hardware devices: run all device communication on dedicated thread (#6561)

hidapi/libusb etc are not thread-safe.

related: #6554

electrum/plugins/coldcard/coldcard.py

@@ -10,7 +10,7 @@ import struct
 from electrum import bip32
 from electrum.bip32 import BIP32Node, InvalidMasterKeyVersionBytes
 from electrum.i18n import _
-from electrum.plugin import Device, hook
+from electrum.plugin import Device, hook, runs_in_hwd_thread
 from electrum.keystore import Hardware_KeyStore, KeyStoreWithMPK
 from electrum.transaction import PartialTransaction
 from electrum.wallet import Standard_Wallet, Multisig_Wallet, Abstract_Wallet
@@ -72,9 +72,8 @@ class CKCCClient(HardwareClientBase):
             self.dev = ElectrumColdcardDevice(dev_path, encrypt=True)
         else:
             # open the real HID device
-            with self.device_manager().hid_lock:
-                hd = hid.device(path=dev_path)
-                hd.open_path(dev_path)
+            hd = hid.device(path=dev_path)
+            hd.open_path(dev_path)
 
             self.dev = ElectrumColdcardDevice(dev=hd, encrypt=True)
 
@@ -85,6 +84,7 @@ class CKCCClient(HardwareClientBase):
         return '<CKCCClient: xfp=%s label=%r>' % (xfp2str(self.dev.master_fingerprint),
                                                         self.label())
 
+    @runs_in_hwd_thread
     def verify_connection(self, expected_xfp: int, expected_xpub=None):
         ex = (expected_xfp, expected_xpub)
 
@@ -121,14 +121,10 @@ class CKCCClient(HardwareClientBase):
         # can't do anything w/ devices that aren't setup (this code not normally reachable)
         return bool(self.dev.master_xpub)
 
-    def timeout(self, cutoff):
-        # nothing to do?
-        pass
-
+    @runs_in_hwd_thread
     def close(self):
         # close the HID device (so can be reused)
-        with self.device_manager().hid_lock:
-            self.dev.close()
+        self.dev.close()
         self.dev = None
 
     def is_initialized(self):
@@ -160,6 +156,7 @@ class CKCCClient(HardwareClientBase):
 
         return LabelStr(lab, self.dev.master_fingerprint, self.dev.master_xpub)
 
+    @runs_in_hwd_thread
     def has_usable_connection_with_device(self):
         # Do end-to-end ping test
         try:
@@ -168,6 +165,7 @@ class CKCCClient(HardwareClientBase):
         except:
             return False
 
+    @runs_in_hwd_thread
     def get_xpub(self, bip32_path, xtype):
         assert xtype in ColdcardPlugin.SUPPORTED_XTYPES
         _logger.info('Derive xtype = %r' % xtype)
@@ -183,6 +181,7 @@ class CKCCClient(HardwareClientBase):
             xpub = node._replace(xtype=xtype).to_xpub()
         return xpub
 
+    @runs_in_hwd_thread
     def ping_check(self):
         # check connection is working
         assert self.dev.session_key, 'not encrypted?'
@@ -193,26 +192,32 @@ class CKCCClient(HardwareClientBase):
         except:
             raise RuntimeError("Communication trouble with Coldcard")
 
+    @runs_in_hwd_thread
     def show_address(self, path, addr_fmt):
         # prompt user w/ address, also returns it immediately.
         return self.dev.send_recv(CCProtocolPacker.show_address(path, addr_fmt), timeout=None)
 
+    @runs_in_hwd_thread
     def show_p2sh_address(self, *args, **kws):
         # prompt user w/ p2sh address, also returns it immediately.
         return self.dev.send_recv(CCProtocolPacker.show_p2sh_address(*args, **kws), timeout=None)
 
+    @runs_in_hwd_thread
     def get_version(self):
         # gives list of strings
         return self.dev.send_recv(CCProtocolPacker.version(), timeout=1000).split('\n')
 
+    @runs_in_hwd_thread
     def sign_message_start(self, path, msg):
         # this starts the UX experience.
         self.dev.send_recv(CCProtocolPacker.sign_message(msg, path), timeout=None)
 
+    @runs_in_hwd_thread
     def sign_message_poll(self):
         # poll device... if user has approved, will get tuple: (addr, sig) else None
         return self.dev.send_recv(CCProtocolPacker.get_signed_msg(), timeout=None)
 
+    @runs_in_hwd_thread
     def sign_transaction_start(self, raw_psbt: bytes, *, finalize: bool = False):
         # Multiple steps to sign:
         # - upload binary
@@ -228,10 +233,12 @@ class CKCCClient(HardwareClientBase):
         if resp != None:
             raise ValueError(resp)
 
+    @runs_in_hwd_thread
     def sign_transaction_poll(self):
         # poll device... if user has approved, will get tuple: (legnth, checksum) else None
         return self.dev.send_recv(CCProtocolPacker.get_signed_txn(), timeout=None)
 
+    @runs_in_hwd_thread
     def download_file(self, length, checksum, file_number=1):
         # get a file
         return self.dev.download_file(length, checksum, file_number=file_number)
@@ -317,7 +324,6 @@ class Coldcard_KeyStore(Hardware_KeyStore):
                                             % MSG_SIGNING_MAX_LENGTH)
             return b''
 
-        client = self.get_client()
         path = self.get_derivation_prefix() + ("/%d/%d" % sequence)
         try:
             cl = self.get_client()
@@ -508,6 +514,7 @@ class ColdcardPlugin(HW_PluginBase):
 
         return []
 
+    @runs_in_hwd_thread
     def create_client(self, device, handler):
         if handler:
             self.handler = handler
@@ -539,6 +546,7 @@ class ColdcardPlugin(HW_PluginBase):
         xpub = client.get_xpub(derivation, xtype)
         return xpub
 
+    @runs_in_hwd_thread
     def get_client(self, keystore, force_pair=True, *,
                    devices=None, allow_user_interaction=True) -> Optional['CKCCClient']:
         # Acquire a connection to the hardware device (via USB)