Commit Graph

72 Commits

Author SHA1 Message Date
Jim Warner
d53ff45b0d library: delete some obsolete parameter checking logic
This commit removes some obsolete parameter validation
code which was needed back when certain functions were
public, called directly by users (1st/2nd generation).

Now that they're static they can be safely eliminated.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-12-20 21:18:54 +11:00
Jim Warner
06be33b43e library: improve and/or standardize 'errno' management
With older library logic having been modified to avoid
using those potentially deadly alloc.h routines, while
improving 'errno' handling, we're ready to standardize
and enhance newlib's approach to any potential errors.

In so doing, we'll establish the following objectives:

. . . . . . . . . . . . . functions returning an 'int'
. an error will be indicated by a negative number that
is always the inverse of some well known errno.h value

. . . . . . . . . . . functions returning an 'address'
. any error will be indicated by a NULL return pointer
with the actual reason found in the formal errno value

And, when errno is manipulated directly we will strive
to do so whenever possible within those routines which
have been declared with PROCPS_EXPORT. In other words,
in the user callable functions defined in source last.

[ But, that won't always be possible. In particular, ]
[ all the 'read_failed' functions will sometimes set ]
[ 'errno' so that they can serve callers returning a ]
[ NULL or an int without duplicating a lot of logic. ]

[ Also, that includes one subordinate function which ]
[ was called by 'read_failed' in the <slabinfo> API. ]

------------------------------------------------------
Along the way, several additional miscellaneous issues
were addressed. They're listed here now for posterity.

. the '-1' return value passed outside the library was
eliminated since it would erroneously equate to -EPERM

. the stacks_fetch functions in <diskstats> and <stat>
weren't checked for their possible minus return values

. hash create was not checked in <meminfo> or <vmstat>

. fixed 'new' function faulty parm check in <slabinfo>

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-12-20 21:18:54 +11:00
Jim Warner
28f405689c library: fixed miscellaneous whitespace/comment issues
. ensure whitespace exists between the code & comments
[ changing txt slightly keeps right margin alignment ]

. strive for more consistency with some comment styles
[ don't use C '/*' style where C++ '//' style exists ]

. removed the instance of double space in 1 assignment
[ still striving for consistency in whitespace usage ]

. fixed comment relating to number of 'derived fields'
[ the <meminfo> api recently added one new such enum ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-10-01 22:25:18 +11:00
Jim Warner
89775d5418 library: normalize stacks_extent struct layout, <PIDS>
This patch just rearranges 1 item in the stacks_extent
struct to make it equivalent to all the other modules.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-10-01 22:25:18 +11:00
Jim Warner
3d39e4fd88 library: set stage for NUMA node field display support
In response to that suggestion referenced below, these
changes allow display of task/thread level NUMA nodes.

Currently, only the 'top' program offers any NUMA type
support and it is limited to the Summary Area display.
With this commit both the 'top' and 'ps' programs will
be able to display NUMA nodes associated with threads.

Reference(s):
https://gitlab.com/procps-ng/procps/issues/58

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-05-22 21:38:10 +10:00
Jim Warner
6644b1a646 library: eliminate a redundant conditional, <PIDS> api
library: eliminate a single redundant conditional test

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-05-22 21:38:10 +10:00
Jim Warner
e70531a945 library: protect against possible 'refcount' underflow
In each module employing a priming read at 'new' time,
should that read fail, a call to 'unref' will be made.

However, there is a hidden dependency that these calls
must never occur before the context 'refcount' was set
due to the way an 'unref' conditional was constructed.

So this commit just ensures that 'unref' will function
as expected, even if called with a 'refcount' of zero.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-12-07 22:06:59 +11:00
Jim Warner
912075605b library <stat>: remove that PIDS_WCHAN_ADDR enumerator
Removing the Item_table 'stat' oldflags for WCHAN_ADDR
was wrong since that 'stat' field is not a constant 0.
Rather, it could assume these 3 values: -1, 0, and +1.

I have not been able to pin down a '-1' result, but it
probably means some sort of permission error (-EPERM).

The '1' or '0' values were supposed to distinguish the
tasks that were or were not blocked (whether there was
a wchan address). However, in practice there is little
correlation between those values and availability of a
kernel symbol in /proc/$$/wchan (perhaps due to race).

