diff --git a/.idea/misc.xml b/.idea/misc.xml
index 28a804d8932aba40f168fd757a74cb718a955a1a..74c8fa57e34b84e28aebd7f20c1c7e0355cf35af 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -3,4 +3,5 @@
   <component name="JavaScriptSettings">
     <option name="languageLevel" value="ES6" />
   </component>
+  <component name="ProjectRootManager" version="2" project-jdk-name="11" project-jdk-type="JavaSDK" />
 </project>
\ No newline at end of file
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index aee8ccae86726e88b14f7c04c74e0ff00d325433..fbc77d681b5353ef3515234ea96e41556c2afb93 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -2,8 +2,13 @@
 <project version="4">
   <component name="ChangeListManager">
     <list default="true" id="849f0ad2-7b24-4b58-93af-d82b889f0304" name="Default Changelist" comment="">
+      <change afterPath="$PROJECT_DIR$/second/week_02/73/AtomicInteger源码分析.md" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/second/week_02/73/AtomicStampedReference源码分析.md" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/second/week_02/73/Unsafe源码分析.md" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/misc.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
     </list>
+    <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
     <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
@@ -12,9 +17,101 @@
   <component name="DefaultGradleProjectSettings">
     <option name="isMigrated" value="true" />
   </component>
+  <component name="FileEditorManager">
+    <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/second/week_02/73/Unsafe源码分析.md">
+          <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+            <state split_layout="SPLIT">
+              <first_editor relative-caret-position="30">
+                <caret line="2" column="16" selection-start-line="2" selection-start-column="16" selection-end-line="2" selection-end-column="16" />
+                <folding>
+                  <element signature="e#799#800#0" expanded="true" />
+                  <element signature="e#829#830#0" expanded="true" />
+                  <element signature="e#855#856#0" expanded="true" />
+                  <element signature="e#881#882#0" expanded="true" />
+                </folding>
+              </first_editor>
+              <second_editor />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/second/week_02/73/AtomicInteger源码分析.md">
+          <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+            <state split_layout="SPLIT">
+              <first_editor relative-caret-position="15">
+                <caret line="1" selection-start-line="1" selection-end-line="1" />
+              </first_editor>
+              <second_editor />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/first/week_02/44/AtomicStampedReference.md">
+          <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+            <state split_layout="SPLIT">
+              <first_editor relative-caret-position="900">
+                <caret line="113" selection-start-line="23" selection-end-line="113" />
+              </first_editor>
+              <second_editor />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/second/week_02/73/AtomicStampedReference源码分析.md">
+          <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+            <state split_layout="SPLIT">
+              <first_editor relative-caret-position="1365">
+                <caret line="91" selection-start-line="91" selection-end-line="91" />
+              </first_editor>
+              <second_editor />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="true">
+        <entry file="file://$APPLICATION_CONFIG_DIR$/scratches/scratch.java">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="30">
