/*

 * Copyright (c) 1999, 2019, 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 OS_LINUX_OS_LINUX_HPP

#define OS_LINUX_OS_LINUX_HPP

// Linux_OS defines the interface to Linux operating systems

// Information about the protection of the page at address '0' on this os.

static bool zero_page_read_protected() { return true; }

class Linux {

  friend class os;

  friend class OSContainer;

  friend class TestReserveMemorySpecial;

  static bool libjsig_is_loaded;        // libjsig that interposes sigaction(),

                                        // __sigaction(), signal() is loaded

  static struct sigaction *(*get_signal_action)(int);

  static void check_signal_handler(int sig);

  static int (*_pthread_getcpuclockid)(pthread_t, clockid_t *);

  static int (*_pthread_setname_np)(pthread_t, const char*);

  static address   _initial_thread_stack_bottom;

  static uintptr_t _initial_thread_stack_size;

  static const char *_glibc_version;

  static const char *_libpthread_version;

  static bool _supports_fast_thread_cpu_time;

  static GrowableArray<int>* _cpu_to_node;

  static GrowableArray<int>* _nindex_to_node;

  // 0x00000000 = uninitialized,

  // 0x01000000 = kernel version unknown,

  // otherwise a 32-bit number:

  // Ox00AABBCC

  // AA, Major Version

  // BB, Minor Version

  // CC, Fix   Version

  static uint32_t _os_version;

 protected:

  static julong _physical_memory;

  static pthread_t _main_thread;

  static Mutex* _createThread_lock;

  static int _page_size;

  static julong available_memory();

  static julong physical_memory() { return _physical_memory; }

  static void set_physical_memory(julong phys_mem) { _physical_memory = phys_mem; }

  static int active_processor_count();

  static void initialize_system_info();

  static int commit_memory_impl(char* addr, size_t bytes, bool exec);

  static int commit_memory_impl(char* addr, size_t bytes,

                                size_t alignment_hint, bool exec);

  static void set_glibc_version(const char *s)      { _glibc_version = s; }

  static void set_libpthread_version(const char *s) { _libpthread_version = s; }

  static void rebuild_cpu_to_node_map();

  static void rebuild_nindex_to_node_map();

  static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }

  static GrowableArray<int>* nindex_to_node()  { return _nindex_to_node; }

  static size_t find_large_page_size();

  static size_t setup_large_page_size();

  static bool setup_large_page_type(size_t page_size);

  static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);

  static bool hugetlbfs_sanity_check(bool warn, size_t page_size);

  static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);

  static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);

  static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);

  static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);

  static bool release_memory_special_impl(char* base, size_t bytes);

  static bool release_memory_special_shm(char* base, size_t bytes);

  static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);

  static void print_full_memory_info(outputStream* st);

  static void print_container_info(outputStream* st);

  static void print_steal_info(outputStream* st);

  static void print_distro_info(outputStream* st);

  static void print_libversion_info(outputStream* st);

  static void print_proc_sys_info(outputStream* st);

  static void print_ld_preload_file(outputStream* st);

 public:

  struct CPUPerfTicks {

    uint64_t used;

    uint64_t usedKernel;

    uint64_t total;

    uint64_t steal;

    bool     has_steal_ticks;

  };

  // which_logical_cpu=-1 returns accumulated ticks for all cpus.

  static bool get_tick_information(CPUPerfTicks* pticks, int which_logical_cpu);

  static bool _stack_is_executable;

  static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);

  static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);

  static void init_thread_fpu_state();

  static int  get_fpu_control_word();

  static void set_fpu_control_word(int fpu_control);

  static pthread_t main_thread(void)                                { return _main_thread; }

  // returns kernel thread id (similar to LWP id on Solaris), which can be

  // used to access /proc

  static pid_t gettid();

  static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }

  static Mutex* createThread_lock(void)                             { return _createThread_lock; }

  static void hotspot_sigmask(Thread* thread);

  static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }

  static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }

  static int page_size(void)                                        { return _page_size; }

  static void set_page_size(int val)                                { _page_size = val; }

  static address   ucontext_get_pc(const ucontext_t* uc);

  static void ucontext_set_pc(ucontext_t* uc, address pc);

  static intptr_t* ucontext_get_sp(const ucontext_t* uc);

  static intptr_t* ucontext_get_fp(const ucontext_t* uc);

  // For Analyzer Forte AsyncGetCallTrace profiling support:

  //

  // This interface should be declared in os_linux_i486.hpp, but

  // that file provides extensions to the os class and not the

  // Linux class.