Anyway, the real point is that a 'stat' wchan does not
now intentionally contain an address. Thus, outputting
'ffffff', '-' or '1' in programs like ps is senseless.

So this patch just eliminates PIDS_WCHAN_ADDR from our
item enumerators leaving only the PIDS_WCHAN_NAME guy.
Now the new library can't be blamed for bad addresses!

Reference(s):
. removed Item_table 'oldflags'
commit c4aa6c0ab4
. linux removal of wchan addresses
commit b2f73922d119686323f14fbbe46587f863852328

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-10-16 08:23:38 +11:00
Jim Warner
71bd5b6485 library <pids>: remove fields obsoleted with linux 2.6
It seems inappropriate to blindly include fields known
to always be zero in our brand new library. Therefore,
this patch removes support for three such enumerators.

[ that stat 'it_real_value' (PIDS_ALARM) field could ]
[ have been made obsolete before a linux 2.6 release ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-10-09 21:31:29 +11:00
Jim Warner
82a0dcda0f library: strictly cosmetic, absolutely no code changes
This commit just contains some tweaks to comments plus
a few adjustments to whitespace for alignment purposes
and a normalization of the header inclusion #define's.

[ plus a spelling error in one header file was fixed ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-10-09 21:31:29 +11:00
Jim Warner
834ed434c9 library: normalize stack and history allocation naming
Recent profiling and timings have resulted in improved
newlib performance. This patch completes that process.

It just normalizes naming conventions employed for all
allocations involving reaped stacks & history support.

The modules offering a 'reap' function will also offer
the now standardized corresponding STACKS_INCR define.

The modules which provide dynamic history support will
now have a separate #define called NEWOLD_INCR used in
allocations/reallocations. And, while values currently
are set equal to that STACKS_INCR value, in the future
some reason for divorcing those two may be discovered.

----------------------------- for future reference ---

In those modules which contain the STACKS_INCR #define
it is tempting to specify a large value so as to avoid
repeated calls to malloc/realloc. However, in doing so
an extra runtime price will be paid in 'cleanup_stack'
calls with any iterative programs like top or slabtop.

So, with the current values a balance has been sought.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-09-11 09:31:05 +10:00
Jim Warner
acda6f40d1 library: miscellaneous additional efficiencies, <pids>
This patch contains the following miscellaneous stuff:

. The pids_stacks_fetch() routine might call for newly
allocated stacks to be itemized. However, that job was
already tended to by the pids_stacks_alloc() function.

So, this patch just eliminates a redundant invocation.
------------------------------------------------------

. The concept of 'dirty_stacks' has not kept pace with
the evolving stacks implementation. Originally, stacks
were considered dirty only if free() of dynamic memory
was needed before refreshing any single result struct.

Later, with the introduction of the 'extra' item and a
promise to reset it to zero, 'dirty' was much broader.

So, this patch just treats the dirty flg as others do.
------------------------------------------------------

. Lastly, a word or three about performance & timings.

Tuning efforts concentrated on the <pids> API and top.
And unless an oldlib equivalent to the preceding patch
is applied (favoring stat vs. status), newlib top will
often outperform the oldlib version (obviously wrong).

So assuming /proc/stat is preferred in both libraries,
generally speaking, a cpu and elapsed time increase of
1-5% was found for this new stacks oriented interface.
Of course, there's also an increased memory footprint.

There are some occasions, however, when the newlib top
is at a substantial disadvantage. For example if WCHAN
or TTY is displayed, such items will be present in all
newlib reaped stacks (i.e. every process). But old top
would only incur such overhead with displayable tasks.

Thus, oldlib top could outperform newlib by up to 25%,
for example, if only fields requiring NO library flags
were displayed. However, such a scenario is not likely
since only GID, UID, PID, TGID & WCHAN would be shown.
In the usual case, that overhead associated with WCHAN
and/or TTY is overshadowed by other top runtime costs.

All in all a pleasing outcome I deem quite acceptable.
------------------------------------------------------

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-23 21:11:09 +10:00
Jim Warner
e9c101edcb library: prefer /proc/stat before /proc/status, <pids>
Long ago, in a galaxy far away (when top was in charge
of library FILL flgs) /proc/status was to be preferred
over /proc/stat if a field could be satisfied by both.