+              <caret line="2" column="8" selection-start-line="2" selection-start-column="8" selection-end-line="2" selection-end-column="8" />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/first/week_02/61/AtomicStampedReference.md">
+          <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+            <state split_layout="SPLIT">
+              <first_editor relative-caret-position="-195" />
+              <second_editor />
+            </state>
+          </provider>
+        </entry>
+      </file>
+    </leaf>
+  </component>
+  <component name="FindInProjectRecents">
+    <findStrings>
+      <find>&lt;/code&gt;</find>
+    </findStrings>
+  </component>
   <component name="Git.Settings">
     <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
   </component>
+  <component name="IdeDocumentHistory">
+    <option name="CHANGED_PATHS">
+      <list>
+        <option value="$PROJECT_DIR$/second/week_02/73/Unsafe源码分析.md" />
+        <option value="$PROJECT_DIR$/second/week_02/73/AtomicInteger源码分析.md" />
+        <option value="$PROJECT_DIR$/second/week_02/73/AtomicStampedReference源码分析.md" />
+        <option value="$PROJECT_DIR$/second/week_02/73/Demo.java" />
+      </list>
+    </option>
+  </component>
   <component name="JsFlowSettings">
     <service-enabled>true</service-enabled>
     <exe-path />
@@ -37,7 +134,81 @@
   <component name="MavenRunner">
     <option name="jreName" value="1.8" />
   </component>
+  <component name="ProjectFrameBounds" extendedState="6" fullScreen="true">
+    <option name="x" value="210" />
+    <option name="y" value="131" />
+    <option name="width" value="1260" />
+    <option name="height" value="788" />
+  </component>
   <component name="ProjectId" id="1W0KnGQQ4lLywjMN8yfRPmdRp8q" />
+  <component name="ProjectLevelVcsManager">
+    <ConfirmationsSetting value="2" id="Add" />
+  </component>
+  <component name="ProjectView">
+    <navigator proportions="" version="1">
+      <foldersAlwaysOnTop value="true" />
+    </navigator>
+    <panes>
+      <pane id="Scope" />
+      <pane id="PackagesPane" />
+      <pane id="ProjectPane">
+        <subPane>
+          <expand>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="first" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="first" type="462c0819:PsiDirectoryNode" />
+              <item name="week_02" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="first" type="462c0819:PsiDirectoryNode" />
+              <item name="week_02" type="462c0819:PsiDirectoryNode" />
+              <item name="28" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="second" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="second" type="462c0819:PsiDirectoryNode" />
+              <item name="week_02" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="JavaStudy" type="462c0819:PsiDirectoryNode" />
+              <item name="second" type="462c0819:PsiDirectoryNode" />
+              <item name="week_02" type="462c0819:PsiDirectoryNode" />
+              <item name="73" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="Scratches and Consoles" type="1a2a3e82:ScratchProjectViewPane$MyProjectNode" />
+            </path>
+            <path>
+              <item name="JavaStudy" type="b2602c69:ProjectViewProjectNode" />
+              <item name="Scratches and Consoles" type="1a2a3e82:ScratchProjectViewPane$MyProjectNode" />
+              <item name="Scratches" type="d62648e6:ScratchProjectViewPane$MyRootNode" />
+            </path>
+          </expand>
+          <select />
+        </subPane>
+      </pane>
+    </panes>
+  </component>
   <component name="ProjectViewState">
     <option name="hideEmptyMiddlePackages" value="true" />
     <option name="showExcludedFiles" value="true" />
@@ -50,7 +221,8 @@
     <property name="WebServerToolWindowFactoryState" value="false" />
     <property name="aspect.path.notification.shown" value="true" />
     <property name="com.android.tools.idea.instantapp.provision.ProvisionBeforeRunTaskProvider.myTimeStamp" value="1577631985552" />
