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Commit 8fa98980 authored by j2-tulloch's avatar j2-tulloch :speech_balloon:
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Update 6 files 

- /Worksheet2/test3.cpp
- /Worksheet2/bumpall.hpp
- /Worksheet2/bumpalld.hpp
- /Worksheet2/test1.cpp
- /Worksheet2/test2.cpp
- /Worksheet2/readme.md
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Worksheet2/bumpall.hpp
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#include <cstddef>
#include <iostream>
//Print lines are commented out for speed when running the benchmark
class BumpAllocator {
......@@ -38,3 +39,5 @@ public:
//std::cout << "Memory block deallocated!" << std::endl;
}
};
// Reference OPENAI CHATGPT, 2023. ChatGPT response to James Tulloch, (personal communication, 10th December)
Worksheet2/bumpalld.hpp
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#include <iostream>
#include <cstddef>
//Print lines are commented out for speed when running the benchmark
class BumpAllocator {
char* start; // Pointer to the start of the allocated memory block
......@@ -38,3 +39,4 @@ public:
}
};
// Reference OPENAI CHATGPT, 2023. ChatGPT response to James Tulloch, (personal communication, 10th December)
\ No newline at end of file
Worksheet2/readme.md
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......@@ -4,96 +4,56 @@ James Tulloch - Student No: 21032766
## *Task 1*
*Implement a class which prints the following output.*
*Implement a bump allocator.*
**Output:**
> Hello world - String S is constructed and printed. \
> Hello world - New scope, T is asssigned as an object which is a copy of S.\
> Hello world - Prints the content of S again.\
> e - Gets the char at the index of [1] in S, which is 'e'. \
> Hello world - Prints the contents of S again.\
> Hello world - Prints the contents of T again.\
> HEllo world - S is modified so that the char at the index of [1] is now 'E'.
> [!To run this file:]
> clang++ filetest_string.cpp my_string.cpp
> ./a.out
**Description:**
The class my_string is correctly implemented and prints the ouput specified. It does so through using constructors, copy constructors and a destructor. It also has the functions get and set char, for the 4th line of output 'e' and the 7th line, where "Hello" is changed to be "HEllo"
The first implementation of the bump allocator is found in the bumpall.hpp file.
It correctly allocates the memory, stores its position and checks when allocating
if there is enough space left within the heap.
## *Task 2*
*Extend the programme to support automatic reference counting.*
**Output:**
>Hello world [1] - *One instance of S exists, reference count is 1.* \
>Hello world [2] - *Two references of S now exist, with T being a \copy of S. The reference count is now 2.* \
>Hello world [2] - *S is printed, there are still two objects which refer to the contents of S.* \
>e - *No reference is printed because a specific index of s, [1], is being called instead of the object.* \
>Hello world [2] - *S is printed again, the objects refering to its content are still 2. \*
>Hello world [2]- T is printed again, the the objects refering to the content of S are still 2.
>HEllo world [1] - T is now out of scope, and S[1] is modified to be 'E' instead of 'e'. There is now only one reference to the contents of S.
*Unit tests*
> [!To run this file:]
> clang++ filetest_string.cpp my_string.cpp
> ./a.out
Implemented three tests, output show below. The first test file tests that memory is correctly
allocated and that the bump allocator performs as expected. The second file
**Description:**
The reference counting is implemented in the my_string class, with a pointer called "reference_count". This pointer keeps track of how many instances of the object are in existence, when they are constructed or destroyed.
**Output:**
## *Task 3*
>Test case 1: Create an allocator and allocate some memory
>Allocation of 50 bytes succeeded.
*Extend the programme to demonstrate a reference count of 0.*
>Test case 2: Attempt to allocate more than remaining space
>Allocation of 60 bytes failed as expected.
**Output:**
>Test case 3: Allocate remaining space
>Allocation of remaining 50 bytes succeeded.
>Hello world [1] \
>Hello world [2] \
>Hello world [2] \
>e \
>Hello world [2] \
>Hello world [2] \
>HEllo world [1] \
>Reference count is now 0, freeing memory. - *Once the final object of S is destroyed, the memory is freed using 'nullptr', setting its value to 0.*
>Test case 4: Reset the allocator and allocate again
>Allocation of 100 bytes after reset succeeded.
> [!To run this file:]
>
> clang++ -o task3 filetest_string.cpp my_string.cpp
>
> ./task3
> clang++ test1.cpp -o test1
> ./test1
**Description:**
The implementation deletes the pointer to the reference count using "nullptr" when the destructor is called. This returns the memory used to null or 0.
## *Task 4*
Implements four test cases:
* Allocating 50 bytes of 100 bytes available.
* Allocating 60 bytes to overflow the allocator.
* Allocating the further 50 bytes available.
* Resetting the allocator and allocating 100 bytes again.
