native/common/jk_shm.c

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 */

/***************************************************************************
 * Description: Shared Memory support                                      *
 * Author:      Mladen Turk <mturk@jboss.com>                              *
 * Author:      Rainer Jung <rjung@apache.org>                             *
 ***************************************************************************/

#include "jk_global.h"
#include "jk_pool.h"
#include "jk_util.h"
#include "jk_mt.h"
#include "jk_lb_worker.h"
#include "jk_ajp13_worker.h"
#include "jk_ajp14_worker.h"
#include "jk_shm.h"

/** jk shm header core data structure
 * This is always the first slot in shared memory.
 */
struct jk_shm_header_data
{
    /* Shared memory magic JK_SHM_MAGIC */
    char         magic[JK_SHM_MAGIC_SIZ];
    unsigned int size;
    unsigned int pos;
    unsigned int childs;
    unsigned int workers;
    unsigned int maintain_checking;
    volatile time_t maintain_time;
};

typedef struct jk_shm_header_data jk_shm_header_data_t;

/** jk shm header record structure
 */
struct jk_shm_header
{
    union {
        jk_shm_header_data_t data;
        char alignbuf[JK_SHM_SLOT_SIZE];
    } h;
    char   buf[1];
};

typedef struct jk_shm_header jk_shm_header_t;

/** jk shm in memory structure.
 */
struct jk_shm
{
    unsigned int size;
    unsigned int ajp_workers;
    unsigned int lb_sub_workers;
    unsigned int lb_workers;
    char        *filename;
    char        *lockname;
    int          fd;
    int          fd_lock;
    int          attached;
    jk_shm_header_t  *hdr;
    JK_CRIT_SEC       cs;
};

typedef struct jk_shm jk_shm_t;

static const char shm_signature[] = { JK_SHM_MAGIC };
static jk_shm_t jk_shmem = { 0, 0, 0, 0, NULL, NULL, -1, -1, 0, NULL};
#if defined (WIN32)
static HANDLE jk_shm_map = NULL;
static HANDLE jk_shm_hlock = NULL;
#endif
static int jk_shm_inited_cs = 0;

static size_t jk_shm_calculate_slot_size()
{
    int align = 64;
    size_t slot_size = 0;
    size_t this_size = 0;

    this_size = sizeof(jk_shm_header_data_t);
    if (this_size > slot_size)
        slot_size = this_size;

    this_size = sizeof(jk_shm_worker_header_t);
    if (this_size > slot_size)
        slot_size = this_size;

    this_size = sizeof(jk_shm_ajp_worker_t);
    if (this_size > slot_size)
        slot_size = this_size;

    this_size = sizeof(jk_shm_lb_sub_worker_t);
    if (this_size > slot_size)
        slot_size = this_size;

    this_size = sizeof(jk_shm_lb_worker_t);
    if (this_size > slot_size)
        slot_size = this_size;

    slot_size = JK_ALIGN(slot_size, align);
    return slot_size;
}

/* Calculate needed shm size */
int jk_shm_calculate_size(jk_map_t *init_data, jk_log_context_t *l)
{
    char **worker_list;
    size_t needed_slot_size = 0;
    unsigned int i;
    unsigned int num_of_workers;
    int num_of_ajp_workers = 0;
    int num_of_lb_sub_workers = 0;
    int num_of_lb_workers = 0;

    JK_TRACE_ENTER(l);

    if (jk_get_worker_list(init_data, &worker_list,
                           &num_of_workers) == JK_FALSE) {
        jk_log(l, JK_LOG_ERROR,
               "Could not get worker list from map");
        JK_TRACE_EXIT(l);
        return 0;
    }
    needed_slot_size = jk_shm_calculate_slot_size();
    if (JK_IS_DEBUG_LEVEL(l))
        jk_log(l, JK_LOG_DEBUG, "JK_SHM_SLOT_SIZE defined as %d, need at least %d",
               JK_SHM_SLOT_SIZE , needed_slot_size);
    if (needed_slot_size > JK_SHM_SLOT_SIZE) {
        jk_log(l, JK_LOG_ERROR,
               "JK_SHM_SLOT_SIZE %d is too small, need at least %d",
               JK_SHM_SLOT_SIZE, needed_slot_size);
        JK_TRACE_EXIT(l);
        return 0;
    }
    for (i = 0; i < num_of_workers; i++) {
        const char *type = jk_get_worker_type(init_data, worker_list[i]);

