src/server/daemon/resourcepool.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2022 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. 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.
 *
 * 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 HOLDER 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.
 */

#include "resourcepool.h"
#include "request.h"
#include "session.h"
#include "../public/nsapi.h"

#define RESOURCE_POOL_MAX_DEFAULT 32

#define RESOURCE_POOL_MAX_ALLOC 268435455

static UcxMap *resource_pool_types;

int init_resource_pools(void) {
    resource_pool_types = ucx_map_new(4);
    return resource_pool_types ? 0 : 1;
}


int resourcepool_new(ServerConfiguration *cfg, scstr_t type, scstr_t name, ConfigNode *node) {
    ResourceType *restype = ucx_map_sstr_get(resource_pool_types, type);
    if(!restype) {
        log_ereport(LOG_MISCONFIG, "Unknown resource pool type: %s", type.ptr);
        return 1;
    }
    
    // convert ConfigNode to pblock
    // no sub-objects allowed for this specific ConfigNode, therefore
    // it can be represented as key-value-pairs
    pblock *param = config_obj2pblock(cfg->pool, node);
    if(!param) {
        log_ereport(LOG_FAILURE, "resourcepool_new: OOM");
        return 1;
    }
    
    ResourcePool *respool = pool_malloc(cfg->pool, sizeof(ResourcePool));
    if(!respool) {
        log_ereport(LOG_FAILURE, "resourcepool_new: OOM");
        return 1;
    }
    respool->pool = cfg->pool;
    
    void *respool_data = restype->init(cfg->pool, param);
    if(!respool_data) {
        log_ereport(LOG_FAILURE, "Cannot create resource pool data: pool: %s type: %s", name.ptr, type.ptr);
        return 1;
    }
    
    respool->type = restype;
    respool->data = respool_data;
    respool->min = 0; // TODO: get from node
    respool->max = RESOURCE_POOL_MAX_DEFAULT; // TODO: get from node
    
    // don't allow too large resource pools
    // this prevents the need to check malloc integer overflows
    if(respool->max > RESOURCE_POOL_MAX_ALLOC) {
        respool->max = RESOURCE_POOL_MAX_ALLOC;
        log_ereport(LOG_WARN, "Resource pool %s: limit max to %d", name.ptr, respool->max);
    }
    
    respool->resalloc = respool->max;
    respool->resources = pool_malloc(cfg->pool, respool->resalloc * sizeof(void*));
    
    if(!respool->resources || ucx_map_sstr_put(cfg->resources, name, respool)) {
        log_ereport(LOG_FAILURE, "Cannot add resource pool: OOM");
        // the only cleanup we have to do
        restype->destroy(respool_data);
        return 1;
    }
    
    pthread_mutex_init(&respool->lock, NULL);
    pthread_cond_init(&respool->available, NULL);
    
    if(resourcepool_create_resources(respool, respool->max)) {
        log_ereport(LOG_FAILURE, "Resource pool %s: Cannot create resources", name.ptr);
        resourcepool_destroy(respool);
        return 1;
    }
    
    return 0;
}

int resourcepool_create_resources(ResourcePool *pool, int num_res) {
    if(num_res > pool->resalloc) {
        num_res = pool->resalloc;
    }
    
    for(int i=pool->numresources;i<num_res;i++) {
        void *resource = pool->type->createresource(pool->data);
        if(resource) {
            pool->resources[pool->numresources++] = resource;
        } else {
            return 1; // error
        }
    }
    
    return 0;
}

ResourceData* resourcepool_lookup(Session *sn, Request *rq, const char *name, int flags) {
    NSAPIRequest *request = (NSAPIRequest*)rq;
    NSAPISession *session = (NSAPISession*)sn;
    ServerConfiguration *cfg = session->config;
    
    ResourceDataPrivate *res = NULL;
    
    // was this resource already used by this request?
    if(request->resources) {
        res = ucx_map_cstr_get(request->resources, name);
        if(res) {
            return (ResourceData*)res;
        }
    }
    
    // TODO: get cached resource
    
    /*
    ResourceType *type = ucx_map_cstr_get(cfg->resources, name);
    if(!type) {
        return NULL;
    }
    */
    
    
    return NULL;
}

void resourcepool_free(ResourceData *data) {
    
}

void resourcepool_destroy(ResourcePool *respool) {
    // TODO
}