add support for ref counts to memory allocator.
mark and sweep, stop the world garbage collector
(intermediate step in the way to ref counting).
can run pretty with an explicit gc after each file.
R=r
DELTA=502 (346 added, 143 deleted, 13 changed)
OCL=20630
CL=20635
diff --git a/src/runtime/proc.c b/src/runtime/proc.c
index fa30c1e..6e947c5f 100644
--- a/src/runtime/proc.c
+++ b/src/runtime/proc.c
@@ -53,9 +53,12 @@
int32 mcount; // number of ms that have been created
int32 mcpu; // number of ms executing on cpu
int32 mcpumax; // max number of ms allowed on cpu
+ int32 gomaxprocs;
int32 msyscall; // number of ms in system calls
int32 predawn; // running initialization, don't run new gs.
+
+ Note stopped; // one g can wait here for ms to stop
};
Sched sched;
@@ -91,10 +94,11 @@
int32 n;
byte *p;
- sched.mcpumax = 1;
+ sched.gomaxprocs = 1;
p = getenv("GOMAXPROCS");
if(p != nil && (n = atoi(p)) != 0)
- sched.mcpumax = n;
+ sched.gomaxprocs = n;
+ sched.mcpumax = sched.gomaxprocs;
sched.mcount = 1;
sched.predawn = 1;
}
@@ -134,7 +138,7 @@
// 160 is the slop amount known to the stack growth code
g = mal(sizeof(G));
- stk = mal(160 + stacksize);
+ stk = stackalloc(160 + stacksize);
g->stack0 = stk;
g->stackguard = stk + 160;
g->stackbase = stk + 160 + stacksize;
@@ -348,6 +352,7 @@
throw("all goroutines are asleep - deadlock!");
m->nextg = nil;
noteclear(&m->havenextg);
+ notewakeup(&sched.stopped);
unlock(&sched);
notesleep(&m->havenextg);
@@ -362,6 +367,33 @@
return gp;
}
+// TODO(rsc): Remove. This is only temporary,
+// for the mark and sweep collector.
+void
+stoptheworld(void)
+{
+ lock(&sched);
+ sched.mcpumax = 1;
+ while(sched.mcpu > 1) {
+ noteclear(&sched.stopped);
+ unlock(&sched);
+ notesleep(&sched.stopped);
+ lock(&sched);
+ }
+ unlock(&sched);
+}
+
+// TODO(rsc): Remove. This is only temporary,
+// for the mark and sweep collector.
+void
+starttheworld(void)
+{
+ lock(&sched);
+ sched.mcpumax = sched.gomaxprocs;
+ matchmg();
+ unlock(&sched);
+}
+
// Called to start an M.
void
mstart(void)
@@ -500,11 +532,15 @@
unlock(&debuglock);
}
lock(&sched);
+ g->status = Gsyscall;
sched.mcpu--;
sched.msyscall++;
if(sched.gwait != 0)
matchmg();
unlock(&sched);
+ // leave SP around for gc; poison PC to make sure it's not used
+ g->sched.SP = (byte*)&callerpc;
+ g->sched.PC = (byte*)0xdeadbeef;
}
// The goroutine g exited its system call.
@@ -521,6 +557,7 @@
}
lock(&sched);
+ g->status = Grunning;
sched.msyscall--;
sched.mcpu++;
// Fast path - if there's room for this m, we're done.
