
/**
* Error thrown if memory allocation fails.
*/
final class OutOfMemoryError : Error
{
/**
* Constructs new error.
*
* Params:
* msg = The message for the exception.
* file = The file where the exception occurred.
* line = The line number where the exception occurred.
* next = The previous exception in the chain of exceptions, if any.
*/
this(string msg = "Out of memory",
string file = __FILE__,
size_t line = __LINE__,
Throwable next = null) @nogc nothrow pure @safe
{
super(msg, file, line, next);
}
/// ditto
this(string msg,
Throwable next,
string file = __FILE__,
size_t line = __LINE__) @nogc nothrow pure @safe
{
super(msg, file, line, next);
}
}
/**
* Destroys and deallocates $(D_PARAM p) of type $(D_PARAM T).
* It is assumed the respective entities had been allocated with the same
* allocator.
*
* Params:
* T = Type of $(D_PARAM p).
* allocator = Allocator the $(D_PARAM p) was allocated with.
* p = Object or array to be destroyed.
*/
void dispose(T)(shared Allocator allocator, auto ref T p)
{
() @trusted { allocator.deallocate(finalize(p)); }();
p = null;
}
/**
* Constructs a new class instance of type $(D_PARAM T) using $(D_PARAM args)
* as the parameter list for the constructor of $(D_PARAM T).
*
* Params:
* T = Class type.
* A = Types of the arguments to the constructor of $(D_PARAM T).
* allocator = Allocator.
* args = Constructor arguments of $(D_PARAM T).
*
* Returns: Newly created $(D_PSYMBOL T).
*
* Precondition: $(D_INLINECODE allocator !is null)
*/
T make(T, A...)(shared Allocator allocator, auto ref A args)
if (is(T == class))
in
{
assert(allocator !is null);
}
do
{
auto mem = (() @trusted => allocator.allocate(stateSize!T))();
if (mem is null)
{
onOutOfMemoryError();
}
scope (failure)
{
() @trusted { allocator.deallocate(mem); }();
}
return emplace!T(mem[0 .. stateSize!T], args);
}
/**
* Constructs a value object of type $(D_PARAM T) using $(D_PARAM args)
* as the parameter list for the constructor of $(D_PARAM T) and returns a
* pointer to the new object.
*
* Params:
* T = Object type.
* A = Types of the arguments to the constructor of $(D_PARAM T).
* allocator = Allocator.
* args = Constructor arguments of $(D_PARAM T).
*
* Returns: Pointer to the created object.
*
* Precondition: $(D_INLINECODE allocator !is null)
*/
T* make(T, A...)(shared Allocator allocator, auto ref A args)
if (!isPolymorphicType!T && !isAssociativeArray!T && !isArray!T)
in
{
assert(allocator !is null);
}
do
{
auto mem = (() @trusted => allocator.allocate(stateSize!T))();
if (mem is null)
{
onOutOfMemoryError();
}
scope (failure)
{
() @trusted { allocator.deallocate(mem); }();
}
return emplace!T(mem[0 .. stateSize!T], args);
}
///
@nogc nothrow pure @safe unittest
{
int* i = defaultAllocator.make!int(5);
assert(*i == 5);
defaultAllocator.dispose(i);
}
/**
* Constructs a new array with $(D_PARAM n) elements.
*
* Params:
* T = Array type.
* E = Array element type.
* allocator = Allocator.
* n = Array size.
*
* Returns: Newly created array.
*
* Precondition: $(D_INLINECODE allocator !is null
* && n <= size_t.max / E.sizeof)
*/
T make(T : E[], E)(shared Allocator allocator, size_t n)
in
{
assert(allocator !is null);
assert(n <= size_t.max / E.sizeof);
}
do
{
auto ret = allocator.resize!E(null, n);
static if (hasElaborateDestructor!E)
{
for (auto range = ret; range.length != 0; range = range[1 .. $])
{
emplace!E(cast(void[]) range[0 .. 1], E.init);
}
}
else
{
ret[] = E.init;
}
return ret;
}
///
@nogc nothrow pure @safe unittest
{
int[] i = defaultAllocator.make!(int[])(2);
assert(i.length == 2);
assert(i[0] == int.init && i[1] == int.init);
defaultAllocator.dispose(i);
}
/*
* Destroys the object.
* Returns the memory should be freed.
*/
package void[] finalize(T)(ref T* p)
{
if (p is null)
{
return null;
}
static if (hasElaborateDestructor!T)
{
destroy(*p);
}
return (cast(void*) p)[0 .. T.sizeof];
}
package void[] finalize(T)(ref T p)
if (isPolymorphicType!T)
{
if (p is null)
{
return null;
}
static if (is(T == interface))
{
version(Windows)
{
import core.sys.windows.unknwn : IUnknown;
static assert(!is(T : IUnknown), "COM interfaces can't be destroyed in "
~ __PRETTY_FUNCTION__);
}
auto ob = cast(Object) p;
}
else
{
alias ob = p;
}
auto ptr = cast(void*) ob;
auto support = ptr[0 .. typeid(ob).initializer.length];
auto ppv = cast(void**) ptr;
if (!*ppv)
{
return null;
}
auto pc = cast(ClassInfo*) *ppv;
scope (exit)
{
*ppv = null;
}
auto c = *pc;
do
{
// Assume the destructor is @nogc. Leave it nothrow since the destructor
// shouldn't throw and if it does, it is an error anyway.
if (c.destructor)
{
alias DtorType = void function(Object) pure nothrow @safe @nogc;
(cast(DtorType) c.destructor)(ob);
}
}
while ((c = c.base) !is null);
if (ppv[1]) // if monitor is not null
{
_d_monitordelete(cast(Object) ptr, true);
}
return support;
}
package void[] finalize(T)(ref T[] p)
{
destroyAllImpl!(T[], T)(p);
return p;
}
/**
* Allocates $(D_PSYMBOL OutOfMemoryError) in a static storage and throws it.
*
* Params:
* msg = Custom error message.
*
* Throws: $(D_PSYMBOL OutOfMemoryError).
*/
void onOutOfMemoryError(string msg = "Out of memory")
@nogc nothrow pure @trusted
{
static ubyte[stateSize!OutOfMemoryError] memory;
alias PureType = OutOfMemoryError function(string) @nogc nothrow pure;
throw (cast(PureType) () => emplace!OutOfMemoryError(memory))(msg);
}
// From druntime
extern (C)
private void _d_monitordelete(Object h, bool det) @nogc nothrow pure;
/*
* Internal function used to create, resize or destroy a dynamic array. It
* may throw $(D_PSYMBOL OutOfMemoryError). The new
* allocated part of the array isn't initialized. This function can be trusted
* only in the data structures that can ensure that the array is
* allocated/rellocated/deallocated with the same allocator.
*
* Params:
* T = Element type of the array being created.
* allocator = The allocator used for getting memory.
* array = A reference to the array being changed.
* length = New array length.
*
* Returns: $(D_PARAM array).
*/
package(tanya) T[] resize(T)(shared Allocator allocator,
auto ref T[] array,
const size_t length) @trusted
{
if (length == 0)
{
if (allocator.deallocate(array))
{
return null;
}
else
{
onOutOfMemoryError();
}
}
void[] buf = array;
if (!allocator.reallocate(buf, length * T.sizeof))
{
onOutOfMemoryError();
}
// Casting from void[] is unsafe, but we know we cast to the original type.
array = cast(T[]) buf;
return array;
}