add signal api

headers/signal.h

@@ -1,9 +1,12 @@
 #pragma once
 
-#define SIG_DFL -1
-#define SIG_IGN 0
+#include <stdbool.h>
+#include <stdint.h>
 
-enum {
+#define SIG_DFL 0
+#define SIG_IGN -1
+
+typedef enum {
 	SIGABRT,   // Abort signal from abort(3)
 	SIGALRM,   // Timer signal from alarm(2)
 	SIGBUS,    // Bus error (bad memory access)
@@ -44,11 +47,16 @@ enum {
 	SIGXFSZ,   // File size limit exceeded (4.2BSD); see setrlimit(2)
 	SIGWINCH,  // Window resize signal (4.3BSD, Sun)
 	SIG_INT,   // Interrupt from keyboard
-};
+	LAST
+} SIGNAL_CODE;
 
-typedef void (*sighandler_t)(int);
+typedef void (*signal_handler_t)(int);
 
-struct signal {
-	int signum;
-	sighandler_t handler;
-};
+void signal(SIGNAL_CODE sig_num, void *handler);
+void kill(int pid, SIGNAL_CODE sig_num);
+void exec_signal_pending(void);
+
+struct signal_data {
+	void *handlers[LAST];
+	uint32_t pending;
+};

headers/task.h

@@ -2,6 +2,7 @@
 
 #include "list.h"
 #include "memory.h"
+#include "signal.h"
 
 #include <stdint.h>
 
@@ -23,7 +24,7 @@ struct task {
 	uint8_t uid;
 	struct task *daddy;
 	struct task *child;
-	struct list **signals;
+	struct signal_data signals;
 	struct task *next;
 	struct task *prev;
 };