        if (!strcmp(type, JK_AJP13_WORKER_NAME) ||
            !strcmp(type, JK_AJP14_WORKER_NAME)) {
            num_of_ajp_workers++;
        }
        else if (!strcmp(type, JK_LB_WORKER_NAME)) {
            char **member_list;
            unsigned int num_of_members;
            num_of_lb_workers++;
            if (jk_get_lb_worker_list(init_data, worker_list[i],
                                      &member_list, &num_of_members) == JK_FALSE) {
                jk_log(l, JK_LOG_ERROR,
                       "Could not get member list for lb worker from map");
            }
            else {
                if (JK_IS_DEBUG_LEVEL(l))
                    jk_log(l, JK_LOG_DEBUG, "worker %s of type %s has %u members",
                           worker_list[i], JK_LB_WORKER_NAME, num_of_members);
                num_of_lb_sub_workers += num_of_members;
            }
        }
    }
    if (JK_IS_DEBUG_LEVEL(l))
        jk_log(l, JK_LOG_DEBUG, "shared memory will contain %d ajp workers and %d lb workers with %d members",
               num_of_ajp_workers,
               num_of_lb_workers,
               num_of_lb_sub_workers);
    jk_shmem.ajp_workers = num_of_ajp_workers;
    jk_shmem.lb_sub_workers = num_of_lb_sub_workers;
    jk_shmem.lb_workers = num_of_lb_workers;
    JK_TRACE_EXIT(l);
    return (JK_SHM_SLOT_SIZE * (jk_shmem.ajp_workers +
            jk_shmem.lb_sub_workers * 2 +
            jk_shmem.lb_workers));
}


#if defined (WIN32)

/* Use plain memory */
int jk_shm_open(const char *fname, int sz, jk_log_context_t *l)
{
    int rc = -1;
    int attached = 0;
    char lkname[MAX_PATH];
    char shname[MAX_PATH] = "";

