sledge/runtime/include/runtime.h

#pragma once

#include <pthread.h>
#include <sys/epoll.h> /* for epoll_create1(), epoll_ctl(), struct epoll_event */
#include <stdatomic.h>
#include <stdbool.h>

#include "types.h"

#define LISTENER_THREAD_CORE_ID          0 /* Dedicated Listener Core */
#define LISTENER_THREAD_MAX_EPOLL_EVENTS 128

#define RUNTIME_LOG_FILE                  "awesome.log"
#define RUNTIME_MAX_SANDBOX_REQUEST_COUNT (1 << 19) /* random! */
#define RUNTIME_READ_WRITE_VECTOR_LENGTH  16
#define RUNTIME_GRANULARITY               100000

#define likely(x)   __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)

/*
 * Descriptor of the epoll instance used to monitor the socket descriptors of registered
 * serverless modules. The listener cores listens for incoming client requests through this.
 */
extern int runtime_epoll_file_descriptor;

/*
 * Assumption: All cores are the same speed
 * See runtime_get_processor_speed_MHz for further details
 */
extern float runtime_processor_speed_MHz;

/* Count of worker threads and array of their pthread identifiers */
extern pthread_t runtime_worker_threads[];
extern uint32_t  runtime_worker_threads_count;
extern uint64_t  runtime_admissions_capacity;

/* Listener Core Counts */
extern _Atomic uint32_t runtime_total_requests;
extern _Atomic uint32_t runtime_total_sandbox_requests;
extern _Atomic uint32_t runtime_total_5XX_responses;

#ifdef LOG_TOTAL_REQS_RESPS
/* Counts to track requests and responses */
extern _Atomic uint32_t runtime_total_2XX_responses;
extern _Atomic uint32_t runtime_total_4XX_responses;
#endif

#ifdef LOG_SANDBOX_TOTALS
/* Counts to track sanboxes running through state transitions */
extern _Atomic uint32_t runtime_total_freed_requests;
extern _Atomic uint32_t runtime_total_initialized_sandboxes;
extern _Atomic uint32_t runtime_total_runnable_sandboxes;
extern _Atomic uint32_t runtime_total_blocked_sandboxes;
extern _Atomic uint32_t runtime_total_running_sandboxes;
extern _Atomic uint32_t runtime_total_preempted_sandboxes;
extern _Atomic uint32_t runtime_total_returned_sandboxes;
extern _Atomic uint32_t runtime_total_error_sandboxes;
extern _Atomic uint32_t runtime_total_complete_sandboxes;
#endif

/*
 * Unitless estimate of the instantaneous fraction of system capacity required to complete all previously
 * admitted work. This is used to calculate free capacity as part of admissions control
 *
 * The estimated requirements of a single admitted request is calculated as
 * estimated execution time (cycles) / relative deadline (cycles)
 *
 * These estimates are incremented on request acceptance and decremented on request completion (either
 * success or failure)
 */
extern _Atomic uint64_t runtime_admitted;

void         alloc_linear_memory(void);
void         expand_memory(void);
INLINE char *get_function_from_table(uint32_t idx, uint32_t type_id);
INLINE char *get_memory_ptr_for_runtime(uint32_t offset, uint32_t bounds_check);
void         runtime_initialize(void);
void         listener_thread_initialize(void);
void         stub_init(int32_t offset);

unsigned long long __getcycles(void);

/**
 * Used to determine if running in the context of a worker thread
 * @returns true if worker. false if listener core
 */
static inline bool
runtime_is_worker()
{
	pthread_t self = pthread_self();
	for (int i = 0; i < runtime_worker_threads_count; i++) {
		if (runtime_worker_threads[i] == self) return true;
	}

	return false;
}

enum RUNTIME_SCHEDULER
{
	RUNTIME_SCHEDULER_FIFO = 0,
	RUNTIME_SCHEDULER_EDF  = 1
};

static inline char *
print_runtime_scheduler(enum RUNTIME_SCHEDULER variant)
{
	switch (variant) {
	case RUNTIME_SCHEDULER_FIFO:
		return "RUNTIME_SCHEDULER_FIFO";
	case RUNTIME_SCHEDULER_EDF:
		return "RUNTIME_SCHEDULER_EDF";
	}
};

extern enum RUNTIME_SCHEDULER runtime_scheduler;