1 files changed, 89 insertions, 0 deletions
diff --git a/src/shared/fdsignal.inc/pipe_malloc.c b/src/shared/fdsignal.inc/pipe_malloc.c
new file mode 100644
index 0000000..b23ddcd
--- /dev/null
+++ b/src/shared/fdsignal.inc/pipe_malloc.c
@@ -0,0 +1,89 @@
+#include <poll.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+struct _dnbd3_signal {
+	int read;
+	int write;
+};
+
+/*
+ * Generic (posix) implelentation of signals, using pipes.
+ * A struct containing both fds will be malloc()ed for each
+ * signal.
+ */
+
+dnbd3_signal_t* signal_new()
+{
+	dnbd3_signal_t *ret = signal_newBlocking();
+	if ( ret == NULL ) return NULL;
+	fcntl( ret->read, F_SETFL, O_NONBLOCK );
+	fcntl( ret->write, F_SETFL, O_NONBLOCK );
+	return ret;
+}
+
+dnbd3_signal_t* signal_newBlocking()
+{
+	int fds[2];
+	if ( pipe( fds ) == -1 ) return NULL;
+	dnbd3_signal_t* ret = malloc( sizeof(dnbd3_signal_t) );
+	ret->read = fds[0];
+	ret->write = fds[1];
+	return ret;
+}
+
+int signal_call(const dnbd3_signal_t* const signal)
+{
+	if ( signal == NULL ) return SIGNAL_ERROR;
+	static char one = 1;
+	// Write one byte on every call, so the number of bytes read will
+	// match the number of events
+	return write( signal->write, &one, 1 ) > 0 ? SIGNAL_OK : SIGNAL_ERROR;
+}
+
+int signal_wait(const dnbd3_signal_t* const signal, int timeoutMs)
+{
+	if ( signal == NULL ) return SIGNAL_ERROR;
+	struct pollfd ps = {
+		.fd = signal->read,
+		.events = POLLIN
+	};
+	int ret = poll( &ps, 1, timeoutMs );
+	if ( ret == 0 ) return SIGNAL_TIMEOUT;
+	if ( ret == -1 ) return SIGNAL_ERROR;
+	if ( ps.revents & ( POLLERR | POLLNVAL ) ) return SIGNAL_ERROR;
+	return signal_clear( signal );
+}
+
+int signal_clear(const dnbd3_signal_t* const signal)
+{
+	if ( signal == NULL ) return SIGNAL_ERROR;
+	char throwaway[100];
+	ssize_t ret, total = 0;
+	do {
+		ret = read( signal->read, throwaway, sizeof throwaway );
+		if ( ret < 0 ) {
+			if ( errno == EAGAIN ) return (int)total;
+			return SIGNAL_ERROR;
+		}
+		total += ret;
+	} while ( (size_t)ret == sizeof throwaway );
+	return (int)total;
+}
+
+void signal_close(const dnbd3_signal_t* const signal)
+{
+	close( signal->read );
+	close( signal->write );
+	free( (void*)signal );
+}
+
+int signal_getWaitFd(const dnbd3_signal_t* const signal)
+{
+	if ( signal == NULL ) return -1;
+	return signal->read;
+}
+