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pmc_attach
PMC_ATTACH(3) BSD Library Functions Manual PMC_ATTACH(3)
NAME
pmc_attach, pmc_detach -- attaching and detaching process scope PMCs to target processes
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include <pmc.h>
int
pmc_attach(pmc_id_t pmcid, pid_t pid);
int
pmc_detach(pmc_id_t pmcid, pid_t pid);
DESCRIPTION
These functions control the set of target processes tracked by a process scope PMC.
Function pmc_attach() is used to attach a process scope PMC specified by argument pmcid to a target process specified by argument pid. Argu-
ment pid may be zero to denote the current process. If the PMC was allocated with modifier PMC_F_DESCENDANTS, the PMC will additionally
attach to current and future descendents of the specified target process. The PMC should be in a quiescent state (i.e., not running).
Function pmc_detach() is used to detach a process scope PMC specified by argument pmcid from a process specified by argument pid. Argument
pid may be zero to denote the current process.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
A call to function pmc_attach() may fail with the following errors:
[EBUSY] Argument pmcid specified a PMC that was not in a quiescent state.
[EBUSY] The target process specified by function pmc_attach is being tracked by another process scope PMC that uses the same PMC
hardware resources.
[EEXIST] The target process is already being tracked by the specified PMC.
[EINVAL] Argument pmcid specified a PMC with system scope.
[EINVAL] Argument pid specified an illegal process id.
[EINVAL] The current process does not own a PMC with the handle specified in argument pmcid.
[EPERM] The caller lacked the privilege needed to attach PMCs to the specified target process.
[EPERM] (i386 and amd64 architectures) The PMC specified by argument pmcid has been setup to allow the use of the RDPMC instruc-
tion for self measurement.
[ESRCH] The current process does not own any PMCs.
[ESRCH] The process specified by argument pid did not exist.
A call to function pmc_detach() may fail with the following errors:
[EINVAL] Argument pmcid specified a PMC with system scope.
[EINVAL] Argument pid specified an illegal process id.
[EINVAL] The current process does not own a PMC with the handle specified in argument pmcid.
[EINVAL] The specified PMC was not attached to the target process.
[ESRCH] The current process does not own any PMCs.
[ESRCH] The process specified by argument pid is not being monitored by hwpmc(4).
[ESRCH] The process specified by argument pid did not exist.
SEE ALSO
pmc(3), pmc_start(3), pmc_stop(3), hwpmc(4)
BSD
November 25, 2007 BSD