我无法退出或终止发送信号的子进程。
你能告诉我我在这段代码中做错了什么吗：
//###################################### INVERTER.C (main)
#include <semaphore.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <math.h>
#include <errno.h>
#include <unistd.h>
#include "timeprofiler.h"
#include "ppmtools.h"
//Global vars:
int shmids[4], shmPixelId, *total_lines, *processed_lines, *next_line, *buf_vars;
//To share unnamed semaphores between processes, they must be allocated in a shared memory.
mem_struct *sh_mm;
//unnamed semaphores
sem_t *mutex1, *mutex2, *mutex3, *sem_remaining_lines;
//struct that will hold the image in shared memory
image_struct *image;
pid_t *workersPID;
header *h;
int main(int argc, char *argv[]) {
int i, j, k, cur = 0, id;
pixel *row;
double start, stop, startms, stopms;
if (argc < 3) {
printf("Incorrect usage.\nPlease use \"./invert input_filename.ppm output_filename.ppm\"\n");
return -1;
}
//BLOCK ALL SIGNAL
sigset_t block_ctrlc;
sigfillset(&block_ctrlc);
sigdelset(&block_ctrlc, SIGINT);
sigprocmask(SIG_BLOCK, &block_ctrlc, NULL);
//start timer
start = getCurrentTimeMicro();
startms = getCurrentTimeMili();
printf("Opening input file [%s]\n", argv[1]);
FILE *fpin = fopen(argv[1], "r");
if (fpin == NULL) {
printf("Could not open input file\n");
return -1;
}
printf("Opening output file [%s]\n", argv[2]);
FILE *fpout = fopen(argv[2], "w");
if (fpout == NULL) {
printf("Could not open output file\n");
return -1;
}
printf("Getting header\n");
h = getImageHeader(fpin);
if (h == NULL) {
printf("Error getting header from file\n");
return -1;
}
printf("Got file Header: %s - %u x %u - %u\n", h->type, h->width, h->height, h->depth);
printf("Saving header to output file\n");
if (writeImageHeader(h, fpout) == -1) {
printf("Could not write to output file\n");
return -1;
}
init();
printf("After init...\n");
//alloc mem space for one row (width * size of one pixel struct)
row = (pixel *) malloc(h->width * sizeof (pixel));
printf("Starting work\n");
for (i = 0; i < h->height; i++) {
printf("Reading row... \n");
if (getImageRow(h->width, row, fpin) == -1) {
printf("Error while reading row\n");
}
printf("Got row %d || \n", (i + 1));
for (j = cur, k = 0; j < cur + h->width; j++, k++) {
image->pixel_data[j].red = row[k].red;
image->pixel_data[j].blue = row[k].blue;
image->pixel_data[j].green = row[k].green;
}
cur += h->width;
}
/*Creates workers*/
workersPID = (pid_t*) malloc(sizeof (pid_t) *((NUM_WORKERS)));
for (i = 0; i < NUM_WORKERS; i++) {
id = fork();
if (id == -1) {
printf("Error creating worker no %d\n", i);
return (EXIT_FAILURE);
} else if (id == 0) {
workersPID[i] = getpid();
printf("Launching son with pid %d\n", getpid());
worker(i);
}
}
cur = 0;
sem_wait(mutex2);
/*Writes the invert image on the output file*/
for (i = 0; i < h->height; i++) {
for (j = cur, k = 0; j < cur + h->width; j++, k++) {
row[k].red = image->pixel_data[j].red;
row[k].blue = image->pixel_data[j].blue;
row[k].green = image->pixel_data[j].green;
}
cur += h->width;
printf("Saving row... \n");
if (writeRow(h->width, row, fpout) == -1) {
printf("Error while writing row\n");
}
printf("Done\n");
}
printf("Cleaning up...\n");
//clean up row
free(row);
//clean up header
free(h);
printf("Closing file pointers.\n");
fclose(fpin);
fclose(fpout);
//stop timer
stop = getCurrentTimeMicro();
stopms = getCurrentTimeMili();
for (i = 0; i < NUM_WORKERS; i++) {
if (workersPID[i]) {
kill(workersPID[i], SIGTERM);
waitpid(workersPID[i], NULL, 0);
}
}
terminate();
printTimeElapsed(start, stop, "microseconds");
printTimeElapsed(startms, stopms, "miliseconds");
printf("Done!\n");
return 0;
}
void init() {
//create shared memory to hold the source image:
if ((shmids[0] = shmget(IPC_PRIVATE, sizeof (image_struct), IPC_CREAT | 0700)) == -1) {
