Commit Graph

494 Commits

Author SHA1 Message Date
Jim Warner
ecd64f4445 library: normalize/standardize an i/f, <DISKSTATS> api
This patch will bring this interface up to our 3rd gen
standards. The following summarizes the major changes.

* New delta provisions have been added to most fields.

There are, of course, some fields for which a delta is
inappropriate. They include the identifying items such
as name, type, major and minor. Plus the io_inprogress
field which already acts, in effect, as a delta value.

* To provide delta support, dev_node historical values
have become persistent. By the same token, the library
must provide for future removal of disks/partitions. A
timestamp is used to detect 'stale' data which will be
deleted so as not to satisfy some get, select or reap.

* Such persistent support is provided by a linked list
which, by default, grows from the bottom down so as to
maintain compatibility with the /proc/diskstats order.

Initially, I was tempted to use the GNU tsearch (tree)
provisions until I discovered the overhead of building
that tree plus costs of a subsequent 'twalk'. Besides,
walking such a tree means retrieval order would differ
from an order required/expected by the vmstat program.

* The '/sys/block' directory is no longer scanned with
every refresh cycle. Rather, it's only accessed when a
node is first encountered. Then, that node's 'type' is
persistent for its lifetime like several other fields.

* A sort provision was included, at virtually no cost,
even though such a provision was not currently needed.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-26 20:46:08 +10:00
Jim Warner
8e5d5e44e9 library: rename 'diskstat' source as 'diskstats' files
Where possible, libprocps files convey the name of the
actual source pseudo file under the '/proc' directory.

This brings diskstats into line with such an approach.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-26 07:59:52 +10:00
Jim Warner
338166df57 misc: just eliminate several 'unused' warning messages
[ plus we also play catch up on some earlier changes ]
[ that impacted skill.c, after using --enable-skill! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-26 07:59:48 +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
c546d9dd44 library: recycle the QUICK_THREADS #define, <PIDS> api
That #define QUICK_THREADS was impossible to implement
under the new <pids> interface. Plus it was also found
to distort some thread information (referenced below).

So, it's always been inactive under the newlib branch.

However, it will (with small changes) still serve some
useful purpose in our library. Now, when the redefined
FALSE_THREADS is active, those special strings showing
"[ duplicate ENUM ]" will appear for any child thread.

Note: the real reason for such strings appearing isn't
being exercised, only their mechanics. In actual usage
they are substituted when a user duplicates such items
in a results stack & only the 1st instance can own it.

With this patch, we are simply fooling the <pids> code
into thinking an item was duplicated via a NULL value.

Reference(s):
. from master branch
commit 25a6ecdbfb

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
a6115bfff4 library: some tweaks to 2 file read functions, 3rd gen
Ever since their introduction, plus continuing through
several evolutions, both the meminfo and vmstat 'read'
functions employed a 'do while' loop for /proc access.

However, that loop construct was wrong since identical
tests were already done (twice!) within each loop body
itself, then accompanied by its own 'break' statement.

So, we will now transform them both into forever loops
which will help us to emphasize such break statements.

[ plus, let's return an error should nothing be read ]

[ lastly, eliminate 1 erroneous PROCPS_EXPORT prefix ]

Reference(s):
. original meminfo introduction
commit a20e88e4e7
. original vmstat introduction
commit a410e236ab

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-07-06 21:36:37 +10:00
Simon Tatham
f888a30d23 library: find tty device name of process quicker
The procps library attempts to work out the tty of a process
through several methods. For things like /dev/tty123 or
/dev/foo it works fine.

For tty devices that put the minor number in a directory
of the major name this fails. So then we have to fallback
to stating things like the processes STDERR and try again.

Considering a lot of processes sit on ttys such as
/dev/pts/3 this is a lot of wasted time. At the point of
entering driver_name we know "/dev/pts" and we know "3"
we just didn't join them up the right way as this is old
code.

This change now looks for /dev/pts/3 as well. It does it
after looking for /dev/pts3 so the behaviour is the same.

References:
 https://bugs.debian.org/770215

Signed-off-by: Craig Small <csmall@enc.com.au>
2016-07-03 10:47:25 +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
4fe52ccd44 library: reduce copies of items to minimum, <STAT> api
This commit will consolidate the three separate copies
of the item enumerators currently supporting that reap
function (summary, cpus & nodes) into one shared copy.

