qa: ensure awake works correctly in signal handlers

Jehanne's notes (like Plan9 ones) are not reentrant.
Thus an alarm can not be used to interrupt a syscall in a note handler.

Awake instead works properly also in a note handler.

qa/kern/awake_note.c

@@ -0,0 +1,59 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
+ *
+ * Jehanne is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * Jehanne is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <u.h>
+#include <lib9.h>
+
+void
+handler(void *v, char *s)
+{
+	int64_t wakeup;
+	wakeup = awake(1000);
+	while(rendezvous(&wakeup, (void*)1) == (void*)~0)
+		if(jehanne_awakened(wakeup)){
+			print("PASS\n");
+			exits(nil);
+		}
+	print("FAIL in note handler\n");
+	exits("FAIL");
+}
+
+void
+main(int argc, char**argv)
+{
+	int fd, i;
+	if(argc > 1){
+		fd = ocreate(argv[1], OWRITE, 0666);
+		dup(fd, 1);
+		close(fd);
+	}
+
+	if (notify(handler)){
+		fprint(2, "%r\n");
+		exits("notify fails");
+	}
+
+	print("%s %d: waiting for note", argv[0], getpid());
+	for(i = 0; i < 10*1000*1000; ++i)
+		if(i % 4999 == 0){
+			sleep(100);
+			print(".");
+		}
+
+	print("FAIL\n");
+	exits("FAIL");
+}

qa/kern/awake_note.runner

@@ -0,0 +1,23 @@
+#!/cmd/rc
+
+runner=$0
+test = `{echo $runner|sed 's/.runner//'}
+test_output = /tmp/output-`{basename $test}
+
+if ( test -e $test_output) rm $test_output
+
+$test $test_output &
+testpid=$apid
+sleep 1
+echo hi > /proc/$testpid/note
+
+wait $testpid
+
+if ( cat $test_output | grep 'PASS' > /dev/null ) {
+	rm $test_output
+	echo PASS
+	exit PASS
+}
+cat $test_output
+echo FAIL
+exit FAIL

qa/kern/build.json

@@ -12,6 +12,7 @@
 			"alarm.c",
 			"args.c",
 			"awake.c",
+			"awake_note.c",
 			"brk.c",
 			"execl.c",
 			"float.c",

qa/kern/nested_note.c

@@ -1,3 +1,20 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
+ *
+ * Jehanne is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * Jehanne is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+ */
 #include <u.h>
 #include <lib9.h>