More lwIP sys_arch.c semaphore stuff

cf618494 · Silas Boyd-Wickizer · ad8d4f37 · cf618494 · cf618494
--- a/net/arch/sys_arch.h
+++ b/net/arch/sys_arch.h
@@ -21,6 +21,7 @@ typedef struct sys_mbox {
 typedef struct sys_sem {
  struct spinlock s;
  struct condvar c;
+  volatile int invalid;
  volatile u8 count;
 } sys_sem_t;


--- a/net/sys_arch.c
+++ b/net/sys_arch.c
@@ -114,7 +114,17 @@ done:
 u32_t
 sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg)
 {
-  DIE;
+  u32_t r = SYS_MBOX_EMPTY;
+
+  acquire(&mbox->s);
+  if (mbox->head - mbox->tail != 0) {
+    if (msg)
+      *msg = mbox->msg[mbox->tail % MBOXSLOTS];
+    mbox->tail++;
+    r = 0;
+  }
+  release(&mbox->s);
+  return r;
 }

 //
@@ -126,25 +136,25 @@ sys_sem_new(sys_sem_t *sem, u8_t count)
  initlock(&sem->s, "lwIP sem");
  initcondvar(&sem->c, "lwIP condvar");
  sem->count = count;
+  sem->invalid = 0;
  return ERR_OK;
 }

 void
 sys_sem_free(sys_sem_t *sem)
 {
-  DIE;
 }

 void
 sys_sem_set_invalid(sys_sem_t *sem)
 {
-  DIE;
+  sem->invalid = 1;
 }

 int
 sys_sem_valid(sys_sem_t *sem)
 {
-  DIE;
+  return !sem->invalid;
 }

 void