--- name: "pfm_get_event_mask_description" section: "3" platform: "linux" package: "libpfm3-3.2-dev" version: "3.2.070507-1.1" release: "Debian 6.0 (Squeeze)" platforms: ["linux"] url: "https://new.carta.tech/pfm_get_event_name" --- # pfm\_get\_event\_mask\_description(3) get event information Part of [pfm\_get\_event\_name(3)](/pfm_get_event_name/3.md). ## NAME pfm\_get\_event\_name, pfm\_get\_full\_event\_name, pfm\_get\_event\_mask\_name, pfm\_get\_event\_code, pfm\_get\_event\_mask\_code, pfm\_get\_event\_counters, pfm\_get\_num\_events, pfm\_get\_max\_event\_name\_len, pfm\_get\_event\_description, pfm\_get\_event\_mask\_description - get event information ## SYNOPSIS ``` #include int pfm_get_event_name(unsigned int e, char *name, size_tmaxlen); int pfm_get_full_event_name(pfmlib_event_t *ev, char *name, size_tmaxlen); int pfm_get_event_mask_name(unsigned int e, unsigned int mask, char *name, size_tmaxlen); int pfm_get_event_code(unsigned int e, int *code); int pfm_get_event_mask_code(unsigned int e, unsigned int mask, int *code); int pfm_get_event_code_counter(unsigned int e, unsigned int cnt, int *code); int pfm_get_event_counters(int e, pfmlib_regmask_t counters); int pfm_get_num_events(unsigned int *count); int pfm_get_max_event_name_len(size_t *len); int pfm_get_event_description(unsigned int ev, char **str); int pfm_get_event_mask_description(unsigned int ev, unsigned int mask, char **str); ``` ## DESCRIPTION The **pfm\_get\_event\_name** function returns in **name** the event name given its opaque descriptor in **e**. The **maxlen** argument indicates the maximum length of the buffer provided for **name**. Up to **maxlen-1** characters will be returned, not including the termination character. Event names are returned in all upper case. The **pfm\_get\_full\_event\_name** function returns in **name** the event name given the full event description in **ev**. The description contains the event code in **ev-\>event** and optional unit masks descriptors in **ev-\>unit\_masks**. The **maxlen** argument indicates the maximum length of the buffer provided for **name**. If more than **maxlen-1** characters are needed to represent the event, an error is returned. In case unit masks are provided, the final event name string is structured as: event\_name:unit\_masks1\[:unit\_masks2\]. Event names and unit masks names are returned in all upper case. The **pfm\_get\_event\_code** function returns the event code in **code** given its opaque descriptor **e**. On some PMU models, the code associated with an event is different based on the counter it is programmed into. The **pfm\_get\_event\_code\_counter** function is used to retrieve the event code in **code** when the event **e** is programmed into counter **cnt**. The counter index **cnt** must correspond to of a counting PMD register. Given an opaque event descriptor **e**, the **pfm\_get\_event\_counters** function returns in **counters** a bitmask of type **pfmlib\_regmask\_t** where each bit set represents a PMU config register which can be used to program this event. The bitmask must be accessed using accessor macros defined by the library. It is possible to list all existing events for the detected host PMU using accessor functions as the full table of events is not accessible to the applications. The index of the first event is always zero, then using **pfm\_get\_num\_events** you get the total number of events. Event descriptors are contiguous therefore a simple loop will allow complete scanning. The typical scan loop is constructed as follows: ``` unsigned int i, count; char name[256]; pfm_get_num_events(&count); for(i=0;i < count; i++) { pfm_get_event_name(i, name, 256); printf("%s\n", name); } ``` The **pfm\_get\_num\_events** function returns in **count** the total number of events supported by the host PMU. The former **pfm\_get\_first\_event** has been deprecated. You can simply initialize your variable to 0 to point to the first event. The former **pfm\_get\_next\_event** has been deprecated. You need to retrieve the total number of events for the host PMU and then increment your loop variable until you reach that count. The **pfm\_get\_max\_event\_name\_len** function returns in **len** the maximum length in bytes for the name of the events or its unit masks, if any, available on one PMU implementation. The value excludes the string termination character ('\\0'). The **pfm\_get\_event\_description** function returns in **str** the description string associated with the event specified in **ev**. The description is returned into a buffer that is allocated to hold the entire description text. It is the responsibility of the caller to free the buffer when it becomes useless by calling the **[free(3)](/free/3.md)** function. The **pfm\_get\_event\_mask\_code** function must be used to retrieve the actual unit mask value given a event descriptor in **e** and a unit mask descriptor in **mask**. The value is returned in **code**. The **pfm\_get\_event\_mask\_name** function must be used to retrieve the name associated with a unit mask specified in **mask** for event **e**. The name is returned in the buffer specified in **name**. The maximum size of the buffer must be specified in **maxlen**. The **pfm\_get\_event\_mask\_description** function returns in **str** the description string associated with the unit mask specified in **mask** for the event specified in **ev**. The description is returned into a buffer that is allocated to hold the entire description text. It is the responsibility of the caller to free the buffer when it becomes useless by calling the **[free(3)](/free/3.md)** function. ## RETURN All functions return whether or not the call was successful. A return value of **PFMLIB\_SUCCESS** indicates success, otherwise the value is the error code. ## ERRORS **PFMLIB\_ERR\_NOINIT** the library has not been initialized properly. - **PFMLIB\_ERR\_FULL** the string buffer provided is too small - **PFMLIB\_ERR\_INVAL** the event or unit mask descriptor, or the **cnt** argument is invalid, or a pointer argument is NULL. ## SEE ALSO [pfm\_get\_impl\_counters(3)](/pfm_get_impl_counters/3.md), [free(3)](/free/3.md) ## AUTHOR Stephane Eranian \