基于反馈(feed back)排队算法的cpu调度的模拟实现
时间: 2023-09-09 10:02:16 浏览: 71
反馈排队算法是一种多级反馈队列调度算法,用于模拟CPU的调度。在这种算法中,进程被分为多个队列,每个队列有不同的优先级。进程在第一个队列中运行,如果没有完成,就会加入到下一个队列,以此类推,直到完成或达到最后一个队列。
模拟实现这个算法的关键是设计队列和调度策略。我们可以使用一个列表来表示每个队列,并使用一个指针来追踪当前正在运行的进程。当一个进程执行一段时间后,如果没有完成,将该进程移到下一个更低优先级的队列。如果所有队列都没有运行的进程,会将指针重置到第一个队列。
为了模拟进程的执行和调度,可以使用一个循环来模拟时间的流逝。在每个循环中,当前正在运行的进程将执行一小段时间,并根据其状态来确定下一步的操作。如果进程已经完成,可以将其从队列中移除。如果进程需要进行IO操作或等待资源,可以将其移到下一个队列。如果没有进程正在运行,可以从第一个队列选择一个进程来执行。
除了基本的实现,我们还可以添加一些优化策略,如提高优先级、动态调整时间片等,以提高调度效率和公平性。此外,我们还可以使用一些指标来评估算法的性能,如平均等待时间、响应时间等。
总之,基于反馈排队算法的CPU调度的模拟实现主要涉及对队列和调度策略的设计,并通过循环来模拟进程的执行和调度。这是一个复杂但重要的问题,涉及到操作系统和计算机体系结构领域的知识。
相关问题
基于百度飞浆的InfoGAN算法实现
InfoGAN是一种生成式对抗网络(GAN)的变体,它利用信息理论来学习数据的隐含表示。InfoGAN同时学习了生成器和判别器,以及一组连续和离散变量,这些变量用于控制生成器生成的图像的特征。在这个项目中,我们将使用百度飞浆实现InfoGAN算法。
首先,我们需要导入必要的库和模块:
```
import paddle
import paddle.fluid as fluid
import numpy as np
import os
import matplotlib.pyplot as plt
```
接下来,我们定义一些常量和超参数:
```
BATCH_SIZE = 128
EPOCH_NUM = 50
NOISE_DIM = 62
CAT_DIM = 10
CONT_DIM = 2
LR = 0.0002
BETA1 = 0.5
BETA2 = 0.999
```
其中,BATCH_SIZE是批大小,EPOCH_NUM是训练轮数,NOISE_DIM是噪声维度,CAT_DIM是离散变量的数量,CONT_DIM是连续变量的数量,LR是学习率,BETA1和BETA2是Adam优化器的超参数。
接下来,我们定义生成器和判别器网络:
```
def generator(noise, cat, cont):
noise_cat_cont = fluid.layers.concat([noise, cat, cont], axis=1)
fc1 = fluid.layers.fc(noise_cat_cont, size=1024)
bn1 = fluid.layers.batch_norm(fc1, act='relu')
fc2 = fluid.layers.fc(bn1, size=128 * 7 * 7)
bn2 = fluid.layers.batch_norm(fc2, act='relu')
reshape = fluid.layers.reshape(bn2, shape=(-1, 128, 7, 7))
conv1 = fluid.layers.conv2d_transpose(reshape, num_filters=64, filter_size=4, stride=2, padding=1)
bn3 = fluid.layers.batch_norm(conv1, act='relu')
conv2 = fluid.layers.conv2d_transpose(bn3, num_filters=1, filter_size=4, stride=2, padding=1, act='sigmoid')
return conv2
def discriminator(img, cat, cont):
conv1 = fluid.layers.conv2d(img, num_filters=64, filter_size=4, stride=2, padding=1, act='leaky_relu')
conv2 = fluid.layers.conv2d(conv1, num_filters=128, filter_size=4, stride=2, padding=1, act='leaky_relu')
reshape = fluid.layers.reshape(conv2, shape=(-1, 128 * 7 * 7))
cat_cont = fluid.layers.concat([cat, cont], axis=1)
cat_cont_expand = fluid.layers.expand(cat_cont, expand_times=(0, 128 * 7 * 7))
concat = fluid.layers.concat([reshape, cat_cont_expand], axis=1)
fc1 = fluid.layers.fc(concat, size=1024, act='leaky_relu')
fc2 = fluid.layers.fc(fc1, size=1)
return fc2
```
在生成器中,我们将噪声、离散变量和连续变量连接起来,经过两个全连接层和两个反卷积层后生成图像。在判别器中,我们将图像、离散变量和连续变量连接起来,经过两个卷积层和两个全连接层后输出判别结果。
接下来,我们定义损失函数和优化器:
```
noise = fluid.layers.data(name='noise', shape=[NOISE_DIM], dtype='float32')
cat = fluid.layers.data(name='cat', shape=[CAT_DIM], dtype='int64')
cont = fluid.layers.data(name='cont', shape=[CONT_DIM], dtype='float32')
real_img = fluid.layers.data(name='real_img', shape=[1, 28, 28], dtype='float32')
fake_img = generator(noise, cat, cont)
d_real = discriminator(real_img, cat, cont)
d_fake = discriminator(fake_img, cat, cont)
loss_d_real = fluid.layers.sigmoid_cross_entropy_with_logits(d_real, fluid.layers.fill_constant_batch_size_like(d_real, shape=[BATCH_SIZE, 1], value=1.0))
loss_d_fake = fluid.layers.sigmoid_cross_entropy_with_logits(d_fake, fluid.layers.fill_constant_batch_size_like(d_fake, shape=[BATCH_SIZE, 1], value=0.0))
