Java example source code file (hprof_md.c)

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Java - Java tags/keywords

agent_onload, eintr, jni_lib_suffix, nano, null, o_creat, o_rdonly, o_trunc, o_wronly, rtld_lazy, s_irgrp, s_iroth, s_irusr, seek_end

The hprof_md.c Java example source code

/*
 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#if !defined(LINUX) && !defined(_ALLBSD_SOURCE)
#include <procfs.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <unistd.h>
#include <errno.h>
#include <dlfcn.h>
#include <sys/time.h>

#include <netdb.h>
#include <netinet/in.h>
#include <sys/param.h>
#include <time.h>

#include "jni.h"
#include "jvm_md.h"
#include "hprof.h"

int
md_getpid(void)
{
    static int pid = -1;

    if ( pid >= 0 ) {
        return pid;
    }
    pid = getpid();
    return pid;
}

void
md_sleep(unsigned seconds)
{
    sleep(seconds);
}

void
md_init(void)
{
#if defined(LINUX) || defined(_ALLBSD_SOURCE)
    /* No Hi-Res timer option? */
#else
    if ( gdata->micro_state_accounting ) {
        char proc_ctl_fn[48];
        int  procfd;

        /* Turn on micro state accounting, once per process */
        (void)md_snprintf(proc_ctl_fn, sizeof(proc_ctl_fn),
                "/proc/%d/ctl", md_getpid());

        procfd = open(proc_ctl_fn, O_WRONLY);
        if (procfd >= 0) {
            long ctl_op[2];

            ctl_op[0] = PCSET;
            ctl_op[1] = PR_MSACCT;
            (void)write(procfd, ctl_op, sizeof(ctl_op));
            (void)close(procfd);
        }
    }
#endif
}

int
md_connect(char *hostname, unsigned short port)
{
    struct hostent *hentry;
    struct sockaddr_in s;
    int fd;

    /* create a socket */
    fd = socket(AF_INET, SOCK_STREAM, 0);
    if ( fd < 0 ) {
        return -1;
    }

    /* find remote host's addr from name */
    if ((hentry = gethostbyname(hostname)) == NULL) {
        (void)close(fd);
        return -1;
    }
    (void)memset((char *)&s, 0, sizeof(s));
    /* set remote host's addr; its already in network byte order */
    (void)memcpy(&s.sin_addr.s_addr, *(hentry->h_addr_list),
           (int)sizeof(s.sin_addr.s_addr));
    /* set remote host's port */
    s.sin_port = htons(port);
    s.sin_family = AF_INET;

    /* now try connecting */
    if (-1 == connect(fd, (struct sockaddr*)&s, sizeof(s))) {
        (void)close(fd);
        return 0;
    }
    return fd;
}

int
md_recv(int f, char *buf, int len, int option)
{
    return recv(f, buf, len, option);
}

int
md_shutdown(int filedes, int option)
{
    return shutdown(filedes, option);
}

int
md_open(const char *filename)
{
    return open(filename, O_RDONLY);
}

int
md_open_binary(const char *filename)
{
    return md_open(filename);
}

int
md_creat(const char *filename)
{
    return open(filename, O_WRONLY | O_CREAT | O_TRUNC,
            S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
}

int
md_creat_binary(const char *filename)
{
    return md_creat(filename);
}

jlong
md_seek(int filedes, jlong cur)
{
    jlong new_pos;

    if ( cur == (jlong)-1 ) {
        new_pos = lseek(filedes, 0, SEEK_END);
    } else {
        new_pos = lseek(filedes, cur, SEEK_SET);
    }
    return new_pos;
}

void
md_close(int filedes)
{
    (void)close(filedes);
}

int
md_send(int s, const char *msg, int len, int flags)
{
    int res;

    do {
        res = send(s, msg, len, flags);
    } while ((res < 0) && (errno == EINTR));

    return res;
}

int
md_write(int filedes, const void *buf, int nbyte)
{
    int res;

    do {
        res = write(filedes, buf, nbyte);
    } while ((res < 0) && (errno == EINTR));

    return res;
}

int
md_read(int filedes, void *buf, int nbyte)
{
    int res;

    do {
        res = read(filedes, buf, nbyte);
    } while ((res < 0) && (errno == EINTR));

    return res;
}

/* Time of day in milli-seconds */
static jlong
md_timeofday(void)
{
    struct timeval tv;

    if ( gettimeofday(&tv, (void *)0) != 0 ) {
        return (jlong)0; /* EOVERFLOW ? */
    }
    /*LINTED*/
    return ((jlong)tv.tv_sec * (jlong)1000) + (jlong)(tv.tv_usec / 1000);
}

/* Hi-res timer in micro-seconds */
jlong
md_get_microsecs(void)
{
#if defined(LINUX) || defined(_ALLBSD_SOURCE)
    return (jlong)(md_timeofday() * (jlong)1000); /* Milli to micro */
#else
    return (jlong)(gethrtime()/(hrtime_t)1000); /* Nano seconds to micro seconds */
#endif
}