    JK_TRACE_ENTER(l);
    if (!jk_shm_inited_cs) {
        jk_shm_inited_cs = 1;
        JK_INIT_CS(&jk_shmem.cs, rc);
    }
    JK_ENTER_CS(&jk_shmem.cs);
    if (jk_shmem.hdr) {
        if (JK_IS_DEBUG_LEVEL(l))
            jk_log(l, JK_LOG_DEBUG, "Shared memory is already opened");
        JK_TRACE_EXIT(l);
        JK_LEAVE_CS(&jk_shmem.cs);
        return 0;
    }
    if (sz < 0) {
        jk_log(l, JK_LOG_ERROR, "Invalid shared memory size (%d)", sz);
        JK_TRACE_EXIT(l);
        return EINVAL;
    }
    jk_shmem.size = JK_SHM_ALIGN(JK_SHM_SLOT_SIZE + sz);
#if defined (WIN32)
    jk_shm_map   = NULL;
    jk_shm_hlock = NULL;
    if (fname) {
        int i;
        SIZE_T shmsz = 0;
        strcpy(shname, "Local\\");
        strncat(shname, fname, MAX_PATH - 8);
        for(i = 7; i < (int)strlen(shname); i++) {
            if (!jk_isalnum(shname[i]))
                shname[i] = '_';
            else
                shname[i] = toupper(shname[i]);
        }
        strcpy(lkname, shname);
        strncat(lkname, "_MUTEX", MAX_PATH - 1);
        jk_shm_hlock = CreateMutex(jk_get_sa_with_null_dacl(), TRUE, lkname);
        if (jk_shm_hlock == NULL) {
            if (GetLastError() == ERROR_ALREADY_EXISTS) {
                attached = 1;
                jk_shm_hlock = OpenMutex(MUTEX_ALL_ACCESS, FALSE, lkname);
            }
        }
        else if (GetLastError() == ERROR_ALREADY_EXISTS)
            attached = 1;
        if (jk_shm_hlock == NULL) {
            rc = GetLastError();
            jk_log(l, JK_LOG_ERROR, "Failed to open shared memory mutex %s with errno=%d",
                   lkname, rc);
            JK_LEAVE_CS(&jk_shmem.cs);
            JK_TRACE_EXIT(l);
            return rc;
        }
        if (attached) {
            DWORD ws = WaitForSingleObject(jk_shm_hlock, INFINITE);
            if (ws == WAIT_FAILED) {
                rc = GetLastError();
                CloseHandle(jk_shm_hlock);
                jk_shm_hlock = NULL;
                JK_LEAVE_CS(&jk_shmem.cs);
                JK_TRACE_EXIT(l);
                return rc;
            }
            jk_shm_map = OpenFileMapping(FILE_MAP_READ | FILE_MAP_WRITE, FALSE, shname);
            if (jk_shm_map == NULL) {
                rc = GetLastError();
                jk_log(l, JK_LOG_ERROR, "Failed to open shared memory %s with errno=%d",
                       shname, rc);
            }
        }
        if (jk_shm_map == NULL) {
            shmsz = jk_shmem.size;
            jk_shm_map = CreateFileMapping(INVALID_HANDLE_VALUE,
                                           jk_get_sa_with_null_dacl(),
                                           PAGE_READWRITE,
                                           0,
                                           (DWORD)shmsz,
                                           shname);
        }
        if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
            rc = GetLastError();
            jk_log(l, JK_LOG_ERROR, "Failed to map shared memory %s with errno=%d",
                   fname, rc);
            CloseHandle(jk_shm_hlock);
            jk_shm_hlock = NULL;
            jk_shm_map   = NULL;
            JK_LEAVE_CS(&jk_shmem.cs);
            JK_TRACE_EXIT(l);
            return rc;
        }
        jk_shmem.hdr = (jk_shm_header_t *)MapViewOfFile(jk_shm_map,
                                                        FILE_MAP_READ | FILE_MAP_WRITE,
                                                        0,
                                                        0,
                                                        shmsz);
    }
    else
#endif
    jk_shmem.hdr = (jk_shm_header_t *)calloc(1, jk_shmem.size);
    if (!jk_shmem.hdr) {
#if defined (WIN32)
        rc = GetLastError();
        if (jk_shm_map) {
            CloseHandle(jk_shm_map);
            jk_shm_map = NULL;
        }
        if (jk_shm_hlock) {
            CloseHandle(jk_shm_hlock);
            jk_shm_hlock = NULL;
        }
#endif
        JK_LEAVE_CS(&jk_shmem.cs);
        JK_TRACE_EXIT(l);
        return rc;
    }
    if (!jk_shmem.filename) {
        if (shname[0])
            jk_shmem.filename = strdup(shname);
        else
            jk_shmem.filename = strdup("memory");
    }
    jk_shmem.fd       = 0;
    jk_shmem.attached = attached;
    if (!attached) {
        memset(jk_shmem.hdr, 0, jk_shmem.size);
        memcpy(jk_shmem.hdr->h.data.magic, shm_signature,
               JK_SHM_MAGIC_SIZ);
        jk_shmem.hdr->h.data.size = sz;
        jk_shmem.hdr->h.data.childs = 1;
        jk_shmem.hdr->h.data.maintain_checking = 0;
        jk_shmem.hdr->h.data.maintain_time = time(NULL);
    }
    else {
        jk_shmem.hdr->h.data.childs++;
        /*
         * Reset the shared memory so that
         * alloc works even for attached memory.
         * XXX: This might break already used memory
         * if the number of workers change between
         * open and attach or between two attach operations.
         */
#if 0
        if (jk_shmem.hdr->h.data.childs > 1) {
            if (JK_IS_DEBUG_LEVEL(l)) {
                jk_log(l, JK_LOG_DEBUG,
                       "Resetting the shared memory for child %d",
                       jk_shmem.hdr->h.data.childs);
            }
        }
        jk_shmem.hdr->h.data.pos     = 0;
        jk_shmem.hdr->h.data.workers = 0;
#endif
    }
#if defined (WIN32)
    if (jk_shm_hlock != NULL) {
        /* Unlock shared memory */
        ReleaseMutex(jk_shm_hlock);
    }
#endif
    JK_LEAVE_CS(&jk_shmem.cs);
    if (JK_IS_DEBUG_LEVEL(l))
        jk_log(l, JK_LOG_DEBUG,
               "%s shared memory %s [%d] size=%u workers=%d free=%u addr=%#lx",
               attached ? "Attached" : "Initialized",
               jk_shm_name(),
               jk_shmem.hdr->h.data.childs,
               jk_shmem.size, jk_shmem.hdr->h.data.workers - 1,
               jk_shmem.hdr->h.data.size - jk_shmem.hdr->h.data.pos,
               jk_shmem.hdr);
    JK_TRACE_EXIT(l);
    return 0;
}

