jk_shm.c

来自「以便Apache与其他服务进行整合 Mod_JK安装」· C语言 代码 · 共 670 行 · 第 1/2 页

/*
 *  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 <[e-mail]>                              *
 * Author:      Rainer Jung <[e-mail]>                             *
 * Version:     $Revision: 551893 $                                        *
 ***************************************************************************/

#include "jk_global.h"
#include "jk_pool.h"
#include "jk_util.h"
#include "jk_mt.h"
#include "jk_shm.h"

/** jk shm header core data structure */
struct jk_shm_header_data
{
    /* Shared memory magic JK_SHM_MAGIC */
    char   magic[JK_SHM_MAGIC_SIZ];
    size_t size;
    size_t pos;
    unsigned int childs;
    unsigned int workers;
    time_t modified;
};

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_ALIGN(sizeof(jk_shm_header_data_t))];
    } h;
    char   buf[1];
};

typedef struct jk_shm_header jk_shm_header_t;

/** jk shm structure */
struct jk_shm
{
    size_t     size;
    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, NULL, NULL, -1, -1, 0, NULL};
static time_t jk_workers_modified_time = 0;
static time_t jk_workers_access_time = 0;
#if defined (WIN32)
static HANDLE jk_shm_map = NULL;
#endif

#if defined (WIN32) || defined(NETWARE)

/* Use plain memory */
int jk_shm_open(const char *fname, size_t sz, jk_logger_t *l)
{
    int rc;
    int attached = 0;
    JK_TRACE_ENTER(l);
    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);
        return 0;
    }

    jk_shmem.size =  JK_SHM_ALIGN(sizeof(jk_shm_header_t) + sz);

#if defined (WIN32)
    if (fname) {
        jk_shm_map = CreateFileMapping(INVALID_HANDLE_VALUE,
                                       NULL,
                                       PAGE_READWRITE,
                                       0,
                                       (DWORD)(sizeof(jk_shm_header_t) + sz),
                                       fname);
        if (GetLastError() == ERROR_ALREADY_EXISTS) {
            attached = 1;
            if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
                jk_shm_map = OpenFileMapping(PAGE_READWRITE, FALSE, fname);
            }
        }
        if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
            JK_TRACE_EXIT(l);
            return -1;
        }
        jk_shmem.hdr = (jk_shm_header_t *)MapViewOfFile(jk_shm_map,
                                                        FILE_MAP_ALL_ACCESS,
                                                        0,
                                                        0,
                                                        0);
    }
    else
#endif
    jk_shmem.hdr = (jk_shm_header_t *)calloc(1, jk_shmem.size);
    if (!jk_shmem.hdr) {
#if defined (WIN32)
        if (jk_shm_map) {
            CloseHandle(jk_shm_map);
            jk_shm_map = NULL;
        }
#endif
        JK_TRACE_EXIT(l);
        return -1;
    }
    if (!jk_shmem.filename) {
        if (fname)
            jk_shmem.filename = strdup(fname);
        else
            jk_shmem.filename = strdup("memory");
    }
    jk_shmem.fd       = 0;
    jk_shmem.attached = attached;
    if (!attached) {
        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;
    }
    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 (jk_shmem.hdr->h.data.childs > 1) {
            if (JK_IS_DEBUG_LEVEL(l)) {
                jk_log(l, JK_LOG_DEBUG,
                       "Reseting 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;
    }
    JK_INIT_CS(&(jk_shmem.cs), rc);
    if (JK_IS_DEBUG_LEVEL(l))
        jk_log(l, JK_LOG_DEBUG,
               "%s shared memory size=%u free=%u addr=%#lx",
               attached ? "Attached" : "Initialized",
               jk_shmem.size, jk_shmem.hdr->h.data.size, jk_shmem.hdr);
    JK_TRACE_EXIT(l);
    return 0;
}

int jk_shm_attach(const char *fname, size_t sz, jk_logger_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 [%d] size=%u free=%u addr=%#lx",
                   jk_shmem.hdr->h.data.childs, jk_shmem.hdr->h.data.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()
{
    if (jk_shmem.hdr) {
        int rc;
#if defined (WIN32)
        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_DELETE_CS(&(jk_shmem.cs), rc);
    }
    jk_shmem.hdr = NULL;
    if (jk_shmem.filename) {
        free(jk_shmem.filename);
        jk_shmem.filename = NULL;
    }
}

#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_logger_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,
                       size_t sz, jk_logger_t *l)
{
    int rc;
    int fd;
    void *base;
#ifdef AS400_UTF8
    char *wptr;
#endif