/* Time of day in milli-seconds */
jlong
md_get_timemillis(void)
{
    return md_timeofday();
}

/* Current CPU hi-res CPU time used */
jlong
md_get_thread_cpu_timemillis(void)
{
#if defined(LINUX) || defined(_ALLBSD_SOURCE)
    return md_timeofday();
#else
    return (jlong)(gethrvtime()/1000); /* Nano seconds to milli seconds */
#endif
}

void
md_get_prelude_path(char *path, int path_len, char *filename)
{
    void *addr;
    char libdir[FILENAME_MAX+1];
    Dl_info dlinfo;

    libdir[0] = 0;
#if defined(LINUX) || defined(_ALLBSD_SOURCE)
    addr = (void*)&Agent_OnLoad;
#else
    /* Just using &Agent_OnLoad will get the first external symbol with
     *   this name in the first .so, which may not be libhprof.so.
     *   On Solaris we can actually ask for the address of our Agent_OnLoad.
     */
    addr = dlsym(RTLD_SELF, "Agent_OnLoad");
    /* Just in case the above didn't work (missing linker patch?). */
    if ( addr == NULL ) {
        addr = (void*)&Agent_OnLoad;
    }
#endif

    /* Use dladdr() to get the full path to libhprof.so, which we use to find
     *  the prelude file.
     */
    dlinfo.dli_fname = NULL;
    (void)dladdr(addr, &dlinfo);
    if ( dlinfo.dli_fname != NULL ) {
        char * lastSlash;

        /* Full path to library name, need to move up one directory to 'lib' */
        (void)strcpy(libdir, (char *)dlinfo.dli_fname);
        lastSlash = strrchr(libdir, '/');
        if ( lastSlash != NULL ) {
            *lastSlash = '\0';
        }
#ifndef __APPLE__
        // not sure why other platforms have to go up two levels, but on macos we only need up one
        lastSlash = strrchr(libdir, '/');
        if ( lastSlash != NULL ) {
            *lastSlash = '\0';
        }
#endif /* __APPLE__ */
    }
    (void)snprintf(path, path_len, "%s/%s", libdir, filename);
}


int
md_vsnprintf(char *s, int n, const char *format, va_list ap)
{
    return vsnprintf(s, n, format, ap);
}

int
md_snprintf(char *s, int n, const char *format, ...)
{
    int ret;
    va_list ap;

    va_start(ap, format);
    ret = md_vsnprintf(s, n, format, ap);
    va_end(ap);
    return ret;
}

void
md_system_error(char *buf, int len)
{
    char *p;

    buf[0] = 0;
    p = strerror(errno);
    if ( p != NULL ) {
        (void)strcpy(buf, p);
    }
}

unsigned
md_htons(unsigned short s)
{
    return htons(s);
}

unsigned
md_htonl(unsigned l)
{
    return htonl(l);
}

unsigned
md_ntohs(unsigned short s)
{
    return ntohs(s);
}

unsigned
md_ntohl(unsigned l)
{
    return ntohl(l);
}

static void dll_build_name(char* buffer, size_t buflen,
                           const char* paths, const char* fname) {
    char *path, *paths_copy, *next_token;

    paths_copy = strdup(paths);
    if (paths_copy == NULL) {
        return;
    }

    next_token = NULL;
    path = strtok_r(paths_copy, ":", &next_token);

    while (path != NULL) {
        snprintf(buffer, buflen, "%s/lib%s" JNI_LIB_SUFFIX, path, fname);
        if (access(buffer, F_OK) == 0) {
            break;
        }
        *buffer = '\0';
        path = strtok_r(NULL, ":", &next_token);
    }

    free(paths_copy);
}

/* Create the actual fill filename for a dynamic library.  */
void
md_build_library_name(char *holder, int holderlen, const char *pname, const char *fname)
{
    int   pnamelen;

    /* Length of options directory location. */
    pnamelen = pname ? strlen(pname) : 0;

    *holder = '\0';
    /* Quietly truncate on buffer overflow.  Should be an error. */
    if (pnamelen + (int)strlen(fname) + 10 > holderlen) {
        return;
    }

    /* Construct path to library */
    if (pnamelen == 0) {
        (void)snprintf(holder, holderlen, "lib%s" JNI_LIB_SUFFIX, fname);
    } else {
      dll_build_name(holder, holderlen, pname, fname);
    }
}

/* Load this library (return NULL on error, and error message in err_buf) */
void *
md_load_library(const char *name, char *err_buf, int err_buflen)
{
    void * result;

    result = dlopen(name, RTLD_LAZY);
    if (result == NULL) {
        (void)strncpy(err_buf, dlerror(), err_buflen-2);
        err_buf[err_buflen-1] = '\0';
    }
    return result;
}

/* Unload this library */
void
md_unload_library(void *handle)
{
    (void)dlclose(handle);
}

/* Find an entry point inside this library (return NULL if not found) */
void *
md_find_library_entry(void *handle, const char *name)
{
    void * sym;

    sym =  dlsym(handle, name);
    return sym;
}