  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, const ucontext_t* uc,

                                              intptr_t** ret_sp, intptr_t** ret_fp);

  static bool get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr);

  // This boolean allows users to forward their own non-matching signals

  // to JVM_handle_linux_signal, harmlessly.

  static bool signal_handlers_are_installed;

  static int get_our_sigflags(int);

  static void set_our_sigflags(int, int);

  static void signal_sets_init();

  static void install_signal_handlers();

  static void set_signal_handler(int, bool);

  static sigset_t* unblocked_signals();

  static sigset_t* vm_signals();

  // For signal-chaining

  static struct sigaction *get_chained_signal_action(int sig);

  static bool chained_handler(int sig, siginfo_t* siginfo, void* context);

  // GNU libc and libpthread version strings

  static const char *glibc_version()          { return _glibc_version; }

  static const char *libpthread_version()     { return _libpthread_version; }

  static void libpthread_init();

  static void sched_getcpu_init();

  static bool libnuma_init();

  static void* libnuma_dlsym(void* handle, const char* name);

  // libnuma v2 (libnuma_1.2) symbols

  static void* libnuma_v2_dlsym(void* handle, const char* name);

  // Return default guard size for the specified thread type

  static size_t default_guard_size(os::ThreadType thr_type);

  static void capture_initial_stack(size_t max_size);

  // Stack overflow handling

  static bool manually_expand_stack(JavaThread * t, address addr);

  static int max_register_window_saves_before_flushing();

  // fast POSIX clocks support

  static void fast_thread_clock_init(void);

  static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {

    return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;

  }

  static bool supports_fast_thread_cpu_time() {

    return _supports_fast_thread_cpu_time;

  }

  static jlong fast_thread_cpu_time(clockid_t clockid);

  static void initialize_os_info();

  static bool os_version_is_known();

  static uint32_t os_version();

  // Stack repair handling

  // none present

 private:

  static void numa_init();

  static void expand_stack_to(address bottom);

  typedef int (*sched_getcpu_func_t)(void);

  typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);

  typedef int (*numa_max_node_func_t)(void);

  typedef int (*numa_num_configured_nodes_func_t)(void);

  typedef int (*numa_available_func_t)(void);

  typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);

  typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);

  typedef void (*numa_interleave_memory_v2_func_t)(void *start, size_t size, struct bitmask* mask);

  typedef struct bitmask* (*numa_get_membind_func_t)(void);

  typedef struct bitmask* (*numa_get_interleave_mask_func_t)(void);

  typedef void (*numa_set_bind_policy_func_t)(int policy);

  typedef int (*numa_bitmask_isbitset_func_t)(struct bitmask *bmp, unsigned int n);

  typedef int (*numa_distance_func_t)(int node1, int node2);

  static sched_getcpu_func_t _sched_getcpu;

  static numa_node_to_cpus_func_t _numa_node_to_cpus;

  static numa_max_node_func_t _numa_max_node;

  static numa_num_configured_nodes_func_t _numa_num_configured_nodes;

  static numa_available_func_t _numa_available;

  static numa_tonode_memory_func_t _numa_tonode_memory;

  static numa_interleave_memory_func_t _numa_interleave_memory;

  static numa_interleave_memory_v2_func_t _numa_interleave_memory_v2;

  static numa_set_bind_policy_func_t _numa_set_bind_policy;

  static numa_bitmask_isbitset_func_t _numa_bitmask_isbitset;

  static numa_distance_func_t _numa_distance;

  static numa_get_membind_func_t _numa_get_membind;

  static numa_get_interleave_mask_func_t _numa_get_interleave_mask;

  static unsigned long* _numa_all_nodes;

  static struct bitmask* _numa_all_nodes_ptr;

  static struct bitmask* _numa_nodes_ptr;

  static struct bitmask* _numa_interleave_bitmask;

  static struct bitmask* _numa_membind_bitmask;

  static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }

  static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }

  static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }

  static void set_numa_num_configured_nodes(numa_num_configured_nodes_func_t func) { _numa_num_configured_nodes = func; }

  static void set_numa_available(numa_available_func_t func) { _numa_available = func; }

  static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }

  static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }

  static void set_numa_interleave_memory_v2(numa_interleave_memory_v2_func_t func) { _numa_interleave_memory_v2 = func; }

  static void set_numa_set_bind_policy(numa_set_bind_policy_func_t func) { _numa_set_bind_policy = func; }

  static void set_numa_bitmask_isbitset(numa_bitmask_isbitset_func_t func) { _numa_bitmask_isbitset = func; }

  static void set_numa_distance(numa_distance_func_t func) { _numa_distance = func; }

  static void set_numa_get_membind(numa_get_membind_func_t func) { _numa_get_membind = func; }

  static void set_numa_get_interleave_mask(numa_get_interleave_mask_func_t func) { _numa_get_interleave_mask = func; }

  static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }

  static void set_numa_all_nodes_ptr(struct bitmask **ptr) { _numa_all_nodes_ptr = (ptr == NULL ? NULL : *ptr); }

  static void set_numa_nodes_ptr(struct bitmask **ptr) { _numa_nodes_ptr = (ptr == NULL ? NULL : *ptr); }

  static void set_numa_interleave_bitmask(struct bitmask* ptr)     { _numa_interleave_bitmask = ptr ;   }

  static void set_numa_membind_bitmask(struct bitmask* ptr)        { _numa_membind_bitmask = ptr ;      }

  static int sched_getcpu_syscall(void);

  enum NumaAllocationPolicy{

    NotInitialized,

    Membind,

    Interleave

  };

  static NumaAllocationPolicy _current_numa_policy;

 public:

  static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }

  static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {

    return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;

