common.h

/*
 * SMT-Aware Multi-Process Job Scheduling System
 * Common Header File
 * 
 * This header defines shared data structures and constants used by
 * producers, scheduler, and worker processes.
 */

#ifndef COMMON_H
#define COMMON_H

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/wait.h>
#include <pthread.h>
#include <sched.h>

/* ============== Configuration Constants ============== */

#define MAX_PRODUCERS       3       /* Number of producer processes */
#define MAX_WORKERS         4       /* Number of worker processes */
#define THREADS_PER_WORKER  4       /* Threads in each worker's pool */
#define MAX_QUEUE_SIZE      100     /* Maximum jobs in scheduler queue */
#define MAX_JOB_NAME        32      /* Maximum job name length */

/* IPC Keys */
#define MSG_QUEUE_KEY       0x1234  /* Message queue key */
#define SHM_KEY             0x5678  /* Shared memory key */
#define SEM_KEY             0x9ABC  /* Semaphore key */

/* Message Types */
#define MSG_TYPE_JOB        1       /* Job submission message */
#define MSG_TYPE_DISPATCH   2       /* Job dispatch to worker */
#define MSG_TYPE_COMPLETE   3       /* Job completion notification */
#define MSG_TYPE_SHUTDOWN   99      /* Shutdown signal */

/* Job Priority Levels */
#define PRIORITY_LOW        1
#define PRIORITY_MEDIUM     2
#define PRIORITY_HIGH       3
#define PRIORITY_CRITICAL   4

/* ============== Data Structures ============== */

/* Job structure - represents a unit of work */
typedef struct {
    int job_id;                     /* Unique job identifier */
    int producer_id;                /* ID of producer that created job */
    int priority;                   /* Job priority (1-4) */
    int complexity;                 /* Simulated work units (ms) */
    char job_name[MAX_JOB_NAME];    /* Human-readable name */
    struct timespec submit_time;    /* Time job was submitted */
    struct timespec start_time;     /* Time job execution started */
    struct timespec end_time;       /* Time job completed */
} job_t;

/* Message structure for IPC message queue */
typedef struct {
    long msg_type;                  /* Message type for filtering */
    int target_worker;              /* Target worker ID (-1 for scheduler) */
    job_t job;                      /* Embedded job data */
} job_message_t;

/* Worker status in shared memory */
typedef struct {
    int worker_id;
    int active_threads;             /* Currently running threads */
    int jobs_completed;             /* Total jobs finished */
    int current_load;               /* Current workload estimate */
    pthread_mutex_t lock;           /* Mutex for thread-safe updates */
} worker_status_t;

/* Shared memory structure */
typedef struct {
    int shutdown_flag;              /* Global shutdown signal */
    int total_jobs_submitted;       /* Counter for all jobs */
    int total_jobs_completed;       /* Counter for completed jobs */
    worker_status_t workers[MAX_WORKERS];
    pthread_mutex_t global_lock;    /* Global mutex */
} shared_state_t;

/* Thread pool job queue entry */
typedef struct job_queue_entry {
    job_t job;
    struct job_queue_entry *next;
} job_queue_entry_t;

/* Thread pool structure */
typedef struct {
    pthread_t threads[THREADS_PER_WORKER];
    pthread_mutex_t queue_lock;
    pthread_cond_t queue_cond;
    job_queue_entry_t *queue_head;
    job_queue_entry_t *queue_tail;
    int queue_size;
    int shutdown;
    int worker_id;
    int msg_queue_id;
    shared_state_t *shared_mem;
} thread_pool_t;

/* ============== Utility Functions ============== */

/* Get current time in milliseconds */
static inline long get_time_ms(void) {
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
}

/* Calculate time difference in milliseconds */
static inline double time_diff_ms(struct timespec *start, struct timespec *end) {
    return (end->tv_sec - start->tv_sec) * 1000.0 +
           (end->tv_nsec - start->tv_nsec) / 1000000.0;
}

/* Color codes for terminal output */
#define COLOR_RESET   "\033[0m"
#define COLOR_RED     "\033[31m"
#define COLOR_GREEN   "\033[32m"
#define COLOR_YELLOW  "\033[33m"
#define COLOR_BLUE    "\033[34m"
#define COLOR_MAGENTA "\033[35m"
#define COLOR_CYAN    "\033[36m"

/* Logging macros */
#define LOG_PRODUCER(id, fmt, ...) \
    printf(COLOR_CYAN "[PRODUCER %d] " fmt COLOR_RESET "\n", id, ##__VA_ARGS__)

#define LOG_SCHEDULER(fmt, ...) \
    printf(COLOR_YELLOW "[SCHEDULER] " fmt COLOR_RESET "\n", ##__VA_ARGS__)

#define LOG_WORKER(id, fmt, ...) \
    printf(COLOR_GREEN "[WORKER %d] " fmt COLOR_RESET "\n", id, ##__VA_ARGS__)

#define LOG_THREAD(wid, tid, fmt, ...) \
    printf(COLOR_MAGENTA "[W%d:T%ld] " fmt COLOR_RESET "\n", wid, tid, ##__VA_ARGS__)

#define LOG_ERROR(fmt, ...) \
    fprintf(stderr, COLOR_RED "[ERROR] " fmt COLOR_RESET "\n", ##__VA_ARGS__)

#define LOG_INFO(fmt, ...) \
    printf(COLOR_BLUE "[INFO] " fmt COLOR_RESET "\n", ##__VA_ARGS__)

#endif /* COMMON_H */