/*

 * 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

#include "jni.h"

#include "jni_util.h"

#include "jlong.h"

#include "jvm.h"

#include <sys/types.h>

#include <sys/stat.h>

#if defined(_ALLBSD_SOURCE)

#include <sys/sysctl.h>

#ifdef __APPLE__

#include <sys/param.h>

#include <sys/mount.h>

#include <mach/mach.h>

#include <sys/proc_info.h>

#include <libproc.h>

#endif

#elif !defined(_AIX)

#include <sys/swap.h>

#endif

#include <sys/resource.h>

#include <sys/times.h>

#ifndef _ALLBSD_SOURCE

#include <sys/sysinfo.h>

#endif

#include <ctype.h>

#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#include <limits.h>

#include <stdlib.h>

#include <unistd.h>

#if defined(_AIX)

#include <libperfstat.h>

#endif

static jlong page_size = 0;

#if defined(_ALLBSD_SOURCE) || defined(_AIX)

#define MB      (1024UL * 1024UL)

#else

/* This gets us the new structured proc interfaces of 5.6 & later */

/* - see comment in <sys/procfs.h> */

#define _STRUCTURED_PROC 1

#include <sys/procfs.h>

#endif /* _ALLBSD_SOURCE */

static struct dirent* read_dir(DIR* dirp, struct dirent* entry) {

#ifdef __solaris__

    struct dirent* dbuf = readdir(dirp);

    return dbuf;

#else /* __linux__ || _ALLBSD_SOURCE */

    struct dirent* p;

    if (readdir_r(dirp, entry, &p) == 0) {

        return p;

    } else {

        return NULL;

    }

#endif

}

// true = get available swap in bytes

// false = get total swap in bytes

static jlong get_total_or_available_swap_space_size(JNIEnv* env, jboolean available) {

#ifdef __solaris__

    long total, avail;

    int nswap, i, count;

    swaptbl_t *stbl;

    char *strtab;

    // First get the number of swap resource entries

    if ((nswap = swapctl(SC_GETNSWP, NULL)) == -1) {

        throw_internal_error(env, "swapctl failed to get nswap");

        return -1;

    }

    if (nswap == 0) {

        return 0;

    }

    // Allocate storage for resource entries

    stbl = (swaptbl_t*) malloc(nswap * sizeof(swapent_t) +

                               sizeof(struct swaptable));

    if (stbl == NULL) {

        JNU_ThrowOutOfMemoryError(env, 0);

        return -1;

    }

    // Allocate storage for the table

    strtab = (char*) malloc((nswap + 1) * MAXPATHLEN);

    if (strtab == NULL) {

        free(stbl);

        JNU_ThrowOutOfMemoryError(env, 0);

        return -1;

    }

    for (i = 0; i < (nswap + 1); i++) {

      stbl->swt_ent[i].ste_path = strtab + (i * MAXPATHLEN);

    }

    stbl->swt_n = nswap + 1;

    // Get the entries

    if ((count = swapctl(SC_LIST, stbl)) < 0) {

        free(stbl);

        free(strtab);

        throw_internal_error(env, "swapctl failed to get swap list");

        return -1;

    }

    // Sum the entries to get total and free swap

    total = 0;

    avail = 0;

    for (i = 0; i < count; i++) {

      total += stbl->swt_ent[i].ste_pages;

      avail += stbl->swt_ent[i].ste_free;

    }

    free(stbl);

    free(strtab);

    return available ? ((jlong)avail * page_size) :

                       ((jlong)total * page_size);

#elif defined(__linux__)

    int ret;

    FILE *fp;

    jlong total = 0, avail = 0;

    struct sysinfo si;

    ret = sysinfo(&si);

    if (ret != 0) {

        throw_internal_error(env, "sysinfo failed to get swap size");

    }

    total = (jlong)si.totalswap * si.mem_unit;

    avail = (jlong)si.freeswap * si.mem_unit;

    return available ? avail : total;

#elif defined(__APPLE__)

    struct xsw_usage vmusage;

    size_t size = sizeof(vmusage);

    if (sysctlbyname("vm.swapusage", &vmusage, &size, NULL, 0) != 0) {

        throw_internal_error(env, "sysctlbyname failed");

    }

    return available ? (jlong)vmusage.xsu_avail : (jlong)vmusage.xsu_total;

#else /* _ALLBSD_SOURCE */

    /*

     * XXXBSD: there's no way available to get swap info in

     *         FreeBSD.  Usage of libkvm is not an option here

     */

    // throw_internal_error(env, "Unimplemented in FreeBSD");

    return (0);