-    <property name="last_opened_file_path" value="$PROJECT_DIR$" />
+    <property name="com.intellij.ide.scratch.LRUPopupBuilder$1/New Scratch File" value="JAVA" />
+    <property name="last_opened_file_path" value="$PROJECT_DIR$/second/week_01/73" />
     <property name="node.js.detected.package.eslint" value="true" />
     <property name="node.js.detected.package.tslint" value="true" />
     <property name="node.js.path.for.package.eslint" value="project" />
@@ -63,11 +235,24 @@
   </component>
   <component name="RecentsManager">
     <key name="CopyFile.RECENT_KEYS">
+      <recent name="$PROJECT_DIR$/second/week_01/73" />
       <recent name="D:\algorithm\JavaStudy" />
       <recent name="D:\algorithm\JavaStudy\week_01" />
       <recent name="D:\algorithm\JavaStudy\week_01\1" />
     </key>
   </component>
+  <component name="RunDashboard">
+    <option name="ruleStates">
+      <list>
+        <RuleState>
+          <option name="name" value="ConfigurationTypeDashboardGroupingRule" />
+        </RuleState>
+        <RuleState>
+          <option name="name" value="StatusDashboardGroupingRule" />
+        </RuleState>
+      </list>
+    </option>
+  </component>
   <component name="ServiceViewManager">
     <option name="viewStates">
       <list>
@@ -100,6 +285,7 @@
       <workItem from="1578919635767" duration="694000" />
       <workItem from="1579450587735" duration="274000" />
       <workItem from="1580545712385" duration="1022000" />
+      <workItem from="1584257542105" duration="2607000" />
     </task>
     <task id="LOCAL-00001" summary="目录创建">
       <created>1575879326719</created>
@@ -164,9 +350,54 @@
       <option name="project" value="LOCAL" />
       <updated>1580545769184</updated>
     </task>
-    <option name="localTasksCounter" value="10" />
+    <task id="LOCAL-00010" summary="073的第一周">
+      <created>1583661003613</created>
+      <option name="number" value="00010" />
+      <option name="presentableId" value="LOCAL-00010" />
+      <option name="project" value="LOCAL" />
+      <updated>1583661003613</updated>
+    </task>
+    <option name="localTasksCounter" value="11" />
     <servers />
   </component>
+  <component name="TimeTrackingManager">
+    <option name="totallyTimeSpent" value="3077000" />
+  </component>
+  <component name="ToolWindowManager">
+    <frame x="0" y="0" width="1680" height="1050" extended-state="6" />
+    <editor active="true" />
+    <layout>
+      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.26190478" />
+      <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
+      <window_info id="Image Layers" order="2" />
+      <window_info id="Designer" order="3" />
+      <window_info id="UI Designer" order="4" />
+      <window_info id="Capture Tool" order="5" />
+      <window_info id="Favorites" order="6" side_tool="true" />
+      <window_info anchor="bottom" id="Message" order="0" />
+      <window_info anchor="bottom" id="Find" order="1" />
+      <window_info anchor="bottom" id="Run" order="2" />
+      <window_info anchor="bottom" id="Debug" order="3" weight="0.4" />
+      <window_info anchor="bottom" id="Cvs" order="4" weight="0.25" />
+      <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
+      <window_info anchor="bottom" id="TODO" order="6" />
+      <window_info anchor="bottom" id="Docker" order="7" show_stripe_button="false" />
+      <window_info anchor="bottom" id="Version Control" order="8" />
+      <window_info anchor="bottom" id="Database Changes" order="9" />
+      <window_info anchor="bottom" id="Terminal" order="10" />
+      <window_info anchor="bottom" id="Event Log" order="11" side_tool="true" />
+      <window_info anchor="right" id="Commander" internal_type="SLIDING" order="0" type="SLIDING" weight="0.4" />
+      <window_info anchor="right" id="Ant Build" order="1" weight="0.25" />
