ART jitted code profiling support.

- Generate perf map for method level profiling.
- Generate jit dump for instruction level profiling.

Command line example of perf map approach:
$ perf record dalvikvm -Xcompiler-option -g -cp <classpath> MyClass
$ perf report

Command line example of perf jit dump approach:
$ perf record -k mono dalvikvm -Xcompiler-option -g -cp <classpath> MyClass
$ perf inject -i perf.data -o perf.data.jitted
$ perf report -i perf.data.jitted
$ perf annotate -i perf.data.jitted
NOTE: 4.1 or newer kernel is needed for this jit dump analysis.

Test: Compile.
Test: Verified that perf-PID.map and jit-PID.dump files are only generated
      when running ART JIT with -g option. Tested on aosp_angler-userdebug
      and hikey-userdebug devices. The file formats are correct.

Change-Id: I1bd3ce280f953811d3dfcc27dc8e59b3e1f481aa
diff --git a/compiler/jit/jit_logger.h b/compiler/jit/jit_logger.h
new file mode 100644
index 0000000..0f8cfe4
--- /dev/null
+++ b/compiler/jit/jit_logger.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_JIT_JIT_LOGGER_H_
+#define ART_COMPILER_JIT_JIT_LOGGER_H_
+
+#include "base/mutex.h"
+#include "compiled_method.h"
+#include "driver/compiler_driver.h"
+#include "driver/compiler_options.h"
+
+namespace art {
+
+class ArtMethod;
+
+namespace jit {
+
+//
+// JitLogger supports two approaches of perf profiling.
+//
+// (1) perf-map:
+//     The perf-map mechanism generates perf-PID.map file,
+//     which provides simple "address, size, method_name" information to perf,
+//     and allows perf to map samples in jit-code-cache to jitted method symbols.
+//
+//     Command line Example:
+//       $ perf record dalvikvm -Xcompiler-option --generate-debug-info -cp <classpath> Test
+//       $ perf report
+//     NOTE:
+//       - Make sure that the perf-PID.map file is available for 'perf report' tool to access,
+//         so that jitted method can be displayed.
+//
+//
+// (2) perf-inject:
+//     The perf-inject mechansim generates jit-PID.dump file,
+//     which provides rich informations about a jitted method.
+//     It allows perf or other profiling tools to do advanced analysis on jitted code,
+//     for example instruction level profiling.
+//
+//     Command line Example:
+//       $ perf record -k mono dalvikvm -Xcompiler-option --generate-debug-info -cp <classpath> Test
+//       $ perf inject -i perf.data -o perf.data.jitted
+//       $ perf report -i perf.data.jitted
+//       $ perf annotate -i perf.data.jitted
+//     NOTE:
+//       REQUIREMENTS
+//       - The 'perf record -k mono' option requires 4.1 (or higher) Linux kernel.
+//       - The 'perf inject' (generating jit ELF files feature) requires perf 4.6 (or higher).
+//       PERF RECORD
+//       - The '-k mono' option tells 'perf record' to use CLOCK_MONOTONIC clock during sampling;
+//         which is required by 'perf inject', to make sure that both perf.data and jit-PID.dump
+//         have unified clock source for timestamps.
+//       PERF INJECT
+//       - The 'perf inject' tool injects information from jit-PID.dump into perf.data file,
+//         and generates small ELF files (jitted-TID-CODEID.so) for each jitted method.
+//       - On Android devices, the jit-PID.dump file is generated in /data/misc/trace/ folder, and
+//         such location is recorded in perf.data file.
+//         The 'perf inject' tool is going to look for jit-PID.dump and generates small ELF files in
+//         this /data/misc/trace/ folder.
+//         Make sure that you have the read/write access to /data/misc/trace/ folder.
+//       - On non-Android devices, the jit-PID.dump file is generated in /tmp/ folder, and
+//         'perf inject' tool operates on this folder.
+//         Make sure that you have the read/write access to /tmp/ folder.
+//       - If you are executing 'perf inject' on non-Android devices (host), but perf.data and
+//         jit-PID.dump files are adb-pulled from Android devices, make sure that there is a
+//         /data/misc/trace/ folder on host, and jit-PID.dump file is copied to this folder.
+//       - Currently 'perf inject' doesn't provide option to change the path for jit-PID.dump and
+//         generated ELF files.
+//       PERF ANNOTATE
+//       - The 'perf annotate' tool displays assembly level profiling report.
+//         Source code can also be displayed if the ELF file has debug symbols.
+//       - Make sure above small ELF files are available for 'perf annotate' tool to access,
+//         so that jitted code can be displayed in assembly view.
+//
+class JitLogger {
+  public:
+    JitLogger() : code_index_(0), marker_address_(nullptr) {}
+
+    void OpenLog() {
+      OpenPerfMapLog();
+      OpenJitDumpLog();
+    }
+
+    void WriteLog(JitCodeCache* code_cache, ArtMethod* method)
+        REQUIRES_SHARED(Locks::mutator_lock_) {
+      WritePerfMapLog(code_cache, method);
+      WriteJitDumpLog(code_cache, method);
+    }
+
+    void CloseLog() {
+      ClosePerfMapLog();
+      CloseJitDumpLog();
+    }
+
+  private:
+    // For perf-map profiling
+    void OpenPerfMapLog();
+    void WritePerfMapLog(JitCodeCache* code_cache, ArtMethod* method)
+        REQUIRES_SHARED(Locks::mutator_lock_);
+    void ClosePerfMapLog();
+
+    // For perf-inject profiling
+    void OpenJitDumpLog();
+    void WriteJitDumpLog(JitCodeCache* code_cache, ArtMethod* method)
+        REQUIRES_SHARED(Locks::mutator_lock_);
+    void CloseJitDumpLog();
+
+    void OpenMarkerFile();
+    void CloseMarkerFile();
+    void WriteJitDumpHeader();
+    void WriteJitDumpDebugInfo();
+
+    std::unique_ptr<File> perf_file_;
+    std::unique_ptr<File> jit_dump_file_;
+    uint64_t code_index_;
+    void* marker_address_;
+
+    DISALLOW_COPY_AND_ASSIGN(JitLogger);
+};
+
+}  // namespace jit
+}  // namespace art
+
+#endif  // ART_COMPILER_JIT_JIT_LOGGER_H_