  }

  static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }

  static int numa_num_configured_nodes() {

    return _numa_num_configured_nodes != NULL ? _numa_num_configured_nodes() : -1;

  }

  static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }

  static int numa_tonode_memory(void *start, size_t size, int node) {

    return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;

  }

  static bool is_running_in_interleave_mode() {

    return _current_numa_policy == Interleave;

  }

  static void set_configured_numa_policy(NumaAllocationPolicy numa_policy) {

    _current_numa_policy = numa_policy;

  }

  static NumaAllocationPolicy identify_numa_policy() {

    for (int node = 0; node <= Linux::numa_max_node(); node++) {

      if (Linux::_numa_bitmask_isbitset(Linux::_numa_interleave_bitmask, node)) {

        return Interleave;

      }

    }

    return Membind;

  }

  static void numa_interleave_memory(void *start, size_t size) {

    // Prefer v2 API

    if (_numa_interleave_memory_v2 != NULL) {

      if (is_running_in_interleave_mode()) {

        _numa_interleave_memory_v2(start, size, _numa_interleave_bitmask);

      } else if (_numa_membind_bitmask != NULL) {

        _numa_interleave_memory_v2(start, size, _numa_membind_bitmask);

      }

    } else if (_numa_interleave_memory != NULL) {

      _numa_interleave_memory(start, size, _numa_all_nodes);

    }

  }

  static void numa_set_bind_policy(int policy) {

    if (_numa_set_bind_policy != NULL) {

      _numa_set_bind_policy(policy);

    }

  }

  static int numa_distance(int node1, int node2) {

    return _numa_distance != NULL ? _numa_distance(node1, node2) : -1;

  }

  static int get_node_by_cpu(int cpu_id);

  static int get_existing_num_nodes();

  // Check if numa node is configured (non-zero memory node).

  static bool is_node_in_configured_nodes(unsigned int n) {

    if (_numa_bitmask_isbitset != NULL && _numa_all_nodes_ptr != NULL) {

      return _numa_bitmask_isbitset(_numa_all_nodes_ptr, n);

    } else

      return false;

  }

  // Check if numa node exists in the system (including zero memory nodes).

  static bool is_node_in_existing_nodes(unsigned int n) {

    if (_numa_bitmask_isbitset != NULL && _numa_nodes_ptr != NULL) {

      return _numa_bitmask_isbitset(_numa_nodes_ptr, n);

    } else if (_numa_bitmask_isbitset != NULL && _numa_all_nodes_ptr != NULL) {

      // Not all libnuma API v2 implement numa_nodes_ptr, so it's not possible

      // to trust the API version for checking its absence. On the other hand,

      // numa_nodes_ptr found in libnuma 2.0.9 and above is the only way to get

      // a complete view of all numa nodes in the system, hence numa_nodes_ptr

      // is used to handle CPU and nodes on architectures (like PowerPC) where

      // there can exist nodes with CPUs but no memory or vice-versa and the

      // nodes may be non-contiguous. For most of the architectures, like

      // x86_64, numa_node_ptr presents the same node set as found in

      // numa_all_nodes_ptr so it's possible to use numa_all_nodes_ptr as a

      // substitute.

      return _numa_bitmask_isbitset(_numa_all_nodes_ptr, n);

    } else

      return false;

  }

  // Check if node is in bound node set.

  static bool is_node_in_bound_nodes(int node) {

    if (_numa_bitmask_isbitset != NULL) {

      if (is_running_in_interleave_mode()) {

        return _numa_bitmask_isbitset(_numa_interleave_bitmask, node);

      } else {

        return _numa_membind_bitmask != NULL ? _numa_bitmask_isbitset(_numa_membind_bitmask, node) : false;

      }

    }

    return false;

  }

  // Check if bound to only one numa node.

  // Returns true if bound to a single numa node, otherwise returns false.

  static bool is_bound_to_single_node() {

    int nodes = 0;

    struct bitmask* bmp = NULL;

    unsigned int node = 0;

    unsigned int highest_node_number = 0;

    if (_numa_get_membind != NULL && _numa_max_node != NULL && _numa_bitmask_isbitset != NULL) {

      bmp = _numa_get_membind();

      highest_node_number = _numa_max_node();

    } else {

      return false;

    }

    for (node = 0; node <= highest_node_number; node++) {

      if (_numa_bitmask_isbitset(bmp, node)) {

        nodes++;

      }

    }

    if (nodes == 1) {

      return true;

    } else {

      return false;

    }

  }

};

#endif // OS_LINUX_OS_LINUX_HPP