Interaction with the environment

Most operations are directed towards the scripting engine, that is - environment makes a function call and scripting engine handles it. For everything else, there are callbacks.

Memory allocation

• sgs_MemFunc must be specified in creation of the scripting engine context
• sgs_MemFunc (re)allocates and frees memory
• unlike realloc, if size = 0, this function must return NULL
• sgs_DefaultMemFunc is the sample implementation
• the expected behavior is same as for sgs_Memory

Output

• sgs_MsgFunc and sgs_OutputFunc are responsible for piping the outputs to their destinations
• they can be set at any moment after the creation of the scripting engine context
• sgs_MsgFunc takes the following arguments:
  • void* data - the user data pointer
  • sgs_Context* C - the scripting engine context
  • int type - the debug type (SGS_INFO, SGS_WARNING etc.)
  • const char* message - the debug message
  • sgs_StdMsgFunc(_NoAbort) are the sample implementations
• sgs_OutputFunc takes the following arguments:
  • void* data - the user data pointer
  • sgs_Context* C - the scripting engine context
  • const void* ptr - the data to write
  • sgs_SizeVal size - the size of data to write
  • sgs_StdOutputFunc is the sample implementation

Execution notifications

• sgs_HookFunc must be set to retrieve events of that kind
• it can be set at any moment after the creation of the scripting engine context
• sgs_HookFunc takes the following arguments:
  • void* data - the user data pointer
  • sgs_Context* C - the scripting engine context
  • int event - the event that occured, can be one of these values:
    • SGS_HOOK_ENTER - function was entered
    • SGS_HOOK_EXIT - function was exited
    • SGS_HOOK_STEP - instruction is about to be executed
    • SGS_HOOK_PAUSE - context was paused
    • SGS_HOOK_CONT - context was resumed
    • SGS_HOOK_CREAT - context was created (empty, no state copy)
    • SGS_HOOK_CFORK - context was forked (full state copy)
    • SGS_HOOK_CFREE - context was freed