From 9fc05efed8744d1e782e5ef1e3b7a51966dc68f0 Mon Sep 17 00:00:00 2001
From: jiasli <4003950+jiasli@users.noreply.github.com>
Date: Thu, 18 Nov 2021 15:32:09 +0800
Subject: [PATCH 1/3] Use optimistic locking for service principal entry reads

---
 .../azure/cli/core/auth/persistence.py        | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/azure-cli-core/azure/cli/core/auth/persistence.py b/src/azure-cli-core/azure/cli/core/auth/persistence.py
index 6ebec24883f..5fb9a7bebe3 100644
--- a/src/azure-cli-core/azure/cli/core/auth/persistence.py
+++ b/src/azure-cli-core/azure/cli/core/auth/persistence.py
@@ -8,6 +8,7 @@
 
 import json
 import sys
+import time
 
 from msal_extensions import (FilePersistenceWithDataProtection, KeychainPersistence, LibsecretPersistence,
                              FilePersistence, PersistedTokenCache, CrossPlatLock)
@@ -60,13 +61,21 @@ def save(self, content):
         with CrossPlatLock(self._lock_file):
             self._persistence.save(json.dumps(content, indent=4))
 
+    def _load(self):
+        try:
+            return json.loads(self._persistence.load())
+        except PersistenceNotFound:
+            return []
+
     def load(self):
-        with CrossPlatLock(self._lock_file):
+        # Use optimistic locking rather than CrossPlatLock, so that multiple processes can
+        # read the same file at the same time.
+        retry = 3
+        for attempt in range(1, retry + 1):
             try:
-                return json.loads(self._persistence.load())
-            except PersistenceNotFound:
-                return []
-            except Exception as ex:
-                raise CLIError("Failed to load token files. If you can reproduce, please log an issue at "
-                               "https://github.com/Azure/azure-cli/issues. At the same time, you can clean "
-                               "up by running 'az account clear' and then 'az login'. (Inner Error: {})".format(ex))
+                return self._load()
+            except Exception:  # pylint: disable=broad-except
+                # Presumably other processes are writing the file, causing dirty read
+                logger.debug(f"Unable to load token cache file in No. {attempt} attempt")
+                time.sleep(0.5)
+        raise RuntimeError(f"Unable to load token cache file in {retry} attempts")

From c9a48e20f27fefe4cda6c56256bf5f997ee32136 Mon Sep 17 00:00:00 2001
From: jiasli <4003950+jiasli@users.noreply.github.com>
Date: Thu, 18 Nov 2021 17:07:19 +0800
Subject: [PATCH 2/3] linter

---
 src/azure-cli-core/azure/cli/core/auth/persistence.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/azure-cli-core/azure/cli/core/auth/persistence.py b/src/azure-cli-core/azure/cli/core/auth/persistence.py
index 5fb9a7bebe3..bf43c2b52a9 100644
--- a/src/azure-cli-core/azure/cli/core/auth/persistence.py
+++ b/src/azure-cli-core/azure/cli/core/auth/persistence.py
@@ -14,7 +14,6 @@
                              FilePersistence, PersistedTokenCache, CrossPlatLock)
 from msal_extensions.persistence import PersistenceNotFound
 
-from knack.util import CLIError
 from knack.log import get_logger
 
 logger = get_logger(__name__)
@@ -76,6 +75,6 @@ def load(self):
                 return self._load()
             except Exception:  # pylint: disable=broad-except
                 # Presumably other processes are writing the file, causing dirty read
-                logger.debug(f"Unable to load token cache file in No. {attempt} attempt")
+                logger.debug("Unable to load token cache file in No. %d attempt", attempt)
                 time.sleep(0.5)
         raise RuntimeError(f"Unable to load token cache file in {retry} attempts")

From fc955e7b6a7d5670b49205cd50f9fe9b53aef4f4 Mon Sep 17 00:00:00 2001
From: jiasli <4003950+jiasli@users.noreply.github.com>
Date: Mon, 6 Dec 2021 16:34:28 +0800
Subject: [PATCH 3/3] raise original error

---
 .../azure/cli/core/auth/persistence.py               | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/azure-cli-core/azure/cli/core/auth/persistence.py b/src/azure-cli-core/azure/cli/core/auth/persistence.py
index bf43c2b52a9..c22a2124f97 100644
--- a/src/azure-cli-core/azure/cli/core/auth/persistence.py
+++ b/src/azure-cli-core/azure/cli/core/auth/persistence.py
@@ -75,6 +75,12 @@ def load(self):
                 return self._load()
             except Exception:  # pylint: disable=broad-except
                 # Presumably other processes are writing the file, causing dirty read
-                logger.debug("Unable to load token cache file in No. %d attempt", attempt)
-                time.sleep(0.5)
-        raise RuntimeError(f"Unable to load token cache file in {retry} attempts")
+                if attempt < retry:
+                    logger.debug("Unable to load secret store in No. %d attempt", attempt)
+                    import traceback
+                    logger.debug(traceback.format_exc())
+                    time.sleep(0.5)
+                else:
+                    raise  # End of retry. Re-raise the exception as-is.
+
+        return []  # Not really reachable here. Just to keep pylint happy.