That select function will continue to maintain its own
dedicated items copy, albeit via a new item structure.

[ and while we're at it, we'll move the 'select' guy ]
[ to its proper alphabetical place, after our 'reap' ]

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
Craig Small
96e6600c84 library: Cater for 32 char device names
The new library has this boundary set in a define.
Also fixed the off-by-one problem with the buffer and scanf

References:
 commit 1794875ab6
2016-07-02 15:01:11 +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
ddb4754b33 library: partial revert of that numa 'fix', <STAT> api
This patch represents the partial revert of the commit
referenced below. And, so that yours truly (the author
for goodness sake) doesn't shoot his tootsies again in
the future, a cautionary programmer comment was added.

Reference(s):
commit dea4033418

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
e41b40e6b0 library: <SLABINFO> api, change that 'get' return type
The following commit message is shared with 4 patches.
------------------------------------------------------

Under the newlib interface most of our 'get' functions
represent a bit of a compromise in that the actual raw
values are coerced into one (probably ok) return type.

That approach creates the possibility of truncation at
best, and wouldn't serve future needs should something
other than numeric data be added to the 'get' results.

This commit trades the current compromise for a return
value guaranteed to satisfy all future needs, namely a
pointer to a particular api's specific results struct.

The impact on existing programs is minimal, especially
when using a new supplied macro. Otherwise, native 'C'
syntax could be used, but may feel somewhat unnatural.

[ as an aside, this new approach allows us to delete ]
[ all 'getsfunc' table entries & the supporting code ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Jim Warner
8f1fb67a78 library: <MEMINFO> api, changed that 'get' return type
The following commit message is shared with 4 patches.
------------------------------------------------------

Under the newlib interface most of our 'get' functions
represent a bit of a compromise in that the actual raw
values are coerced into one (probably ok) return type.

That approach creates the possibility of truncation at
best, and wouldn't serve future needs should something
other than numeric data be added to the 'get' results.

This commit trades the current compromise for a return
value guaranteed to satisfy all future needs, namely a
pointer to a particular api's specific results struct.

The impact on existing programs is minimal, especially
when using a new supplied macro. Otherwise, native 'C'
syntax could be used, but may feel somewhat unnatural.

[ as an aside, this new approach allows us to delete ]
[ all 'getsfunc' table entries & the supporting code ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Jim Warner
e8d7f869b5 library: <VMSTAT> api, change in the 'get' return type
The following commit message is shared with 4 patches.
------------------------------------------------------

Under the newlib interface most of our 'get' functions
represent a bit of a compromise in that the actual raw
values are coerced into one (probably ok) return type.

That approach creates the possibility of truncation at
best, and wouldn't serve future needs should something
other than numeric data be added to the 'get' results.

This commit trades the current compromise for a return
value guaranteed to satisfy all future needs, namely a
pointer to a particular api's specific results struct.

The impact on existing programs is minimal, especially
when using a new supplied macro. Otherwise, native 'C'
syntax could be used, but may feel somewhat unnatural.

[ as an aside, this new approach allows us to delete ]
[ all 'getsfunc' table entries & the supporting code ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Jim Warner
8c7f89ad8d library: <STAT> api, change for that 'get' return type
The following commit message is shared with 4 patches.
------------------------------------------------------

Under the newlib interface most of our 'get' functions
represent a bit of a compromise in that the actual raw
values are coerced into one (probably ok) return type.

That approach creates the possibility of truncation at
best, and wouldn't serve future needs should something
other than numeric data be added to the 'get' results.

This commit trades the current compromise for a return
value guaranteed to satisfy all future needs, namely a
pointer to a particular api's specific results struct.

The impact on existing programs is minimal, especially
when using a new supplied macro. Otherwise, native 'C'
syntax could be used, but may feel somewhat unnatural.

[ as an aside, this new approach allows us to delete ]
[ all 'getsfunc' table entries & the supporting code ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Jim Warner
dea4033418 library: bug fix if libnuma.so unavailable, <STAT> api
All our numa logic was well encapsulated under #ifndef
NUMA_DISABLE (as ./configure --disable-numa), with the
exception of 1 case label. The reason it didn't create
any problems is because the sole consumer (top) itself
responded to the presence of #define NUMA_DISABLE too.