This was done to avoid costly 64-bit math emulation in
a 32-bit application due to 'unsigned long long' data.

Well it's time to acknowledge the prevalence of 64-bit
platforms. And in such an environment the cost picture
has shifted significantly. It now costs 14 times (wow)
as much to access /proc/status compared to /proc/stat.

In other words, even with '%llu' variables, a sscanf()
call in stat2proc() beats the pants off that home brew
gperf based hashing employed by the status2proc() guy.
In fact, status2proc incurs higher costs than found in
the most expensive aspect of top's forest view option.

Here's a gprof extract to illustrate the costs. It was
produced with an rcfile requiring fields from both the
/proc/stat & /proc/status pseudo files (among others).
There were 5000 iterations in each of 4 separate gprof
runs subsequently merged into 1 gmon.sum for analysis.

  %      self              self
 time   seconds    calls  us/call  name
 -----  -------  -------  -------  -----------
 28.65     4.10  4689423     0.87  status2proc
 26.14     3.74    40000    93.50  forest_adds
 ...
 01.96     0.28  4689427     0.06  stat2proc

[ since forest_adds is recursive, the calls value is ]
[ the non-recursive #, its 'call graph' shows totals ]

Anyway, now that such cost is known this patch becomes
what is euphemistically known as the usual no-brainer.

[ jeeze, was it really this long between profilings? ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-23 21:11:09 +10:00
Jim Warner
4fe42d0be9 library: most function names now more profile friendly
This patch will begin some refinements associated with
gprof. Initially, functions names have been changed to
help in identifying potential bottlenecks. This effort
also included the obscure set, free and sort routines.

Plus the following additional modifications were made:

. the stacks_alloc prologue was generalized plus added
to a couple of modules where it had not yet propagated

. a couple of the '// end ...' comments were corrected

. some functions have been formally tagged as 'inline'

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-23 21:11:09 +10:00
Jim Warner
7d20df9ef0 library: if the VAL type is wrong still return a value
Rather than return a 0 result for all VAL type errors,
return what would have been without validation active.

This will enable a program like pgrep to still print a
result even though it used some incorrect type member.

With this commit, our VAL macro validations logic will
behave in exactly the same way as the GET validations.
While warning messages may be issued, except for a bad
enumerator, values will always be returned to callers.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-11 07:56:00 +10:00
Jim Warner
9f27e9d8d9 library: strengthen the VAL macro validation functions
One ought not to assume that random memory access will
always succeed or, when it does, that an obviously bad
item enumerator will always be found at that location.

Thus, this patch corrects some really poor assumptions
associated with the 'xtra_procps_debug.h' header file.

[ and it does so in somewhat contorted ways so as to ]
[ avoid several darn gcc -Wnonnull warning messages! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-08 22:01:37 +10:00
Jim Warner
e3270d463d library: provide for validating result type references
During development, we now have a means for validating
that a type referenced in application code matches the
actual type set by the library. The new feature can be
activated through either of the following two methods:

1) ./configure CFLAGS='-DXTRA_PROCPS_DEBUG' (all pgms)

2) an #include <proc/xtra-procps-debug.h> (single pgm)

[ in the future, one could add a formal configure.ac ]
[ provision. but for now a manual approach is safer. ]

Lastly, for any module which provides a sort function,
the handling for both 'noop' & 'extra' enumerators was
made consistent. Now, 'noop' is not sorted and 'extra'
will be sorted as that module's widest supported type.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-07 21:40:48 +10:00
Jim Warner
c4aa6c0ab4 library: normalize & minimize result types, <PIDS> api
This commit attempts to minimize the variety of types
currently used. Plus, the following were also changed:

. the MEM fields were switched to parallel the VM guys
. PIDS_MEM_VIRT -> PIDS_MEM_VIRT_PGS
. PIDS_MEM_VIRT_KIB -> PIDS_MEM_VIRT

. made NICE 's_int' so that it then parallels PRIORITY

. change RTPRIO & SCHED_CLASS from 'ul_int' to 's_int'

. removed Item_table 'oldflags' for an obsoleted field
. PIDS_WCHAN_ADDR

. added calculations like TICS_ALL_C for the following
. PIDS_TICS_USER_C
. PIDS_TICS_SYSTEM_C