+      <window_info anchor="right" content_ui="combo" id="Hierarchy" order="2" weight="0.25" />
+      <window_info anchor="right" id="Palette" order="3" />
+      <window_info anchor="right" id="Theme Preview" order="4" />
+      <window_info anchor="right" id="Maven" order="5" />
+      <window_info anchor="right" id="PlantUML" order="6" />
+      <window_info anchor="right" id="Capture Analysis" order="7" />
+      <window_info anchor="right" id="Palette&#9;" order="8" />
+      <window_info anchor="right" id="Database" order="9" />
+    </layout>
+  </component>
   <component name="TypeScriptGeneratedFilesManager">
     <option name="version" value="1" />
   </component>
@@ -179,7 +410,8 @@
     <MESSAGE value="059_week05_补充" />
     <MESSAGE value="059_week06" />
     <MESSAGE value="059_week06_增强任务及补充" />
-    <option name="LAST_COMMIT_MESSAGE" value="059_week06_增强任务及补充" />
+    <MESSAGE value="073的第一周" />
+    <option name="LAST_COMMIT_MESSAGE" value="073的第一周" />
   </component>
   <component name="WindowStateProjectService">
     <state x="385" y="10" key="CommitChangelistDialog2" timestamp="1580545767703">
@@ -199,6 +431,259 @@
     </state>
     <state x="461" y="241" key="com.intellij.ide.util.TipDialog/0.0.1536.824@0.0.1536.824" timestamp="1578708675877" />
   </component>
+  <component name="editorHistoryManager">
+    <entry file="file://$PROJECT_DIR$/first/week_01/22/ArrayList.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/22/LinkedList.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/20/ArrayList.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/22/AtomicInteger.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/25/AtomicStampReference.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/20/HashMap.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/12/HashMap1-012.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/12/ArrayList-012.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_01/12/HashMap2-012.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/second/week_01/73/ArrayList源码分析.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="240">
+            <caret line="16" selection-start-line="16" selection-end-line="16" selection-end-column="2" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/09/unsafe-009.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-1620" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/17/AtomicStampedReference">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="345">
+          <caret line="23" column="34" lean-forward="true" selection-start-line="23" selection-start-column="34" selection-end-line="23" selection-end-column="34" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/17/unsafe">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="-53" />
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/16/unsafe.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-660" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/15/Unsafe-015.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-6795" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/14/Unsafe.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-247" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/44/Unsafe.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-1221">
+            <folding>
+              <element signature="n#!!doc" expanded="true" />
+            </folding>
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/25/Unsafe_25.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="184">
+            <caret line="72" column="3" lean-forward="true" selection-start-line="42" selection-end-line="72" selection-end-column="3" />
+            <folding>
+              <element signature="e#0#236#0" expanded="true" />
+            </folding>
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/26/Unsafe-026.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="900">
