sledge/runtime/include/module.h

#ifndef SFRT_MODULE_H
#define SFRT_MODULE_H

#include <uv.h>
#include "types.h"

struct module {
	char name[MOD_NAME_MAX];
	char path[MOD_PATH_MAX];

	void *dl_handle;
	mod_main_fn_t entry_fn;
	mod_glb_fn_t glb_init_fn;
	mod_mem_fn_t mem_init_fn;
	mod_tbl_fn_t tbl_init_fn;

	struct indirect_table_entry indirect_table[INDIRECT_TABLE_SIZE];

	i32 nargs;
	u32 stack_size; // a specification?
	u64 max_memory; //perhaps a specification of the module. (max 4GB)
	u32 timeout; //again part of the module specification.

	u32 refcnt; //ref count how many instances exist here.

	// stand-alone vs serverless
#ifndef STANDALONE
	struct sockaddr_in srvaddr;
	int srvsock, srvport;
	// unfortunately, using UV for accepting connections is not great!
	// on_connection, to create a new accepted connection, will have to
	// init a tcp handle, which requires a uvloop. cannot use main as 
	// rest of the connection is handled in sandboxing threads, with per-core(per-thread) tls data-structures.
	// so, using direct epoll for accepting connections.
//	uv_handle_t srvuv;
	unsigned long max_req_sz, max_resp_sz, max_rr_sz; // req/resp from http..
#endif
};

struct module *module_alloc(char *mod_name, char *mod_path, i32 nargs, u32 stack_sz, u32 max_heap, u32 timeout, int port, int req_sz, int resp_sz);
// frees only if refcnt == 0
void module_free(struct module *mod);
struct module *module_find_by_name(char *name);
struct module *module_find_by_sock(int sock);

static inline int
module_is_valid(struct module *mod)
{
	if (mod && mod->dl_handle && mod->entry_fn) return 1;

	return 0;
}

static inline void
module_table_init(struct module *mod)
{
	// called in a sandbox.
	mod->tbl_init_fn();
}

static inline void
module_memory_init(struct module *mod)
{
	// called in a sandbox.
	mod->mem_init_fn();
}

static inline i32
module_entry(struct module *mod, i32 argc, i32 argv)
{
	return mod->entry_fn(argc, argv);
}

// instantiate this module.
static inline void
module_acquire(struct module *mod)
{
	// FIXME: atomic.
	mod->refcnt++;
}

static inline void
module_release(struct module *mod)
{
	// FIXME: atomic.
	mod->refcnt--;
}

static inline i32
module_nargs(struct module *mod)
{
	return mod->nargs;
}

#endif /* SFRT_MODULE_H */