Implement cancellation points in libc interfaces, as specified by POSIX.

2 files changed, 314 insertions, 0 deletions

diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index 06caf96..bda67ca 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -52,6 +52,7 @@
 #include <sys/types.h>
 #include <sys/cdefs.h>
 #include <sys/errno.h>
+#include <sys/msg.h>
 #include <sys/time.h>
 #include <sys/queue.h>
 #include <pthread_np.h>
@@ -833,6 +834,12 @@ int	__sys_kevent(int, const struct kevent *, int, struct kevent *,
 int	__sys_ioctl(int, unsigned long, ...);
 #endif
 
+/* #include <sys/msg.h> */
+#ifdef _SYS_MSG_H_
+int __sys_msgrcv(int, void *, size_t, long, int);
+int __sys_msgsnd(int, const void *, size_t, int);
+#endif
+
 /* #include <sys/mman.h> */
 #ifdef _SYS_MMAN_H_
 int	__sys_msync(void *, size_t, int);
@@ -852,6 +859,7 @@ int	__sys_getpeername(int, struct sockaddr *, socklen_t *);
 int	__sys_getsockname(int, struct sockaddr *, socklen_t *);
 int	__sys_getsockopt(int, int, int, void *, socklen_t *);
 int	__sys_listen(int, int);
+ssize_t __sys_recv(int, void *, size_t, int);
 ssize_t	__sys_recvfrom(int, void *, size_t, int, struct sockaddr *, socklen_t *);
 ssize_t	__sys_recvmsg(int, struct msghdr *, int);
 int	__sys_sendfile(int, int, off_t, size_t, struct sf_hdtr *, off_t *, int);
@@ -898,12 +906,23 @@ int	__sys_open(const char *, int, ...);
 int	__sys_poll(struct pollfd *, unsigned, int);
 #endif
 
+/* #include <semaphore.h> */
+#ifdef _SEMAPHORE_H_
+int      __sem_timedwait(sem_t * __restrict, const struct timespec * __restrict);
+int      __sem_wait(sem_t *);
+#endif
+
 /* #include <signal.h> */
 #ifdef _SIGNAL_H_
 int	__sys_sigaction(int, const struct sigaction *, struct sigaction *);
 int	__sys_sigaltstack(const struct sigaltstack *, struct sigaltstack *);
 int	__sys_sigprocmask(int, const sigset_t *, sigset_t *);
 int	__sys_sigreturn(ucontext_t *);
+int     __sys_sigsuspend(const sigset_t *);
+int     __sys_sigtimedwait(const sigset_t * __restrict, siginfo_t * __restrict,
+	    const struct timespec * __restrict);
+int     __sys_sigwait(const sigset_t * __restrict, int * __restrict);
+int     __sys_sigwaitinfo(const sigset_t * __restrict, siginfo_t * __restrict);
 #endif
 
 /* #include <unistd.h> */
@@ -918,6 +937,8 @@ pid_t	__sys_fork(void);
 long	__sys_fpathconf(int, int);
 int	__sys_fsync(int);
 int	__sys_pipe(int *);
+ssize_t __sys_pread(int, void *, size_t, off_t);
+ssize_t __sys_pwrite(int, const void *, size_t, off_t);
 ssize_t	__sys_read(int, void *, size_t);
 ssize_t	__sys_write(int, const void *, size_t);
 #endif
diff --git a/lib/libthr/thread/thr_syscalls.c b/lib/libthr/thread/thr_syscalls.c
index b899cbf..7e2b075 100644
--- a/lib/libthr/thread/thr_syscalls.c
+++ b/lib/libthr/thread/thr_syscalls.c
@@ -69,6 +69,7 @@
 #include <sys/mman.h>
 #include <sys/param.h>
 #include <sys/select.h>
+#include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/uio.h>
@@ -80,6 +81,7 @@
 #include <fcntl.h>
 #include <poll.h>
 #include <pthread.h>
+#include <semaphore.h>
 #include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -103,6 +105,19 @@ extern pid_t __wait(int *);
 extern pid_t __sys_wait4(pid_t, int *, int, struct rusage *);
 extern pid_t __waitpid(pid_t, int *, int);
 
+__weak_reference(_accept, accept);
+
+int
+_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_accept(s, addr, addrlen);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
 __weak_reference(_aio_suspend, aio_suspend);
 
 int
@@ -131,6 +146,20 @@ _close(int fd)
 	
 	return ret;
 }
+
+__weak_reference(_connect, connect);
+
+int
+_connect(int s, const struct sockaddr *n, socklen_t l)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_connect(s, n, l);
+	_thread_leave_cancellation_point();
+	return ret;
+}
+	
 __weak_reference(_creat, creat);
 
 int
@@ -246,6 +275,32 @@ _fsync(int fd)
 	return ret;
 }
 
+__weak_reference(_msgrcv, msgrcv);
+
+int
+_msgrcv(int id, void *p, size_t sz, long t, int f)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_msgrcv(id, p, sz, t, f);
+	_thread_leave_cancellation_point();
+	return ret;
+}
+
+__weak_reference(_msgsnd, msgsnd);
+
+int
+_msgsnd(int id, const void *p, size_t sz, int f)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_msgsnd(id, p, sz, f);
+	_thread_leave_cancellation_point();
+	return ret;
+}
+
 __weak_reference(_msync, msync);
 
 int
@@ -300,6 +355,22 @@ _open(const char *path, int flags,...)
 	return ret;
 }
 
+/*
+ * The implementation in libc calls sigpause(), which is also
+ * a cancellation point.
+ */
+#if 0
+__weak_reference(_pause, pause);
+
+int
+_pause(void)
+{
+	_thread_enter_cancellation_point();
+	__pause();
+	_thread_leave_cancellation_point();
+}
+#endif
+
 __weak_reference(_poll, poll);
 
 int
@@ -314,6 +385,24 @@ _poll(struct pollfd *fds, unsigned int nfds, int timeout)
 	return ret;
 }
 