+            <caret line="243" column="3" selection-start-line="33" selection-end-line="243" selection-end-column="3" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/35/AtomicInteger-035.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/28/AtomicInteger.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-1530" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/44/AtomicInteger.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="390">
+            <caret line="26" lean-forward="true" selection-start-line="26" selection-end-line="90" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/second/week_02/73/Unsafe源码分析.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="30">
+            <caret line="2" column="16" selection-start-line="2" selection-start-column="16" selection-end-line="2" selection-end-column="16" />
+            <folding>
+              <element signature="e#799#800#0" expanded="true" />
+              <element signature="e#829#830#0" expanded="true" />
+              <element signature="e#855#856#0" expanded="true" />
+              <element signature="e#881#882#0" expanded="true" />
+            </folding>
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/second/week_02/73/AtomicInteger源码分析.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="15">
+            <caret line="1" selection-start-line="1" selection-end-line="1" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/44/AtomicStampedReference.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="900">
+            <caret line="113" selection-start-line="23" selection-end-line="113" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/first/week_02/61/AtomicStampedReference.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="-195" />
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/second/week_02/73/Demo.java">
+      <provider selected="true" editor-type-id="text-editor" />
+    </entry>
+    <entry file="file://$PROJECT_DIR$/second/week_02/73/AtomicStampedReference源码分析.md">
+      <provider selected="true" editor-type-id="split-provider[text-editor;markdown-preview-editor]">
+        <state split_layout="SPLIT">
+          <first_editor relative-caret-position="1365">
+            <caret line="91" selection-start-line="91" selection-end-line="91" />
+          </first_editor>
+          <second_editor />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$APPLICATION_CONFIG_DIR$/scratches/scratch.java">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="30">
+          <caret line="2" column="8" selection-start-line="2" selection-start-column="8" selection-end-line="2" selection-end-column="8" />
+        </state>
+      </provider>
+    </entry>
+  </component>
   <component name="masterDetails">
     <states>
       <state key="ProjectJDKs.UI">
diff --git "a/second/week_02/73/AtomicInteger\346\272\220\347\240\201\345\210\206\346\236\220.md" "b/second/week_02/73/AtomicInteger\346\272\220\347\240\201\345\210\206\346\236\220.md"
new file mode 100644
index 0000000000000000000000000000000000000000..e5514b60f7fe453096d4c1b6d64c4e2b70226b13
--- /dev/null
+++ "b/second/week_02/73/AtomicInteger\346\272\220\347\240\201\345\210\206\346\236\220.md"
@@ -0,0 +1,96 @@
+## 关于AtomicInteger的随笔
+
+ 
+### 属性
+
+```java
+// 获取Unsafe实例    
+private static final Unsafe unsafe = Unsafe.getUnsafe();
+// 标识value字段的偏移量，用来寻找
+private static final long valueOffset;
+// 静态代码块，通过unsafe获取value的偏移量
+static {
+   try {
+       valueOffset = unsafe.objectFieldOffset
+           (AtomicInteger.class.getDeclaredField("value"));
+   } catch (Exception ex) { throw new Error(ex); }
+}
+
+// 存储int类型值的地方，使用volatile修饰
+private volatile int value;
+```
+
+（1）使用int类型的value存储值，且使用volatile修饰，volatile主要是保证可见性，即一个线程修改对另一个线程立即可见，主要的实现原理是内存屏障，这里不展开来讲，有兴趣的可以自行查阅相关资料。
+
+（2）调用Unsafe的objectFieldOffset()方法获取value字段在类中的偏移量，用于后面CAS操作时使用。