int jk_shm_attach(const char *fname, int sz, jk_log_context_t *l)
{
    JK_TRACE_ENTER(l);
    if (!jk_shm_open(fname, sz, l)) {
        if (!jk_shmem.attached) {
            jk_shmem.attached = 1;
            if (JK_IS_DEBUG_LEVEL(l)) {
                jk_log(l, JK_LOG_DEBUG,
                       "Attached shared memory %s [%d] size=%u free=%u addr=%#lx",
                       jk_shm_name(), jk_shmem.hdr->h.data.childs, jk_shmem.size,
                       jk_shmem.hdr->h.data.size - jk_shmem.hdr->h.data.pos,
                       jk_shmem.hdr);
            }
        }
        JK_TRACE_EXIT(l);
        return 0;
    }
    else {
        JK_TRACE_EXIT(l);
        return -1;
    }
}

void jk_shm_close(jk_log_context_t *l)
{
    if (jk_shm_inited_cs) {
        JK_ENTER_CS(&jk_shmem.cs);
    }
    if (jk_shmem.hdr) {
        if (JK_IS_DEBUG_LEVEL(l)) {
            jk_log(l, JK_LOG_DEBUG,
                   "Closed shared memory %s childs=%u",
                   jk_shm_name(), jk_shmem.hdr->h.data.childs);
        }
#if defined (WIN32)
        if (jk_shm_hlock) {
            WaitForSingleObject(jk_shm_hlock, 60000);
            ReleaseMutex(jk_shm_hlock);
            CloseHandle(jk_shm_hlock);
            jk_shm_hlock = NULL;
        }
        if (jk_shm_map) {
            --jk_shmem.hdr->h.data.childs;
            UnmapViewOfFile(jk_shmem.hdr);
            CloseHandle(jk_shm_map);
            jk_shm_map = NULL;
        }
        else
#endif
        free(jk_shmem.hdr);
    }
    jk_shmem.hdr = NULL;
    if (jk_shmem.filename) {
        free(jk_shmem.filename);
        jk_shmem.filename = NULL;
    }
    if (jk_shm_inited_cs) {
        JK_LEAVE_CS(&jk_shmem.cs);
    }
}

#else

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/uio.h>

#ifndef MAP_FAILED
#define MAP_FAILED  (-1)
#endif

#ifndef MAP_FILE
#define MAP_FILE    (0)
#endif

static int do_shm_open_lock(const char *fname, int attached, jk_log_context_t *l)
{
    int rc;
    char flkname[256];
#ifdef AS400_UTF8
    char *wptr;
#endif

    JK_TRACE_ENTER(l);

    if (attached && jk_shmem.lockname) {
#ifdef JK_SHM_LOCK_REOPEN
        jk_shmem.fd_lock = open(jk_shmem.lockname, O_RDWR, 0666);
#else
        errno = EINVAL;
#endif
        if (jk_shmem.fd_lock == -1) {
            rc = errno;
            JK_TRACE_EXIT(l);
            return rc;
        }
        if (JK_IS_DEBUG_LEVEL(l))
            jk_log(l, JK_LOG_DEBUG,
                   "Duplicated shared memory lock %s", jk_shmem.lockname);
        JK_TRACE_EXIT(l);
        return 0;
    }

    if (!jk_shmem.lockname) {
#ifdef JK_SHM_LOCK_REOPEN
        int i;
        jk_shmem.fd_lock = -1;
        mode_t mask = umask(0);
        for (i = 0; i < 8; i++) {
            strcpy(flkname, "/tmp/jkshmlock.XXXXXX");
            if (mktemp(flkname)) {
                jk_shmem.fd_lock = open(flkname, O_RDWR|O_CREAT|O_TRUNC, 0666);
                if (jk_shmem.fd_lock >= 0)
                    break;
            }
        }
        umask(mask);
#else
        strcpy(flkname, fname);
        strcat(flkname, ".lock");
#ifdef AS400_UTF8
        wptr = (char *)malloc(strlen(flkname) + 1);
        jk_ascii2ebcdic((char *)flkname, wptr);
        jk_shmem.fd_lock = open(wptr, O_RDWR|O_CREAT|O_TRUNC, 0666);
        free(wptr);
#else
        jk_shmem.fd_lock = open(flkname, O_RDWR|O_CREAT|O_TRUNC, 0666);
#endif
#endif
        if (jk_shmem.fd_lock == -1) {
            rc = errno;
            JK_TRACE_EXIT(l);
            return rc;
        }
        jk_shmem.lockname = strdup(flkname);
    }
    else {
        /* Nothing to do */
        JK_TRACE_EXIT(l);
        return 0;
    }

