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-rw-r--r-- | tools/perf/util/trigger.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/tools/perf/util/trigger.h b/tools/perf/util/trigger.h new file mode 100644 index 000000000000..e97d7016d771 --- /dev/null +++ b/tools/perf/util/trigger.h @@ -0,0 +1,94 @@ +#ifndef __TRIGGER_H_ +#define __TRIGGER_H_ 1 + +#include "util/debug.h" +#include "asm/bug.h" + +/* + * Use trigger to model operations which need to be executed when + * an event (a signal, for example) is observed. + * + * States and transits: + * + * + * OFF--(on)--> READY --(hit)--> HIT + * ^ | + * | (ready) + * | | + * \_____________/ + * + * is_hit and is_ready are two key functions to query the state of + * a trigger. is_hit means the event already happen; is_ready means the + * trigger is waiting for the event. + */ + +struct trigger { + volatile enum { + TRIGGER_ERROR = -2, + TRIGGER_OFF = -1, + TRIGGER_READY = 0, + TRIGGER_HIT = 1, + } state; + const char *name; +}; + +#define TRIGGER_WARN_ONCE(t, exp) \ + WARN_ONCE(t->state != exp, "trigger '%s' state transist error: %d in %s()\n", \ + t->name, t->state, __func__) + +static inline bool trigger_is_available(struct trigger *t) +{ + return t->state >= 0; +} + +static inline bool trigger_is_error(struct trigger *t) +{ + return t->state <= TRIGGER_ERROR; +} + +static inline void trigger_on(struct trigger *t) +{ + TRIGGER_WARN_ONCE(t, TRIGGER_OFF); + t->state = TRIGGER_READY; +} + +static inline void trigger_ready(struct trigger *t) +{ + if (!trigger_is_available(t)) + return; + t->state = TRIGGER_READY; +} + +static inline void trigger_hit(struct trigger *t) +{ + if (!trigger_is_available(t)) + return; + TRIGGER_WARN_ONCE(t, TRIGGER_READY); + t->state = TRIGGER_HIT; +} + +static inline void trigger_off(struct trigger *t) +{ + if (!trigger_is_available(t)) + return; + t->state = TRIGGER_OFF; +} + +static inline void trigger_error(struct trigger *t) +{ + t->state = TRIGGER_ERROR; +} + +static inline bool trigger_is_ready(struct trigger *t) +{ + return t->state == TRIGGER_READY; +} + +static inline bool trigger_is_hit(struct trigger *t) +{ + return t->state == TRIGGER_HIT; +} + +#define DEFINE_TRIGGER(n) \ +struct trigger n = {.state = TRIGGER_OFF, .name = #n} +#endif |