+
+### 方法
+
+#### 构造方法和没有使用cas的get和set方法
+
+```java
+    public AtomicInteger(int initialValue) {
+        value = initialValue;
+    }
+
+    public AtomicInteger() {
+    }
+
+	public final int get() {
+        return value;
+    }
+
+	public final void set(int newValue) {
+        value = newValue;
+    }
+```
+
+#### 通过Unsafe实现的set方法
+
+```java
+    // 调用putOrderedInt方法，有序写入，不保证原子性
+	public final void lazySet(int newValue) {
+        unsafe.putOrderedInt(this, valueOffset, newValue);
+    }
+    // 最终通过CAS方法赋值
+    public final int getAndSet(int newValue) {
+        return unsafe.getAndSetInt(this, valueOffset, newValue);
+    }
+    // 直接调用
+    public final boolean compareAndSet(int expect, int update) {
+        return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
+    }
+	// 没看出来和上一个语句的差别
+    public final boolean weakCompareAndSet(int expect, int update) {
+        return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
+    }
+```
+
+#### 自增自减以及加减的原子操作方法
+
+```java
+	// 自增1，调用unsafe的getAndAddInt方法，而unsafe中这个方法是调用CAS方法完成。返回未增加1时的值
+    public final int getAndIncrement() {
+        return unsafe.getAndAddInt(this, valueOffset, 1);
+    }
+    // 自减1，同上
+    public final int getAndDecrement() {
+        return unsafe.getAndAddInt(this, valueOffset, -1);
+    }
+    // 加上给定值，同上
+    public final int getAndAdd(int delta) {
+        return unsafe.getAndAddInt(this, valueOffset, delta);
+    }
+	// 自增1，返回加1后的值
+    public final int incrementAndGet() {
+        return unsafe.getAndAddInt(this, valueOffset, 1) + 1;
+    }
+    // 自减1，返回减1后的值
+    public final int decrementAndGet() {
+        return unsafe.getAndAddInt(this, valueOffset, -1) - 1;
+    }
+    // 加上一个值，返回操作后的值。
+    public final int addAndGet(int delta) {
+        return unsafe.getAndAddInt(this, valueOffset, delta) + delta;
+    }
+```
diff --git "a/second/week_02/73/AtomicStampedReference\346\272\220\347\240\201\345\210\206\346\236\220.md" "b/second/week_02/73/AtomicStampedReference\346\272\220\347\240\201\345\210\206\346\236\220.md"
new file mode 100644
index 0000000000000000000000000000000000000000..cf26a79c4361fb9bec2a167fc5805ec5ee47105a
--- /dev/null
+++ "b/second/week_02/73/AtomicStampedReference\346\272\220\347\240\201\345\210\206\346\236\220.md"
@@ -0,0 +1,92 @@
+## 关于AtomicStampedReference的随笔
+
+
+### 属性
+
+```java
+    // 内部定义类Pair<T>，两个属性，reference，stamp，将元素值和版本号绑定在一起
+    private static class Pair<T> {
+        final T reference;
+        final int stamp;
+        private Pair(T reference, int stamp) {
+            this.reference = reference;
+            this.stamp = stamp;
+        }
+        static <T> Pair<T> of(T reference, int stamp) {
+            return new Pair<T>(reference, stamp);
+        }
+    }    
+    // 声明一个Pair类型变量，在上面已经定义
+    private volatile Pair<V> pair;
+    // 获取Unsafe实例
+    private static final sun.misc.Unsafe UNSAFE = sun.misc.Unsafe.getUnsafe();
+    // 获取pair变量的偏移量，方便寻址
+    private static final long pairOffset =
+        objectFieldOffset(UNSAFE, "pair", AtomicStampedReference.class);          
+```
+
+### 方法
+
+#### 构造方法
+
+```java
+    public AtomicStampedReference(V initialRef, int initialStamp) {
+        pair = Pair.of(initialRef, initialStamp);
+    }
+```
+
+构造方法只有一个，需要传入两个参数，一个是初始值，一个是初始版本号。
+
+#### 普通get/set方法
+
+```java
+    // 返回值
+    public V getReference() {
+        return pair.reference;
+    }
+    // 返回版本号
+    public int getStamp() {
+        return pair.stamp;
+    }
+    // 返回值，参数接收版本号	
+    public V get(int[] stampHolder) {
+        Pair<V> pair = this.pair;
+        stampHolder[0] = pair.stamp;
+        return pair.reference;
+    }
+
+    public void set(V newReference, int newStamp) {
+        Pair<V> current = pair;
+        if (newReference != current.reference || newStamp != current.stamp)
+            this.pair = Pair.of(newReference, newStamp);
+    }