    if (ftruncate(jk_shmem.fd_lock, 1)) {
        rc = errno;
        close(jk_shmem.fd_lock);
        jk_shmem.fd_lock = -1;
        JK_TRACE_EXIT(l);
        return rc;
    }
    if (lseek(jk_shmem.fd_lock, 0, SEEK_SET) != 0) {
        rc = errno;
        close(jk_shmem.fd_lock);
        jk_shmem.fd_lock = -1;
        return rc;
    }
    if (JK_IS_DEBUG_LEVEL(l))
        jk_log(l, JK_LOG_DEBUG,
               "Opened shared memory lock %s", jk_shmem.lockname);
    JK_TRACE_EXIT(l);
    return 0;
}

static int do_shm_open(const char *fname, int attached,
                       int sz, jk_log_context_t *l)
{
    int rc;
    int fd;
    void *base;
#ifdef AS400_UTF8
    char *wptr;
#endif

    JK_TRACE_ENTER(l);
    if (!jk_shm_inited_cs) {
        jk_shm_inited_cs = 1;
        JK_INIT_CS(&jk_shmem.cs, rc);
    }
    if (jk_shmem.hdr) {
        /* Probably a call from vhost */
        if (!attached)
            attached = 1;
    }
    else if (attached) {
        /* We should already have a header
         * Use memory if we don't
         */
        JK_TRACE_EXIT(l);
        return 0;
    }
    if (sz < 0) {
        jk_log(l, JK_LOG_ERROR, "Invalid shared memory size (%d)", sz);
        JK_TRACE_EXIT(l);
        return EINVAL;
    }
    jk_shmem.size = JK_SHM_ALIGN(JK_SHM_SLOT_SIZE + sz);

    if (!fname) {
        /* Use plain memory in case there is no file name */
        if (!jk_shmem.filename)
            jk_shmem.filename  = strdup("memory");
        if (JK_IS_DEBUG_LEVEL(l))
            jk_log(l, JK_LOG_DEBUG,
                   "Using process memory as shared memory");
        JK_TRACE_EXIT(l);
        return 0;
    }

    if (!jk_shmem.filename) {
        jk_shmem.filename = (char *)malloc(strlen(fname) + 32);
        sprintf(jk_shmem.filename, "%s.%" JK_PID_T_FMT, fname, getpid());
    }
    if (!attached) {
        size_t size;
        jk_shmem.attached = 0;
#ifdef AS400_UTF8
        wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
        jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
        fd = open(wptr, O_RDWR|O_CREAT|O_TRUNC, 0666);
        free(wptr);
#else
        fd = open(jk_shmem.filename, O_RDWR|O_CREAT|O_TRUNC, 0666);
#endif
        if (fd == -1) {
            jk_shmem.size = 0;
            JK_TRACE_EXIT(l);
            return errno;
        }
        size = lseek(fd, 0, SEEK_END);
        if (size < jk_shmem.size) {
            size = jk_shmem.size;
            if (ftruncate(fd, jk_shmem.size)) {
                rc = errno;
                close(fd);
#ifdef  AS400_UTF8
                wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
                jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
                unlink(wptr);
                free(wptr);
#else
                unlink(jk_shmem.filename);
#endif
                jk_shmem.size = 0;
                JK_TRACE_EXIT(l);
                return rc;
            }
            if (JK_IS_DEBUG_LEVEL(l))
                jk_log(l, JK_LOG_DEBUG,
                       "Truncated shared memory to %u", size);
        }
        if (lseek(fd, 0, SEEK_SET) != 0) {
            rc = errno;
            close(fd);
#ifdef  AS400_UTF8
            wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
            jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
            unlink(wptr);
            free(wptr);
#else
            unlink(jk_shmem.filename);
#endif
            jk_shmem.size = 0;
            JK_TRACE_EXIT(l);
            return rc;
        }

