clean up handling of thread/nothread mode, locking

src/internal/libc.h

@@ -7,8 +7,8 @@
 struct __libc {
 	int *(*errno_location)(void);
 	void (*testcancel)(void);
-	void (*lock)(volatile int *);
-	void (*lockfile)(FILE *);
+	int threaded;
+	int canceldisable;
 	void (*fork_handler)(int);
 	int (*atexit)(void (*)(void));
 	void (*fini)(void);
@@ -16,7 +16,6 @@ struct __libc {
 	volatile int threads_minus_1;
 	int ofl_lock;
 	FILE *ofl_head;
-	int canceldisable;
 };
 
 
@@ -40,7 +39,7 @@ extern struct __libc *__libc_loc(void) __attribute__((const));
 void __lock(volatile int *);
 void __lockfile(FILE *);
 #define LOCK(x) (libc.threads_minus_1 ? (__lock(x),1) : ((void)(x),1))
-#define UNLOCK(x) (*(x)=0)
+#define UNLOCK(x) (*(volatile int *)(x)=0)
 
 int __rsyscall(int, long, long, long, long, long, long);
 

src/internal/stdio_impl.h

@@ -24,7 +24,7 @@
 
 #define UNGET 8
 
-#define FLOCK(f) ((libc.lockfile && (f)->lock>=0) ? (libc.lockfile((f)),0) : 0)
+#define FLOCK(f) ((libc.threads_minus_1 && (f)->lock>=0) ? (__lockfile((f)),0) : 0)
 #define FUNLOCK(f) ((f)->lockcount && (--(f)->lockcount || ((f)->lock=0)))
 
 #define F_PERM 1

src/process/fork.c

@@ -8,7 +8,7 @@ pid_t fork(void)
 	pid_t ret;
 	if (libc.fork_handler) libc.fork_handler(-1);
 	ret = syscall(SYS_fork);
-	if (libc.lock && !ret) {
+	if (libc.threaded && !ret) {
 		pthread_t self = __pthread_self();
 		self->tid = self->pid = syscall(SYS_getpid);
 		libc.threads_minus_1 = 0;

src/stdio/flockfile.c

@@ -3,9 +3,6 @@
 
 void flockfile(FILE *f)
 {
-	if (!libc.lockfile) {
-		pthread_self();
-		libc.lockfile = __lockfile;
-	}
+	if (!libc.threaded) pthread_self();
 	__lockfile(f);
 }

src/stdio/ftrylockfile.c

@@ -4,7 +4,6 @@
 int ftrylockfile(FILE *f)
 {
 	int tid = pthread_self()->tid;
-	if (!libc.lockfile) libc.lockfile = __lockfile;
 	if (f->lock == tid) {
 		if (f->lockcount == INT_MAX)
 			return -1;

src/thread/cancel_impl.c

@@ -17,7 +17,7 @@ long (__syscall_cp)(long nr, long u, long v, long w, long x, long y, long z)
 	uintptr_t old_sp, old_ip;
 	long r;
 
-	if (!libc.lock || (self = __pthread_self())->canceldisable)
+	if (!libc.threaded || (self = __pthread_self())->canceldisable)
 		return __syscall(nr, u, v, w, x, y, z);
 
 	old_sp = self->cp_sp;

src/thread/pthread_create.c

@@ -44,18 +44,6 @@ void __pthread_unwind_next(struct __ptcb *cb)
 	__syscall(SYS_exit, 0);
 }
 
-static void init_threads()
-{
-	sigset_t set;
-	libc.lock = __lock;
-	libc.lockfile = __lockfile;
-
-	sigemptyset(&set);
-	sigaddset(&set, SIGSYSCALL);
-	sigaddset(&set, SIGCANCEL);
-	__libc_sigprocmask(SIG_UNBLOCK, &set, 0);
-}
-
 static int start(void *p)
 {
 	struct pthread *self = p;
@@ -79,7 +67,6 @@ weak_alias(dummy, __pthread_tsd_size);
 
 int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(void *), void *arg)
 {
-	static int init;
 	int ret;
 	size_t size, guard;
 	struct pthread *self = pthread_self(), *new;
@@ -87,7 +74,14 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
 	const pthread_attr_t default_attr = { 0 };
 
 	if (!self) return ENOSYS;
-	if (!init && ++init) init_threads();
+	if (!libc.threaded) {
+		sigset_t set;
+		sigemptyset(&set);
+		sigaddset(&set, SIGSYSCALL);
+		sigaddset(&set, SIGCANCEL);
+		__libc_sigprocmask(SIG_UNBLOCK, &set, 0);
+		libc.threaded = 1;
+	}
 
 	if (!attr) attr = &default_attr;
 	guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);

src/thread/pthread_setcancelstate.c

@@ -3,7 +3,7 @@
 int pthread_setcancelstate(int new, int *old)
 {
 	if (new > 1U) return EINVAL;
-	if (libc.lock) {
+	if (libc.threaded) {
 		struct pthread *self = __pthread_self();
 		if (old) *old = self->canceldisable;
 		self->canceldisable = new;