But if that option wasn't used, an oops still awaited.

When experimenting with a 32-bit library plus a 64-bit
kernel, a bug was revealed should the numa library not
have been found. Our 'reap' function must tolerate the
potential of a 0 return from that stacks_fetch_tics().

Now, if numa is desired but not possible, we'll be ok.

[ and, we'll build numa history from fresher sources ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-21 20:58:09 +10:00
Craig Small
5a244c1095 library: rename clashing pwcache functions
On MacOS the system already has user_from_uid and group_from_gid.
These are renamed pwcache_get_user and pwcache_get_group.

They were also exported but did not appear in the symbol file
or used by any of the procps binaries. They are no longer exported.

References:
 https://gitlab.com/procps-ng/procps/issues/34

Signed-off-by: Craig Small <csmall@enc.com.au>
2016-06-18 08:17:45 +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
4a0e974b7f library: more tweaks for code and/or comments, 3rd gen
Following is a summary of significant changes (if any)
to each of these now upgraded 3rd gen library modules.

<meminfo> ............................................
. eliminated duplicate decl of 'struct procps_meminfo'
. standardized/normalized results struct union members
. added 'std' & 'var' dividers in .c file, like <pids>
. how did i miss relocating all these friggin' #undefs
. cleanup 'get' return logic (remove a redundant 'if')

<pids> ...............................................
. repositioned the procps_pidsinfo structure in header
. removed the extra trailing comma from enum pids_item
. standardized/normalized results struct union members

<slabinfo> ...........................................
. corrected comment typo (jeeze, in an 'aligned' para)
. standardized/normalized results struct union members
. added 'std' & 'var' dividers in .c file, like <pids>
. removed an obsolete #undef from procps_slabinfo_sort
. cleanup 'get' return logic (remove a redundant 'if')

<stat> ...............................................
. how did i miss relocating all these friggin' #undefs
. corrected an initialization fencepost used with numa <=== see Craig, here's a bug fix
. removed the extra trailing comma from enum stat_item
. standardized/normalized results struct union members
. added 'std' & 'var' dividers in .c file, like <pids>
. strengthen those parm checks in procps_stat_get func
. cleanup 'get' return logic (remove a redundant 'if')

<vmstat> .............................................
. standardized/normalized results struct union members
. added 'std' & 'var' dividers in .c file, like <pids>
. cleanup 'get' return logic (remove a redundant 'if')

[ virtually all of these tweaks reflect the 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>
2016-06-17 21:44:29 +10:00
Jim Warner
92c72166db library: file now parsed with 'hsearch', <MEMINFO> api
After reviewing the hsearch code in glibc, performance
will almost certainly benefit from abandoning a strcmp
approach in favor of hashing, just like that <vmstat>.

[ As an aside, now having struggled toward that goal ]
[ of opaqueness & making our API as user friendly as ]
[ possible, haven't we earned the rights to evaluate ]
[ other implementations? For example, GNU's hsearch? ]

[ We expose none of our 'info' struct details to the ]
[ users, but GNU exposes their 'hsearch_data' thingy ]
[ right there in <search.h>. But worse, they require ]
[ the user to zero it out before 1st use. Jeeze, you ]
[ mean that a function called hcreate_r could not do ]
[ its own memset? Aw, come on GNU! What's with that? ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-13 10:33:37 +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
adfa2bc75a library: please keep procps-private.h free of #include
The 'procps.h' header includes all other headers which
contain exported (public) functions, while this header
has some (private) macros required for implementation.

If we mix the two, by including procps.h in this file,
we'll lose all hope of the compiler catching the kinds
of errors corrected in an immediately preceding patch.

[ we must be diligent, always constantly striving to ]
[ protect jimmy from ill effects due to copy & paste ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-11 11:50:37 +10:00
Jim Warner
6a70466ae5 library: overcome effect of copy/paste, <SLABINFO> api
Needless to say, when one copies and then pastes, it's
always better when those results are refined somewhat.

The qsort callback declarations used the wrong results
type and 2 of their 3 input parameters were wrong too.

So this patch will fix that & generalize declarations.

[ plus add comment guidance about noop & extra enums ]
[ & provide for 'noop' sorting, as is done in <PIDS> ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-11 11:50:37 +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
335cbc2e61 library: make struct name more descriptive, <STAT> api
After normalizing the <SLABINFO> module, much of which
was based on this module, a structure which is crucial
to concurrent select/reap support is renamed the same.