. these three new 'TICS' fields have been incorporated
. PIDS_TICS_BLKIO - jiffies spent in block i/o
. PIDS_TICS_GUEST - jiffies spent as a guest
. PIDS_TICS_GUEST_C - as above, includes dead children

. that PIDS_TICS_DELTA was renamed PIDS_TICS_ALL_DELTA
( so it did not hide between TICS_BLKIO & TICS_GUEST )
( and to make clearer what's included: utime + stime )

. eliminated 'sl_int' entirely from that result struct

[ often, the <pids> module changes necessitated that ]
[ readproc header and source files had to change too ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-08-01 20:09:18 +10:00
Jim Warner
c4d097c709 library: removed all the 'PROCPS_' enumerator prefixes
Many of our item enumerator identifiers are very long,
especially in that <VMSTAT> module. Additionally, they
all contain the exact same universal 'PROCPS_' prefix.

The origins for this are likely found in the desire to
avoid name clashes with other potential include files.
But with procps-ng newlib, we've probably gone way too
far. Did 'PROCPS_PIDS_TICS_SYSTEM' actually offer more
protection against clash than 'PIDS_TICS_SYSTEM' does?

I don't think so. Besides, no matter how big that name
becomes, one can never guarantee they'll never be some
clash. And, conversely, extremely short names will not
always create conflict. Of course, in either case when
some clash occurs, one can always #undef that problem.

Thus, this commit will eliminate that 'PROCPS_' prefix
making all of those enum identifiers a little shorter.
And, we'll still be well above some ridiculously short
(criminally short) names found in some common headers:

- - - - - - - - - - <term.h>
- 'tab', 'TTY', etc
- - - - - - - - - - - - - - - - <search.h>
- 'ENTER', ENTRY', 'FIND', etc

------------------------------------------------------
Finally, with this as a last of the wholesale changes,
we will have established the naming conventions below:

. only functions will begin with that 'procps_' prefix
. exposed structures begin with the module/header name
. item enumerators begin like structs, but capitalized
. other enumerators work exactly like item enumerators
. macros and constants begin just like the enumerators
------------------------------------------------------

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-26 20:49:00 +10:00
Jim Warner
82d5661603 library: standardize all the 'context' structure names
This patch attempts to standardize the naming of those
most important (declared not defined) context structs.

The present practice represents a hodge podge of names
only some of which reflect the source /proc file name.
And 2 of those file names embed a literal 'info' which
is likely the origin of that required parm identifier.

Now we'll append a universal '_info' to such structure
names, while including the names of those /proc pseudo
files where possible. In any case, that context struct
will *always* begin with the actual module/header file
name. And only the following two sound a little weird!

---------> 'meminfo_info' + 'slabinfo_info' <---------

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-26 20:47:34 +10:00
Jim Warner
220236a9af library: some minor miscellaeous improvements, 3rd gen
A collection of miscellaneous code and comment tweaks.

[ such changes will stop when desk checking ends too ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-17 08:49:48 +10:00
Jim Warner
9bea1b2def library: the overlooked twerks (oops, tweaks), 3rd gen
Yes, all of these changes are strictly cosmetic. It is
likely symptomatic of some deep-seated character flaw.

[ or, it might be because of a certain pride in this ]
[ new library and the desire to make it even better! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-09 12:48:28 +10:00
Jim Warner
80ad63dc31 library: refactor exposed pointers management, 3rd gen
This commit brings all of those 'fetch' type functions
(supporting some form of 'reap') into closer alignment
with one another. The biggest impact is to be found in
the <stat> module, which now provides for the separate
copy of stack pointers which will be exposed to users.

The reason such a copy was not employed initially with
<stat>, unlike those for <pids> and <slabinfo>, is due
to the fact that such stacks were never sortable. Thus
the original raw consolidated extent pointers wouldn't
have been disturbed. But that meant no NULL delimiter.

So with this commit, all reap/fetch operations now use
pointer copies when returning results to callers. And,
all such arrays are now NULL delimited meaning callers
can choose their own access fencepost: totals or NULL.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-02 16:33:01 +10:00
Jim Warner
8cd1214aac library: stop treating lxcname differently, <PIDS> api
Unlike other cached string fields (such as USER name),
that lxcname field was defined as 'const char *'. This
required a custom 'set' function using a cast in order
to avoid a compiler warning regarding that assignment.

