DO NOT MERGE, use previous. Trying to get ctrl-z to work.. no success yet, maybe breaks stufffixing_signals

6 files changed, 62 insertions, 38 deletions

diff --git a/02_exercise/CMakeLists.txt b/02_exercise/CMakeLists.txt
index e47f0ee..6a2077f 100644
--- a/02_exercise/CMakeLists.txt
+++ b/02_exercise/CMakeLists.txt
@@ -12,7 +12,7 @@ find_package(Sanitizers)
 
 add_executable(prog prog.c)
 
-add_executable(shell shell.c)
+add_executable(shell shell.c signal_handler.c signal_handler.h)
 target_link_libraries(shell PRIVATE array prompt_utils process builtin)
 target_compile_options(shell INTERFACE ${PROJECT_WARNINGS})
 add_sanitizers(shell)
diff --git a/02_exercise/builtins.c b/02_exercise/builtins.c
index 4ab4c7c..1d1cc69 100644
--- a/02_exercise/builtins.c
+++ b/02_exercise/builtins.c
@@ -1,22 +1,16 @@
-#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <wait.h>
 #include <stdlib.h>
 
-
 #include "array.h"
 #include "builtins.h"
-
-void handle(int sig) {
-    /* Do nothing. */
-}
-
+#include "signal_handler.h"
 
 void builtin_wait(process p, bool bind) {
     struct sigaction handler;
-    handler.sa_handler = handle;
+    handler.sa_handler = signal_handler;
     sigemptyset(&handler.sa_mask);
     handler.sa_flags = 0;
 
@@ -43,24 +37,15 @@ void builtin_wait(process p, bool bind) {
             pid_t current_pid = arrayPop(pids);
             if (bind) {
                 printf("Resuming %ld...\n", (long) current_pid);
+                sigaction(SIGINT, &handler, NULL);
             } else {
                 printf("Waiting for %ld...\n", (long) current_pid);
             }
             // install signal handler without SA_RESTART, so waitpid gets interrupted
             sigaction(SIGINT, &handler, NULL);
             if (waitpid(current_pid, &status, WUNTRACED) < 0) {
-                if (EINTR == errno) {
-                    // cancelled by ctrl-c
-                    if (bind) {
-                        kill(current_pid, SIGKILL);
-                        waitpid(current_pid, &status, WUNTRACED);
-                        printf("Killed [%ld]\n", (long)current_pid);
-                    } else {
-                        kill(current_pid, SIGCONT);
-                    }
-                } else {
-                    perror("Could not wait for process");
-                }
+                sigaction(SIGINT, &handler, NULL);
+                handle_interrupt(current_pid);
             } else {
                 printf("[%i] TERMINATED\n", current_pid);
                 if (WIFEXITED(status)) {
@@ -77,7 +62,7 @@ void builtin_wait(process p, bool bind) {
                            WEXITSTATUS(status));
                 }
             }
-            signal(SIGINT, SIG_DFL);
+            sigaction(SIGINT, &handler, NULL);
         }
     }
 
diff --git a/02_exercise/process.c b/02_exercise/process.c
index 0b69074..2479955 100644
--- a/02_exercise/process.c
+++ b/02_exercise/process.c
@@ -3,10 +3,11 @@
 #include <string.h>
 #include <unistd.h>
 #include <wait.h>
+#include <errno.h>
 
 #include "array.h"
 #include "process.h"
-
+#include "signal_handler.h"
 
 // given a substring of a line tries to parse out as much information as possible
 int parse_command(char const *line, char const *end, process *p) {
@@ -142,7 +143,12 @@ int exec_command(process p) {
         printf("[%i]\n", p.pid);
 
     if (waitpid(p.pid, &status, p.blocking ? 0 : WNOHANG) < 0) {
-        fprintf(stderr, "wait error'ed out\n");
+        if (EINTR == errno) {
+            // cancelled by ctrl-c
+            handle_interrupt(p.pid);
+        } else {
+            perror("Could not wait for process");
+        }
     }
 
     return WEXITSTATUS(status);
diff --git a/02_exercise/shell.c b/02_exercise/shell.c
index 03ff6b3..f32bb95 100644
--- a/02_exercise/shell.c
+++ b/02_exercise/shell.c
@@ -3,28 +3,16 @@
 #include <string.h>
 #include <unistd.h>
 #include <stdbool.h>
-#include <wait.h>
 #include <errno.h>
 
 #include "array.h"
 #include "process.h"
-#include "prompt_utils.h"
 #include "builtins.h"
+#include "prompt_utils.h"
+#include "signal_handler.h"
 
 process *processes;
 
-void signal_handler(int signal) {
-    printf("Received signal %d", signal);
-    if (signal == SIGINT) {
-        for (size_t i = 0; i < arrayLen(processes); ++i) {
-            pid_t pid = processes[i].pid;
-            if (pid != 0) {
-                kill(pid, SIGINT);
-            }
-        }
-    }
-}
-
 int main(void) {
     setvbuf(stderr, NULL, _IONBF, 0);
     setvbuf(stdout, NULL, _IONBF, 0);
@@ -59,6 +47,8 @@ int main(void) {
             exit(-1);
         }
 
+        interrupt_issued = 0;
+
         if (strspn(line, " \n\t") == strlen(line)) {
             // skip empty lines - empty being just spaces or tabs
             continue;
diff --git a/02_exercise/signal_handler.c b/02_exercise/signal_handler.c
new file mode 100644
index 0000000..e135739
--- /dev/null
+++ b/02_exercise/signal_handler.c
@@ -0,0 +1,30 @@
+#include "signal_handler.h"
+
+#include <wait.h>
+#include <stdio.h>
+#include <unistd.h>
+
+void signal_handler(int signal) {
+    if (signal == SIGINT) {
+        interrupt_issued = 1;
+    } else if (signal == SIGTSTP) {
+        stop_issued = 1;
+        kill(getpid(), SIGINT);
+    }
+}
+
+void handle_interrupt(pid_t pid) {
+    int status;
+    if (stop_issued) {
+        stop_issued = 0;
+        interrupt_issued = 0;
+    } else if (interrupt_issued) {
+        interrupt_issued = 0;
+        kill(pid, SIGKILL);
+        waitpid(pid, &status, 0);
+        printf("Killed [%ld]\n", (long)pid);
+        return;
+    }
+    kill(pid, SIGCONT);
+    printf("[%ld]\n", (long)pid);
+}
\ No newline at end of file
diff --git a/02_exercise/signal_handler.h b/02_exercise/signal_handler.h
new file mode 100644
index 0000000..b30c5ec
--- /dev/null
+++ b/02_exercise/signal_handler.h
@@ -0,0 +1,13 @@
+#ifndef BETRIEBSYSTEME_SIGNAL_HANDLER_H
+#define BETRIEBSYSTEME_SIGNAL_HANDLER_H
+
+#include <signal.h>
+
+static volatile sig_atomic_t stop_issued = 0;
+static volatile sig_atomic_t interrupt_issued = 0;
+
+void signal_handler(int sig);
+
+void handle_interrupt(pid_t pid);
+
+#endif //BETRIEBSYSTEME_SIGNAL_HANDLER_H