Such a need for concurrent support was revealed during
slabtop testing. That program requests (select) global
data after calling for individual node data (reap) but
before those stacks have been accessed. Therefore, one
set of 'items'/'extents' could not possibly be shared.

So now we will know the former struct fetch_support as
ext_support. The former name was potentially confusing
since the struct was used by both 'select' and 'reap'.
However, only 'reap' ever called the 'fetch' function.

[ this <STAT> already accommodated concurrent usage. ]
[ in fact it contains 3 separate sets of items/exts. ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Jim Warner
8650518b5a library: fix upper bounds enum delimiter, <VMSTAT> api
Oops, the PROCPS_VMSTAT_logical_end enum reflected the
source state before all those DELTA enum's were added.

[ plus add a couple of overlooked #undef directives, ]
[ and whack an unneeded stacks_alloc assignment too! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Jim Warner
b700d91f84 library: whack a superfluous assignment, <MEMINFO> api
This patch was prompted through work on the <slabinfo>
upgrade from 2nd gen to 3rd. And while this assignment
caused no real harm, it most certainly was misleading.

[ plus add a couple of overlooked #undef directives! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Jim Warner
5d5a52a380 library: normalize/standardize the i/f, <SLABINFO> api
Before this major redesign, the slabs interface likely
was our messiest 2nd generation attempt at opaqueness.
Beyond the standard 'new', 'ref' & 'unref', there were
a total of 12 exported functions. Now, there are four.

The 1st step was to remove several of those functions.
These were quick to go since they were not used (yet):
. procps_slabnode_count
. procps_slabnode_getname
. procps_slabnode_getstack

Then, the following were internalized so users needn't
be burdened with implementation details in the future:
. procps_slabinfo_read (renamed: read_slabinfo_failed)
. procps_slabnode_stacks_alloc (renamed: stacks_alloc)

Still others evolved into the minimal interface we had
strived for in the other upgraded 3rd generation APIs:
. procps_slabnode_get -----------> procps_slabinfo_get
. separate stack_alloc/fill --> procps_slabinfo_select
. separate stacks_alloc/fill ---> procps_slabinfo_reap
. procps_slabnode_stacks_sort --> procps_slabinfo_sort

------------------------------------------------------
Beyond those reductions, the major modifications were:

. This API tries to be as forgiving as possible and as
such won't throw errors when a caller request makes no
sense. For example, if a 'get' or 'select' requested a
SLABNODE item (with no current means to id that node),
results will be zero. By the same token, should 'reap'
include a global SLABS item (meaning those values will
be duplicated in *every* node stack) it'll be allowed.

. If the above behavior is undesired, a new #define of
ENFORCE_LOGICAL can be used to restrict certain items.

. Permission problems will now be caught at 'new' time
thanks to a priming 'read' call. That read also serves
to make DELTA values potentially useful at 1st access.

. Separate slab/slabnode enumerators were consolidated
into one, simplifying validation & the results struct.

. Several internal parameter checks were relaxed since
they were already checked by the caller. Besides if we
cannot trust our own code we might as well hang it up.

. That sort provision was made more efficient and will
offer the ascending choice, in addition to descending.

------------------------------------------------------
Lastly, some additional thoughts regarding the future:

. It would not be difficult to expand 'select' to also
accept a nodeid, or to clone it as 'select_node'. And,
should the same be extended to 'get', a results struct
could be returned instead of signed long accommodating
the extra data type(s) like a node name (string data).

. The 'get' function is not currently affected by that
 define ENFORCE_LOGICAL. However, at some future point
perhaps -EINVAL would be more appropriate than a zero.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Jim Warner
5be4167782 library: rename the 'slab' sources as 'slabinfo' files
Where possible, libprocps files convey the name of the
actual source pseudo file under the '/proc' directory.

This patch brings slab into line with such a standard.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-09 20:51:06 +10:00
Craig Small
d2b29312bb library: fix new and unref pids test
The original test did not NULL the unallocated info pointer. This
was incorrectly calling the procps_pids_new() function.

