initial commit of lk (little kernel) project
diff --git a/include/kernel/thread.h b/include/kernel/thread.h
new file mode 100644
index 0000000..7753ad4
--- /dev/null
+++ b/include/kernel/thread.h
@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef __KERNEL_THREAD_H
+#define __KERNEL_THREAD_H
+
+#include <sys/types.h>
+#include <list.h>
+#include <compiler.h>
+#include <arch/ops.h>
+#include <arch/thread.h>
+
+enum thread_state {
+ THREAD_SUSPENDED = 0,
+ THREAD_READY,
+ THREAD_RUNNING,
+ THREAD_BLOCKED,
+ THREAD_SLEEPING,
+ THREAD_DEATH,
+};
+
+typedef int (*thread_start_routine)(void *arg);
+
+#define THREAD_MAGIC 'thrd'
+
+typedef struct thread {
+ int magic;
+ struct list_node thread_list_node;
+
+ /* active bits */
+ struct list_node queue_node;
+ int priority;
+ enum thread_state state;
+ int saved_critical_section_count;
+ int remaining_quantum;
+
+ /* if blocked, a pointer to the wait queue */
+ struct wait_queue *blocking_wait_queue;
+ status_t wait_queue_block_ret;
+
+ /* architecture stuff */
+ struct arch_thread arch;
+
+ /* stack stuff */
+ void *stack;
+ size_t stack_size;
+
+ /* entry point */
+ thread_start_routine entry;
+ void *arg;
+
+ /* return code */
+ int retcode;
+
+ char name[32];
+} thread_t;
+
+/* thread priority */
+#define NUM_PRIORITIES 32
+#define LOWEST_PRIORITY 0
+#define HIGHEST_PRIORITY (NUM_PRIORITIES - 1)
+#define DPC_PRIORITY (NUM_PRIORITIES - 2)
+#define IDLE_PRIORITY LOWEST_PRIORITY
+#define LOW_PRIORITY (NUM_PRIORITIES / 4)
+#define DEFAULT_PRIORITY (NUM_PRIORITIES / 2)
+#define HIGH_PRIORITY ((NUM_PRIORITIES / 4) * 3)
+
+/* stack size */
+#define DEFAULT_STACK_SIZE 8192
+
+/* functions */
+void thread_init(void);
+void thread_become_idle(void) __NO_RETURN;
+void thread_set_name(const char *name);
+void thread_set_priority(int priority);
+thread_t *thread_create(const char *name, thread_start_routine entry, void *arg, int priority, size_t stack_size);
+status_t thread_resume(thread_t *);
+void thread_exit(int retcode) __NO_RETURN;
+void thread_sleep(time_t delay);
+
+void dump_thread(thread_t *t);
+void dump_all_threads(void);
+
+/* scheduler routines */
+void thread_yield(void); /* give up the cpu voluntarily */
+void thread_preempt(void); /* get preempted (inserted into head of run queue) */
+void thread_block(void); /* block on something and reschedule */
+
+/* called on every timer tick for the scheduler to do quantum expiration */
+enum handler_return thread_timer_tick(void);
+
+/* the current thread */
+extern thread_t *current_thread;
+
+/* the idle thread */
+extern thread_t *idle_thread;
+
+/* critical sections */
+extern int critical_section_count;
+
+static inline void enter_critical_section(void)
+{
+ critical_section_count++;
+ if (critical_section_count == 1)
+ arch_disable_ints();
+}
+
+static inline void exit_critical_section(void)
+{
+ critical_section_count--;
+ if (critical_section_count == 0)
+ arch_enable_ints();
+}
+
+static inline bool in_critical_section(void)
+{
+ return critical_section_count > 0;
+}
+
+/* only used by interrupt glue */
+static inline void inc_critical_section(void) { critical_section_count++; }
+static inline void dec_critical_section(void) { critical_section_count--; }
+
+/* wait queue stuff */
+#define WAIT_QUEUE_MAGIC 'wait'
+
+typedef struct wait_queue {
+ int magic;
+ struct list_node list;
+ int count;
+} wait_queue_t;
+
+/* wait queue primitive */
+/* NOTE: must be inside critical section when using these */
+void wait_queue_init(wait_queue_t *);
+
+/*
+ * release all the threads on this wait queue with a return code of ERR_OBJECT_DESTROYED.
+ * the caller must assure that no other threads are operating on the wait queue during or
+ * after the call.
+ */
+void wait_queue_destroy(wait_queue_t *, bool reschedule);
+
+/*
+ * block on a wait queue.
+ * return status is whatever the caller of wait_queue_wake_*() specifies.
+ * a timeout other than INFINITE_TIME will set abort after the specified time
+ * and return ERR_TIMED_OUT. a timeout of 0 will immediately return.
+ */
+status_t wait_queue_block(wait_queue_t *, time_t timeout);
+
+/*
+ * release one or more threads from the wait queue.
+ * reschedule = should the system reschedule if any is released.
+ * wait_queue_error = what wait_queue_block() should return for the blocking thread.
+ */
+int wait_queue_wake_one(wait_queue_t *, bool reschedule, status_t wait_queue_error);
+int wait_queue_wake_all(wait_queue_t *, bool reschedule, status_t wait_queue_error);
+
+/*
+ * remove the thread from whatever wait queue it's in.
+ * return an error if the thread is not currently blocked (or is the current thread)
+ */
+status_t thread_unblock_from_wait_queue(thread_t *t, bool reschedule, status_t wait_queue_error);
+
+/* thread level statistics */
+#define THREAD_STATS 0
+#if THREAD_STATS
+struct thread_stats {
+ bigtime_t idle_time;
+ bigtime_t last_idle_timestamp;
+ int reschedules;
+ int context_switches;
+ int preempts;
+ int yields;
+ int interrupts; /* platform code increment this */
+ int timer_ints; /* timer code increment this */
+ int timers; /* timer code increment this */
+};
+
+extern struct thread_stats thread_stats;
+
+#endif
+
+#endif
+