So this commit brings lxcname into line with all those
other cached string fields. And while we're at it, the
reason some string fields have no 'freefunc' will also
be explained with some new comments in the Item_table.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-02 16:33:01 +10:00
Jim Warner
eff9fbc06e library: standardize extents_free_all() logic, 3rd gen
As those 3rd generation newlib APIs evolved so too did
the extents_free_all() function. Most versions of this
function required the callers to first verify that the
extents anchor wasn't empty, which was poor etiquette.

This simple function should have been much more robust
and forgiving. With this commit, it fnally becomes so.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-02 16:33:01 +10:00
Jim Warner
380253ff7f library: more pids_fetch struct opaqueness, <PIDS> api
With all our 3rd generation interfaces, we're now well
positioned to preserve binary compatibility should new
fields be added to any public structure (assuming that
the 'result' union already contains its largest type).

This remains true even for the <pids> interface, which
unlike the others, has one structure embedded within a
separate struct rather than declaring a pointer to it.

The counts struct was positioned after the stacks ptrs
array so as to preserve that ABI if ever new ints were
added. Logically, however, the counts (especially that
total) should precede the stacks array if we wished to
properly place a horse (total) before a cart (stacks).

So to enable relocating those counts we will no longer
embed that structure, but provide a pointer to it. And
this will make accessing syntax feel more natural too.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-28 21:11:25 +10:00
Jim Warner
8444a6fe0b library: a couple of miscellaneous changes, <PIDS> api
This patch represents the following minor adjustments:

. old PROCTAB used with select & reap more descriptive

. reformatted PROCPS_PIDS_VAL macro like other 3rd gen

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Jim Warner
d7100d071d library: optional parms protection missing, <PIDS> api
When those items were made dynamic at 'new' time, some
other functions, previously assured of their presence,
failed to verify a 'reset' had acually been requested.

This commit just corrects that oversight and avoids an
attempt to 'assign_results' when no items are present.

Reference(s):
. when items/numitems became optional
commit 9ebadc1438

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-17 21:44:29 +10:00
Jim Warner
876ec555c3 library: final tweaks to code and/or comments, 3rd gen
With the dust now settling on all those 3rd generation
upgrades, this patch tries to provide some consistency
among the separate modules involved. Someday we should
consider a 4th generation where all redundant code has
been removed and isolated in a new shared source file.

Following is a summary of significant changes (if any)
to each of these now upgraded 3rd gen library modules.

<meminfo> ............................................
. strictly formatting/comment changes, code unaffected

<pids> ...............................................
. replaced a local mkSTR macro with existing STRINGIFY
. added fetch narrative explaining duplicate addresses

<slabinfo> ...........................................
. rearranged some free logic for procps_slabinfo_unref
. added fetch narrative explaining duplicate addresses

<stat> ...............................................
. added #define ENFORCE_LOGICAL, just as in <slabinfo>
. replaced a local mkSTR macro with existing STRINGIFY
. alphabetized the function declarations in the header

<vmstat> .............................................
. made one coverity concession with read_vmstat_failed

[ several of these changes may reflect this author's ]
[ continuing pursuit of an unreasonable goal -- that ]
[ of a 'perfect' (plus 'pretty') C language program! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-13 10:33:37 +10:00
Jim Warner
f897a495ee library: adjust 'noop' callback definition, <PIDS> api
Though all those callback's parameters are ignored and
qsort treats them as pointers to void, it's wrong when
3rd parm is 'enum pids_item', not 'struct sort_parms'.

So we will fix it in a way that lessens the likelihood
of another such a mistake when some new type is added.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-11 11:50:37 +10:00
Jim Warner
aa9f00dcaf library: misc tweaks for code and comments, <PIDS> api
This commit simply tries to keep naming plus formating
conventions on a par with the continuing climb up that
learning curve. These changes were suggested following
<slabinfo> sources upgrade from 2nd to 3rd generation.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Jim Warner
09503dc597 library: eliminated a final potential NULL, <PIDS> api
In that reference below a specific systemd problem was
fixed in the commit shown. However lurking deep within
the <pids> interface was yet one final case where NULL
could be returned, involving 'strv' and the following:

. a user requested both a single string vector (always
returned as a normal string) & the vectorized version,
as with PROCPS_PIDS_CMDLINE and PROCPS_PIDS_CMDLINE_V.

