99 lines
2.1 KiB
C
99 lines
2.1 KiB
C
#include "pid_manager.h"
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#include <pthread.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <unistd.h>
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#define MIN_PID 300
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#define MAX_PID 5000
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#define SIZE (MAX_PID - MIN_PID + 1)
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typedef struct __PID_REGISTRY__ {
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bool *pids;
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pthread_mutex_t mtx;
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} pid_registry_t;
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void *runner(void *param);
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pid_registry_t registry;
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int allocate_map(void) {
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registry.pids = (bool *)calloc(SIZE, sizeof(bool));
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if (pthread_mutex_init(®istry.mtx, NULL) != 0) {
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perror("Cannot create mutex\n");
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return -1;
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}
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return 1;
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}
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int deallocate_map(void) {
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if (registry.pids == NULL) {
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perror("Cannot deallocate unallocated struct\n");
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return 1;
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}
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free(registry.pids);
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registry.pids = NULL;
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return pthread_mutex_destroy(®istry.mtx);
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}
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int allocate_pid(void) {
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int pid = -1;
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for (int i = 0; i < SIZE && pid == -1; i++) {
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pthread_mutex_lock(®istry.mtx);
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if (!registry.pids[i]) {
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registry.pids[i] = true;
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pid = i + MIN_PID;
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}
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pthread_mutex_unlock(®istry.mtx);
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}
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return pid;
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}
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void release_pid(int pid) {
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if (pid >= MIN_PID && pid <= MAX_PID) {
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pthread_mutex_lock(®istry.mtx);
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registry.pids[pid - MIN_PID] = false;
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pthread_mutex_unlock(®istry.mtx);
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}
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}
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void *runner(void *param) {
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const pid_t self = gettid();
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const int pid = allocate_pid();
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printf("Run thread %d handle PID %d.\n", self, pid);
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sleep(rand() % 31);
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release_pid(pid);
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printf("Thread %d ended\n", self);
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pthread_exit(0);
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}
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int main(void) {
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const int thread_count = 100;
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pthread_t threads[thread_count];
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if (!allocate_map()) {
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perror("Failed to allocate PID Manager\n");
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exit(EXIT_FAILURE);
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}
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for (int i = 0; i < thread_count; i++) {
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printf("Created thread %d\n", i);
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pthread_create(&threads[i], NULL, runner, NULL);
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}
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for (int i = 0; i < thread_count; i++) {
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printf("Waiting thread %d\n", i);
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pthread_join(threads[i], NULL);
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}
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if (!deallocate_map()) {
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perror("Failed to deallocate PID Manager\n");
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exit(EXIT_FAILURE);
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}
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return EXIT_SUCCESS;
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}
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