+```
+
+#### compareAndSet()方法
+
+```java
+    public boolean compareAndSet(V   expectedReference,
+                                 V   newReference,
+                                 int expectedStamp,
+                                 int newStamp) {
+        // 获取当前pair
+        Pair<V> current = pair;
+        return
+            // 判断当前reference有没有变化
+            expectedReference == current.reference &&
+            // 判断版本号有没有变化
+            expectedStamp == current.stamp &&
+            // 判断要更改的reference和版本号是否与当前的pair一致，是则不用更改，否则更新
+            ((newReference == current.reference &&
+              newStamp == current.stamp) ||
+             casPair(current, Pair.of(newReference, newStamp)));
+    }
+    
+    private boolean casPair(Pair<V> cmp, Pair<V> val) {
+        return UNSAFE.compareAndSwapObject(this, pairOffset, cmp, val);
+    }
+```
+
+调用了Unsafe类中的CAS方法，实现了原子操作，并通过版本号的引入克服了ABA问题。
+
+
diff --git "a/second/week_02/73/Unsafe\346\272\220\347\240\201\345\210\206\346\236\220.md" "b/second/week_02/73/Unsafe\346\272\220\347\240\201\345\210\206\346\236\220.md"
new file mode 100644
index 0000000000000000000000000000000000000000..c4e7844724b254ec21fb02db627a530eef96dbab
--- /dev/null
+++ "b/second/week_02/73/Unsafe\346\272\220\347\240\201\345\210\206\346\236\220.md"
@@ -0,0 +1,209 @@
+##关于Unsafe的随笔
+
+> Unsafe为我们提供了访问底层的机制，这种机制仅供java核心类库使用，而不应该被普通用户使用。
+
+> java是没有指针的，默认是由JVM进行内存的分配与垃圾回收，这时候就需要Unsafe类。UnSafe提供了硬件级别的原子操作，Unsafe类通过JNI的方式访问本地的C++实现库从而使java具有了直接操作内存空间的能力，但这同时也带来了一定的问题，如果不合理地使用Unsafe类操作内存空间，可能导致内存泄漏
+
+
+##1  获取Unsafe
+```Java
+@CallerSensitive
+public static Unsafe getUnsafe() {
+   Class<?> caller = Reflection.getCallerClass();
+   if (!VM.isSystemDomainLoader(caller.getClassLoader()))
+       throw new SecurityException("Unsafe");
+   return theUnsafe;
+}
+```
+#### Unsafe提供了一个静态方法getUnsafe()用于获取它的实例对象，但直接调用会抛出SecurityException异常，这是因为Unsafe只提供给Java核心类使用，那么可以通过反射获取它的实例：
+```Java
+public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException{
+        Field field = Unsafe.class.getDeclaredField("theUnsafe");//getField只能获取public属性
+        field.setAccessible(true);//关闭访问安全检查开关
+        Unsafe unsafe = (Unsafe) field.get(null);
+    }  
+```
+
+##2 使用Unsafe实例化一个类
+```java
+	//Unsafe通过一个native方法实现实例化一个类, 但是只会分配内存, 并不会调用该类的构造方法
+	public native Object allocateInstance(Class<?> var1) throws InstantiationException;
+```
+
+##3 修改私有字段的值
+使用Unsafe的putXXX()方法，我们可以修改任意私有字段的值。
+```java
+public class UnsafeTest {
+    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
+    	//获取unsafe实例
+        Field f = Unsafe.class.getDeclaredField("theUnsafe");
+        f.setAccessible(true);
+        Unsafe unsafe = (Unsafe) f.get(null);
+		//获取user实例, 并指定age = 19
+        User user = new User(19);
+        System.out.println(user.getAge());//19
+		//通过反射获取User.class的age属性
+        Field age = user.getClass().getDeclaredField("age");
+        //调用unsafe.putInt, 参数为: 指定对象, 偏移量, 修改后的值
+        //putInt方法通过获取user对象的起始地址, 加上objectFieldOffset()获取到的偏移值得到对应的update地址, 然后将20写入对应的update地址
+        unsafe.putInt(user, unsafe.objectFieldOffset(age), 20);
+        System.out.println(user.getAge());//20
+    }
+}
+
+class User {
+    private int age;
+
+    public User(int age) {
+        this.age = age;
+    }
+
+    public int getAge() {
+        return age;
+    }
+}
+```
+
+##4 Unsafe类
+ 
+ ```Java
+//下面是sun.misc.Unsafe.java类源码
+package sun.misc;
+import java.lang.reflect.Field;
+/***
+ * 这个类提供了一个更底层的操作并且应该在受信任的代码中使用。可以通过内存地址
+ * 存取fields,如果给出的内存地址是无效的那么会有一个不确定的运行表现。
+ */
+public class Unsafe
+{
+  private static Unsafe unsafe = new Unsafe();
+//使用私有默认构造器防止创建多个实例
+  private Unsafe()
+  {
+  }
+  /***
+   * 获取Unsafe的单例,这个方法调用应该防止在不可信的代码中实例，
+   * 因为unsafe类提供了一个低级别的操作，例如直接内存存取。
+   * 如果安全管理器不存在或者禁止访问系统属性
+   */
+  public static Unsafe getUnsafe()
+  {
+    SecurityManager sm = System.getSecurityManager();
+    if (sm != null)