#endif

}

JNIEXPORT void JNICALL

  (JNIEnv *env, jclass cls)

{

    page_size = sysconf(_SC_PAGESIZE);

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

#ifdef __solaris__

    psinfo_t psinfo;

    ssize_t result;

    size_t remaining;

    char* addr;

    int fd;

    fd = open64("/proc/self/psinfo", O_RDONLY, 0);

    if (fd < 0) {

        throw_internal_error(env, "Unable to open /proc/self/psinfo");

        return -1;

    }

    addr = (char *)&psinfo;

    for (remaining = sizeof(psinfo_t); remaining > 0;) {

        result = read(fd, addr, remaining);

        if (result < 0) {

            if (errno != EINTR) {

                close(fd);

                throw_internal_error(env, "Unable to read /proc/self/psinfo");

                return -1;

            }

        } else {

            remaining -= result;

            addr += result;

        }

    }

    close(fd);

    return (jlong) psinfo.pr_size * 1024;

#elif defined(__linux__)

    FILE *fp;

    unsigned long vsize = 0;

    if ((fp = fopen("/proc/self/stat", "r")) == NULL) {

        throw_internal_error(env, "Unable to open /proc/self/stat");

        return -1;

    }

    // Ignore everything except the vsize entry

    if (fscanf(fp, "%*d %*s %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u %*d %*d %*d %*d %*d %*d %*u %*u %*d %lu %*[^\n]\n", &vsize) == EOF) {

        throw_internal_error(env, "Unable to get virtual memory usage");

        fclose(fp);

        return -1;

    }

    fclose(fp);

    return (jlong)vsize;

#elif defined(__APPLE__)

    struct task_basic_info t_info;

    mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;

    kern_return_t res = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);

    if (res != KERN_SUCCESS) {

        throw_internal_error(env, "task_info failed");

    }

    return t_info.virtual_size;

#else /* _ALLBSD_SOURCE */

    /*

     * XXXBSD: there's no way available to do it in FreeBSD, AFAIK.

     */

    // throw_internal_error(env, "Unimplemented in FreeBSD");

    return (64 * MB);

#endif

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

    return get_total_or_available_swap_space_size(env, JNI_FALSE);

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

    return get_total_or_available_swap_space_size(env, JNI_TRUE);

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

#ifdef __APPLE__

    struct rusage usage;

    if (getrusage(RUSAGE_SELF, &usage) != 0) {

        throw_internal_error(env, "getrusage failed");

        return -1;

    }

    jlong microsecs =

        usage.ru_utime.tv_sec * 1000 * 1000 + usage.ru_utime.tv_usec +

        usage.ru_stime.tv_sec * 1000 * 1000 + usage.ru_stime.tv_usec;

    return microsecs * 1000;

#else

    jlong clk_tck, ns_per_clock_tick;

    jlong cpu_time_ns;

    struct tms time;

    /*

     * BSDNOTE: FreeBSD implements _SC_CLK_TCK since FreeBSD 5, so

     *          add a magic to handle it

     */

#if defined(__solaris__) || defined(_SC_CLK_TCK)

    clk_tck = (jlong) sysconf(_SC_CLK_TCK);

#elif defined(__linux__) || defined(_ALLBSD_SOURCE)

    clk_tck = 100;

#endif

    if (clk_tck == -1) {

        throw_internal_error(env,

                             "sysconf failed - not able to get clock tick");

        return -1;

    }

    times(&time);

    ns_per_clock_tick = (jlong) 1000 * 1000 * 1000 / (jlong) clk_tck;

    cpu_time_ns = ((jlong)time.tms_utime + (jlong) time.tms_stime) *

                      ns_per_clock_tick;

    return cpu_time_ns;

#endif

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

#ifdef __APPLE__

    mach_msg_type_number_t count;

    vm_statistics_data_t vm_stats;

    kern_return_t res;

    count = HOST_VM_INFO_COUNT;

    res = host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vm_stats, &count);

    if (res != KERN_SUCCESS) {

        throw_internal_error(env, "host_statistics failed");

        return -1;

    }

    return (jlong)vm_stats.free_count * page_size;

#elif defined(_ALLBSD_SOURCE)

    /*

     * XXBSDL no way to do it in FreeBSD

     */

    // throw_internal_error(env, "unimplemented in FreeBSD")

    return (128 * MB);

