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cpc_access(3cpc) [opensolaris man page]

cpc_access(3CPC)				    CPU Performance Counters Library Functions					  cpc_access(3CPC)

NAME
cpc_access - test access CPU performance counters SYNOPSIS
cc [ flag... ] file... -lcpc [ library... ] #include <libcpc.h> int cpc_access(void); DESCRIPTION
Access to CPU performance counters is possible only on systems where the appropriate hardware exists and is correctly configured. The cpc_access() function must be used to determine if the hardware exists and is accessible on the platform before any of the interfaces that use the counters are invoked. When the hardware is available, access to the per-process counters is always allowed to the process itself, and allowed to other processes mediated using the existing security mechanisms of /proc. RETURN VALUES
Upon successful completion, cpc_access() returns 0. Otherwise, it returns -1 and sets errno to indicate the error. By default, two common errno values are decoded and cause the library to print an error message using its reporting mechanism. See cpc_seterrfn(3CPC) for a description of how this behavior can be modified. ERRORS
The cpc_access() function will fail if: EAGAIN Another process may be sampling system-wide CPU statistics. ENOSYS CPU performance counters are inaccessible on this machine. This error can occur when the machine supports CPU performance coun- ters, but some software components are missing. Check to see that all CPU Performance Counter packages have been correctly installed. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ |ATTRIBUTE TYPE |ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ |Interface Stability |Obsolete | +-----------------------------+-----------------------------+ SEE ALSO
cpc(3CPC), cpc_open(3CPC), cpc_seterrfn(3CPC), libcpc(3LIB), proc(4), attributes(5) NOTES
The cpc_access() function exists for binary compatibility only. Source containing this function will not compile. This function is obsolete and might be removed in a future release. Applications should use cpc_open(3CPC) instead. SunOS 5.11 28 Mar 2005 cpc_access(3CPC)

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cpc_count_usr_events(3CPC)			    CPU Performance Counters Library Functions				cpc_count_usr_events(3CPC)

NAME
cpc_count_usr_events, cpc_count_sys_events - enable and disable performance counters SYNOPSIS
cc [ flag... ] file... -lcpc [ library... ] #include <libcpc.h> int cpc_count_usr_events(int enable); int cpc_count_sys_events(int enable); DESCRIPTION
In certain applications, it can be useful to explicitly enable and disable performance counters at different times so that the performance of a critical algorithm can be examined. The cpc_count_usr_events() function can be used to control whether events are counted on behalf of the application running in user mode, while cpc_count_sys_events() can be used to control whether events are counted on behalf of the application while it is running in the kernel, without otherwise disturbing the binding of events to the invoking LWP. If the enable argu- ment is non-zero, counting of events is enabled, otherwise they are disabled. RETURN VALUES
Upon successful completion, cpc_count_usr_events() and cpc_count_sys_events() return 0. Otherwise, the functions return -1 and set errno to indicate the error. ERRORS
The cpc_count_usr_events() and cpc_count_sys_events() functions will fail if: EAGAIN The associated performance counter context has been invalidated by another process. EINVAL No performance counter context has been created, or an attempt was made to enable system events while delivering counter over- flow signals. EXAMPLES
Example 1 Use cpc_count_usr_events() to minimize code needed by application. In this example, the routine cpc_count_usr_events() is used to minimize the amount of code that needs to be added to the application. The cputrack(1) command can be used in conjunction with these interfaces to provide event programming, sampling, and reporting facilities. If the application is instrumented in this way and then started by cputrack with the nouser flag set in the event specification, counting of user events will only be enabled around the critical code section of interest. If the program is run normally, no harm will ensue. int have_counters = 0; int main(int argc, char *argv[]) { if (cpc_version(CPC_VER_CURRENT) == CPC_VER_CURRENT && cpc_getcpuver() != -1 && cpc_access() == 0) have_counters = 1; /* ... other application code */ if (have_counters) (void) cpc_count_usr_events(1); /* ==> Code to be measured goes here <== */ if (have_counters) (void) cpc_count_usr_events(0); /* ... other application code */ } ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ |Interface Stability |Obsolete | +-----------------------------+-----------------------------+ SEE ALSO
cputrack(1), cpc(3CPC), cpc_access(3CPC), cpc_bind_event(3CPC), cpc_enable(3CPC), cpc_getcpuver(3CPC), cpc_pctx_bind_event(3CPC), cpc_ver- sion(3CPC), libcpc(3LIB), attributes(5) NOTES
The cpc_count_usr_events() and cpc_count_sys_events() 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_enable(3CPC) instead. SunOS 5.11 28 Mar 2005 cpc_count_usr_events(3CPC)
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