Flag inner Thread methods for JDK 19 and greater (#395)

Since JDK19, java.lang.Thread's methods have changed to support virtual threads. Specifically, for non-virtual threads, sleep(long) invokes sleep0(long) and yield() invokes yield0(). Moreover, since JDK21, sleep(long, int) and sleep(Duration) directly call sleep0(long) as opposed to sleep(long). Now, to identify all blocking java.lang.Thread calls, BlockHound will flag invocations of sleep0(long) and yield0() as opposed to sleep(long) and yield() when running on JDK19 or greater. Fixes #394.
reactor · Feb 6, 2024 · 882a753 · 882a753
1 parent 5581929
commit 882a753
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Showing 3 changed files with 20 additions and 9 deletions.
diff --git a/agent/src/main/java/reactor/blockhound/BlockHound.java b/agent/src/main/java/reactor/blockhound/BlockHound.java
@@ -134,12 +134,6 @@ public TypePool typePool(ClassFileLocator classFileLocator, ClassLoader classLoa
     public static class Builder {
 
         private final Map<String, Map<String, Set<String>>> blockingMethods = new HashMap<String, Map<String, Set<String>>>() {{
-            put("java/lang/Thread", new HashMap<String, Set<String>>() {{
-                put("sleep", singleton("(J)V"));
-                put("yield", singleton("()V"));
-                put("onSpinWait", singleton("()V"));
-            }});
-
             put("java/lang/Object", new HashMap<String, Set<String>>() {{
                 put("wait", singleton("(J)V"));
             }});
@@ -219,6 +213,23 @@ public static class Builder {
                     put("forkAndExec", singleton("(I[B[B[BI[BI[B[IZ)I"));
                 }});
             }
+
+            try {
+                // Check if Java 19+
+                Class.forName("java.lang.WrongThreadException");
+
+                put("java/lang/Thread", new HashMap<String, Set<String>>() {{
+                    put("sleep0", singleton("(J)V"));
+                    put("yield0", singleton("()V"));
+                    put("onSpinWait", singleton("()V"));
+                }});
+            } catch (ClassNotFoundException __) {
+                put("java/lang/Thread", new HashMap<String, Set<String>>() {{
+                    put("sleep", singleton("(J)V"));
+                    put("yield", singleton("()V"));
+                    put("onSpinWait", singleton("()V"));
+                }});
+            }
         }};
 
         private final Map<String, Map<String, Boolean>> allowances = new HashMap<String, Map<String, Boolean>>() {{

diff --git a/example/src/test/java/com/example/BlockingDisallowTest.java b/example/src/test/java/com/example/BlockingDisallowTest.java
@@ -58,7 +58,7 @@ public void shouldDisallow() throws InterruptedException {
         //given the configuration we expect that Thread.yield() is allowed, but Thread.sleep() inside inner() isn't
         assertThat(boeRef.get())
                 .isNotNull()
-                .hasMessage("Blocking call! java.lang.Thread.sleep")
+                .hasMessageContaining("Blocking call! java.lang.Thread.sleep")
                 .hasStackTraceContaining("at com.example.BlockingDisallowTest$NonBlockingClass.inner")
                 .hasStackTraceContaining("at com.example.BlockingDisallowTest$NonBlockingClass.outer");
     }

diff --git a/example/src/test/java/com/example/ReactorTest.java b/example/src/test/java/com/example/ReactorTest.java
@@ -124,14 +124,14 @@ public static Iterable<Object[]> data() {
             });
         });
 
-        tests.put("java.lang.Thread.sleep", () -> {
+        tests.put("java.lang.Thread." + (version.feature() >= 19 ? "sleep0" : "sleep"), () -> {
             return Mono.fromCallable(() -> {
                 Thread.sleep(10);
                 return "";
             });
         });
 
-        tests.put("java.lang.Thread.yield", () -> {
+        tests.put("java.lang.Thread." + (version.feature() >= 19 ? "yield0" : "yield"), () -> {
             return Mono.fromCallable(() -> {
                 Thread.yield();
                 return "";