#elif defined(_AIX)

    perfstat_memory_total_t memory_info;

    if (-1 != perfstat_memory_total(NULL, &memory_info, sizeof(perfstat_memory_total_t), 1)) {

        return (jlong)(memory_info.real_free * 4L * 1024L);

    }

    return -1;

#else // solaris / linux

    jlong num_avail_physical_pages = sysconf(_SC_AVPHYS_PAGES);

    return (num_avail_physical_pages * page_size);

#endif

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

#ifdef _ALLBSD_SOURCE

    jlong result = 0;

    int mib[2];

    size_t rlen;

    mib[0] = CTL_HW;

    mib[1] = HW_MEMSIZE;

    rlen = sizeof(result);

    if (sysctl(mib, 2, &result, &rlen, NULL, 0) != 0) {

        throw_internal_error(env, "sysctl failed");

        return -1;

    }

    return result;

#elif defined(_AIX)

    perfstat_memory_total_t memory_info;

    if (-1 != perfstat_memory_total(NULL, &memory_info, sizeof(perfstat_memory_total_t), 1)) {

        return (jlong)(memory_info.real_total * 4L * 1024L);

    }

    return -1;

#else // solaris / linux

    jlong num_physical_pages = sysconf(_SC_PHYS_PAGES);

    return (num_physical_pages * page_size);

#endif

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

#ifdef __APPLE__

    // This code is influenced by the darwin lsof source

    pid_t my_pid;

    struct proc_bsdinfo bsdinfo;

    struct proc_fdinfo *fds;

    int nfiles;

    kern_return_t kres;

    int res;

    size_t fds_size;

    kres = pid_for_task(mach_task_self(), &my_pid);

    if (kres != KERN_SUCCESS) {

        throw_internal_error(env, "pid_for_task failed");

        return -1;

    }

    // get the maximum number of file descriptors

    res = proc_pidinfo(my_pid, PROC_PIDTBSDINFO, 0, &bsdinfo, PROC_PIDTBSDINFO_SIZE);

    if (res <= 0) {

        throw_internal_error(env, "proc_pidinfo with PROC_PIDTBSDINFO failed");

        return -1;

    }

    // allocate memory to hold the fd information (we don't acutally use this information

    // but need it to get the number of open files)

    fds_size = bsdinfo.pbi_nfiles * sizeof(struct proc_fdinfo);

    fds = malloc(fds_size);

    if (fds == NULL) {

        JNU_ThrowOutOfMemoryError(env, "could not allocate space for file descriptors");

        return -1;

    }

    // get the list of open files - the return value is the number of bytes

    // proc_pidinfo filled in

    res = proc_pidinfo(my_pid, PROC_PIDLISTFDS, 0, fds, fds_size);

    if (res <= 0) {

        free(fds);

        throw_internal_error(env, "proc_pidinfo failed for PROC_PIDLISTFDS");

        return -1;

    }

    nfiles = res / sizeof(struct proc_fdinfo);

    free(fds);

    return nfiles;

#elif defined(_ALLBSD_SOURCE)

    /*

     * XXXBSD: there's no way available to do it in FreeBSD, AFAIK.

     */

    // throw_internal_error(env, "Unimplemented in FreeBSD");

    return (100);

#else /* solaris/linux */

    DIR *dirp;

    struct dirent dbuf;

    struct dirent* dentp;

    jlong fds = 0;

#if defined(_AIX)

/* AIX does not understand '/proc/self' - it requires the real process ID */

#define FD_DIR aix_fd_dir

    char aix_fd_dir[32];     /* the pid has at most 19 digits */

    snprintf(aix_fd_dir, 32, "/proc/%d/fd", getpid());

#else

#define FD_DIR "/proc/self/fd"

#endif

    dirp = opendir(FD_DIR);

    if (dirp == NULL) {

        throw_internal_error(env, "Unable to open directory /proc/self/fd");

        return -1;

    }

    // iterate through directory entries, skipping '.' and '..'

    // each entry represents an open file descriptor.

    while ((dentp = read_dir(dirp, &dbuf)) != NULL) {

        if (isdigit(dentp->d_name[0])) {

            fds++;

        }

    }

    closedir(dirp);

    // subtract by 1 which was the fd open for this implementation

    return (fds - 1);

#endif

}

JNIEXPORT jlong JNICALL

  (JNIEnv *env, jobject mbean)

{

    struct rlimit rlp;

    if (getrlimit(RLIMIT_NOFILE, &rlp) == -1) {

        throw_internal_error(env, "getrlimit failed");

        return -1;

    }

    return (jlong) rlp.rlim_cur;

}