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pmc_attach, pmc_detach(3) attaching and detaching process scope PMCs to target processes
pmc_detach, pmc_attach(3) attaching and detaching process scope PMCs to target processes
PMC_ATTACH(3) MidnightBSD Library Functions Manual PMC_ATTACH(3)

pmc_attach, pmc_detach — attaching and detaching process scope PMCs to target processes

Performance Counters Library (libpmc, -lpmc)

#include <pmc.h>

int
pmc_attach(pmc_id_t pmcid, pid_t pid);

int
pmc_detach(pmc_id_t pmcid, pid_t pid);

These functions control the set of target processes tracked by a process scope PMC.

Function () is used to attach a process scope PMC specified by argument pmcid to a target process specified by argument pid. Argument 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 () 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.

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.

A call to function pmc_attach() may fail with the following errors:

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Argument pmcid specified a PMC that was not in a quiescent state.
[]
The target process specified by function pmc_attach is being tracked by another process scope PMC that uses the same PMC hardware resources.
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The target process is already being tracked by the specified PMC.
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Argument pmcid specified a PMC with system scope.
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Argument pid specified an illegal process id.
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The current process does not own a PMC with the handle specified in argument pmcid.
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The caller lacked the privilege needed to attach PMCs to the specified target process.
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(i386 and amd64 architectures) The PMC specified by argument pmcid has been setup to allow the use of the RDPMC instruction for self measurement.
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The current process does not own any PMCs.
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The process specified by argument pid did not exist.

A call to function pmc_detach() may fail with the following errors:

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Argument pmcid specified a PMC with system scope.
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Argument pid specified an illegal process id.
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The current process does not own a PMC with the handle specified in argument pmcid.
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The specified PMC was not attached to the target process.
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The current process does not own any PMCs.
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The process specified by argument pid is not being monitored by hwpmc(4).
[]
The process specified by argument pid did not exist.

pmc(3), pmc_start(3), pmc_stop(3), hwpmc(4)

November 25, 2007 midnightbsd-3.1