Add slightly odd signal testing + fork() example

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile

@@ -101,7 +101,7 @@ bench: Makefile bench.o $(STATICLIB)
 	@printf "  BENCH   %s\n" $(STATICLIB)
 	@$(CC) $(CPPFLAGS) -g -o bench bench.c $(STATICLIB) && ./bench
 
-examples:
+examples: all
 	@$(MAKE) -C examples
 
 test joystick:

examples/Makefile

@@ -24,7 +24,7 @@
 #
 .PHONY: all clean
 
-TARGET      = joystick test
+TARGET      = signal test joystick
 OBJS       := $(addsuffix .o, $(TARGET))
 SRCS       := $(OBJS:.o=.c)
 DEPS       := $(SRCS:.c=.d)
@@ -38,6 +38,8 @@ include ../rules.mk
 
 all: $(TARGET)
 
+signal: signal.o
+
 test: test.o
 
 joystick: joystick.o

examples/signal.c

@@ -0,0 +1,136 @@
+/* Multiple signals, segfault and fork() to test sub-processes.
+ *
+ * Copyright (c) 2015  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#define _GNU_SOURCE
+#include <err.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/user.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "uev.h"
+
+#define UNUSED(arg) arg __attribute__ ((unused))
+#define DO_SEGFAULT 1
+
+typedef struct {
+	int magic;
+	void *ptr;
+} arg_t;
+
+/* Stack is not shared between parent and child, only the heap. */
+static arg_t arg = {
+	.magic = 1337,
+	.ptr = NULL
+};
+
+static int callback(arg_t *arg, int event, void *foo)
+{
+	arg_t *event_arg  = (arg_t *)foo;
+
+	printf("child: got magic %d and ptr %p, with event %d and event arg %p\n",
+	       arg->magic, arg->ptr, event, event_arg);
+
+	arg->magic = 7331;
+	arg->ptr   = &event_arg;
+
+	/* Cause segfault! */
+#if DO_SEGFAULT == 1
+	event_arg->ptr = arg->ptr;
+	printf("child: segfaulting failed!\n");
+#endif
+
+        return 42;
+}
+
+static void sigsegv_cb(uev_ctx_t *UNUSED(ctx), uev_t *UNUSED(w), void *UNUSED(arg), int UNUSED(events))
+{
+	warnx("PID %d caused segfault.", getpid());
+	exit(-1);
+}
+
+static void sigchld_cb(uev_ctx_t *UNUSED(ctx), uev_t *UNUSED(w), void *UNUSED(arg), int UNUSED(events))
+{
+        pid_t pid = waitpid(-1, NULL, WNOHANG);
+
+        if (-1 != pid)
+                warnx("PID %d exited, bye.", pid);
+}
+
+static void work_cb(uev_ctx_t *UNUSED(ctx), uev_t *UNUSED(w), void *arg, int UNUSED(events))
+{
+	int    status = 0;
+        pid_t  pid;
+
+        pid = fork();
+        if (-1 == pid)
+                err(1, "fork");
+	if (!pid) {
+		status = callback(arg, 6137, NULL);
+                exit(status);
+        }
+
+        if (waitpid(pid, &status, 0) == -1)
+                err(1, "waitpid");
+
+	if (WIFEXITED(status))
+		printf("Child exited normally => %d\n", WEXITSTATUS(status));
+	else if (WCOREDUMP(status))
+		printf("Child crashed!\n");
+}
+
+static void exit_cb(uev_ctx_t *ctx, uev_t *UNUSED(w), void *UNUSED(arg), int UNUSED(events))
+{
+        printf("Process deadline reached, exiting!\n");
+	uev_exit(ctx);
+}
+
+int main(void)
+{
+	uev_t sigsegv_watcher, sigchld_watcher, timeout_watcher, deadline_watcher;
+	uev_ctx_t ctx;
+
+	/* Initialize libuEv */
+	uev_init(&ctx);
+	uev_signal_init(&ctx, &sigsegv_watcher, sigsegv_cb, NULL, SIGSEGV);
+	uev_signal_init(&ctx, &sigchld_watcher, sigchld_cb, NULL, SIGCHLD);
+	uev_timer_init(&ctx, &timeout_watcher, work_cb, &arg, 400, 0);
+	uev_timer_init(&ctx, &deadline_watcher, exit_cb, NULL, 1000, 0);
+
+	/* Start event loop */
+	return uev_run(&ctx, 0);
+}
+
+/**
+ * Local Variables:
+ *  version-control: t
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */