Fix TCPStore type coercion (#49685)

Summary:
Fixes #49052

The TCPStore example with 4 arguments was working because the datetime value was being implicitly converted to a bool. Modified the pybind definition and updated documentation.

Pull Request resolved: #49685

Test Plan:
```
import torch.distributed as dist
from datetime import timedelta

dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
```

Now fails with
```
TypeError: __init__(): incompatible constructor arguments. The following argument types are supported:
    1. torch._C._distributed_c10d.TCPStore(host_name: str, port: int, world_size: int, is_master: bool, timeout: datetime.timedelta = datetime.timedelta(seconds=300))

Invoked with: '127.0.0.1', 0, True, datetime.timedelta(seconds=30)
```

Reviewed By: mrshenli, ngimel

Differential Revision: D25668021

Pulled By: H-Huang

fbshipit-source-id: ce40b8648d0a414f0255666fbc680f1a66fae090

torch/csrc/distributed/c10d/init.cpp

@@ -383,7 +383,8 @@ value with the new supplied ``value``.
 
 Example::
     >>> import torch.distributed as dist
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> from datetime import timedelta
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.set("first_key", "first_value")
     >>> # Should return "first_value"
     >>> store.get("first_key")
@@ -411,7 +412,8 @@ when initializing the store, before throwing an exception.
 
 Example::
     >>> import torch.distributed as dist
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> from datetime import timedelta
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.set("first_key", "first_value")
     >>> # Should return "first_value"
     >>> store.get("first_key")
@@ -434,8 +436,9 @@ in an exception.
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, other store types can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.add("first_key", 1)
     >>> store.add("first_key", 6)
     >>> # Should return 7
@@ -461,8 +464,9 @@ Deletes the key-value pair associated with ``key`` from the store. Returns
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, HashStore can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.set("first_key")
     >>> # This should return true
     >>> store.delete_key("first_key")
@@ -487,8 +491,9 @@ the workers using the store.
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, other store types can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.set("first_key", "first_value")
     >>> # This should return 2
     >>> store.num_keys()
@@ -506,8 +511,9 @@ Sets the store's default timeout. This timeout is used during initialization and
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, other store types can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> store.set_timeout(timedelta(seconds=10))
     >>> # This will throw an exception after 10 seconds
     >>> store.wait(["bad_key"])
@@ -528,8 +534,9 @@ will throw an exception.
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, other store types can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> # This will throw an exception after 30 seconds
     >>> store.wait(["bad_key"])
 )")
@@ -551,8 +558,9 @@ if the keys have not been set by the supplied ``timeout``.
 
 Example::
     >>> import torch.distributed as dist
+    >>> from datetime import timedelta
     >>> # Using TCPStore as an example, other store types can also be used
-    >>> store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
+    >>> store = dist.TCPStore("127.0.0.1", 0, 1, True, timedelta(seconds=30))
     >>> # This will throw an exception after 10 seconds
     >>> store.wait(["bad_key"], timedelta(seconds=10))
 )");
@@ -617,8 +625,11 @@ pair, :meth:`~torch.distributed.store.get` to retrieve a key-value pair, etc.
 
 Example::
     >>> import torch.distributed as dist
-    >>> server_store = dist.TCPStore("127.0.0.1", 0, True, timedelta(seconds=30))
-    >>> client_store = dist.TCPStore("127.0.0.1", 0, False)
+    >>> from datetime import timedelta
+    >>> # Run on process 1 (server)
+    >>> server_store = dist.TCPStore("127.0.0.1", 1234, 2, True, timedelta(seconds=30))
+    >>> # Run on process 2 (client)
+    >>> client_store = dist.TCPStore("127.0.0.1", 1234, 2, False)
     >>> # Use any of the store methods from either the client or server after initialization
     >>> server_store.set("first_key", "first_value")
     >>> client_store.get("first_key")
@@ -633,7 +644,9 @@ Example::
           py::arg("host_name"),
           py::arg("port"),
           py::arg("world_size"),
-          py::arg("is_master"),
+          // using noconvert() requires this argument to be True or False
+          // prevents accidental implicit conversion to bool
+          py::arg("is_master").noconvert(),
           py::arg("timeout") =
               std::chrono::milliseconds(::c10d::Store::kDefaultTimeout));