+/* XXXFix */
+#if 0
+__weak_reference(_pread, pread);
+
+ssize_t
+_pread(int d, void *b, size_t n, off_t o)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_pread(d, b, n, o);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
+
+/* The libc version calls select(), which is also a cancellation point. */
+#if 0
 extern int __pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds, 
 		const struct timespec *timo, const sigset_t *mask);
 
@@ -329,6 +418,23 @@ pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds,
 
 	return (ret);
 }
+#endif
+
+/* XXXFix */
+#if 0
+__weak_reference(_pwrite, pwrite);
+
+ssize_t
+_pwrite(int d, const void *b, size_t n, off_t o)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_pwrite(d, b, n, o);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
 
 __weak_reference(_raise, raise);
 
@@ -373,6 +479,52 @@ _readv(int fd, const struct iovec *iov, int iovcnt)
 	return ret;
 }
 
+/*
+ * The libc implementation of recv() calls recvfrom, which
+ * is also a cancellation point.
+ */
+#if 0
+__weak_reference(_recv, recv);
+
+ssize_t
+_recv(int s, void *b, size_t l, int f)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_recv(s, b, l, f);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
+
+__weak_reference(_recvfrom, recvfrom);
+
+ssize_t
+_recvfrom(int s, void *b, size_t l, int f, struct sockaddr *from,
+    socklen_t *fl)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_recvfrom(s, b, l, f, from, fl);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+__weak_reference(_recvmsg, recvmsg);
+
+ssize_t
+_recvmsg(int s, struct msghdr *m, int f)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_recvmsg(s, m, f);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
 __weak_reference(_select, select);
 
 int 
@@ -388,6 +540,123 @@ _select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	return ret;
 }
 
+/*
+ * Libc implements this by calling _sendto(), which is also a
+ * cancellation point.
+ */
+#if 0
+__weak_reference(_send, send);
+
+ssize_t
+_send(int s, const void *m, size_t l, int f)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = _sendto(s, m, l, f, NULL, 0);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
+
+__weak_reference(_sendmsg, sendmsg);
+
+ssize_t
+_sendmsg(int s, const struct msghdr *m, int f)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sendmsg(s, m, f);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+__weak_reference(_sendto, sendto);
+
+ssize_t
+_sendto(int s, const void *m, size_t l, int f, const struct sockaddr *t,
+    socklen_t tl)
+{
+	ssize_t ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sendto(s, m, l, f, t, tl);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+/*
+ * The implementation in libc calls sigsuspend(), which is also
+ * a cancellation point.
+ */
+#if 0
+__weak_reference(_sigpause, sigpause);
+
+int
+_sigpause(int m)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sigpause(m);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
+
+__weak_reference(_sigsuspend, sigsuspend);
+
+int
+_sigsuspend(const sigset_t *m)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sigsuspend(m);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+__weak_reference(_sigtimedwait, sigtimedwait);
+
+int
+_sigtimedwait(const sigset_t *s, siginfo_t *i, const struct timespec *t)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sigtimedwait(s, i, t);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+__weak_reference(_sigwait, sigwait);
+
+int
+_sigwait(const sigset_t *s, int *i)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sigwait(s, i);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
+__weak_reference(_sigwaitinfo, sigwaitinfo);
+
+int
+_sigwaitinfo(const sigset_t *s, siginfo_t *i)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_sigwaitinfo(s, i);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+
 __weak_reference(_sleep, sleep);
 
 unsigned int
@@ -431,6 +700,25 @@ _tcdrain(int fd)
 	return ret;
 }
 
+/*
+ * The usleep() implementation calls nanosleep(), which is also
+ * a cancellation point.
+ */
+#if 0
+__weak_reference(_usleep, usleep);
+
+int
+_usleep(useconds_t u)
+{
+	int ret;
+
+	_thread_enter_cancellation_point();
+	ret = __sys_usleep(u);
+	_thread_leave_cancellation_point();
+	return (ret);
+}
+#endif
+
 __weak_reference(_wait, wait);
 
 pid_t
@@ -459,6 +747,10 @@ _wait4(pid_t pid, int *istat, int options, struct rusage *rusage)
 	return ret;
 }
 
+/*
+ * The libc implementation of waitpid calls wait4().
+ */
+#if 0
 __weak_reference(_waitpid, waitpid);
 
 pid_t
@@ -472,6 +764,7 @@ _waitpid(pid_t wpid, int *status, int options)
 	
 	return ret;
 }
+#endif
 
 __weak_reference(_write, write);