loss_d = fluid.layers.mean(loss_d_real + loss_d_fake)
loss_g_fake = fluid.layers.sigmoid_cross_entropy_with_logits(d_fake, fluid.layers.fill_constant_batch_size_like(d_fake, shape=[BATCH_SIZE, 1], value=1.0))
loss_g = fluid.layers.mean(loss_g_fake)
opt_d = fluid.optimizer.Adam(learning_rate=LR, beta1=BETA1, beta2=BETA2)
opt_g = fluid.optimizer.Adam(learning_rate=LR, beta1=BETA1, beta2=BETA2)
opt_d.minimize(loss_d)
opt_g.minimize(loss_g)
```
在损失函数中,我们使用二元交叉熵损失函数,其中对于判别器,真实图像的标签为1,生成图像的标签为0;对于生成器,生成图像的标签为1。我们使用Adam优化器来训练模型。
接下来,我们定义训练过程:
```
train_reader = paddle.batch(
paddle.reader.shuffle(
paddle.dataset.mnist.train(), buf_size=500
),
batch_size=BATCH_SIZE
)
place = fluid.CUDAPlace(0) if fluid.core.is_compiled_with_cuda() else fluid.CPUPlace()
exe = fluid.Executor(place)
exe.run(fluid.default_startup_program())
for epoch_id in range(EPOCH_NUM):
for batch_id, data in enumerate(train_reader()):
noise_data = np.random.uniform(-1.0, 1.0, size=[BATCH_SIZE, NOISE_DIM]).astype('float32')
cat_data = np.random.randint(low=0, high=10, size=[BATCH_SIZE, CAT_DIM]).astype('int64')
cont_data = np.random.uniform(-1.0, 1.0, size=[BATCH_SIZE, CONT_DIM]).astype('float32')
real_img_data = np.array([x[0].reshape([1, 28, 28]) for x in data]).astype('float32')
d_loss, g_loss = exe.run(
fluid.default_main_program(),
feed={'noise': noise_data, 'cat': cat_data, 'cont': cont_data, 'real_img': real_img_data},
fetch_list=[loss_d, loss_g]
)
if batch_id % 100 == 0:
print("Epoch %d, Batch %d, D Loss: %f, G Loss: %f" % (epoch_id, batch_id, d_loss[0], g_loss[0]))
if batch_id % 500 == 0:
fake_img_data = exe.run(
fluid.default_main_program(),
feed={'noise': noise_data[:16], 'cat': cat_data[:16], 'cont': cont_data[:16]},
fetch_list=[fake_img]
)[0]
fig, axes = plt.subplots(nrows=4, ncols=4, figsize=(8, 8))
for i, ax in enumerate(axes.flatten()):
img = fake_img_data[i][0]
ax.imshow(img, cmap='gray')
ax.axis('off')
plt.show()
```
我们使用MNIST数据集进行训练,每次迭代从数据集中随机采样一个批次的数据。在每个迭代中,我们生成噪声、离散变量和连续变量,使用生成器生成图像,并对生成的图像和真实图像进行判别。根据损失函数计算判别器和生成器的损失,并使用Adam优化器更新网络参数。
每训练500个批次,我们使用生成器生成16张图像进行可视化。最后,我们输出生成的图像和训练过程中的损失。
完整代码如下:
python实现transformer算法
Transformer算法是一种用于自然语言处理和机器翻译等任务的重要模型。它由Google在2017年提出,并在机器翻译任务中取得了显著的成果。下面是Python实现Transformer算法的一般步骤:
1. 导入必要的库:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
```
2. 定义Transformer模型的基本组件,包括自注意力机制(self-attention)、前馈神经网络(feed-forward network)和残差连接(residual connection):
```python
class SelfAttention(nn.Module):
def __init__(self, d_model, n_heads):
super(SelfAttention, self).__init__()
self.d_model = d_model
self.n_heads = n_heads
self.head_dim = d_model // n_heads
self.query = nn.Linear(d_model, d_model)
self.key = nn.Linear(d_model, d_model)
self.value = nn.Linear(d_model, d_model)
def forward(self, x):
batch_size = x.shape
q = self.query(x)
k = self.key(x)
v = self.value(x)
q = q.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
k = k.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
v = v.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
scores = torch.matmul(q, k.transpose(-2, -1)) / torch.sqrt(torch.tensor(self.head_dim, dtype=torch.float32))
attention_weights = F.softmax(scores, dim=-1)
x = torch.matmul(attention_weights, v)
