man pages section 3: Extended Library Functions, Volume 1

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Updated: July 2014



cpc_pctx_bind_event, cpc_pctx_take_sample, cpc_pctx_rele, cpc_pctx_invalidate - access CPU performance counters in other processes


cc [ flag... ] file... −lcpc −lpctx [ library... ]
#include <libpctx.h>
#include <libcpc.h>

int cpc_pctx_bind_event(pctx_t *pctx, id_t lwpid, cpc_event_t *event,
     int flags);
int cpc_pctx_take_sample(pctx_t *pctx, id_t lwpid, cpc_event_t *event);
int cpc_pctx_rele(pctx_t *pctx, id_t lwpid);
int cpc_pctx_invalidate(pctx_t *pctx, id_t lwpid);


These functions are designed to be run in the context of an event handler created using the libpctx(3LIB) family of functions that allow the caller, also known as the controlling process, to manipulate the performance counters in the context of a controlled process. The controlled process is described by the pctx argument, which must be obtained from an invocation of pctx_capture(3CPC) or pctx_create(3CPC) and passed to the functions described on this page in the context of an event handler.

The semantics of the functions cpc_pctx_bind_event(), cpc_pctx_take_sample(), and cpc_pctx_rele() are directly analogous to those of cpc_bind_event(), cpc_take_sample(), and cpc_rele() described on the cpc_bind_event(3CPC) manual page.

The cpc_pctx_invalidate() function allows the performance context to be invalidated in an LWP in the controlled process.

Return Values

These functions return 0 on success. On failure, they return −1 and set errno to indicate the error.


The cpc_pctx_bind_event(), cpc_pctx_take_sample(), and cpc_pctx_rele() functions return the same errno values the analogous functions described on the cpc_bind_event(3CPC) manual page. In addition, these function may fail if:


For cpc_pctx_bind_event(), access to the requested hypervisor event was denied.


The value of the lwpid argument is invalid in the context of the controlled process.


See attributes(5) for descriptions of the following attributes:

Interface Stability

See also

cpc(3CPC), cpc_bind_event(3CPC), libcpc(3LIB), pctx_capture(3CPC), pctx_create(3CPC), attributes(5)


The cpc_pctx_bind_event(), cpc_pctx_invalidate(), cpc_pctx_rele(), and cpc_pctx_take_sample() functions exist for binary compatibility only. Source containing these functions will not compile. These functions are obsolete and might be removed in a future release. Applications should use cpc_bind_pctx(3CPC), cpc_unbind(3CPC), and cpc_set_sample(3CPC) instead.

The capability to create and analyze overflow events in other processes is not available, though it may be made available in a future version of this API. In the current implementation, the flags field must be specified as 0.