. a user simply duplicated some vectorized enum items.

The root of that NULL problem is the fact those single
string vectors shared the same proc_t field with their
true vectorized version. So while multiple occurrences
for most strings could be satisfied with strdup versus
the normal ownership usurpation, those true vectorized
fields could not be quite so easily copied/duplicated.

Thus newlib chose to return a NULL result.strv pointer
under either of the above scenarios (which perhaps was
just a user boo-boo in the first place). In any event,
the NULL was a potential for true string vectors only.

Now, since newlib is the sole caller into the readproc
module, separate fields have been created for what are
just normal strings (never vectorized) and those which
remain the true vectorized versions. And, former flags
which only worked if combined, now act as stand alone.

Thus, both PROCPS_PIDS_CMDLINE & PROCPS_PIDS_CMDLINE_V
can be used simultaneously (as they should have been).

Also with this patch, items which a user duplicates in
the stack (beyond the first such item) will return the
the string "[ duplicate ENUM_ID ]". This practice will
apply to both single strings and true vectorized ones.
In addition to informing users of their error, it will
also mean potential NULLs need now never be a concern.

Reference(s);
http://www.freelists.org/post/procps/systemd-binary-vs-library
commit 0580a7b4c6

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-05-22 21:59:18 +10:00
Jim Warner
0511ab0245 library: respond to coverity (reluctantly), <PIDS> api
Calls to free() have now been reintroduce in the new()
function to quiet coverity warnings. Those free's were
removed originally as that library 'new' was returning
with a fatal error and a caller should end abnormally.

Plus, it is virtually impossible to fail a malloc call
under linux. And lastly, they required braces with the
if statement making the code considerably less pretty.

[ commit also includes 2 unrelated whitespace tweaks ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-05-17 21:13:34 +10:00
Jim Warner
540342620b library: try to minimize the results types, <PIDS> api
This is just beginning an effort to minimize/normalize
the sheer variety of results types in use for our API.

In taking these first baby steps, a few anomalies were
found. There'll no doubt be many more yet to discover.

. the _FLT_ (fault) fields were already signed long in
the proc_t (even though their sscanf format used %lu).

. although strtoul will alway return an unsigned long,
all of the _VM_ fields were made signed long just like
other memory fields (& signed sorts more efficiently).

Reference(s):
http://www.freelists.org/post/procps/newlib-drip-drip,4

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-05-16 19:58:20 +10:00
Jim Warner
9ebadc1438 library: standardize portions of interface, <PIDS> api
This represents a rather major interface redesign. The
following highlights most of the changes/enhancements.

. The 'read' interface (employed by pgrep & pidof) saw
the biggest change. The 'open', 'next' and 'shut' guys
all went bye-bye, replaced by a single 'get' function.

. The items specified at 'new' time no longer serve as
the maximum. In fact, items & numitems are now treated
as optional, should callers prefer to wait until later
when the 'reset' function would then become mandatory.

. Even at 'reset' time, the stacks are not tied to any
sort of maximum. They will grow dynamically as needed.

. The order of some parameters was changed to parallel
that found in our other APIs. Specifically, when items
& numitems are needed they're specified in that order.

. A user will no longer be prevented from concurrently
employing any accessor functions. In other words, that
'get' (old 'read') won't preclude 'reap' and 'select'.

. A duplicate enumerator was found dealing with locked
resident pages. So, the name VM_LOCK was eliminated in
favor of VM_RSS_LOCKED, which is way more descriptive.

. The struct address returned to callers following any
reap() or select() is now more sharable as pids_fetch.

. Some input parameter names were changed to make them
more descriptive of the intended purpose/requirements.

------------------------------------------------------
Internally, there were numerous implementation changes
made that did not directly impact any potential users.

. That #define FPRINT_STACKS was eliminated along with
the associated supporting function and its invocation.

. Addresses returned following 'reap' or 'select' will
now be NULL delimited, so one has the option of stacks
access via the total count or this new NULL fencepost.

