lmdb_rdonly3.c

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "lmdb.h"

#define DBDIR       "./testdb"
#define DBNAME      "name"

static MDB_env *env;

static void *thread_func(void *pArg)
{
    int code = (int)pArg;       //warningが出るが、気にしない

    int rc;
    MDB_txn *txn;
    MDB_dbi dbi;
    MDB_val key, data;
    int slp = 0;
    unsigned long flags = 0;
    switch (code) {
    case 1:
        sleep(1);
        flags = 0;
        slp = 10;
        break;
    case 2:
        flags = MDB_RDONLY;
        slp = 3;
        break;
    }

    fprintf(stderr, "txn begin: code=%d(%s)\n", code, (flags & MDB_RDONLY ? "rdonly" : "normal"));
    rc = mdb_txn_begin(env, NULL, flags, &txn);
    if (rc) {
        fprintf(stderr, "fail: mdb_txn_begin(%d:%s)\n", code, mdb_strerror(rc));
        goto LABEL_EXIT2;
    }
    rc = mdb_dbi_open(txn, DBNAME, 0, &dbi);
    if (rc) {
        fprintf(stderr, "fail: mdb_dbi_open(%d:%s)\n", code, mdb_strerror(rc));
        mdb_txn_abort(txn);
        goto LABEL_EXIT2;
    }

    printf("sleeping(%d)...\n", code);
    sleep(slp);
    printf("wake up(%d)\n", code);

    switch (code) {
    case 1:
        key.mv_size = sizeof(code);
        key.mv_data = &code;
        data.mv_size = sizeof(slp);
        data.mv_data = &slp;
        rc = mdb_put(txn, dbi, &key, &data, 0);
        if (rc == 0) {
            fprintf(stderr, "txn commit: code=%d\n", code);
            mdb_txn_commit(txn);
        } else {
            fprintf(stderr, "fail: mdb_put(%d:%s)\n", code, mdb_strerror(rc));
            mdb_txn_abort(txn);
        }
        break;
    case 2:
        fprintf(stderr, "txn abort: code=%d\n", code);
        mdb_txn_abort(txn);
        break;
    default:
        ;
    }

LABEL_EXIT2:
    return NULL;
}

int main(void)
{
    int rc;
    MDB_txn *txn;
    MDB_dbi dbi;

    mkdir(DBDIR, 0755);

    rc = mdb_env_create(&env);
    if (rc) {
        fprintf(stderr, "fail: mdb_env_create(%s)\n", mdb_strerror(rc));
    }
    rc = mdb_env_set_maxdbs(env, 1);
    if (rc) {
        fprintf(stderr, "fail: mdb_env_set_maxdbs(%s)\n", mdb_strerror(rc));
    }
    rc = mdb_env_open(env, DBDIR, MDB_FIXEDMAP, 0664);
    if (rc) {
        fprintf(stderr, "fail: mdb_env_open(%s)\n", mdb_strerror(rc));
        goto LABEL_EXIT1;
    }
    rc = mdb_txn_begin(env, NULL, 0, &txn);
    if (rc) {
        fprintf(stderr, "fail: mdb_txn_begin(%s)\n", mdb_strerror(rc));
        goto LABEL_EXIT1;
    }
    rc = mdb_dbi_open(txn, DBNAME, MDB_CREATE, &dbi);
    if (rc) {
        fprintf(stderr, "fail: mdb_dbi_open(%s)\n", mdb_strerror(rc));
        mdb_txn_abort(txn);
        goto LABEL_EXIT1;
    }
    mdb_txn_commit(txn);


    pthread_t th1;
    pthread_create(&th1, NULL, &thread_func, (void *)1);

    pthread_t th2;
    pthread_create(&th2, NULL, &thread_func, (void *)2);

    pthread_join(th1, NULL);
    pthread_join(th2, NULL);

LABEL_EXIT1:
    mdb_env_close(env);

    return 0;
}