/*

 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_SERVICES_MEM_TRACKER_HPP

#define SHARE_VM_SERVICES_MEM_TRACKER_HPP

#include "memory/allocation.hpp"

#include "runtime/globals.hpp"

#include "runtime/mutex.hpp"

#include "runtime/os.hpp"

#include "runtime/thread.hpp"

#include "services/memPtr.hpp"

#include "services/memRecorder.hpp"

#include "services/memSnapshot.hpp"

#include "services/memTrackWorker.hpp"

#ifdef SOLARIS

#include "thread_solaris.inline.hpp"

#endif

#ifdef _DEBUG

  #define DEBUG_CALLER_PC  os::get_caller_pc(3)

#else

  #define DEBUG_CALLER_PC  0

#endif

// The thread closure walks threads to collect per-thread

// memory recorders at NMT sync point

class SyncThreadRecorderClosure : public ThreadClosure {

 private:

  int _thread_count;

 public:

  SyncThreadRecorderClosure() {

    _thread_count =0;

  }

  void do_thread(Thread* thread);

  int  get_thread_count() const {

    return _thread_count;

  }

};

class BaselineOutputer;

class MemSnapshot;

class MemTrackWorker;

class Thread;

/*

 * MemTracker is the 'gate' class to native memory tracking runtime.

 */

class MemTracker : AllStatic {

  friend class MemTrackWorker;

  friend class MemSnapshot;

  friend class SyncThreadRecorderClosure;

  // NMT state

  enum NMTStates {

    NMT_uninited,                        // not yet initialized

    NMT_bootstrapping_single_thread,     // bootstrapping, VM is in single thread mode

    NMT_bootstrapping_multi_thread,      // bootstrapping, VM is about to enter multi-thread mode

    NMT_started,                         // NMT fully started

    NMT_shutdown_pending,                // shutdown pending

    NMT_final_shutdown,                  // in final phase of shutdown

    NMT_shutdown                         // shutdown

  };

  // native memory tracking level

  enum NMTLevel {

    NMT_off,              // native memory tracking is off

    NMT_summary,          // don't track callsite

    NMT_detail            // track callsite also

  };

 public:

   enum ShutdownReason {

     NMT_shutdown_none,     // no shutdown requested

     NMT_shutdown_user,     // user requested shutdown

     NMT_normal,            // normal shutdown, process exit

     NMT_out_of_memory,     // shutdown due to out of memory

     NMT_initialization,    // shutdown due to initialization failure

     NMT_use_malloc_only,   // can not combine NMT with UseMallocOnly flag

     NMT_error_reporting,   // shutdown by vmError::report_and_die()

     NMT_out_of_generation, // running out of generation queue

     NMT_sequence_overflow  // overflow the sequence number

   };

 public:

  // initialize NMT tracking level from command line options, called

   // from VM command line parsing code

  static void init_tracking_options(const char* option_line);

  // if NMT is enabled to record memory activities

  static inline bool is_on() {

    return (_tracking_level >= NMT_summary &&

      _state >= NMT_bootstrapping_single_thread);

  }

  // user readable reason for shutting down NMT

  static const char* reason() {

    switch(_reason) {

      case NMT_shutdown_none:

        return "Native memory tracking is not enabled";

      case NMT_shutdown_user:

        return "Native memory tracking has been shutdown by user";

      case NMT_normal:

        return "Native memory tracking has been shutdown due to process exiting";

      case NMT_out_of_memory:

        return "Native memory tracking has been shutdown due to out of native memory";

      case NMT_initialization:

        return "Native memory tracking failed to initialize";

      case NMT_error_reporting:

        return "Native memory tracking has been shutdown due to error reporting";

      case NMT_out_of_generation:

        return "Native memory tracking has been shutdown due to running out of generation buffer";

      case NMT_sequence_overflow:

        return "Native memory tracking has been shutdown due to overflow the sequence number";

      case NMT_use_malloc_only:

        return "Native memory tracking is not supported when UseMallocOnly is on";

      default:

        ShouldNotReachHere();

        return NULL;

    }

  }

  // test if we can walk native stack

  static bool can_walk_stack() {

  // native stack is not walkable during bootstrapping on sparc

#if defined(SPARC)

    return (_state == NMT_started);

#else

    return (_state >= NMT_bootstrapping_single_thread && _state  <= NMT_started);

#endif

  }

  // if native memory tracking tracks callsite

  static inline bool track_callsite() { return _tracking_level == NMT_detail; }

  // shutdown native memory tracking capability. Native memory tracking

  // can be shutdown by VM when it encounters low memory scenarios.