x = x.transpose(1, 2).contiguous().view(batch_size, -1, self.d_model)
return x
class FeedForward(nn.Module):
def __init__(self, d_model, d_ff):
super(FeedForward, self).__init__()
self.linear1 = nn.Linear(d_model, d_ff)
self.linear2 = nn.Linear(d_ff, d_model)
def forward(self, x):
x = F.relu(self.linear1(x))
x = self.linear2(x)
return x
class ResidualConnection(nn.Module):
def __init__(self, d_model, dropout_rate):
super(ResidualConnection, self).__init__()
self.dropout = nn.Dropout(dropout_rate)
self.layer_norm = nn.LayerNorm(d_model)
def forward(self, x, sublayer):
return x + self.dropout(sublayer(self.layer_norm(x)))
```
3. 定义Transformer模型的编码器和解码器:
```python
class EncoderLayer(nn.Module):
def __init__(self, d_model, n_heads, d_ff, dropout_rate):
super(EncoderLayer, self).__init__()
self.self_attention = SelfAttention(d_model, n_heads)
self.feed_forward = FeedForward(d_model, d_ff)
self.residual_connection = ResidualConnection(d_model, dropout_rate)
def forward(self, x):
x = self.residual_connection(x, lambda x: self.self_attention(x))
x = self.residual_connection(x, lambda x: self.feed_forward(x))
return x
class Encoder(nn.Module):
def __init__(self, d_model, n_heads, d_ff, dropout_rate, n_layers):
super(Encoder, self).__init__()
self.layers = nn.ModuleList([EncoderLayer(d_model, n_heads, d_ff, dropout_rate) for _ in range(n_layers)])
def forward(self, x):
for layer in self.layers:
x = layer(x)
return x
class DecoderLayer(nn.Module):
def __init__(self, d_model, n_heads, d_ff, dropout_rate):
super(DecoderLayer, self).__init__()
self.self_attention = SelfAttention(d_model, n_heads)
self.encoder_attention = SelfAttention(d_model, n_heads)
self.feed_forward = FeedForward(d_model, d_ff)
self.residual_connection = ResidualConnection(d_model, dropout_rate)
def forward(self, x, encoder_output):
x = self.residual_connection(x, lambda x: self.self_attention(x))
x = self.residual_connection(x, lambda x: self.encoder_attention(x))
x = self.residual_connection(x, lambda x: self.feed_forward(x))
return x
class Decoder(nn.Module):
def __init__(self, d_model, n_heads, d_ff, dropout_rate, n_layers):
super(Decoder, self).__init__()
self.layers = nn.ModuleList([DecoderLayer(d_model, n_heads, d_ff, dropout_rate) for _ in range(n_layers)])
def forward(self, x, encoder_output):
for layer in self.layers:
x = layer(x, encoder_output)
return x
```
4. 定义Transformer模型:
```python
class Transformer(nn.Module):
def __init__(self, src_vocab_size, tgt_vocab_size, d_model, n_heads, d_ff, dropout_rate, n_layers):
super(Transformer, self).__init__()
self.encoder = Encoder(d_model, n_heads, d_ff, dropout_rate, n_layers)
self.decoder = Decoder(d_model, n_heads, d_ff, dropout_rate, n_layers)
self.src_embedding = nn.Embedding(src_vocab_size, d_model)
self.tgt_embedding = nn.Embedding(tgt_vocab_size, d_model)
self.fc = nn.Linear(d_model, tgt_vocab_size)
def forward(self, src_input, tgt_input):
src_embedded = self.src_embedding(src_input)
tgt_embedded = self.tgt_embedding(tgt_input)
encoder_output = self.encoder(src_embedded)
decoder_output = self.decoder(tgt_embedded, encoder_output)
output = self.fc(decoder_output)
return output
```
以上是一个简单的Python实现Transformer算法的示例。你可以根据具体任务的需求进行修改和扩展。如果你有任何问题,请随时提问。
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