        base = mmap((caddr_t)0, jk_shmem.size,
                    PROT_READ | PROT_WRITE,
                    MAP_FILE | MAP_SHARED,
                    fd, 0);
        if (base == (caddr_t)MAP_FAILED || base == (caddr_t)0) {
            rc = errno;
            close(fd);
#ifdef  AS400_UTF8
            wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
            jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
            unlink(wptr);
            free(wptr);
#else
            unlink(jk_shmem.filename);
#endif
            jk_shmem.size = 0;
            JK_TRACE_EXIT(l);
            return rc;
        }
        jk_shmem.hdr = base;
        jk_shmem.fd  = fd;
        memset(jk_shmem.hdr, 0, jk_shmem.size);
        memcpy(jk_shmem.hdr->h.data.magic, shm_signature, JK_SHM_MAGIC_SIZ);
        jk_shmem.hdr->h.data.size = sz;
        jk_shmem.hdr->h.data.childs = 1;
        jk_shmem.hdr->h.data.maintain_checking = 0;
        jk_shmem.hdr->h.data.maintain_time = time(NULL);
        if (JK_IS_DEBUG_LEVEL(l))
            jk_log(l, JK_LOG_DEBUG,
                   "Initialized shared memory %s size=%u free=%u addr=%#lx",
                   jk_shm_name(), jk_shmem.size,
                   jk_shmem.hdr->h.data.size - jk_shmem.hdr->h.data.pos,
                   jk_shmem.hdr);
    }
    else {
        jk_shmem.hdr->h.data.childs++;
        jk_shmem.attached = (int)getpid();
        if (JK_IS_DEBUG_LEVEL(l))
            jk_log(l, JK_LOG_DEBUG,
                   "Attached shared memory %s [%d] size=%u workers=%u free=%u addr=%#lx",
                   jk_shm_name(),
                   jk_shmem.hdr->h.data.childs,
                   jk_shmem.size, jk_shmem.hdr->h.data.workers - 1,
                   jk_shmem.hdr->h.data.size - jk_shmem.hdr->h.data.pos,
                   jk_shmem.hdr);
#if 0
        /*
         * Reset the shared memory so that
         * alloc works even for attached memory.
         * XXX: This might break already used memory
         * if the number of workers change between
         * open and attach or between two attach operations.
         */
        if (nchild > 1) {
            if (JK_IS_DEBUG_LEVEL(l)) {
                jk_log(l, JK_LOG_DEBUG,
                       "Resetting the shared memory for child %d",
                       nchild);
            }
        }
        jk_shmem.hdr->h.data.pos     = 0;
        jk_shmem.hdr->h.data.workers = 0;
#endif
    }
    if ((rc = do_shm_open_lock(jk_shmem.filename, attached, l))) {
        if (!attached) {
            munmap((void *)jk_shmem.hdr, jk_shmem.size);
            close(jk_shmem.fd);
#ifdef  AS400_UTF8
            wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
            jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
            unlink(wptr);
            free(wptr);
#else
            unlink(jk_shmem.filename);
#endif
        }
        jk_shmem.hdr = NULL;
        jk_shmem.fd  = -1;
        JK_TRACE_EXIT(l);
        return rc;
    }
    JK_TRACE_EXIT(l);
    return 0;
}

int jk_shm_open(const char *fname, int sz, jk_log_context_t *l)
{
    return do_shm_open(fname, 0, sz, l);
}

int jk_shm_attach(const char *fname, int sz, jk_log_context_t *l)
{
    return do_shm_open(fname, 1, sz, l);
}

void jk_shm_close(jk_log_context_t *l)
{
#ifdef AS400_UTF8
    char *wptr;
#endif

    if (jk_shmem.hdr) {
        if (JK_IS_DEBUG_LEVEL(l)) {
            jk_log(l, JK_LOG_DEBUG,
                   "Closed shared memory %s childs=%u",
                   jk_shm_name(), jk_shmem.hdr->h.data.childs);
        }
        --jk_shmem.hdr->h.data.childs;

