1 /***************************************************************************** 2 3 File: scheduler.h 4 5 Description: Scheduling inquiry functions 6 7 Copyright 1998-, Be Incorporated, All Rights Reserved. 8 9 *****************************************************************************/ 10 11 12 #if !defined(SCHEDULER_H) 13 #define SCHEDULER_H 14 15 #include <SupportDefs.h> 16 #include <OS.h> 17 18 /* To get a good thread priority, call suggest_thread_priority() with the following information: */ 19 /* 'what' is a bit mask describing what you're doing in the thread. */ 20 /* 'period' is how many times a second your thread needs to run (-1 if you're running continuously.) */ 21 /* 'jitter' is an estimate (in us) of how much that period can vary, as long as it stays centered on the average. */ 22 /* 'length' is how long (in us) you expect to run for each invocation. */ 23 /* "invocation" means, typically, receiving a message, dispatching it, and then returning to reading a message. */ 24 /* MANIPULATION means both filtering and compression/decompression. */ 25 /* PLAYBACK and RECORDING means threads feeding/reading ACTUAL HARDWARE ONLY. */ 26 /* 0 means don't care */ 27 enum be_task_flags { /* bitmasks for "what" */ 28 B_DEFAULT_MEDIA_PRIORITY = 0, 29 B_OFFLINE_PROCESSING = 0x1, 30 B_STATUS_RENDERING = 0x2, /* can also use this for "preview" type things */ 31 B_USER_INPUT_HANDLING = 0x4, 32 B_LIVE_VIDEO_MANIPULATION = 0x8, /* non-live processing is OFFLINE_PROCESSING */ 33 B_VIDEO_PLAYBACK = 0x10, /* feeding hardware */ 34 B_VIDEO_RECORDING = 0x20, /* grabbing from hardware */ 35 B_LIVE_AUDIO_MANIPULATION = 0x40, /* non-live processing is OFFLINE_PROCESSING */ 36 B_AUDIO_PLAYBACK = 0x80, /* feeding hardware */ 37 B_AUDIO_RECORDING = 0x100, /* grabbing from hardware */ 38 B_LIVE_3D_RENDERING = 0x200, /* non-live rendering is OFFLINE_PROCESSING */ 39 B_NUMBER_CRUNCHING = 0x400, 40 B_MIDI_PROCESSING = 0x800 41 }; 42 #if defined(__cplusplus) 43 extern "C" { 44 _IMPEXP_ROOT int32 suggest_thread_priority(uint32 task_flags = B_DEFAULT_MEDIA_PRIORITY, 45 int32 period = 0, bigtime_t jitter = 0, bigtime_t length = 0); 46 _IMPEXP_ROOT bigtime_t estimate_max_scheduling_latency(thread_id th = -1); /* default is current thread */ 47 } 48 #else 49 _IMPEXP_ROOT int32 suggest_thread_priority(uint32 what, int32 period, bigtime_t jitter, bigtime_t length); 50 _IMPEXP_ROOT bigtime_t estimate_max_scheduling_latency(thread_id th); /* default is current thread */ 51 #endif 52 53 #endif /* SCHEDULER_H */ 54 55