core: simple thread library

Simple thread library with the intent of making lwIP easier to port.
-- Modified to use milliseconds instead of jiffies,
   as lwIP expresses everything in milliseconds. EWB

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/core/include/thread.h b/core/include/thread.h
new file mode 100644
index 00000000..917c36a6
--- /dev/null
+++ b/core/include/thread.h
@@ -0,0 +1,84 @@
+#ifndef _THREAD_H
+#define _THREAD_H
+
+#include <stddef.h>
+#include <inttypes.h>
+#include "core.h"
+
+struct semaphore;
+
+struct thread_state {
+    uint32_t ebx, esp, ebp, esi, edi;
+};
+
+struct thread_list {
+    struct thread_list *next, *prev;
+};
+
+struct thread_block {
+    struct thread_list list;
+    struct thread *thread;
+    struct semaphore *semaphore;
+    mstime_t block_time;
+    mstime_t timeout;
+    bool timed_out;
+};
+
+struct thread {
+    struct thread_state state;
+    struct thread_list  list;
+    struct thread_block *blocked;
+    int prio;
+};
+
+void __schedule(void);
+void __switch_to(struct thread *);
+void thread_yield(void);
+
+extern struct thread *__current;
+static inline struct thread *current(void)
+{
+    return __current;
+}
+
+struct semaphore {
+    int count;
+    struct thread_list list;
+};
+
+mstime_t sem_down(struct semaphore *, mstime_t);
+void sem_up(struct semaphore *);
+void sem_init(struct semaphore *, int);
+
+typedef unsigned long irq_state_t;
+
+static inline irq_state_t irq_state(void)
+{
+    irq_state_t __st;
+
+    asm volatile("pushfl ; popl %0" : "=rm" (__st));
+    return __st;
+}
+
+static inline irq_state_t irq_save(void)
+{
+    irq_state_t __st;
+
+    asm volatile("pushfl ; popl %0 ; cli" : "=rm" (__st));
+    return __st;
+}
+
+static inline void irq_restore(irq_state_t __st)
+{
+    asm volatile("pushl %0 ; popfl" : : "rm" (__st));
+}
+
+void start_thread(struct thread *t, void *stack, size_t stack_size, int prio,
+		  void (*start_func)(void *), void *func_arg);
+void __exit_thread(void);
+void kill_thread(struct thread *);
+
+void start_idle_thread(void);
+void test_thread(void);
+
+#endif /* _THREAD_H */