[mc] Define one struct per MC message type

diff --git a/src/mc/mc_client.c b/src/mc/mc_client.c
index 2f30581..120c05b 100644 (file)
--- a/src/mc/mc_client.c
+++ b/src/mc/mc_client.c
@@ -19,12 +19,7 @@
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_client, mc, "MC client logic");
 
-typedef struct s_mc_client {
-  int active;
-  int fd;
-} s_mc_client_t, mc_client_t;
-
-static s_mc_client_t mc_client;
+s_mc_client_t mc_client;
 
 void MC_client_init(void)
 {
@@ -60,11 +55,18 @@ void MC_client_handle_messages(void)
 {
   while (1) {
     XBT_DEBUG("Waiting messages from model-checker");
-    s_mc_message_t message;
-    if (recv(mc_client.fd, &message, sizeof(message), 0) == -1)
+
+    char message_buffer[MC_MESSAGE_LENGTH];
+    size_t s;
+    if ((s = recv(mc_client.fd, &message_buffer, sizeof(message_buffer), 0)) == -1)
       xbt_die("Could not receive commands from the model-checker: %s",
         strerror(errno));
+
     XBT_DEBUG("Receive message from model-checker");
+    s_mc_message_t message;
+    if (s < sizeof(message))
+      xbt_die("Message is too short");
+    memcpy(&message, message_buffer, sizeof(message));
     switch (message.type) {
     case MC_MESSAGE_CONTINUE:
       return;

diff --git a/src/mc/mc_client.h b/src/mc/mc_client.h
index d013a17..fc1cf67 100644 (file)
--- a/src/mc/mc_client.h
+++ b/src/mc/mc_client.h
@@ -11,6 +11,13 @@
 
 SG_BEGIN_DECL()
 
+typedef struct s_mc_client {
+  int active;
+  int fd;
+} s_mc_client_t, mc_client_t;
+
+extern s_mc_client_t mc_client;
+
 void MC_client_init(void);
 void MC_client_hello(void);
 void MC_client_handle_messages(void);

diff --git a/src/mc/mc_protocol.c b/src/mc/mc_protocol.c
index 3396a38..405a61a 100644 (file)
--- a/src/mc/mc_protocol.c
+++ b/src/mc/mc_protocol.c
@@ -13,15 +13,13 @@
 #include <xbt/log.h>
 
 #include "mc_protocol.h"
+#include "mc_client.h"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_protocol, mc, "Generic MC protocol logic");
 
-int MC_protocol_send_simple_message(int socket, int type)
+int MC_protocol_send(int socket, void* message, size_t size)
 {
-  s_mc_message_t message;
-  message.type = type;
-
-  while (send(socket, &message, sizeof(message), 0) == -1) {
+  while (send(socket, message, size, 0) == -1) {
     if (errno == EINTR)
       continue;
     else
@@ -30,6 +28,13 @@ int MC_protocol_send_simple_message(int socket, int type)
   return 0;
 }
 
+int MC_protocol_send_simple_message(int socket, int type)
+{
+  s_mc_message_t message;
+  message.type = type;
+  return MC_protocol_send(socket, &message, sizeof(message));
+}
+
 int MC_protocol_hello(int socket)
 {
   int e;
@@ -41,7 +46,8 @@ int MC_protocol_hello(int socket)
   s_mc_message_t message;
   message.type = MC_MESSAGE_NONE;
 
-  while (recv(socket, &message, sizeof(message), 0) == -1) {
+  size_t s;
+  while ((s = recv(socket, &message, sizeof(message), 0)) == -1) {
     if (errno == EINTR)
       continue;
     else {
@@ -49,7 +55,7 @@ int MC_protocol_hello(int socket)
       return 2;
     }
   }
-  if (message.type != MC_MESSAGE_HELLO) {
+  if (s < sizeof(message) || message.type != MC_MESSAGE_HELLO) {
     XBT_ERROR("Did not receive suitable HELLO message. Who are you?");
     return 3;
   }

diff --git a/src/mc/mc_protocol.h b/src/mc/mc_protocol.h
index ba80145..be17129 100644 (file)
--- a/src/mc/mc_protocol.h
+++ b/src/mc/mc_protocol.h
@@ -9,6 +9,8 @@
 
 #include <xbt/misc.h>
 
+#include "mc/datatypes.h"
+
 SG_BEGIN_DECL()
 
 // ***** Environment variables for passing context to the model-checked process
@@ -23,19 +25,37 @@ SG_BEGIN_DECL()
 
 // ***** Messages
 
-enum {
+typedef enum {
   MC_MESSAGE_NONE = 0,
   MC_MESSAGE_HELLO = 1,
   MC_MESSAGE_CONTINUE = 2,
-};
+  MC_MESSAGE_IGNORE_REGION = 3,
+} e_mc_message_type;
+
+#define MC_MESSAGE_LENGTH 512
 
+/** Basic structure for a MC message
+ *
+ *  The current version of the client/server protocol sends C structures over `AF_LOCAL`
+ *  `SOCK_DGRAM` sockets. This means that the protocol is ABI/architecture specific:
+ *  we currently can't model-check a x86 process from a x86_64 process.
+ *
+ *  Moreover the protocol is not stable. The same version of the library should be used
+ *  for the client and the server.
+ *
+ *  This is the basic structure shared by all messages: all message start with a message
+ *  type.
+ */
 typedef struct s_mc_message {
-  int type;
+  e_mc_message_type type;
 } s_mc_message_t, *mc_message_t;
 
-/**
- *  @return errno
- */
+typedef struct s_mc_ignore_region_message {
+  e_mc_message_type type;
+  s_mc_heap_ignore_region_t region;
+} s_mc_ignore_region_message_t, *mc_ignore_region_message_t;
+
+int MC_protocol_send(int socket, void* message, size_t size);
 int MC_protocol_send_simple_message(int socket, int type);
 int MC_protocol_hello(int socket);
 

diff --git a/src/mc/mc_server.cpp b/src/mc/mc_server.cpp
index cd6653e..88f2bb0 100644 (file)
--- a/src/mc/mc_server.cpp
+++ b/src/mc/mc_server.cpp
@@ -143,6 +143,10 @@ void s_mc_server::handle_events()
       if (size == -1 && errno != EAGAIN)
         throw std::system_error(errno, std::system_category());
       else switch(message.type) {
+      case MC_MESSAGE_IGNORE_REGION:
+        XBT_DEBUG("Received ignored region");
+        // Ignored for now
+        break;
       default:
         xbt_die("Unexpected message from model-checked application");
       }