Common pipe replaced with sender/receiver functors.

[#27] C library now only takes care of relaying data to/from functors,
which must be provided by the wrapping application (in this case, a
new python module named 'common.py').

3 files changed, 29 insertions, 52 deletions

diff --git a/src/common.c b/src/common.c
index 3653252..402320e 100644
--- a/src/common.c
+++ b/src/common.c
@@ -1,69 +1,49 @@
 #include <assert.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <unistd.h>
 #include "types.h"
 #include "instset.h"
 #include "common.h"
 
-static boolean g_is_init;
-static int g_file_desc;
+static Sender g_sender;
+static Receiver g_receiver;
 
-void _sal_comm_init(string pipe)
+void sal_comm_set_sender(Sender sender)
 {
-	/* Initialize the common pipe. This module is the only one on Salis that
-	makes use of Linux specific headers and types. If you want, feel free to
-	port this code into other platforms (should be easy). If you do so, let me
-	know and we can incorporate it into the Salis repository.
+	/* Set sender functor. Whenever an organism calls the SEND instruction,
+	this function will get called. When unset, SEND instruction is ignored.
 	*/
-	assert(!g_is_init);
-	mkfifo(pipe, 0666);
-	g_is_init = TRUE;
-
-	/* It's important to open the FIFO file in non-blocking mode, or else the
-	simulators might halt if the pipe becomes empty.
-	*/
-	g_file_desc = open(pipe, O_RDWR | O_NONBLOCK);
-	assert(g_file_desc != -1);
+	assert(sender);
+	g_sender = sender;
 }
 
-void _sal_comm_quit(void)
+void sal_comm_set_receiver(Receiver receiver)
 {
-	/* Close the common pipe FIFO file from within this instance. An empty pipe
-	file will remain unless it gets manually deleted.
+	/* Set receiver functor. Whenever an organism calls the RCVE instruction,
+	this function will get called. When unset, RCVE instruction is ignored.
 	*/
-	assert(g_is_init);
-	close(g_file_desc);
-	g_is_init = FALSE;
-	g_file_desc = 0;
+	assert(receiver);
+	g_receiver = receiver;
 }
 
 void _sal_comm_send(uint8 inst)
 {
-	/* Send a single byte (instruction) to the common pipe. This function is
-	called by processes that execute the SEND instruction. Hopefully, some of
-	them 'learn' to use this as an advantage.
-
-	In the future, I want to make the common pipe able to communicate across
-	local networks (LANs) and over the Internet.
+	/* Send a single byte (instruction) to the sender. This function is called
+	by processes that execute the SEND instruction.
 	*/
-	assert(g_is_init);
 	assert(sal_is_inst(inst));
-	write(g_file_desc, &inst, 1);
+
+	if (g_sender) {
+		g_sender(inst);
+	}
 }
 
 uint8 _sal_comm_receive(void)
 {
-	/* Receive a single byte (instruction) from the common pipe. This function
-	is called by processes that execute the RCVE instruction. If the pipe is
-	empty, this function returns the NOP0 instruction.
+	/* Receive a single byte (instruction) from the receiver. This function is
+	called by processes that execute the RCVE instruction. It returns NOP0 is
+	receiver is unset.
 	*/
-	uint8 inst;
-	ssize_t res;
-	assert(g_is_init);
-	res = read(g_file_desc, &inst, 1);
-
-	if (res) {
+	if (g_receiver) {
+		uint8 inst = g_receiver();
 		assert(sal_is_inst(inst));
 		return inst;
 	} else {
diff --git a/src/process.c b/src/process.c
index 2b9fff8..eb89a8d 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1077,7 +1077,7 @@ static void write(uint32 pidx)
 
 static void send(uint32 pidx)
 {
-	/* Send instruction on given register into the common pipe.
+	/* Send instruction on given register into the common sender.
 	*/
 	uint32_p reg;
 	assert(g_is_init);
@@ -1102,8 +1102,8 @@ static void send(uint32 pidx)
 
 static void receive(uint32 pidx)
 {
-	/* Receive a single instruction from the common pipe and store it into a
-	specified register. In case the common pipe is empty, it will return the
+	/* Receive a single instruction from the common receiver and store it into
+	a specified register. In case the receiver is unset, it will return the
 	NOP0 instruction.
 	*/
 	uint32_p reg;
diff --git a/src/salis.c b/src/salis.c
index 1aae1fa..32a14b8 100644
--- a/src/salis.c
+++ b/src/salis.c
@@ -7,14 +7,13 @@ static boolean g_is_init;
 static uint32 g_cycle;
 static uint32 g_epoch;
 
-void sal_main_init(uint32 order, string pipe)
+void sal_main_init(uint32 order)
 {
 	/* Initialize all Salis modules to their initial states. We pass along any
 	arguments to their respective modules.
 	*/
 	assert(!g_is_init);
 	_sal_mem_init(order);
-	_sal_comm_init(pipe);
 	_sal_evo_init();
 	_sal_proc_init();
 	g_is_init = TRUE;
@@ -30,17 +29,16 @@ void sal_main_quit(void)
 	assert(g_is_init);
 	_sal_proc_quit();
 	_sal_evo_quit();
-	_sal_comm_quit();
 	_sal_mem_quit();
 	g_is_init = FALSE;
 	g_cycle = 0;
 	g_epoch = 0;
 }
 
-void sal_main_load(string file_name, string pipe)
+void sal_main_load(string file_name)
 {
 	/* Load simulation state from file. This file must have been created by
-	'sal_main_save()'. File name of common pipe must also be provided.
+	'sal_main_save()'.
 	*/
 	FILE *file;
 	assert(!g_is_init);
@@ -54,7 +52,6 @@ void sal_main_load(string file_name, string pipe)
 	_sal_evo_load_from(file);
 	_sal_proc_load_from(file);
 	fclose(file);
-	_sal_comm_init(pipe);
 }
 
 void sal_main_save(string file_name)