--- /dev/null
+/*
+ * Kernel threads
+ * Copyright (c) 2001,2003 David H. Hovemeyer <daveho@cs.umd.edu>
+ * $Revision: 1.1 $
+ *
+ * This is free software. You are permitted to use,
+ * redistribute, and modify it as specified in the file "COPYING".
+ */
+
+#ifndef GEEKOS_KTHREAD_H
+#define GEEKOS_KTHREAD_H
+
+#include <geekos/ktypes.h>
+#include <geekos/list.h>
+
+struct Kernel_Thread;
+struct User_Context;
+struct Interrupt_State;
+
+/*
+ * Queue of threads.
+ * This is used for the run queue(s), and also for
+ * thread synchronization and communication.
+ */
+DEFINE_LIST(Thread_Queue, Kernel_Thread);
+
+/*
+ * List which includes all threads.
+ */
+DEFINE_LIST(All_Thread_List, Kernel_Thread);
+
+/*
+ * Kernel thread context data structure.
+ * NOTE: there is assembly code in lowlevel.asm that depends
+ * on the offsets of the fields in this struct, so if you change
+ * the layout, make sure everything gets updated.
+ */
+struct Kernel_Thread {
+ ulong_t esp; /* offset 0 */
+ volatile ulong_t numTicks; /* offset 4 */
+ int priority;
+ DEFINE_LINK(Thread_Queue, Kernel_Thread);
+ void* stackPage;
+ struct User_Context* userContext;
+ struct Kernel_Thread* owner;
+ int refCount;
+
+ /* These fields are used to implement the Join() function */
+ bool alive;
+ struct Thread_Queue joinQueue;
+ int exitCode;
+
+ /* The kernel thread id; also used as process id */
+ int pid;
+
+ /* Link fields for list of all threads in the system. */
+ DEFINE_LINK(All_Thread_List, Kernel_Thread);
+
+ /* Array of MAX_TLOCAL_KEYS pointers to thread-local data. */
+#define MAX_TLOCAL_KEYS 128
+ const void* tlocalData[MAX_TLOCAL_KEYS];
+
+};
+
+/*
+ * Define Thread_Queue and All_Thread_List access and manipulation functions.
+ */
+IMPLEMENT_LIST(Thread_Queue, Kernel_Thread);
+IMPLEMENT_LIST(All_Thread_List, Kernel_Thread);
+
+static __inline__ void Enqueue_Thread(struct Thread_Queue *queue, struct Kernel_Thread *kthread) {
+ Add_To_Back_Of_Thread_Queue(queue, kthread);
+}
+
+static __inline__ void Remove_Thread(struct Thread_Queue *queue, struct Kernel_Thread *kthread) {
+ Remove_From_Thread_Queue(queue, kthread);
+}
+
+/*
+ * Thread start functions should have this signature.
+ */
+typedef void (*Thread_Start_Func)(ulong_t arg);
+
+/*
+ * Thread priorities
+ */
+#define PRIORITY_IDLE 0
+#define PRIORITY_USER 1
+#define PRIORITY_LOW 2
+#define PRIORITY_NORMAL 5
+#define PRIORITY_HIGH 10
+
+
+/*
+ * Scheduler operations.
+ */
+void Init_Scheduler(void);
+struct Kernel_Thread* Start_Kernel_Thread(
+ Thread_Start_Func startFunc,
+ ulong_t arg,
+ int priority,
+ bool detached
+);
+struct Kernel_Thread* Start_User_Thread(struct User_Context* userContext, bool detached);
+void Make_Runnable(struct Kernel_Thread* kthread);
+void Make_Runnable_Atomic(struct Kernel_Thread* kthread);
+struct Kernel_Thread* Get_Current(void);
+struct Kernel_Thread* Get_Next_Runnable(void);
+void Schedule(void);
+void Yield(void);
+void Exit(int exitCode) __attribute__ ((noreturn));
+int Join(struct Kernel_Thread* kthread);
+struct Kernel_Thread* Lookup_Thread(int pid);
+
+/*
+ * Thread context switch function, defined in lowlevel.asm
+ */
+void Switch_To_Thread(struct Kernel_Thread*);
+
+/*
+ * Wait queue functions.
+ */
+void Wait(struct Thread_Queue* waitQueue);
+void Wake_Up(struct Thread_Queue* waitQueue);
+void Wake_Up_One(struct Thread_Queue* waitQueue);
+void Wake_Up_Thread(struct Thread_Queue* waitQueue, int pid);
+
+/*
+ * Pointer to currently executing thread.
+ */
+extern struct Kernel_Thread* g_currentThread;
+
+/*
+ * Boolean flag indicating that we need to choose a new runnable thread.
+ */
+extern int g_needReschedule;
+
+/*
+ * Boolean flag indicating that preemption should be disabled.
+ */
+extern volatile int g_preemptionDisabled;
+
+/*
+ * Thread-local data information
+ */
+#define MIN_DESTRUCTOR_ITERATIONS 4
+
+typedef void (*tlocal_destructor_t)(void *);
+typedef unsigned int tlocal_key_t;
+
+extern int Tlocal_Create(tlocal_key_t *, tlocal_destructor_t);
+extern void Tlocal_Put(tlocal_key_t, const void *);
+extern void *Tlocal_Get(tlocal_key_t);
+
+/* Print list of all threads, for debugging. */
+extern void Dump_All_Thread_List(void);
+
+
+#endif /* GEEKOS_KTHREAD_H */