Extend the example so reference counting is in a template rather than the "my_string" class.
**Output:**
## *Task 3*
>Hello world [1] \
>Hello world [2] \
>Hello world [2] \
>e \
>Hello world [2] \
>Hello world [2] \
>HEllo world [2] - *The output is the same as task 2, despite the template being called and instead of using "ref_count" from within the class.* \
*Reverse the bump allocators direction and benchmark both implementations*
The direction of the bump allocator is reversed by switching the direction which
the "allocator" function uses and initialising its pointer at the end of the block of memory.
> [!To run this file:]
> clang++ -o task4 filetest_string.cpp my_string.cpp
>
> ./task4
**Description:**
When running the benchmark, you can comment out the different header files to switch between
them.
The class RefCount is implemented in the header file refcount.hpp. This file contains the functionality of task 3's "refcount" implementation inside of the "my_string" class and creates it as a template.
As expected the downwards facing bump allocator is much faster than upwards.
Worksheet2/test1.cpp
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......@@ -36,3 +36,5 @@ int main() {
return 0;
}
// Reference OPENAI CHATGPT, 2023. ChatGPT response to James Tulloch, (personal communication, 10th December)
\ No newline at end of file
Worksheet2/test2.cpp
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#include <chrono>
#include <iostream>
#include <cstddef>
#include "bumpalld.hpp" // Include the BumpAllocator class definition
// Simple Test Framework
#define TEST_MESSAGE(condition, message) \
if (!(condition)) { \
std::cout << "Test failed: " << message << std::endl; \
return 1; \
} \
else { \
std::cout << "Test passed: " << #condition << std::endl; \
}
#include "bumpalld.hpp"
//#include "bumpall.hpp" // Remove and comment the above to compare the compile times
int BumpTest() {
std::cout << "Running BumpTest..." << std::endl;
BumpAllocator bumper(20 * sizeof(int)); // Create an allocator with space for 20 integers
void benchmarkBumpAllocator() {
const size_t blockSize = 1000000; // Size of the memory block
BumpAllocator allocator(blockSize);
int *x = static_cast<int*>(bumper.allocate(10 * sizeof(int))); // Allocate space for 10 integers
TEST_MESSAGE(x != nullptr, "Failed to allocate 10 integers");
// Example allocation/deallocation operations
for (int i = 0; i < 10000; ++i) {
allocator.allocate(100); // Allocate 100 bytes
allocator.reset(); // Reset the allocator for the next iteration
}
}
int *y = static_cast<int*>(bumper.allocate(10 * sizeof(int))); // Allocate space for another 10 integers
TEST_MESSAGE(y != nullptr, "Failed to allocate another 10 integers");
int main() {
using std::chrono::high_resolution_clock;
using std::chrono::duration_cast;
using std::chrono::duration;
using std::chrono::milliseconds;
int *z = static_cast<int*>(bumper.allocate(10 * sizeof(int))); // Try to allocate space for 10 more integers
TEST_MESSAGE(z == nullptr, "Should have failed to allocate 10 more integers");
auto t1 = high_resolution_clock::now();
benchmarkBumpAllocator();
auto t2 = high_resolution_clock::now();
return 0; // Return 0 to indicate success
}
auto ms_int = duration_cast<milliseconds>(t2 - t1);
duration<double, std::milli> ms_double = t2 - t1;
int main() {
int result = BumpTest();
if (result != 0) {
std::cerr << "Some tests failed." << std::endl;
return 1;
}
std::cout << "All tests passed!" << std::endl;
std::cout << ms_int.count() << "ms\n";
std::cout << ms_double.count() << "ms\n";
return 0;
}
// Reference OPENAI CHATGPT, 2023. ChatGPT response to James Tulloch, (personal communication, 10th December)
\ No newline at end of file
Worksheet2/test3.cpp deleted 100644 → 0
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#include <chrono>
#include <iostream>
#include "bumpalld.hpp"
//#include "bumpall.hpp" // Remove and comment the above to compare the compile times
void benchmarkBumpAllocator() {
const size_t blockSize = 1000000; // Size of the memory block
BumpAllocator allocator(blockSize);
// Example allocation/deallocation operations
for (int i = 0; i < 10000; ++i) {
allocator.allocate(100); // Allocate 100 bytes
allocator.reset(); // Reset the allocator for the next iteration
}
}
int main() {
using std::chrono::high_resolution_clock;
using std::chrono::duration_cast;
using std::chrono::duration;
using std::chrono::milliseconds;
auto t1 = high_resolution_clock::now();
benchmarkBumpAllocator();
auto t2 = high_resolution_clock::now();
auto ms_int = duration_cast<milliseconds>(t2 - t1);
duration<double, std::milli> ms_double = t2 - t1;
std::cout << ms_int.count() << "ms\n";
std::cout << ms_double.count() << "ms\n";
return 0;
}
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