cpc_set_create, cpc_set_destroy, cpc_set_add_request, cpc_walk_requests
- manage sets of counter requests
cc [ flag... ] file... -lcpc [ library... ]
cpc_set_t *cpc_set_create(cpc_t *cpc);
int cpc_set_destroy(cpc_t *cpc, cpc_set_t *set);
int cpc_set_add_request(cpc_t *cpc, cpc_set_t *set,
const char *event, uint64_t preset, uint_t flags,
uint_t nattrs, const cpc_attr_t *attrs);
void cpc_walk_requests(cpc_t *cpc, cpc_set_t *set, void *arg,
void (*action)(void *arg, int index, const char *event,
uint64_t preset, uint_t flags, int nattrs,
const cpc_attr_t *attrs));
The cpc_set_create() function returns an initialized and empty CPC set.
A CPC set contains some number of requests, where a request represents
a specific configuration of a hardware performance instrumentation
counter present on the processor. The cpc_set_t data structure is
opaque and must not be accessed directly by the application.
Applications wanting to program one or more performance counters must
create an empty set with cpc_set_create() and add requests to the set
with cpc_set_add_request(). Once all requests have been added to a set,
the set must be bound to the hardware performance counters (see
cpc_bind_curlwp(), cpc_bind_pctx(), and cpc_bind_cpu(), all described
on cpc_bind_curlwp(3CPC)) before counting events. At bind time, the
system attempts to match each request with an available physical
counter capable of counting the event specified in the request. If the
bind is successful, a 64-bit virtualized counter is created to store
the counts accumulated by the hardware counter. These counts are stored
and managed in CPC buffers separate from the CPC set whose requests are
being counted. See cpc_buf_create(3CPC) and cpc_set_sample(3CPC).
The cpc_set_add_request() function specifies a configuration of a hard‐
ware counter. The arguments to cpc_set_add_request() are:
A string containing the name of an event supported by
the system's processor. The cpc_walk_events_all() and
cpc_walk_events_pic() functions (both described on
cpc_npic(3CPC)) can be used to query the processor for
the names of available events. Certain processors
allow the use of raw event codes, in which case a
string representation of an event code in a form
acceptable to strtol(3C) can be used as the event
The value with which the system initializes the
Three flags are defined that modify the behavior of
the counter acting on behalf of this request:
The counter should count events that occur while
the processor is in user mode.
The counter should count events that occur while
the processor is in privileged mode.
Request a signal to be sent to the application
when the physical counter overflows. A SIGEMT sig‐
nal is delivered if the processor is capable of
delivering an interrupt when the counter counts
past its maximum value. All requests in the set
containing the counter that overflowed are stopped
until the set is rebound.
At least one of CPC_COUNT_USER or CPC_COUNT_SYSTEM
must be specified to program the hardware for count‐
The nattrs argument specifies the number of attributes
pointed to by the attrs argument, which is an array of
cpc_attr_t structures containing processor-specific
attributes that modify the request's configuration.
The cpc_walk_attrs() function (see cpc_npic(3CPC)) can
be used to query the processor for the list of
attributes it accepts. The library makes a private
copy of the attrs array, allowing the application to
dispose of it immediately after calling
The cpc_walk_requests() function calls the action function on each
request that has been added to the set. The arg argument is passed
unmodified to the action function with each call.
Upon successful completion, cpc_set_create() returns a handle to the
opaque cpc_set_t data structure. Otherwise, NULL is returned and errno
is set to indicate the error.
Upon successful completion, Cpc_set_destroy() returns 0. Otherwise, -1
is returned and errno is set to indicate the error.
Upon successful completion, cpc_set_add_request() returns an integer
index used to refer to the data generated by that request during data
retrieval. Otherwise, -1 is returned and errno is set to indicate the
These functions will fail if:
An event, attribute, or flag passed to cpc_set_add_request()
For cpc_set_destroy() and cpc_set_add_request(), the set
parameter was not created with the given cpc_t.
There was not enough memory available to the process to cre‐
ate the library's data structures.
See attributes(5) for descriptions of the following attributes:
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
│Interface Stability │ Committed │
│MT-Level │ Safe │
SEE ALSOcpc_bind_curlwp(3CPC), cpc_buf_create(3CPC), cpc_npic(3CPC), cpc_seter‐
rhndlr(3CPC), libcpc(3LIB), strtol(3C), attributes(5)NOTES
The system automatically determines which particular physical counter
to use to count the events specified by each request. Applications can
force the system to use a particular counter by specifying the counter
number in an attribute named picnum that is passed to
cpc_set_add_request(). Counters are numbered from 0 to n - 1, where n
is the number of counters in the processor as returned by
Some processors, such as UltraSPARC, do not allow the hardware counters
to be programmed differently. In this case, all requests in the set
must have the same configuration, or an attempt to bind the set will
return EINVAL. If a cpc_errhndlr_t has been registered with cpc_seter‐
rhndlr(3CPC), the error handler is called with subcode CPC_CONFLICT‐
ING_REQS. For example, on UltraSPARC pic0 and pic1 must both program
events in the same processor mode (user mode, kernel mode, or both).
For example, pic0 cannot be programmed with CPC_COUNT_USER while pic1
is programmed with CPC_COUNT_SYSTEM. Refer to the hardware documenta‐
tion referenced by cpc_cpuref(3CPC) for details about a particular pro‐
cessor's performance instrumentation hardware.
Aug 20, 2007 CPC_SET_CREATE(3CPC)