fix for being workable on the systems with PID > 65536

Author: heni

Makefile

@@ -27,9 +27,10 @@ DEPDIRS := ${DEP} $(addprefix ${DEP}/,${PROJECTS})
 ALLDIRS := ${DEPDIRS} ${OBJDIRS}
 
 
-.PHONY:	all clean 
+.PHONY:	all clean test
 
 EXELIST	:= ${EXE}/mtproto-proxy
+TESTLIST := ${EXE}/test_pid
 
 
 OBJECTS	=	\
@@ -96,6 +97,13 @@ ${EXE}/mtproto-proxy:	${OBJ}/mtproto/mtproto-proxy.o ${OBJ}/mtproto/mtproto-conf
 ${LIB}/libkdb.a: ${LIB_OBJS}
 	rm -f $@ && ar rcs $@ $^
 
+${EXE}/test_pid: tests/test_pid.c ${OBJ}/common/pid.o | ${EXE}
+	${CC} ${CFLAGS} ${CINCLUDE} -o $@ $^
+
+test: ${TESTLIST}
+	@for t in ${TESTLIST}; do echo "--- Running $$t ---"; $$t || exit 1; done
+	@echo "All tests passed."
+
 clean:
 	rm -rf ${OBJ} ${DEP} ${EXE} || true
 

common/pid.c

@@ -39,8 +39,8 @@ npid_t PID;
 void init_common_PID (void) {
   if (!PID.pid) {
     int p = getpid ();
-    assert (!(p & 0xffff0000));
-    PID.pid = p;
+    unsigned short folded = (unsigned short)((p & 0xffff) ^ (p >> 16));
+    PID.pid = folded ? folded : 1;
   }
   if (!PID.utime) {
     PID.utime = time (0);

common/pid.h

@@ -29,14 +29,14 @@
 struct process_id {
   unsigned ip;
   short port;
-  unsigned short pid;
+  unsigned short pid;  /* XOR-folded from OS pid to fit wire protocol (16 bits) */
   int utime;
 };
 
 struct process_id_ext {
   unsigned ip;
   short port;
-  unsigned short pid;
+  unsigned short pid;  /* XOR-folded from OS pid to fit wire protocol (16 bits) */
   int utime;
   int actor_id;
 };

mtproto/mtproto-proxy.c

@@ -2304,6 +2304,11 @@ void mtfront_pre_init (void) {
       int pid = fork ();
       assert (pid >= 0);
       if (!pid) {
+        npid_t old_PID = PID;
+        PID.pid = 0;
+        PID.utime = 0;
+        init_common_PID ();
+        assert (PID.pid != old_PID.pid || PID.utime != old_PID.utime);
         worker_id = i;
         workers = 0;
         slave_mode = 1;