. Input params were simplified and generalized in both
oldproc_open() & close() to enable more than 1 PROCTAB
to be open simultaneously, which was required for get.

. The PROCPS_PIDS_logical_end enum was relocated after
the Item_table making the need to keep it synchronized
more apparent (if the table expands it's right there).

. The 'Public function' section of the source file was
subdivided into 1) the three basic required functions;
and 2) functions that can sometimes vary between APIs.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-05-16 19:58:20 +10:00
Craig Small
bfb7361980 library: oldproc_open has always yes check
if (info->flags | PROC_UID)
Something OR a non-zero constant is always true.
Looks like it should be and'ed for the standard flag masking
pattern.

References:
  Coverity #99118

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2016-05-14 22:55:16 +10:00
Jim Warner
b778a267fe library: fix boo-boo left by earlier patch, <PIDS> api
After the commit referenced below the potential exists
for a SEGV (resulting from an out-of-bounds Item_table
reference if PROCPS_PIDS_physical_end is encountered).

So this patch eliminates that PROCPS_PIDS_physical_end
as no longer necessary and completes the task of using
PROCPS_PIDS_logical_end as a sole necessary fencepost.

Reference(s):
commit e7585992d9
2016-04-26 22:27:16 +10:00
Jim Warner
8c38a58d94 library: reorder (alphabetize) some things, <PIDS> api
Without breaking either ABI or API just rearrange some
stuff to provide a little more consistent source file.

[ these were prompted by some work on the <stat> API ]
[ in preparation for him borrowing some of our code. ]

Reference(s):

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-04-26 22:27:16 +10:00
Jim Warner
edb124ec86 library: changed use of 'fill' to 'select', <pids> API
Remove a remnant of this new API's evolution.  Here we
no longer fill stacks, rather we reap and select them.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-04-19 20:38:18 +10:00
Jim Warner
e7585992d9 library: protect against a future breakage, <pids> ABI
By co-mingling both external/internal identifiers with
actual implementation code, potential future additions
to our API would have been considerably more difficult.

So, this patch will now rely solely on internal/hidden
identifiers serving as fenceposts in validation logic.

And if the following convention is used for new fields
we will maintain that enumerator alphabetic ordering a
a little longer (even though 2 user fields now don't):

. PROCPS_PIDS_XTRA_FOO_A, PROCPS_PIDS_XTRA_FOO_B, etc.

Reference(s):
http://www.freelists.org/post/procps/me-too-newlib,7

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-04-19 20:38:18 +10:00
Jim Warner
8dc378f6a8 library: exploit linux-4.5 resident memory enhancement
Beginning with linux-4.5, the following new fields are
being added under that /proc/<pid>/status pseudo file:
 . RssAnon - size of resident anonymous memory
 . RssFile - size of resident file mappings
 . RssShmem - size of resident shared memory

This patch just represents the initial library and top
support, sharing a commit message with 2 more patches.

p.s. locked resident memory support was also added but
isn't directly related to the kernel 4.5 enhancements.

Reference(s):
commit 1f8e41d019
Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-04-14 21:03:03 +10:00
Jim Warner
65000d7c64 library: miscellaneous tweaks for code and/or comments
Summarized below, miscellany addressed in this commit:

. deleted extraneous newline(s) for consistent spacing

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-03-12 14:52:56 +11:00
Jim Warner
2b0dd2d702 library: correct <pids> support of true string vectors
When reference counts were added to some string fields
the 3 true string vector fields were not duplicated as
were those other fields. Instead they were supposed to
disallow a duplicate stack reference beyond the first.
However, the actual implementation gave NULL for every
true vector field whenever such items were duplicated.

More importantly, such true string vector fields never
considered references to the shared proc_t source root
which would have forced the conversion of such vectors
into a single string form via the '_CVT' library flag.

So this commit restores the intended outcome with true
string vectors. There's only 1 valid reference allowed
and duplicates and converted fields will yield a NULL.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-28 20:58:28 +11:00
Jim Warner
9db796f8cb library: correct one <pids> reference from str to strv
While not changing generated code this commit corrects
one free reference from 'str' to a more proper 'strv'.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-28 20:58:12 +11:00
Jim Warner
88489be542 library: allow duplicated results for <pids> interface
Ok, here is that rather major internal redesign hinted
at in the three previous commits. Its need was quickly
revealed after adapting top then attempting to display
newly added 'CGNAME' fields and an existing 'CGROUPS'.