#ifdef JK_SHM_LOCK_REOPEN
        if (jk_shmem.fd_lock >= 0) {
            close(jk_shmem.fd_lock);
            jk_shmem.fd_lock = -1;
        }
#endif
        if (jk_shmem.attached) {
            int p = (int)getpid();
            if (p == jk_shmem.attached) {
                /* In case this is a forked child
                 * do not close the shared memory.
                 * It will be closed by the parent.
                 */
                jk_shmem.size = 0;
                jk_shmem.hdr  = NULL;
                jk_shmem.fd   = -1;
                return;
            }
        }
        if (jk_shmem.fd >= 0) {
            munmap((void *)jk_shmem.hdr, jk_shmem.size);
            close(jk_shmem.fd);
        }
        if (jk_shmem.fd_lock >= 0)
            close(jk_shmem.fd_lock);
        if (jk_shmem.lockname) {
#ifdef  AS400_UTF8
            wptr = (char *)malloc(strlen(jk_shmem.lockname) + 1);
            jk_ascii2ebcdic((char *)jk_shmem.lockname, wptr);
            unlink(wptr);
            free(wptr);
#else
            unlink(jk_shmem.lockname);
#endif
            free(jk_shmem.lockname);
            jk_shmem.lockname = NULL;
        }
        if (jk_shmem.filename) {
#ifdef  AS400_UTF8
            wptr = (char *)malloc(strlen(jk_shmem.filename) + 1);
            jk_ascii2ebcdic((char *)jk_shmem.filename, wptr);
            unlink(wptr);
            free(wptr);
#else
            unlink(jk_shmem.filename);
#endif
            free(jk_shmem.filename);
            jk_shmem.filename = NULL;
        }
    }
    jk_shmem.size    = 0;
    jk_shmem.hdr     = NULL;
    jk_shmem.fd      = -1;
    jk_shmem.fd_lock = -1;
}


#endif

static int jk_shm_check_str_length(const char *name, const char *value,
                                   jk_log_context_t *l)
{
    size_t len = strlen(value);
    if (len >= JK_SHM_STR_SIZ) {
        jk_log(l, JK_LOG_ERROR,
               "Worker %s '%s' is %d bytes too long, "
               "a maximum of %d bytes is supported",
               name, value, len - (JK_SHM_STR_SIZ - 1), JK_SHM_STR_SIZ - 1);
        return JK_FALSE;
    }
    return JK_TRUE;
}

int jk_shm_str_init(shm_str dst, const char *src,
                    const char *name, jk_log_context_t *l)
{
    if (jk_shm_check_str_length(name, src, l) == JK_FALSE) {
        return JK_FALSE;
    }
    strncpy(dst, src, JK_SHM_STR_SIZ - 1);
    dst[JK_SHM_STR_SIZ - 1] = '\0';
    return JK_TRUE;
}

int jk_shm_str_init_ne(shm_str dst, const char *src,
                       const char *name, jk_log_context_t *l)
{
    if (jk_shm_check_str_length(name, src, l) == JK_FALSE) {
        return -1;
    }
    if (!strncmp(dst, src, JK_SHM_STR_SIZ)) {
        return 0;
    }
    strncpy(dst, src, JK_SHM_STR_SIZ - 1);
    dst[JK_SHM_STR_SIZ - 1] = '\0';
    return 1;
}

void jk_shm_str_copy(shm_str dst, shm_str src,
                     jk_log_context_t *l)
{
    memcpy((dst), (src), JK_SHM_STR_SIZ);
}

jk_shm_worker_header_t *jk_shm_alloc_worker(jk_pool_t *p, int type,
                                            int parent_id, const char *name,
                                            jk_log_context_t *l)
{
    unsigned int i;
    jk_shm_worker_header_t *w = 0;
    shm_str str;

    if (jk_shm_str_init(str, name, "name", l) == JK_FALSE) {
        return NULL;
    }

