Add the pid to the status output

This will be needed if we daemonise flexnbd.

src/status.c

@@ -8,6 +8,7 @@ struct status * status_create( struct server * serve )
 	struct status * status;
 	
 	status = xmalloc( sizeof( struct status ) );
+	status->pid = getpid();
 	status->has_control = serve->has_control;
 	status->is_mirroring = NULL != serve->mirror;
 	return status;
@@ -15,13 +16,16 @@ struct status * status_create( struct server * serve )
 }
 
 #define BOOL_S(var) (var ? "true" : "false" )
-#define PRINT_FIELD( var ) \
+#define PRINT_BOOL( var ) \
 	do{dprintf( fd, #var "=%s ", BOOL_S( status->var ) );}while(0)
+#define PRINT_INT( var ) \
+	do{dprintf( fd, #var "=%d ", status->var );}while(0)
 
 int status_write( struct status * status, int fd )
 {
-	PRINT_FIELD( is_mirroring );
-	PRINT_FIELD( has_control );
+	PRINT_INT( pid );
+	PRINT_BOOL( is_mirroring );
+	PRINT_BOOL( has_control );
 	dprintf(fd, "\n");
 	return 1;
 }

src/status.h

@@ -17,6 +17,9 @@
  *
  * The following status fields are defined:
  *
+ * pid:
+ *      The current process ID.
+ *
  * has_control:
  * 	This will be false when the server is listening for an incoming
  * 	migration.  It will switch to true when the end-of-migration
@@ -36,7 +39,11 @@
 
 #include "serve.h"
 
+#include <sys/types.h>
+#include <unistd.h>
+
 struct status {
+	pid_t pid;
 	int has_control;
 	int is_mirroring;
 };