update.

README.md

@@ -8,6 +8,21 @@
 ./gradlew build 
 ```
 
+## Example
+
+We provide an example application in the `integration-tests/src/main/java/example/FrayExample.java`. You may run the following command to build it:
+
+```bash
+mkdir out
+javac integration-tests/src/main/java/example/FrayExample.java -d out
+```
+
+You can run the program with regular Java command 
+```
+java -ea -cp ./out/ example.FrayExample
+```
+In the most cases, the program will show an `AssertionError`.
+
 ## Run Fray
 
 ### Push-button Testing
@@ -18,7 +33,7 @@ The easiest way to run Fray is to replace `java` with `fray` in your command lin
 ./bin/fray -cp ./out/ example.FrayExample
 ```
 
-Fray will run the application with a random scheduler and print the following error:
+Fray will run the application with a random scheduler. Dependening on the schedule you may either see a `DeadlockException`:
 
 ```
 Error found: cmu.pasta.fray.runtime.DeadlockException
@@ -48,24 +63,34 @@ Stacktrace:
         at example.FrayExample.run(FrayExample.java:12)
 ```
 
-And you may find the recorded schedule in the `/tmp/report/` directory.
-
-To replay a schedule, you may run the following command:
-
-[//]: # (```bash)
-
-[//]: # (./bin/fray -cp ./out/ example.FrayExample -scheduler replay -path /tmp/report/schedule_XXX.json)
-
-[//]: # (```)
+Or an `AssertionError`:
 
+```
+Error found: java.lang.reflect.InvocationTargetException
+java.lang.reflect.InvocationTargetException
+        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:118)
+        at java.base/java.lang.reflect.Method.invoke(Method.java:580)
+        at cmu.pasta.fray.core.command.MethodExecutor.execute(Executor.kt:50)
+        at cmu.pasta.fray.core.TestRunner.run(TestRunner.kt:44)
+        at cmu.pasta.fray.core.MainKt.main(Main.kt:9)
+Caused by: java.lang.AssertionError
+        at example.FrayExample.main(FrayExample.java:25)
+        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
+        ... 4 more
+```
 
+And you may find the recorded schedule in the `/tmp/report/` directory.
 
+To replay a schedule, you may run the following command:
 
+```bash
+./bin/fray -cp ./out/ example.FrayExample --replay /tmp/report/schedule_0.json
+```
 
 
-### Application Configuration
+### Customized Fray Configuration
 
-First you need to provide a configuration file for the application you want to test. The configuration file should be in the following format:
+You may also choose to provide a configuration file for the application you want to test. The configuration file should be in the following format:
 
 ```json
 {
@@ -95,8 +120,6 @@ First you need to provide a configuration file for the application you want to t
 - `max_scheduled_step`: the maximum number of scheduled steps. And Fray will throw `LivenessException` if the number of scheduled steps exceeds this value. If the value is -1, then there is no limit.
 
 
-### Fray Configuration
-
 You may use the following gradle task to run Fray:
 
 ```bash
@@ -124,28 +147,24 @@ Options:
   -h, --help               Show this message and exit
 ```
 
-### Output 
+#### Output 
 
 The output of Fray will be saved in the `output` directory. The output directory contains the following files:
 
 - `output.txt`: the Fray of the testing.
 - `schedule_{id}.json/csv`: the schedule you can replay.
 
-## Replay a buggy schedule
+#### Replay a buggy schedule
 
 Once Fray finds a bug as indicated in `output.txt`. You may replay it by providing the corresponding schedule.
 
 ```bash
 ./gradlew runFray -PconfigPath=path/to/your/application_config.json -PextraArgs="--scheduler=replay --path=path/to/schedule.json"
 ```
 
-## Example
-
-We provide an example application in the `integration-tests/src/main/java/example/FrayExample.java`. You may run the following command to test it:
+#### Example
 
 ```bash
-mkdir out
-javac integration-tests/src/main/java/example/FrayExample.java -d out
 echo '{
   "executor": {
     "clazz": "example.FrayExample",
@@ -162,9 +181,6 @@ echo '{
 ./gradlew runFray -PconfigPath="out/config.json" -PextraArgs="--iter=1000 --logger=json --scheduler=random -o=/tmp/fray-example/"
 ```
 
-And you may see a failure `AssertionError` or `DeadlockException` in stdout. In `/tmp/report/`, you will see one schedule is 
-saved which will lead to the failure.
-
 To replay that schedule, you may run the following command:
 
 ```bash

bin/fray.template

@@ -27,6 +27,7 @@ def main():
         class_path = class_path + ":" + args.class_path
     command = [
         JAVA_PATH,
+        "-ea",
         "-cp", class_path,
         "-agentpath:" + JVMTI_PATH,
         "-javaagent:" + AGENT_PATH,