First implementation of lab1

.gitignore

@@ -1,5 +1,5 @@
 /.idea/
-/*build*/
+*build*/
 *.o
 *.obj
 *.exe

docker-compose.yml

@@ -1,5 +1,5 @@
 services:
   environment:
-    image: "bgtu/os/environment:l1v0.3"
+    image: "bgtu/os/environment:l1v1"
     build:
       dockerfile: ./environment.dockerfile

environment.dockerfile

@@ -1,6 +1,3 @@
 FROM alpine:3.20.3
 RUN apk update && apk upgrade
-RUN apk add clang cmake linux-headers
+RUN apk add clang cmake linux-headers lldb make gdb
-RUN apk add lldb
-RUN apk add make
-RUN apk add gdb

lab1/v7/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.25)
+project(os)
+
+set(CMAKE_CXX_STANDARD 20)
+
+add_executable(using_pause using_pause.c)
+add_executable(using_signal_handlers using_signal_handlers.c)

lab1/v7/using_pause.c

@@ -0,0 +1,56 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+
+void wait_clocks(clock_t clocks_to_wait) {
+    const clock_t end = clock() + clocks_to_wait;
+    while (clock() < end);
+}
+
+struct ping_pong_data {
+    char const *name;
+    const pid_t pid_to_print;
+    const pid_t pid_to_send;
+    double delay_seconds;
+};
+
+int run_exchange(char const *name, pid_t pid_to_print, pid_t pid_to_send, int wait_first, double delay_seconds) {
+    const clock_t delay_clocks = (clock_t) (CLOCKS_PER_SEC * delay_seconds);
+    if (wait_first)
+        goto WAIT;
+    while (1) {
+        printf("[%s] Got signal\n", name);
+        printf("[%s] PID=%d\n", name, pid_to_print);
+        printf("[%s] Sleeping %lf seconds before sending signal\n", name, delay_seconds);
+        wait_clocks(delay_clocks);
+        printf("[%s] Sending signal\n", name);
+        kill(pid_to_send, SIGUSR1);
+        WAIT:
+        pause();
+    }
+    perror("Program interrupted");
+    return EXIT_SUCCESS;
+}
+
+void noop(int){
+}
+
+int main(void) {
+    signal(SIGUSR1, noop);
+    pid_t parent_pid = getpid();
+    pid_t child_pid = fork();
+
+    switch (child_pid) {
+        case -1:
+            perror("Failed to fork\n");
+            return EXIT_FAILURE;
+        case 0:
+            child_pid = getpid();
+            return run_exchange("c", parent_pid, parent_pid, 1, 2.5);
+        default:
+            return run_exchange("p", child_pid, child_pid, 0, 2.5);
+    }
+}

lab1/v7/using_pipes.c

@@ -0,0 +1,45 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int run_exchange(int in_pipe, int out_pipe) {
+
+}
+
+int main(void) {
+    struct {
+        int in_pipe;
+        int out_pipe;
+    } p2c_pipe, c2p_pipe;
+
+    if (pipe2((int *) &p2c_pipe, O_DIRECT) == -1) {
+        perror("Failed to create pipes\n");
+        return EXIT_FAILURE;
+    }
+    if (pipe2((int *) &c2p_pipe, O_DIRECT) == -1) {
+        close(p2c_pipe.in_pipe);
+        close(p2c_pipe.out_pipe);
+        perror("Failed to create pipes\n");
+        return EXIT_FAILURE;
+    }
+
+    pid_t parent_pid = getpid();
+    pid_t child_pid = fork();
+
+    switch (child_pid) {
+        case -1:
+            close(p2c_pipe.in_pipe);
+            close(p2c_pipe.out_pipe);
+            close(c2p_pipe.in_pipe);
+            close(c2p_pipe.out_pipe);
+            perror("Failed to fork\n");
+            return EXIT_FAILURE;
+        case 0:
+            close(p2c_pipe.in_pipe);
+            close(c2p_pipe.out_pipe);
+        default:
+            close(c2p_pipe.in_pipe);
+            close(p2c_pipe.out_pipe);
+    }
+}

lab1/v7/using_signal_handlers.c

@@ -0,0 +1,83 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+#include <strings.h>
+
+void wait_clocks(clock_t clocks_to_wait) {
+    const clock_t end = clock() + clocks_to_wait;
+    while (clock() < end);
+}
+
+struct ping_pong_data_t {
+    char const *name;
+    pid_t pid_to_print;
+    pid_t pid_to_send;
+    double delay_seconds;
+} ping_pong_data;
+
+
+void do_ping_pong(int signo) {
+    if (signo != SIGUSR1)
+        return;
+
+    const clock_t delay_clocks = (clock_t) (CLOCKS_PER_SEC * ping_pong_data.delay_seconds);
+
+    printf("[%s] Got signal\n", ping_pong_data.name);
+    printf("[%s] PID=%d\n", ping_pong_data.name, ping_pong_data.pid_to_print);
+    printf("[%s] Sleeping %lf seconds before sending signal\n", ping_pong_data.name, ping_pong_data.delay_seconds);
+    wait_clocks(delay_clocks);
+    printf("[%s] Sending signal\n", ping_pong_data.name);
+    kill(ping_pong_data.pid_to_send, SIGUSR1);
+}
+
+volatile int is_running = 1;
+
+void interrupt(int signo) {
+    if (signo != SIGINT)
+        return;
+    is_running = 0;
+}
+
+int main(void) {
+    signal(SIGINT, interrupt);
+
+    pid_t parent_pid = getpid();
+    pid_t child_pid = fork();
+
+
+    switch (child_pid) {
+        case -1:
+            perror("Failed to fork\n");
+            return EXIT_FAILURE;
+        case 0:
+            child_pid = getpid();
+
+            ping_pong_data.name = "c";
+            ping_pong_data.delay_seconds = 2.5;
+            ping_pong_data.pid_to_print = parent_pid;
+            ping_pong_data.pid_to_send = parent_pid;
+
+            signal(SIGUSR1, do_ping_pong);
+
+            break;
+        default:
+            ping_pong_data.name = "c";
+            ping_pong_data.delay_seconds = 2.5;
+            ping_pong_data.pid_to_print = child_pid;
+            ping_pong_data.pid_to_send = child_pid;
+
+            signal(SIGUSR1, do_ping_pong);
+
+            kill(parent_pid, SIGUSR1);
+            
+            break;
+
+    }
+
+    while (is_running)
+        pause();
+    return EXIT_SUCCESS;
+}