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2016-06-07 21:13:57 +10:00
Jim Warner
d69a2b6899 library: normalize/standardize interface, <VMSTAT> api
This interface represented a 2nd generation attempt at
the opaque newlib approach. In other words, it did not
involve the 1st generation 'chains'. Instead, 'stacks'
were employed. But the interface wasn't user friendly.

Users were required to create their own stacks, before
calling 'getstack' to retrieve multiple results with a
single call. Even worse, sometimes 'read' was required
before calling 'get' when working with single results.

So this commit represents the 3rd generation approach.
We eliminate the burden of 'read' and creating stacks.
Rather, beyond those standard 'new', 'ref' and 'unref'
functions, we'll offer just 'get' (single result) plus
a 'select' function (for multiple results in 1 stack).

And along the way, this commit vastly expands the data
extracted from /proc/vmstat. All values that currently
exist (and their delta equivalents) are now available.
Deltas were included for everything because there's no
real runtime costs beyond using a little extra memory.

The only problem is a lack of documentation for all of
those fields, as is reflected in the references below.
Oh well, maybe someday someone will dig through kernel
sources & finally plug that rather large document gap.

[ as an aside, rather than using a 'strcmp' approach ]
[ when parsing the /proc/vmstat file, as is found in ]
[ the <meminfo> module, we exploit those hash search ]
[ provisions that are found in the <search.h> header ]

Reference(s):
http://www.spinics.net/lists/linux-man/msg09096.html
http://www.linuxinsight.com/proc_vmstat.html

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-07 21:04:43 +10:00
Jim Warner
2aaae6f29b library: improve internal 'get' processing, <STAT> api
With an eye to the future, rather than managing a long
switch/case construct in the procps_stat_get function,
we'll adopt the approach used in the <meminfo> module.

By making 'get' processing table driven too, just like
'select' is already, that may ease future maintenance.

Along the way a rather large boo-boo was fixed dealing
with that /proc/stat 'procs_running' field which crept
in with the commit referenced below. It wasn't spelled
correctly and thus was never captured as PROC_RUNNING.

Reference(s):
commit abc71a46ad

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-07 21:04:43 +10:00
Jim Warner
af0c65900b library: add parameter checks for 'get', <MEMINFO> api
When this interface was normalized/standardized, under
the commit referenced below, the parameters were never
validated in the 'get' function. Let's plug that hole.

Reference(s):
commit 407f1b71de

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-06-07 21:04:43 +10:00
Craig Small
b96c994390 library: Fix pids API tests
Update the pids tests for tweaked API. Unsure why the toomany
test doesn't work, may point to a problem in the change as it used
to trigger, or the library has flexibility.
2016-05-22 22:12:54 +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
Craig Small
8d7945fd0c library: move QUICK_THREADS hack before return
Minor complaint where a line to stop GCC from complaining occured
after the return.
2016-05-17 21:56:21 +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
0580a7b4c6 library: avoid any --with-systemd conflict, <PIDS> api
A potential conflict arises should should some program
attempt to access systemd data using our library built
without that support (--disable-systemd). And while we
could argue that all callers should check against NULL
string pointers, it's not expected of libprocps users.

So we'll guarantee 'em valid string consisting of "?".

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

Signed-off-by: Jim Warner <james.warner@comcast.net>
2016-05-16 21:36:54 +10:00
Jim Warner
f68dfabc35 library: try different alignment for types, <PIDS> api
Rather than adopt an approach offered below, involving
changing all enumerator names to convey types, perhaps
this much more modest change is a worthwhile 1st step.

By just changing the comments to 'right justification'
it dramatically improves readability, at least it does
to my eye.  Perhaps such an approach can postpone that
massive alternative effort for the foreseeable future.

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
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
Craig Small
f85d9a2b95 library: Remove dead branch in file2strvec
A while loop used n >=0
A branch inside the loop had a test for n<0
That's never going to happen!
So the branch must go. There is similiar code outside
the branch. Yes, I miss pythons while else here.

Also cleaned up the ***-awful indentation this function had.
No wonder that branch lived for so long there.

References:
 Coverity #99119

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2016-05-14 22:43:19 +10:00
Craig Small
4f6b8c9c60 library: slab sort derefence after check
procps_slabnode_stacks_sort() would check if stacks was NULL
*after* the pointer was derefenced in the initialisation of
the variable p.

p is now assigned after the check.

References:
 Coverity #99160
2016-05-14 22:32:35 +10:00