Add a threadalloc function that behaves like Linux' kthread_create.

Use threadalloc to create gc_worker threads (and eventually use it for lwIP threads.)

Add a threadalloc function that behaves like Linux' kthread_create.
d02154e3 · Silas Boyd-Wickizer · 0410531d · d02154e3 · d02154e3 · d02154e3
--- a/gc.c
+++ b/gc.c
@@ -123,12 +123,8 @@ gc(void)


 void
-gc_worker(void)
+gc_worker(void *x)
 {
-  release(&myproc()->lock);	// initially held by scheduler
-
-  mtstart(rcu_gc_worker, myproc());
-
  struct spinlock wl;
  initlock(&wl, "rcu_gc_worker");   // dummy lock


--- a/kernel.h
+++ b/kernel.h
@@ -108,8 +108,7 @@ void            gc_begin_epoch();
 void            gc_end_epoch();
 void            gc_delayed(void*, void (*dofree)(void*));
 void            gc_delayed2(int, u64, void (*dofree)(int, u64));
-void		gc_start(void);
-void		gc_worker(void);
+void            gc_start(void);

 // hwvm.c
 void            freevm(pml4e_t*);
@@ -228,6 +227,7 @@ void            userinit(void);
 int             wait(void);
 void            yield(void);
 void            migrate(struct proc *);
+struct proc*    threadalloc(void (*fn)(void*), void *arg);

 // prof.c
 extern int profenable;

--- a/proc.c
+++ b/proc.c
@@ -12,6 +12,8 @@
 #include "vm.h"
 #include "sched.h"

+extern void threadstub(void);
+
 int __mpalign__ idle[NCPU];
 struct ns *nspid __mpalign__;
 static struct proc *bootproc __mpalign__;
@@ -267,17 +269,19 @@ inituser(void)
  release(&p->lock);

  for (u32 c = 0; c < NCPU; c++) {
-    struct proc *rcup = allocproc();
-    rcup->vmap = vmap_alloc();
-    rcup->context->rip = (u64) gc_worker;
-    rcup->cwd = 0;
-    rcup->cpuid = c;
-    rcup->cpu_pin = 1;
-
-    acquire(&rcup->lock);
-    rcup->state = RUNNABLE;
-    addrun(rcup);
-    release(&rcup->lock);
+    extern void gc_worker(void*);
+    struct proc *gcp; 
+
+    gcp = threadalloc(gc_worker, NULL);
+    if (gcp == NULL)
+      panic("threadalloc: gc_worker");
+
+    gcp->cpuid = c;
+    gcp->cpu_pin = 1;
+    acquire(&gcp->lock);
+    gcp->state = RUNNABLE;
+    addrun(gcp);
+    release(&gcp->lock);
  }
 }

@@ -352,7 +356,7 @@ scheduler(void)

        mtpause(schedp);
        if (p->context->rip != (uptr)forkret && 
-            p->context->rip != (uptr)gc_worker)
+            p->context->rip != (uptr)threadstub)
        {
          mtresume(p);
        }
@@ -663,3 +667,34 @@ wait(void)
    release(&myproc()->lock);
  }
 }
+
+void
+threadhelper(void (*fn)(void *), void *arg)
+{
+  release(&myproc()->lock); // initially held by scheduler
+  mtstart(fn, myproc());
+  fn(arg);
+  exit();
+}
+
+struct proc*
+threadalloc(void (*fn)(void *), void *arg)
+{
+  struct proc *p;
+
+  p = allocproc();
+  if (p == NULL)
+    return NULL;
+  
+  p->vmap = vmap_alloc();
+  if (p->vmap == NULL) {
+    gc_delayed(p, kmfree);
+    return NULL;
+  }
+
+  p->context->rip = (u64)threadstub;
+  p->context->r12 = (u64)fn;
+  p->context->r13 = (u64)arg;
+  p->cwd = 0;
+  return p;
+}
--- a/swtch.S
+++ b/swtch.S
@@ -24,3 +24,9 @@ swtch:
        popq %rbp
        popq %rbx
        ret
+
+.globl threadstub
+threadstub:
+        movq %r12, %rdi
+        movq %r13, %rsi
+        jmp threadhelper