Fix global writer usage in utils.py

Remove global variable `writer` and initialize `writer` directly in `write_metric` function across multiple files.

* **AggregatorBasedWorkflow/101_torch_cnn_mnist/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **AggregatorBasedWorkflow/102_aggregator_validation/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **AggregatorBasedWorkflow/104_keras_mnist/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **AggregatorBasedWorkflow/301_torch_cnn_mnist_watermarking/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **AggregatorBasedWorkflow/501_pytorch_tinyimagenet_transfer_learning/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **AggregatorBasedWorkflow/vertical_fl_two_party/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **torch_cnn_mnist/src/utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **torch_cnn_mnist_eden_compression/src/mnist_utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **torch_cnn_mnist_fed_eval/src/mnist_utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **torch_cnn_mnist_straggler_check/src/mnist_utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

* **torch_llm_horovod/src/emotion_utils.py**
  - Remove global variable `writer`
  - Remove `get_writer` function
  - Initialize `writer` directly in `write_metric` function

---

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openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/101_torch_cnn_mnist/src/utils.py

@@ -4,17 +4,7 @@
 from torch.utils.tensorboard import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/102_aggregator_validation/src/utils.py

@@ -4,17 +4,7 @@
 from torch.utils.tensorboard import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/104_keras_mnist/src/utils.py

@@ -4,17 +4,7 @@
 from tensorflow.summary import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/301_torch_cnn_mnist_watermarking/src/utils.py

@@ -6,17 +6,7 @@
 from torch.utils.tensorboard import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/501_pytorch_tinyimagenet_transfer_learning/src/utils.py

@@ -4,17 +4,7 @@
 from torch.utils.tensorboard import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/experimental/workflow/AggregatorBasedWorkflow/vertical_fl_two_party/src/utils.py

@@ -4,17 +4,7 @@
 from torch.utils.tensorboard import SummaryWriter
 
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
-
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/torch_cnn_mnist/src/utils.py

@@ -5,17 +5,8 @@
 
 from torch.utils.tensorboard import SummaryWriter
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
 
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)

openfl-workspace/torch_cnn_mnist_eden_compression/src/mnist_utils.py

@@ -12,19 +12,10 @@
 
 logger = getLogger(__name__)
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
 
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)
 
 

openfl-workspace/torch_cnn_mnist_fed_eval/src/mnist_utils.py

@@ -12,19 +12,10 @@
 
 logger = getLogger(__name__)
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
 
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)
 
 

openfl-workspace/torch_cnn_mnist_straggler_check/src/mnist_utils.py

@@ -12,19 +12,10 @@
 
 logger = getLogger(__name__)
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
-
 
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter('./logs/cnn_mnist', flush_secs=5)
     writer.add_scalar(f'{node_name}/{task_name}/{metric_name}', metric, round_number)
 
 

openfl-workspace/torch_llm_horovod/src/emotion_utils.py

@@ -11,19 +11,10 @@
 
 logger = getLogger(__name__)
 
-writer = None
-
-
-def get_writer():
-    """Create global writer object."""
-    global writer
-    if not writer:
-        writer = SummaryWriter("./logs/llm", flush_secs=5)
-
 
 def write_metric(node_name, task_name, metric_name, metric, round_number):
     """Write metric callback."""
-    get_writer()
+    writer = SummaryWriter("./logs/llm", flush_secs=5)
     writer.add_scalar(f"{node_name}/{task_name}/{metric_name}", metric, round_number)