  // Memory tracker should gracefully shutdown itself, and preserve the

  // latest memory statistics for post morten diagnosis.

  static void shutdown(ShutdownReason reason);

  // if there is shutdown requested

  static inline bool shutdown_in_progress() {

    return (_state >= NMT_shutdown_pending);

  }

  // bootstrap native memory tracking, so it can start to collect raw data

  // before worker thread can start

  // the first phase of bootstrapping, when VM still in single-threaded mode

  static void bootstrap_single_thread();

  // the second phase of bootstrapping, VM is about or already in multi-threaded mode

  static void bootstrap_multi_thread();

  // start() has to be called when VM still in single thread mode, but after

  // command line option parsing is done.

  static void start();

  // record a 'malloc' call

  static inline void record_malloc(address addr, size_t size, MEMFLAGS flags,

                            address pc = 0, Thread* thread = NULL) {

    if (NMT_CAN_TRACK(flags)) {

      create_memory_record(addr, (flags|MemPointerRecord::malloc_tag()), size, pc, thread);

    }

  }

  // record a 'free' call

  static inline void record_free(address addr, MEMFLAGS flags, Thread* thread = NULL) {

    if (is_on() && NMT_CAN_TRACK(flags)) {

      create_memory_record(addr, MemPointerRecord::free_tag(), 0, 0, thread);

    }

  }

  // record a 'realloc' call

  static inline void record_realloc(address old_addr, address new_addr, size_t size,

       MEMFLAGS flags, address pc = 0, Thread* thread = NULL) {

    if (is_on()) {

      record_free(old_addr, flags, thread);

      record_malloc(new_addr, size, flags, pc, thread);

    }

  }

  // record arena size

  static inline void record_arena_size(address addr, size_t size) {

    // we add a positive offset to arena address, so we can have arena size record

    // sorted after arena record

    if (is_on() && !UseMallocOnly) {

      create_memory_record((addr + sizeof(void*)), MemPointerRecord::arena_size_tag(), size,

        0, NULL);

    }

  }

  // record a virtual memory 'reserve' call

  static inline void record_virtual_memory_reserve(address addr, size_t size,

                            address pc = 0, Thread* thread = NULL) {

    if (is_on()) {

      create_memory_record(addr, MemPointerRecord::virtual_memory_reserve_tag(),

                           size, pc, thread);

    }

  }

  static inline void record_thread_stack(address addr, size_t size, Thread* thr,

                           address pc = 0) {

    if (is_on()) {

      assert(size > 0 && thr != NULL, "Sanity check");

      create_memory_record(addr, MemPointerRecord::virtual_memory_reserve_tag() | mtThreadStack,

                          size, pc, thr);

      create_memory_record(addr, MemPointerRecord::virtual_memory_commit_tag() | mtThreadStack,

                          size, pc, thr);

    }

  }

  static inline void release_thread_stack(address addr, size_t size, Thread* thr) {

    if (is_on()) {

      assert(size > 0 && thr != NULL, "Sanity check");

      create_memory_record(addr, MemPointerRecord::virtual_memory_uncommit_tag() | mtThreadStack,

                          size, DEBUG_CALLER_PC, thr);

      create_memory_record(addr, MemPointerRecord::virtual_memory_release_tag() | mtThreadStack,

                          size, DEBUG_CALLER_PC, thr);

    }

  }

  // record a virtual memory 'commit' call

  static inline void record_virtual_memory_commit(address addr, size_t size,

                            address pc = 0, Thread* thread = NULL) {

    if (is_on()) {

      create_memory_record(addr, MemPointerRecord::virtual_memory_commit_tag(),

                           size, DEBUG_CALLER_PC, thread);

    }

  }

  // record a virtual memory 'uncommit' call

  static inline void record_virtual_memory_uncommit(address addr, size_t size,

                            Thread* thread = NULL) {

    if (is_on()) {

      create_memory_record(addr, MemPointerRecord::virtual_memory_uncommit_tag(),

                           size, DEBUG_CALLER_PC, thread);