    if (jk_shmem.hdr) {
        jk_shm_lock();
        for (i = 0; i < jk_shmem.hdr->h.data.pos; i += JK_SHM_SLOT_SIZE) {
            w = (jk_shm_worker_header_t *)(jk_shmem.hdr->buf + i);
            if (w->type == type && w-> parent_id == parent_id &&
                strcmp(w->name, name) == 0) {
                /* We have found already created worker */
                jk_shm_unlock();
                return w;
            }
        }
        /* Allocate new worker */
        if ((jk_shmem.hdr->h.data.size - jk_shmem.hdr->h.data.pos) >= JK_SHM_SLOT_SIZE) {
            w = (jk_shm_worker_header_t *)(jk_shmem.hdr->buf + jk_shmem.hdr->h.data.pos);
            memset(w, 0, JK_SHM_SLOT_SIZE);
            jk_shm_str_copy(w->name, str, l);
            jk_shmem.hdr->h.data.workers++;
            w->id = jk_shmem.hdr->h.data.workers;
            w->type = type;
            w->parent_id = parent_id;
            jk_shmem.hdr->h.data.pos += JK_SHM_SLOT_SIZE;
        }
        else {
            /* No more free memory left.
             */
            jk_log(l, JK_LOG_ERROR,
                   "Could not allocate shared memory for worker %s",
                   name);
            w = NULL;
        }
        jk_shm_unlock();
    }
    else if (p) {
        w = (jk_shm_worker_header_t *)jk_pool_alloc(p, JK_SHM_SLOT_SIZE);
        if (w) {
            memset(w, 0, JK_SHM_SLOT_SIZE);
            jk_shm_str_copy(w->name, str, l);
            w->id = 0;
            w->type = type;
            w->parent_id = parent_id;
        }
    }

    return w;
}

const char *jk_shm_name()
{
    return jk_shmem.filename;
}

int jk_shm_check_maintain(time_t trigger)
{
    int rv = JK_FALSE;
    int maintain_checking = JK_ATOMIC_INCREMENT(&(jk_shmem.hdr->h.data.maintain_checking));
    /* Another process (or thread) is already checking */
    if (maintain_checking > 1) {
        JK_ATOMIC_DECREMENT(&(jk_shmem.hdr->h.data.maintain_checking));
        return rv;
    }
    if (jk_shmem.hdr->h.data.maintain_time <= trigger) {
        jk_shmem.hdr->h.data.maintain_time = time(NULL);
        rv = JK_TRUE;
    }
    JK_ATOMIC_DECREMENT(&(jk_shmem.hdr->h.data.maintain_checking));
    return rv;
}

int jk_shm_lock()
{
    int rc = JK_TRUE;

    if (!jk_shm_inited_cs)
        return JK_FALSE;
    JK_ENTER_CS(&jk_shmem.cs);
#if defined (WIN32)
    if (jk_shm_hlock != NULL) {
        if (WaitForSingleObject(jk_shm_hlock, INFINITE) == WAIT_FAILED)
            rc = JK_FALSE;
    }
#else
    if (jk_shmem.fd_lock != -1) {
        JK_ENTER_LOCK(jk_shmem.fd_lock, rc);
    }
#endif
    return rc;
}

int jk_shm_unlock()
{
    int rc = JK_TRUE;

    if (!jk_shm_inited_cs)
        return JK_FALSE;
#if defined (WIN32)
    if (jk_shm_hlock != NULL) {
        ReleaseMutex(jk_shm_hlock);
    }
#else
    if (jk_shmem.fd_lock != -1) {
        JK_LEAVE_LOCK(jk_shmem.fd_lock, rc);
    }
#endif
    JK_LEAVE_CS(&jk_shmem.cs);
    return rc;
}

jk_shm_ajp_worker_t *jk_shm_alloc_ajp_worker(jk_pool_t *p, const char *name,
                                             jk_log_context_t *l)
{
    return (jk_shm_ajp_worker_t *)jk_shm_alloc_worker(p,
                                    JK_AJP13_WORKER_TYPE, 0, name, l);
}

jk_shm_lb_sub_worker_t *jk_shm_alloc_lb_sub_worker(jk_pool_t *p, int lb_id, const char *name,
                                                   jk_log_context_t *l)
{
    return (jk_shm_lb_sub_worker_t *)jk_shm_alloc_worker(p,
                                    JK_LB_SUB_WORKER_TYPE, lb_id, name, l);
}

jk_shm_lb_worker_t *jk_shm_alloc_lb_worker(jk_pool_t *p, const char *name,
                                           jk_log_context_t *l)
{
    return (jk_shm_lb_worker_t *)jk_shm_alloc_worker(p,
                                    JK_LB_WORKER_TYPE, 0, name, l);
}