使用首次适应算法改写class MemoryManager: def __init__(self, allocator): self.allocator = allocator def allocate(self, process, request_size): memory_view = self.allocator.memory_view() '''这里是写的''' # Find the best fit block for the process best_fit_block = None best_fit_size = float('inf') for i in range(len(memory_view)): if memory_view[i] is None: # Check if the block is free block_size = 0 j = i while j < len(memory_view) and memory_view[j] is None: block_size += 1 j += 1 if block_size >= request_size and block_size < best_fit_size: best_fit_block = i best_fit_size = block_size if best_fit_block is not None: # Allocate memory for the process block_start = best_fit_block self.allocator.allocate_memory(block_start, request_size, process) else: # No suitable block found, allocation failed raise AssertionError('allocation failed')

可以将首次适应算法改写成以下代码：

class MemoryManager:
    def __init__(self, allocator):
        self.allocator = allocator
        self.last_allocated = 0

    def allocate(self, process, request_size):
        memory_view = self.allocator.memory_view()
        # Find the best fit block for the process
        best_fit_block = None
        best_fit_size = float('inf')
        i = self.last_allocated
        while i < len(memory_view):
            if memory_view[i] is None:  # Check if the block is free
                block_size = 0
                j = i
                while j < len(memory_view) and memory_view[j] is None:
                    block_size += 1
                    j += 1
                if block_size >= request_size and block_size < best_fit_size:
                    best_fit_block = i
                    best_fit_size = block_size
            i += 1

        # If no block is found from last allocated position to end then search from beginning
        if best_fit_block is None:
            i = 0
            while i < self.last_allocated:
                if memory_view[i] is None:  # Check if the block is free
                    block_size = 0
                    j = i
                    while j < len(memory_view) and memory_view[j] is None:
                        block_size += 1
                        j += 1
                    if block_size >= request_size and block_size < best_fit_size:
                        best_fit_block = i
                        best_fit_size = block_size
                i += 1

        if best_fit_block is not None:
            # Allocate memory for the process
            block_start = best_fit_block
            self.allocator.allocate_memory(block_start, request_size, process)
            self.last_allocated = block_start + request_size
        else:
            # No suitable block found, allocation failed
            raise AssertionError('allocation failed')

这里的改动在于在 `allocate` 方法中加入了 `self.last_allocated` 变量，它表示上一次分配内存时的位置，从这个位置开始向后搜索空闲块，避免在整个内存中搜索。如果在搜索到结尾仍然没有找到适合的块，则从头开始搜索。