diff --git a/app/src/main/assets/data/common/tooling-api-all.jar b/app/src/main/assets/data/common/tooling-api-all.jar
index 5ff75a6be..fc4aeab37 100644
Binary files a/app/src/main/assets/data/common/tooling-api-all.jar and b/app/src/main/assets/data/common/tooling-api-all.jar differ
diff --git a/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/JavaLSPTest.kt b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/JavaLSPTest.kt
index 113682c7f..66a22e126 100644
--- a/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/JavaLSPTest.kt
+++ b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/JavaLSPTest.kt
@@ -20,6 +20,7 @@ package com.itsaky.androidide.lsp.java
 import com.itsaky.androidide.lsp.api.ILanguageServerRegistry
 import com.itsaky.androidide.lsp.api.LSPTest
 import com.itsaky.androidide.lsp.java.actions.AddImportTester
+import com.itsaky.androidide.lsp.java.compiler.CompilerTest
 import com.itsaky.androidide.lsp.java.compiler.JavaCompilerService
 import com.itsaky.androidide.lsp.java.partial.PartialReparserImplTester
 import com.itsaky.androidide.lsp.java.providers.JavaCompletionProviderTester
@@ -59,6 +60,7 @@ open class JavaLSPTest : LSPTest() {
 
   @Test
   override fun test() {
+    CompilerTest().test()
     AddImportTester().test()
     PartialReparserImplTester().test()
     JavaCompletionProviderTester().test()
diff --git a/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/actions/AddImportTester.kt b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/actions/AddImportTester.kt
index 8a69e982b..4b02ba18c 100644
--- a/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/actions/AddImportTester.kt
+++ b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/actions/AddImportTester.kt
@@ -33,9 +33,12 @@ class AddImportTester : JavaLSPTest() {
     openFile("AddImportAction")
 
     val diagnostic =
-      server.analyze(file!!).diagnostics.first { it.code == "compiler.err.cant.resolve.location" }
+      server.analyze(file!!).diagnostics.firstOrNull { it.code == "compiler.err.cant.resolve.location" }
+    
+    assertThat(diagnostic).isNotNull()
+    
     val file = this.file!!.toFile()
-    val data = createActionData(diagnostic, file, this.file!!, this.server)
+    val data = createActionData(diagnostic!!, file, this.file!!, this.server)
 
     val action = AddImportAction()
     action.prepare(data)
diff --git a/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/compiler/CompilerTest.kt b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/compiler/CompilerTest.kt
new file mode 100644
index 000000000..ab3d4260f
--- /dev/null
+++ b/lsp/java/src/test/java/com/itsaky/androidide/lsp/java/compiler/CompilerTest.kt
@@ -0,0 +1,98 @@
+/*
+ *  This file is part of AndroidIDE.
+ *
+ *  AndroidIDE is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  AndroidIDE is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.itsaky.androidide.lsp.java.compiler
+
+import com.google.common.truth.Truth.assertThat
+import com.itsaky.androidide.lsp.java.JavaLSPTest
+import java.time.Instant
+
+/** @author Akash Yadav */
+class CompilerTest : JavaLSPTest() {
+
+  override fun test() {
+    testConcurrentAccess()
+    testClosedFileChannel()
+    testMultipleThreads()
+  }
+  
+  private fun testMultipleThreads() {
+    openFile("completion/MembersCompletionTest")
+    val threads = mutableListOf<Thread>()
+    val thread = Thread {
+      getCompiler().compile(file!!).run {
+        println(Thread.currentThread().name)
+        delay(1000)
+      }
+    }
+    thread.name = "Long running task"
+    threads.add(thread)
+    thread.start()
+    
+    for (i in 0..300) {
+      val th = Thread {
+        getCompiler().compile(file!!).run {
+          println(Thread.currentThread().name)
+        }
+      }
+      th.name = "Thread #$i"
+      threads.add(th)
+      th.start()
+    }
+    
+    threads.forEach { it.join() }
+  }
+  
+  private fun testClosedFileChannel() {
+    openFile("completion/MembersCompletionTest")
+
+    Thread { getCompiler().compile(file!!).run { delay(500) } }.start()
+    Thread { getCompiler().compile(file!!).run { delay(200) } }.start()
+
+    getCompiler().compile(file!!).run { assertThat(it.diagnostics).isNotEmpty() }
+  }
+
+  private fun delay(millis: Long) {
+    Thread.sleep(millis)
+  }
+
+  private fun testConcurrentAccess() {
+    openFile("completion/MembersCompletionTest")
+
+    var task = getCompiler().compile(file!!)
+    var fileObject = SourceFileObject(file!!)
+    val threads = mutableListOf<Thread>()
+    for (i in 1..10) {
+      threads.add(
+        Thread {
+            task.run {
+              delay(100)
+              println(Thread.currentThread())
+            }
+          }
+          .apply { name = "CompileTask Acessor #$i" }
+      )
+    }
+
+    fileObject = SourceFileObject(file!!, fileObject.contents, Instant.now())
+    task = getCompiler().compile(listOf(fileObject))
+    threads.forEach { it.start() }
+    
+    Thread { task.run { println("Writer thread") } }.start()
+    threads.forEach { it.join() }
+  }
+}
diff --git a/tests/test-home/.androidide/init/model.jar b/tests/test-home/.androidide/init/model.jar
index 5991dba6c..e10bcdcf9 100644
Binary files a/tests/test-home/.androidide/init/model.jar and b/tests/test-home/.androidide/init/model.jar differ