still working in shm

.vscode/settings.json

@@ -3,6 +3,8 @@
         "ostream": "cpp",
         "chrono": "cpp",
         "iostream": "cpp",
-        "iosfwd": "cpp"
+        "iosfwd": "cpp",
+        "fstream": "cpp",
+        "xlocmes": "cpp"
     }
 }

lab4/src/makefile

@@ -15,4 +15,4 @@ run-coms: ./coms.out
 clean:
 	rm a.out coms.out
 
-.PHONY: run-coms
+.PHONY: run-coms clean

lab4/src/shared.cpp

@@ -0,0 +1,260 @@
+#include "important.h"
+#include <iostream>
+#include <cstdint>
+#include <chrono>
+#include <fstream>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include<sys/mman.h>
+#include<sys/stat.h>
+#include<fcntl.h>
+
+using namespace std;
+
+int main(int argc, char *argv[]) {
+
+	// if(argc != 3)
+	// {
+	// 	cout << "usage: ./a.out <path-to-original-image> <path-to-transformed-image>\n\n";
+	// 	exit(0);
+	// }
+
+
+    // struct image_t *input_image = read_ppm_file(argv[1]);
+    // struct image_t *smoothened_image = S1_smoothen(input_image);
+	char buf;
+	pid_t CHILD;
+
+
+	CHILD = fork();
+	if (CHILD == -1) {
+		perror("fork failed!");
+		exit(EXIT_FAILURE);
+	}
+
+	// Parent Process
+	if(CHILD != 0){
+
+        const char *name = "/parent-child";
+        int shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);
+        if (shm_fd == -1) {
+            perror("shm_open");
+            return 1;
+        }
+
+        // Set the size of the shared memory region
+        // size_t size = smoothened_image->height * smoothened_image->width * 3;
+        size_t size = 1024;
+
+        // Resize the shared memory object to the desired size
+        if (ftruncate(shm_fd, size) == -1) {
+            perror("ftruncate");
+            return 1;
+        }
+
+        // Map the shared memory object into the process address space
+        void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+        if (ptr == MAP_FAILED) {
+            perror("mmap");
+            return 1;
+        }
+
+        // Write data to the shared memory
+        sprintf((char *)ptr, "...PACKET...");
+
+        // Unmap the shared memory object
+        if (munmap(ptr, size) == -1) {
+            perror("munmap");
+            return 1;
+        }
+
+        // Close the shared memory file descriptor
+        if (close(shm_fd) == -1) {
+            perror("close");
+            return 1;
+        }
+
+        // Unlink the shared memory object
+        // if (shm_unlink(name) == -1) {
+        //     perror("shm_unlink");
+        //     return 1;
+        // }
+
+
+		printf("parent writing to shm\n");
+		wait(NULL);                /* Wait for child */
+	}
+
+	// Child process
+	else if (CHILD == 0) {    /* Child reads from pipe */
+
+		
+		pid_t GRAND_CHILD = fork();
+
+		if (GRAND_CHILD == -1) {
+			perror("fork failed!");
+			exit(EXIT_FAILURE);
+		}
+
+		// Child Process
+		if(GRAND_CHILD != 0){
+			// close(pipe1[1]);          /* Close unused write end for s1_s2 pipe */
+			// close(pipe2[0]);		   /* Close unused read end for s2_s3 pipe */
+			// char to_print[] = "C : x\n";
+			// while (read(pipe1[0], &buf, 1) > 0)
+			// {
+			// 	printf("child reading from pipe\n");
+			// 	to_print[4] = buf;
+			// 	write(STDOUT_FILENO, &to_print, strlen(to_print));
+			// }
+
+            printf("Child reading from shm...\n");
+
+            const char *name = "/parent-child";
+            int shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);
+            if (shm_fd == -1) {
+                perror("shm_open");
+                return 1;
+            }
+
+            // Set the size of the shared memory region
+            size_t size = 1024;
+
+            // Resize the shared memory object to the desired size
+            if (ftruncate(shm_fd, size) == -1) {
+                perror("ftruncate");
+                return 1;
+            }
+
+            // Map the shared memory object into the process address space
+            void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+            if (ptr == MAP_FAILED) {
+                perror("mmap");
+                return 1;
+            }
+
+            sleep(2);
+
+            // Print the contents of the shared memory
+            char *packet = (char *)ptr;
+            printf("Shared memory contents: %s\n", packet);
+
+            char buffer[1024];
+            strncpy(buffer, packet, 1024);
+
+            // Unmap the shared memory object
+            if (munmap(ptr, size) == -1) {
+                perror("munmap");
+                return 1;
+            }
+
+            // Close the shared memory file descriptor
+            if (close(shm_fd) == -1) {
+                perror("close");
+                return 1;
+            }
+
+			printf("child writing to shm\n");
+
+            const char *name2 = "/child-grandchild";
+            int shm2_fd = shm_open(name2, O_CREAT | O_RDWR, 0666);
+            if (shm2_fd == -1) {
+                perror("shm_open");
+                return 1;
+            }
+
+            // Set the size of the shared memory region
+            // size_t size = smoothened_image->height * smoothened_image->width * 3;
+            // size_t size = 1024;
+
+            // Resize the shared memory object to the desired size
+            if (ftruncate(shm2_fd, size) == -1) {
+                perror("ftruncate");
+                return 1;
+            }
+
+            // Map the shared memory object into the process address space
+            void *ptr2 = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm2_fd, 0);
+            if (ptr2 == MAP_FAILED) {
+                perror("mmap");
+                return 1;
+            }
+
+            // Write data to the shared memory
+            sprintf((char *)ptr2, buffer, 1024);
+
+            // Unmap the shared memory object
+            if (munmap(ptr2, size) == -1) {
+                perror("munmap");
+                return 1;
+            }
+
+            // Close the shared memory file descriptor
+            if (close(shm2_fd) == -1) {
+                perror("close");
+                return 1;
+            }
+
+
+			wait(NULL);
+			exit(EXIT_SUCCESS);
+		}
+
+
+		// GrandChild Process
+		else if (GRAND_CHILD == 0) {    /* GrandChild reads from pipe */
+
+            printf("Grandchild reading from shm...\n");
+
+            const char *name = "/child-grandchild";
+            int shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);
+            if (shm_fd == -1) {
+                perror("shm_open");
+                return 1;
+            }
+
+            // Set the size of the shared memory region
+            size_t size = 1024;
+
+            // Resize the shared memory object to the desired size
+            if (ftruncate(shm_fd, size) == -1) {
+                perror("ftruncate");
+                return 1;
+            }
+
+            // Map the shared memory object into the process address space
+            void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+            if (ptr == MAP_FAILED) {
+                perror("mmap");
+                return 1;
+            }
+
+            sleep(2);
+
+            // Print the contents of the shared memory
+            printf("Shared memory contents: %s\n", (char *)ptr);
+
+            // Unmap the shared memory object
+            if (munmap(ptr, size) == -1) {
+                perror("munmap");
+                return 1;
+            }
+
+            // Close the shared memory file descriptor
+            if (close(shm_fd) == -1) {
+                perror("close");
+                return 1;
+            }
+
+			exit(EXIT_SUCCESS);
+			
+		}
+	}
+
+    cout << "success" << endl;
+    return 0;
+}

lab4/src/shm1.cpp

@@ -29,7 +29,7 @@ int main() {
     }
 
     // Write data to the shared memory
-    sprintf(ptr, "Hello, shared memory!");
+    sprintf((char *)ptr, "Hello, shared memory!");
 
     // Unmap the shared memory object
     if (munmap(ptr, size) == -1) {