+      sm.checkPropertiesAccess();
+    return unsafe;
+  }
+  
+  /***
+   * 返回指定静态field的内存地址偏移量,在这个类的其他方法中这个值只是被用作一个访问
+   * 特定field的一个方式。这个值对于 给定的field是唯一的，并且后续对该方法的调用都应该
+   * 返回相同的值。
+   */
+  public native long objectFieldOffset(Field field);
+  /***
+   * 在obj的offset位置比较integer field和期望的值，如果相同则更新。这个方法
+   * 的操作应该是原子的，因此提供了一种不可中断的方式更新integer field。
+   */
+  public native boolean compareAndSwapInt(Object obj, long offset,
+                                          int expect, int update);
+  /***
+   * 在obj的offset位置比较long field和期望的值，如果相同则更新。这个方法
+   * 的操作应该是原子的，因此提供了一种不可中断的方式更新long field。
+   */
+  public native boolean compareAndSwapLong(Object obj, long offset,
+                                           long expect, long update);
+  /***
+   * 在obj的offset位置比较object field和期望的值，如果相同则更新。这个方法
+   * 的操作应该是原子的，因此提供了一种不可中断的方式更新object field。
+   */
+  public native boolean compareAndSwapObject(Object obj, long offset,
+                                             Object expect, Object update);
+  /***
+   * 设置obj对象中offset偏移地址对应的整型field的值为指定值。这是一个有序或者
+   * 有延迟的putIntVolatile方法，并且不保证值的改变被其他线程立
+   * 即看到。只有在field被volatile修饰并且期望被意外修改的时候
+   * 使用才有用。
+   */
+  public native void putOrderedInt(Object obj, long offset, int value);
+  /***
+   * 设置obj对象中offset偏移地址对应的long型field的值为指定值。这是一个有序或者
+   * 有延迟的putLongVolatile方法，并且不保证值的改变被其他线程立
+   * 即看到。只有在field被volatile修饰并且期望被意外修改的时候
+   * 使用才有用。
+   */
+  public native void putOrderedLong(Object obj, long offset, long value);
+  /***
+   * 设置obj对象中offset偏移地址对应的object型field的值为指定值。这是一个有序或者
+   * 有延迟的putObjectVolatile方法，并且不保证值的改变被其他线程立
+   * 即看到。只有在field被volatile修饰并且期望被意外修改的时候
+   * 使用才有用。
+   */
+  public native void putOrderedObject(Object obj, long offset, Object value);
+  /***
+   * 设置obj对象中offset偏移地址对应的整型field的值为指定值。支持volatile store语义
+   */
+  public native void putIntVolatile(Object obj, long offset, int value);
+  /***
+   * 获取obj对象中offset偏移地址对应的整型field的值,支持volatile load语义。
+   */
+  public native int getIntVolatile(Object obj, long offset);
+  /***
+   * 设置obj对象中offset偏移地址对应的long型field的值为指定值。支持volatile store语义
+   */
+  public native void putLongVolatile(Object obj, long offset, long value);
+  /***
+   * 设置obj对象中offset偏移地址对应的long型field的值为指定值。
+   */
+  public native void putLong(Object obj, long offset, long value);
+  /***
+   * 获取obj对象中offset偏移地址对应的long型field的值,支持volatile load语义。
+   */
+  public native long getLongVolatile(Object obj, long offset);
+  /***
+   * 获取obj对象中offset偏移地址对应的long型field的值
+   */
+  public native long getLong(Object obj, long offset);
+  /***
+   * 设置obj对象中offset偏移地址对应的object型field的值为指定值。支持volatile store语义
+   */
+  public native void putObjectVolatile(Object obj, long offset, Object value);
+  /***
+   * 设置obj对象中offset偏移地址对应的object型field的值为指定值。
+   */
+  public native void putObject(Object obj, long offset, Object value);
+  /***
+   * 获取obj对象中offset偏移地址对应的object型field的值,支持volatile load语义。
+   */
+  public native Object getObjectVolatile(Object obj, long offset);
+  /***
+   * 获取给定数组中第一个元素的偏移地址。
+   * 为了存取数组中的元素，这个偏移地址与<a href="#arrayIndexScale">arrayIndexScale
+   * </a>方法的非0返回值一起被使用。
+   */
+  public native int arrayBaseOffset(Class arrayClass);
+  /***
+   * 获取用户给定数组寻址的换算因子.一个合适的换算因子不能返回的时候(例如：基本类型),
+   * 返回0.这个返回值能够与<a href="#arrayBaseOffset">arrayBaseOffset
+   * </a>一起使用去存取这个数组class中的元素
+   */
+  public native int arrayIndexScale(Class arrayClass);
+  
+  /***
+   * 释放被<a href="#park">park</a>创建的在一个线程上的阻塞.这个
+   * 方法也可以被使用来终止一个先前调用park导致的阻塞.
+   * 这个操作操作时不安全的,因此线程必须保证是活的.这是java代码不是native代码。
+   */
+  public native void unpark(Thread thread);
+  /***
+   * 阻塞一个线程直到<a href="#unpark">unpark</a>出现、线程
+   * 被中断或者timeout时间到期。如果一个unpark调用已经出现了，
+   * 这里只计数。timeout为0表示永不过期.当isAbsolute为true时，
+   * timeout是相对于新纪元之后的毫秒。否则这个值就是超时前的纳秒数。这个方法执行时
+   * 也可能不合理地返回(没有具体原因)
+   */
+  public native void park(boolean isAbsolute, long time);
+}
+```
+
+
+