runtime: Add netpoll code that uses select.

Required for Solaris support.

From-SVN: r204817

1 files changed, 223 insertions, 0 deletions

diff --git a/libgo/runtime/netpoll_select.c b/libgo/runtime/netpoll_select.c
new file mode 100644
index 0000000..c330f28
--- /dev/null
+++ b/libgo/runtime/netpoll_select.c
@@ -0,0 +1,223 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build solaris
+
+#include "config.h"
+
+#include <errno.h>
+#include <sys/times.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#include "runtime.h"
+#include "malloc.h"
+
+static Lock selectlock;
+static int rdwake;
+static int wrwake;
+static fd_set fds;
+static PollDesc **data;
+static int allocated;
+
+void
+runtime_netpollinit(void)
+{
+	int p[2];
+	int fl;
+
+	FD_ZERO(&fds);
+	allocated = 128;
+	data = runtime_mallocgc(allocated * sizeof(PollDesc *), 0,
+				FlagNoScan|FlagNoProfiling|FlagNoInvokeGC);
+
+	if(pipe(p) < 0)
+		runtime_throw("netpollinit: failed to create pipe");
+	rdwake = p[0];
+	wrwake = p[1];
+
+	fl = fcntl(rdwake, F_GETFL);
+	if(fl < 0)
+		runtime_throw("netpollinit: fcntl failed");
+	fl |= O_NONBLOCK;
+	if(fcntl(rdwake, F_SETFL, fl))
+		 runtime_throw("netpollinit: fcntl failed");
+	fcntl(rdwake, F_SETFD, FD_CLOEXEC);
+
+	fl = fcntl(wrwake, F_GETFL);
+	if(fl < 0)
+		runtime_throw("netpollinit: fcntl failed");
+	fl |= O_NONBLOCK;
+	if(fcntl(wrwake, F_SETFL, fl))
+		 runtime_throw("netpollinit: fcntl failed");
+	fcntl(wrwake, F_SETFD, FD_CLOEXEC);
+
+	FD_SET(rdwake, &fds);
+}
+
+int32
+runtime_netpollopen(uintptr fd, PollDesc *pd)
+{
+	byte b;
+
+	runtime_lock(&selectlock);
+
+	if((int)fd >= allocated) {
+		int c;
+		PollDesc **n;
+
+		c = allocated;
+
+		runtime_unlock(&selectlock);
+
+		while((int)fd >= c)
+			c *= 2;
+		n = runtime_mallocgc(c * sizeof(PollDesc *), 0,
+				     FlagNoScan|FlagNoProfiling|FlagNoInvokeGC);
+
+		runtime_lock(&selectlock);
+
+		if(c > allocated) {
+			__builtin_memcpy(n, data, allocated * sizeof(PollDesc *));
+			allocated = c;
+			data = n;
+		}
+	}
+	FD_SET(fd, &fds);
+	data[fd] = pd;
+
+	runtime_unlock(&selectlock);
+
+	b = 0;
+	write(wrwake, &b, sizeof b);
+
+	return 0;
+}
+
+int32
+runtime_netpollclose(uintptr fd)
+{
+	byte b;
+
+	runtime_lock(&selectlock);
+
+	FD_CLR(fd, &fds);
+	data[fd] = nil;
+
+	runtime_unlock(&selectlock);
+
+	b = 0;
+	write(wrwake, &b, sizeof b);
+
+	return 0;
+}
+
+G*
+runtime_netpoll(bool block)
+{
+	fd_set rfds, wfds, efds, tfds;
+	struct timeval timeout;
+	struct timeval *pt;
+	int max, c, i;
+	G *gp;
+	int32 mode;
+	byte b;
+	struct stat st;
+
+ retry:
+	runtime_lock(&selectlock);
+
+	max = allocated;
+
+	if(max == 0) {
+		runtime_unlock(&selectlock);
+		return nil;
+	}
+
+	__builtin_memcpy(&rfds, &fds, sizeof fds);
+
+	runtime_unlock(&selectlock);
+
+	__builtin_memcpy(&wfds, &rfds, sizeof fds);
+	FD_CLR(rdwake, &wfds);
+	__builtin_memcpy(&efds, &wfds, sizeof fds);
+
+	__builtin_memcpy(&tfds, &wfds, sizeof fds);
+
+	__builtin_memset(&timeout, 0, sizeof timeout);
+	pt = &timeout;
+	if(block)
+		pt = nil;
+
+	c = select(max, &rfds, &wfds, &efds, pt);
+	if(c < 0) {
+		if(errno == EBADF) {
+			// Some file descriptor has been closed.
+			// Check each one, and treat each closed
+			// descriptor as ready for read/write.
+			c = 0;
+			FD_ZERO(&rfds);
+			FD_ZERO(&wfds);
+			FD_ZERO(&efds);
+			for(i = 0; i < max; i++) {
+				if(FD_ISSET(i, &tfds)
+				   && fstat(i, &st) < 0
+				   && errno == EBADF) {
+					FD_SET(i, &rfds);
+					FD_SET(i, &wfds);
+					c += 2;
+				}
+			}
+		}
+		else {
+			if(errno != EINTR)
+				runtime_printf("runtime: select failed with %d\n", errno);
+			goto retry;
+		}
+	}
+	gp = nil;
+	for(i = 0; i < max && c > 0; i++) {
+		mode = 0;
+		if(FD_ISSET(i, &rfds)) {
+			mode += 'r';
+			--c;
+		}
+		if(FD_ISSET(i, &wfds)) {
+			mode += 'w';
+			--c;
+		}
+		if(FD_ISSET(i, &efds)) {
+			mode = 'r' + 'w';
+			--c;
+		}
+		if(i == rdwake) {
+			while(read(rdwake, &b, sizeof b) > 0)
+				;
+			continue;
+		}
+		if(mode) {
+			PollDesc *pd;
+
+			runtime_lock(&selectlock);
+			pd = data[i];
+			runtime_unlock(&selectlock);
+			if(pd != nil)
+				runtime_netpollready(&gp, pd, mode);
+		}
+	}
+	if(block && gp == nil)
+		goto retry;
+	return gp;
+}
+
+void
+runtime_netpoll_scan(void (*addroot)(Obj))
+{
+	addroot((Obj){(byte*)&data, sizeof data, 0});
+}