//                              -*- Mode: C -*-
//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// invoke.h --
//
// Author           : Thierry Delisle
// Created On       : Tue Jan 17 12:27:26 2016
// Last Modified By : Thierry Delisle
// Last Modified On : --
// Update Count     : 0
//

#include <stdbool.h>
#include <stdint.h>

#ifdef __CFORALL__
extern "C" {
#endif

#if ! defined(__CFA_INVOKE_PRIVATE__)
#ifndef _INVOKE_H_
#define _INVOKE_H_

      #define unlikely(x)    __builtin_expect(!!(x), 0)
      #define thread_local _Thread_local

      struct spinlock {
            volatile int lock;
            #ifdef __CFA_DEBUG__
                  const char * prev_name;
                  void* prev_thrd;
            #endif
      };

      struct __thread_queue_t {
            struct thread_desc * head;
            struct thread_desc ** tail;
      };

      struct __condition_stack_t {
            struct __condition_criterion_t * top;
      };

      #ifdef __CFORALL__
      extern "Cforall" {
            void ?{}( struct __thread_queue_t * );
            void append( struct __thread_queue_t *, struct thread_desc * );
            struct thread_desc * pop_head( struct __thread_queue_t * );

            void ?{}( struct __condition_stack_t * );
            void push( struct __condition_stack_t *, struct __condition_criterion_t * );
            struct __condition_criterion_t * pop( struct __condition_stack_t * );

            void ?{}(spinlock * this);
            void ^?{}(spinlock * this);
      }
      #endif

      struct coStack_t {
            unsigned int size;                        // size of stack
            void *storage;                            // pointer to stack
            void *limit;                              // stack grows towards stack limit
            void *base;                               // base of stack
            void *context;                            // address of cfa_context_t
            void *top;                                // address of top of storage
            bool userStack;                           // whether or not the user allocated the stack
      };

      enum coroutine_state { Halted, Start, Inactive, Active, Primed };

      struct coroutine_desc {
            struct coStack_t stack;                   // stack information of the coroutine
            const char *name;                         // textual name for coroutine/task, initialized by uC++ generated code
            int errno_;                               // copy of global UNIX variable errno
            enum coroutine_state state;               // current execution status for coroutine
            struct coroutine_desc *starter;           // first coroutine to resume this one
            struct coroutine_desc *last;	            // last coroutine to resume this one
      };

      struct monitor_desc {
            struct spinlock lock;                     // spinlock to protect internal data
            struct thread_desc * owner;               // current owner of the monitor
            struct __thread_queue_t entry_queue;      // queue of threads that are blocked waiting for the monitor
            struct __condition_stack_t signal_stack;  // stack of conditions to run next once we exit the monitor
            unsigned int recursion;                   // monitor routines can be called recursively, we need to keep track of that
      };

      struct thread_desc {
            struct coroutine_desc cor;                // coroutine body used to store context
            struct monitor_desc mon;                  // monitor body used for mutual exclusion
            struct thread_desc * next;                // instrusive link field for threads
            struct monitor_desc ** current_monitors;  // currently held monitors
            unsigned short current_monitor_count;     // number of currently held monitors
      };

#endif //_INVOKE_H_
#else //! defined(__CFA_INVOKE_PRIVATE__)
#ifndef _INVOKE_PRIVATE_H_
#define _INVOKE_PRIVATE_H_

      struct machine_context_t {
            void *SP;
            void *FP;
            void *PC;
      };

      // assembler routines that performs the context switch
      extern void CtxInvokeStub( void );
      void CtxSwitch( void * from, void * to ) asm ("CtxSwitch");

      #if   defined( __x86_64__ )
      #define CtxGet( ctx ) __asm__ ( \
                  "movq %%rsp,%0\n"   \
                  "movq %%rbp,%1\n"   \
            : "=rm" (ctx.SP), "=rm" (ctx.FP) )
      #elif defined( __i386__ )
      #define CtxGet( ctx ) __asm__ ( \
                  "movl %%esp,%0\n"   \
                  "movl %%ebp,%1\n"   \
            : "=rm" (ctx.SP), "=rm" (ctx.FP) )
      #endif

#endif //_INVOKE_PRIVATE_H_
#endif //! defined(__CFA_INVOKE_PRIVATE__)
#ifdef __CFORALL__
}
#endif