printf("shmget to allocate image struct failed. Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
image = (image_struct*) shmat(shmids[0], NULL, 0);
//shared memory to allocate the pointer to pointer pixel_data
if ((shmids[1] = shmget(IPC_PRIVATE, h->width * h->height * sizeof (pixel), IPC_CREAT | 0700)) == -1) {
printf("shmget to allocate pixel_data array failed. Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
image->pixel_data = (pixel*) shmat(shmids[1], NULL, 0);
/*Shared Memory segment for 3 integers*/
if ((shmids[2] = shmget(IPC_PRIVATE, 3 * sizeof (int), IPC_CREAT | 0700)) == -1) {
printf("shmget to allocate the 3 integers failed. Errno returned; %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
buf_vars = (int*) shmat(shmids[2], NULL, 0);
total_lines = &buf_vars[0];
processed_lines = &buf_vars[1];
next_line = &buf_vars[2];
*processed_lines = *next_line = 0;
*total_lines = h->height;
if ((shmids[3] = shmget(IPC_PRIVATE, sizeof (mem_struct), IPC_CREAT | 0700)) == -1) {
printf("shmget to allocate mem_Struct for semaphores failed. Errno returned %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
sh_mm = (mem_struct*) shmat(shmids[3], NULL, 0);
if (sem_init(&sh_mm->mutex1, 1, 1) == -1) {
printf("Error initializing semaphore mutex1.Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
mutex1 = &sh_mm->mutex1;
if (sem_init(&sh_mm->mutex2, 1, 0) == -1) {
printf("Error initializing semaphore mutex2.Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
mutex2 = &sh_mm->mutex2;
if (sem_init(&sh_mm->mutex3, 1, 1) == -1) {
printf("Error initializing semaphore mutex3.Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
mutex3 = &sh_mm->mutex3;
if (sem_init(&sh_mm->sem_remaining_lines, 1, h->height) == -1) {
printf("Error initializing semaphore sem_remaining_lines.Errno returned: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
sem_remaining_lines = &sh_mm->sem_remaining_lines;
}
/*Worker process*/
void worker(int id) {
int i, k, cur = 0;
pixel *row;
//Block all signals, except SIGINT and SIGKILL which are handled
sigset_t block_ctrlc;
sigfillset(&block_ctrlc);
sigdelset(&block_ctrlc, SIGINT);
sigdelset(&block_ctrlc, SIGTERM);
sigprocmask(SIG_BLOCK, &block_ctrlc, NULL);
signal(SIGINT, handle_signal);
signal(SIGTERM, handle_signal);
while (sem_wait(sem_remaining_lines)!= -1) { //if there are still lines to read, go on
sem_wait(mutex3);
cur = *next_line; //current image's line
*next_line += h->width; //refreshs line for the next worker
sem_post(mutex3);
row = (pixel *) malloc(h->width * sizeof (pixel));
for (i = cur, k = 0; i < cur + h->width; i++, k++) {
row[k].red = image->pixel_data[i].red;
row[k].blue = image->pixel_data[i].blue;
row[k].green = image->pixel_data[i].green;
}
//printf("% - Inverting row... \n",id);
invertRow(h->width, row); //invert
//printf("Done || \n");
for (i = cur, k = 0; i < cur + h->width; i++, k++) {
image->pixel_data[i].red = row[k].red;
image->pixel_data[i].blue = row[k].blue;
image->pixel_data[i].green = row[k].green;
}
sem_wait(mutex1);
*processed_lines += 1; //increases the number of inverted lines
if (*processed_lines == *total_lines) { //check if it reaches last line
sem_post(mutex2); //if so, wakes the master telling that is ready
}
sem_post(mutex1);
}
//printf("Son %d is exiting\n",id);
exit(0);
}
void handle_signal(int signum) {
if(signum == SIGINT)
signal(SIGINT, handle_signal);
else
signal(SIGTERM, handle_signal);
exit(0);
}
void terminate() {
int i;
//close semaphores
sem_destroy(mutex1);
sem_destroy(mutex2);
sem_destroy(mutex3);
sem_destroy(sem_remaining_lines);
//cleans up shared memory = removes shared memory segments
for (i = 0; i < 4; i++) {
shmctl(shmids[i], IPC_RMID, NULL);
}
}
我将在此处留下对作业的解释（顺便说一句已经完成）：
1 页 pdf