Change API

- now there's no SAMI_recv(), but handler is called each time message
  is received
- children can send messages to their parent, which is obtainable
  using SAMI_parent()

4 files changed, 91 insertions, 33 deletions

diff --git a/README b/README
index 1f0cb82..6cc1e88 100644
--- a/README
+++ b/README
@@ -7,25 +7,27 @@ SYNOPSIS
      #include <sami.h>
 
      int
-     SAMI_make(SAMI *actor, SAMI_Handler *handler, void *arg);
+     SAMI_make(SAMI *actor, SAMI_Handler *handler);
 
      int
      SAMI_send(SAMI *actor, void *buf, size_t length);
 
      int
-     SAMI_recv(void *buf, size_t length);
-
-     int
      SAMI_kill(SAMI *actor);
 
+     SAMI *
+     SAMI_parent(void);
+
 DESCRIPTION
      sami is a library for handling actors.  It uses fork(2) for making
      actors, and unix(7) sockets for message delivering.
 
 RETURN VALUE
-     All functions return 0 on success, and any other number on failure.
+     Functions usually return 0 on success, and any other number on failure.
      Consider checking errno(7) in the latter case.
 
+     SAMI_parent() returns a valid pointer.
+
 SEE ALSO
      fork(2), unix(7)
 
diff --git a/sami.3 b/sami.3
index 371c682..ba6b63b 100644
--- a/sami.3
+++ b/sami.3
@@ -10,17 +10,17 @@
 .
 .In sami.h
 .Ft "int"
-.Fn SAMI_make "SAMI *actor" "SAMI_Handler *handler" "void *arg"
+.Fn SAMI_make "SAMI *actor" "SAMI_Handler *handler"
 .
 .Ft "int"
 .Fn SAMI_send "SAMI *actor" "void *buf" "size_t length"
 .
 .Ft "int"
-.Fn SAMI_recv "void *buf" "size_t length"
-.
-.Ft "int"
 .Fn SAMI_kill "SAMI *actor"
 .
+.Ft "SAMI *"
+.Fn SAMI_parent "void"
+.
 .Sh DESCRIPTION
 .Nm
 is a library
@@ -33,12 +33,16 @@ and
 sockets for message delivering.
 .
 .Sh RETURN VALUE
-All functions return 0 on success,
+Functions usually return 0 on success,
 and any other number on failure.
 Consider checking
 .Xr errno 7
 in the latter case.
 .
+.Pp
+.Fn SAMI_parent
+returns a valid pointer.
+.
 .Sh SEE ALSO
 .Xr fork 2 ,
 .Xr unix 7
diff --git a/sami.c b/sami.c
index 6c8d42b..69f0796 100644
--- a/sami.c
+++ b/sami.c
@@ -3,17 +3,42 @@
 #include <errno.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include <unistd.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/poll.h>
 
 
-int SAMI__fd;
+#define ACTORS_MAX 1024
+#define MESSAGE_LENGTH_MAX 65536
 
-int SAMI_make(SAMI *actor, SAMI_Handler *handler, void *arg)
+static struct pollfd pfd[ACTORS_MAX];
+static SAMI actors[ACTORS_MAX];
+char buffer[MESSAGE_LENGTH_MAX];
+static int self_fd;
+
+static ssize_t findspace(void)
 {
-	int pair[2];
+	size_t i;
+
+	for (i = 1; i < ACTORS_MAX; ++i)
+		if (pfd[i].fd == -1)
+			return i;
+
+	return -1;
+}
+
+int SAMI_make(SAMI *actor, SAMI_Handler *handler)
+{
+	int pair[2], res;
+	ssize_t i, sz;
+
+	i = findspace();
+	if (i == -1)
+		return 1;
 
 	if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) == -1)
 		return 1;
@@ -21,11 +46,47 @@ int SAMI_make(SAMI *actor, SAMI_Handler *handler, void *arg)
 
 	if (!(actor->pid = fork()))
 	{
-		SAMI__fd = pair[1];
-		handler(arg);
+		close(pair[0]);
+		actors[0].fd = pfd[0].fd = self_fd;
+		self_fd = pair[1];
+		actors[0].pid = -1;
+
+		for (i = 1; i < ACTORS_MAX; ++i)
+			actors[i].fd = -1,
+			pfd[i].fd = -1,
+			pfd[i].events = POLLIN;
+retry:
+		waitpid(-1, 0, WNOHANG);
+		res = poll(pfd, ACTORS_MAX, 0);
+		if (res == -1)
+			if (errno = EINTR)
+				goto retry;
+			else /* TODO: log fail */
+				exit(1);
+		else if (res == 0)
+			goto retry;
+
+		for (i = 0; i < ACTORS_MAX; ++i)
+		{
+			if (!(pfd[i].revents & POLLIN))
+				break;
+
+			sz = recv(pfd[i].fd, buffer, sizeof(buffer), 0);
+			/* TODO: log if sz == -1 */
+			if (handler(&actor[i], buffer, sz))
+				goto end;
+		}
+		goto retry;
+end:
 		exit(0);
 	}
 
+	close(pair[1]);
+	if (actor->pid == -1)
+		close(pair[0]);
+	else
+		memcpy(&actors[i], actor, sizeof(*actor));
+
 	return actor->pid == -1;
 }
 
@@ -34,24 +95,16 @@ int SAMI_send(SAMI *actor, void *buf, size_t length)
 	return send(actor->fd, buf, length, 0) == -1;
 }
 
-int SAMI_recv(void *buf, size_t length)
-{
-	return recvfrom(SAMI__fd, buf, length, 0, 0, 0) == -1;
-}
-
 int SAMI_kill(SAMI *actor)
 {
 	int res;
 
-	if (kill(actor->pid, SIGKILL))
+	if (actor->pid == -1
+	 || kill(actor->pid, SIGKILL))
 		return 1;
+}
 
-	for (;;)
-		if (waitpid(actor->pid, 0, 0) == -1)
-			if (errno == EINTR)
-				continue;
-			else
-				return 1;
-		else
-			return 0;
+SAMI *SAMI_parent(void)
+{
+	return &actors[0];
 }
diff --git a/sami.h b/sami.h
index 53e5ad8..fdab71c 100644
--- a/sami.h
+++ b/sami.h
@@ -4,7 +4,6 @@
 #include <stddef.h>
 #include <unistd.h>
 
-extern int SAMI__fd;
 
 struct SAMI
 {
@@ -13,11 +12,11 @@ struct SAMI
 };
 typedef struct SAMI SAMI;
 
-typedef void SAMI_Handler(void *arg);
+typedef int SAMI_Handler(const SAMI *sender, void *message, size_t length);
 
-int SAMI_make(SAMI *actor, SAMI_Handler *handler, void *arg);
+int SAMI_make(SAMI *actor, SAMI_Handler *handler);
 int SAMI_send(SAMI *actor, void *buf, size_t length);
-int SAMI_recv(void *buf, size_t length);
 int SAMI_kill(SAMI *actor);
+SAMI *SAMI_parent(void);
 
 #endif /* __SAMI_H__ */