    }

  }

  // record a virtual memory 'release' call

  static inline void record_virtual_memory_release(address addr, size_t size,

                            Thread* thread = NULL) {

    if (is_on()) {

      create_memory_record(addr, MemPointerRecord::virtual_memory_release_tag(),

                           size, DEBUG_CALLER_PC, thread);

    }

  }

  // record memory type on virtual memory base address

  static inline void record_virtual_memory_type(address base, MEMFLAGS flags,

                            Thread* thread = NULL) {

    if (is_on()) {

      assert(base > 0, "wrong base address");

      assert((flags & (~mt_masks)) == 0, "memory type only");

      create_memory_record(base, (flags | MemPointerRecord::virtual_memory_type_tag()),

                           0, DEBUG_CALLER_PC, thread);

    }

  }

  // create memory baseline of current memory snapshot

  static bool baseline();

  // is there a memory baseline

  static bool has_baseline() {

    return _baseline.baselined();

  }

  // print memory usage from current snapshot

  static bool print_memory_usage(BaselineOutputer& out, size_t unit,

           bool summary_only = true);

  // compare memory usage between current snapshot and baseline

  static bool compare_memory_usage(BaselineOutputer& out, size_t unit,

           bool summary_only = true);

  // sync is called within global safepoint to synchronize nmt data

  static void sync();

  // called when a thread is about to exit

  static void thread_exiting(JavaThread* thread);

  // retrieve global snapshot

  static MemSnapshot* get_snapshot() {

    if (shutdown_in_progress()) {

      return NULL;

    }

    return _snapshot;

  }

  // print tracker stats

  NOT_PRODUCT(static void print_tracker_stats(outputStream* st);)

  NOT_PRODUCT(static void walk_stack(int toSkip, char* buf, int len);)

 private:

  // start native memory tracking worker thread

  static bool start_worker();

  // called by worker thread to complete shutdown process

  static void final_shutdown();

 protected:

  // retrieve per-thread recorder of the specified thread.

  // if the recorder is full, it will be enqueued to overflow

  // queue, a new recorder is acquired from recorder pool or a

  // new instance is created.

  // when thread == NULL, it means global recorder

  static MemRecorder* get_thread_recorder(JavaThread* thread);

  // per-thread recorder pool

  static void release_thread_recorder(MemRecorder* rec);

  static void delete_all_pooled_recorders();

  // pending recorder queue. Recorders are queued to pending queue

  // when they are overflowed or collected at nmt sync point.

  static void enqueue_pending_recorder(MemRecorder* rec);

  static MemRecorder* get_pending_recorders();

  static void delete_all_pending_recorders();

 private:

  // retrieve a pooled memory record or create new one if there is not

  // one available

  static MemRecorder* get_new_or_pooled_instance();

  static void create_memory_record(address addr, MEMFLAGS type,

                   size_t size, address pc, Thread* thread);

  static void create_record_in_recorder(address addr, MEMFLAGS type,

                   size_t size, address pc, JavaThread* thread);

 private:

  // global memory snapshot

  static MemSnapshot*     _snapshot;

  // a memory baseline of snapshot

  static MemBaseline      _baseline;

  // query lock

  static Mutex*           _query_lock;

  // a thread can start to allocate memory before it is attached

  // to VM 'Thread', those memory activities are recorded here.

  // ThreadCritical is required to guard this global recorder.

  static MemRecorder*     _global_recorder;

  // main thread id

  debug_only(static intx   _main_thread_tid;)

  // pending recorders to be merged

  static volatile MemRecorder*      _merge_pending_queue;

  NOT_PRODUCT(static volatile jint   _pending_recorder_count;)

  // pooled memory recorders

  static volatile MemRecorder*      _pooled_recorders;

  // memory recorder pool management, uses following

  // counter to determine if a released memory recorder

  // should be pooled

  // latest thread count

  static int               _thread_count;

  // pooled recorder count

  static volatile jint     _pooled_recorder_count;

  // worker thread to merge pending recorders into snapshot

  static MemTrackWorker*  _worker_thread;

  // how many safepoints we skipped without entering sync point

  static int              _sync_point_skip_count;

  // if the tracker is properly intialized

  static bool             _is_tracker_ready;

  // tracking level (off, summary and detail)

  static enum NMTLevel    _tracking_level;

  // current nmt state

  static volatile enum NMTStates   _state;

  // the reason for shutting down nmt

  static enum ShutdownReason       _reason;

};

#endif // SHARE_VM_SERVICES_MEM_TRACKER_HPP