That very quickly generated a SEGV. And the reason was
just as quickly recognized. Both fields relied on that
proc_t.cgroup member yet whichever result structure is
first in a stack is the one which assumes ownership of
of the vectored sting by resetting its cgroup to NULL.

So this commit introduces reference counting for a few
of the fields in the proc_t. Specifically there are 17
entries in the Item_table dealing with strings/vectors
where ownership is transferred to newlib. Now whenever
such fields are represented more than once in a stack,
the strings will be duplicated instead of transferred.
In this way we can generally remain optimized avoiding
string copies, yet still accommodate them when needed.

There's an exception to this scheme: those true string
vectors (CGROUP_V, CMDLINE_V and ENVIRON_V). When such
fields are duplicated in a stack the result structures
beyond the first will be set to NULL, which the caller
will (should) already be equipped to deal with anyway.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-14 21:50:31 +11:00
Jim Warner
a59a269661 library: added PROCPS_PIDS_CGNAME for <pids> interface
The ps program was modified to print the control group
names, based on the library provided list of all those
control groups to which a process belongs. But this is
probably something the newlib should be doing for all.

So this commit borrows the ps approach to cg names and
thus will make that available to all future consumers.

[ but stay tuned! there is a commit coming soon that ]
[ represents a rather major internal redesign, which ]
[ was prompted by the ps and top adaptation testing. ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-14 21:48:41 +11:00
Jim Warner
838e7852cb library: rename the 'procps_pids_stacks_sort' function
The above function was the sole public function in the
<pids> interface to use the word 'stacks' in its name.
All of the others dealt exclusively with their duties,

So this commit normalizes that outlier by renaming it.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-14 21:47:04 +11:00
Jim Warner
c9388ed512 library: re-enable <pids) dealloc_stacks, found a need
The above function had been disabled via '#if 0' so as
to prevent a compiler warning. But it really should be
called by that 'procps_pids_read_shut' function rather
than it duplicating/reinventing the same logic itself.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-14 21:35:53 +11:00
Jim Warner
bc616b3615 library: correct a flawed approach for PROCPS_FILL_UID
Gosh, just because nobody uses some newlib provision I
guess, since it is being offered, it ought to actually
be tested at some point. Well, that point just arrived
and guess what? A surprise: some bugs were discovered.

The procps_pids_select function established a for loop
wherein readproc is called until the passed 'maxthese'
limit. Unfortunately this was incorrect for 2 reasons:

1. For PROCPS_FILL_PID results are limited by what the
oldlib finds, having established the pid list at open.
Total found already cannot exceed a passed 'maxthese';

2. With PROCPS_FILL_UID, returned results could exceed
a 'maxthese' thus making the for loop incorrect again.

[ plus yours truly neglected to forward the required ]
[ UIDs total to our old library, another oops biggie ]

In summary: the loop should have been forever, exiting
only when all those identified procs had been located.

So, while addressing those bugs, I've consolidated all
the retrieval code (initialize, iterate, summarize) in
a single helper function which will now serve both the
procps_pids_reap and select functions. And as a result
those guys were reduced to quite trivial housekeeping.

This patch, hopefully, completes the normalization for
reap/select (fill), which began with references shown.

Reference(s):
commit 0c953eccc5
commit 747dfc5987

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-09 21:35:04 +11:00
Jim Warner
0354fc1c8f library: miscellaneous minor accumulated <pids> tweaks
This patch contains the following minor modifications:

. When assigning to boot_seconds from a double, a cast
to 'unsigned long' was employed that in reality should
have been 'unsigned long long'. But, on second thought
it's probably best if the compiler makes the decision.

. Results for ID_TGID do not require an 'f_status' flg
since both tid and tgid will be available by virtue of
the 'simple_nextpid' function normal operations. Thus,
that flag has been removed from the <pids> Item_table.

. When the pids_stacks structure was eliminated with a
change to the alloc/dealloc functions in the reference
below, several casts became redundant and are removed.

Reference(s):
commit 747dfc5987.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2015-10-09 21:33:14 +11:00