feat: support perf walltime in Java

src/executor/helpers/env.rs

@@ -29,6 +29,19 @@ pub fn get_base_injected_env(
                 "0".into()
             },
         ),
+        // Java: Enable frame pointers and perf map generation for flamegraph profiling.
+        // - UnlockDiagnosticVMOptions must come before DumpPerfMapAtExit (diagnostic option).
+        // - PreserveFramePointer: Preserves frame pointers for profiling.
+        // - DumpPerfMapAtExit: Writes /tmp/perf-<pid>.map on JVM exit for symbol resolution.
+        // - DebugNonSafepoints: Enables debug info for JIT-compiled non-safepoint code.
+        (
+            "JAVA_TOOL_OPTIONS",
+            if mode == RunnerMode::Walltime {
+                "-XX:+PreserveFramePointer -XX:+UnlockDiagnosticVMOptions -XX:+DumpPerfMapAtExit -XX:+DebugNonSafepoints".into()
+            } else {
+                "".into()
+            },
+        ),
         ("ARCH", ARCH.into()),
         ("CODSPEED_ENV", "runner".into()),
         (

src/executor/helpers/run_with_env.rs

@@ -54,7 +54,7 @@ fn create_env_file(extra_env: &HashMap<&'static str, String>) -> Result<NamedTem
     let system_env = get_exported_system_env()?;
     let base_injected_env = extra_env
         .iter()
-        .map(|(k, v)| format!("export {k}={v}"))
+        .map(|(k, v)| format!("export {k}='{v}'"))
         .collect::<Vec<_>>()
         .join("\n");
 

src/executor/wall_time/perf/mod.rs

@@ -96,6 +96,9 @@ impl PerfRunner {
         // Infer the unwinding mode from the benchmark cmd
         let (cg_mode, stack_size) = if let Some(mode) = config.perf_unwinding_mode {
             (mode, None)
+        } else if config.command.contains("gradle") | config.command.contains("java") | config.command.contains("maven") {
+            // In Java, we must use FP unwinding otherwise we'll have broken call stacks.
+            (UnwindingMode::FramePointer, None)
         } else if config.command.contains("cargo") {
             (UnwindingMode::Dwarf, None)
         } else if config.command.contains("pytest")
@@ -216,6 +219,16 @@ impl PerfRunner {
         let on_cmd = async |cmd: &FifoCommand| {
             #[allow(deprecated)]
             match cmd {
+                // Print /proc/{pid}/maps for the benchmark process. This helps with debugging missing symbols, as
+                // it allows finding the module in which an address is located.
+                FifoCommand::CurrentBenchmark { pid, .. } if is_codspeed_debug_enabled() => {
+                    let maps_path = format!("/proc/{pid}/maps");
+                    match std::fs::read_to_string(&maps_path) {
+                        Ok(maps) => debug!("/proc/{pid}/maps:\n{maps}"),
+                        Err(e) => debug!("Failed to read {maps_path}: {e}"),
+                    }
+                    return Ok(None);
+                }
                 FifoCommand::StartBenchmark => {
                     perf_fifo.start_events().await?;
                 }