Commit Graph

2865 Commits

Author SHA1 Message Date
Jim Warner
95990dceb1 top: just trade an assignement for a manifest constant
The assignment was originally created to reduce length
of one line of code (i.e. for readability). But we can
achieve this objective without adding executable code.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-02-27 21:27:02 +11:00
Jim Warner
98ca9fe367 top: trade that 'strncpy' for more efficient 'memccpy'
This patch was prompted by the merge request for pgrep
referenced below. In top's case, any performance gains
will be minimal since the now defunct strncpy was only
employed for termcap rebuilds after interacting with a
user (+ 1 other non-termcap related user interaction).

[ golly, strncpy always calls at least two functions ]
[ but usually calls a total of 3. on the other hand, ]
[ memccpy will only call a maximum of two functions. ]

And thanks to Baruch Siach for these strncpy insights.

Reference(s):
https://gitlab.com/procps-ng/procps/-/merge_requests/148

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-02-17 18:23:30 +11:00
Jim Warner
787615d8da top: tweak a couple task_show() macros for consistency
There was a potential problem with these macros should
that '#define SCROLLVAR_NO' be active and they were to
appear in an 'if' statement (like is necessary for the
master branch version of top under that EU_CMD label).

[ now they're always usable without requiring an ';' ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-02-17 18:23:30 +11:00
Jim Warner
2c12f1f295 top: let's eliminate some additional compiler warnings
This patch eliminates those warnings referenced below.
They are sometimes associated with an obscure #define.

We'll also corrrect one header file function prototype
so it will aggree with the actual function definition.

Reference(s):
top.c: In function 'adj_geometry':
top.c:1874:20: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
 1874 |    if (Screen_cols < DOUBLE_limit) Curwin->rc.double_up = 0;
      |                    ^
top.c: In function 'zap_fieldstab':
top.c:2359:26: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare]
 2359 |    if (wtab[EU_CPN].wmin < digits) {
      |                          ^
top.c:2365:26: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare]
 2365 |    if (wtab[EU_NMA].wmin < digits) {
      |                          ^
top.c: In function 'keys_summary':
top.c:5128:45: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
 5128 |          if (w->rc.double_up && Screen_cols < DOUBLE_limit) {
      |                                             ^
top.c: In function 'sum_tics':
top.c:5605:22: warning: unused variable 'num_syst' [-Wunused-variable]
 5605 |    int ix, num_user, num_syst;
      |                      ^~~~~~~~
top.c:5605:12: warning: unused variable 'num_user' [-Wunused-variable]
 5605 |    int ix, num_user, num_syst;
      |            ^~~~~~~~

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-02-17 18:23:30 +11:00
Jim Warner
0847ea8360 top: attempt to clarify the 'iokey' parameter meanings
The 'iokey' function's parameter 'action' was utilized
with literal numbers in the calling functions. So this
change will replace those literal numbers with #define
constants which, one hopes, will clarify their impact.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-02-17 18:23:30 +11:00
Craig Small
e5542f1fc3 free: Use wstr width and not length
The previous commit used the value from mbstowcs() to work out
the spacing required, as printf() got it completely wrong.

However, for alignment of text you don't use the string length
but the string width.

As the referenced website says:
 Use wcslen when allocating memory for wide characters, and use wcswidth to
 align text.

Which is what free does now. Chinese is still off by one but I cannot
see why this is so. It's close enough for now. If someone can work
it out, I'd love to know what the fix is.

As a side effect, #213 is fixed because we are putting the correct
number of spaces in.

French is still an issue (see #24 ) but this is because the string is
too long!

References:
 procps-ng/procps#24
 procps-ng/procps#213
 procps-ng/procps#229
 commit 9f4db0fb56
 https://www.linux.com/news/programming-wide-characters/

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2022-02-01 16:46:09 +11:00
Craig Small
9f4db0fb56 free: Fix first column justification
free has for many years had a problem with translated header columns
or the first column. This is because printf("-9s", str) doesn't use
the wide length of the string but the char length meaning they are
mis-aligned.

Using the mbstowcs() function to get the wide length and then
a precision parameter to append the right number of spaces after the
number means we get what we need.

References:
 procps-ng/procps#229
 procps-ng/procps#204
 procps-ng/procps#206
 https://bugs.debian.org/1001689

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2022-01-31 18:14:12 +11:00
Jim Warner
50a0d9a56c NEWS: updated to acknowledge 'LIBPROC_HIDE_KERNEL' var
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-31 18:10:48 +11:00
Jim Warner
9ad78da984 top: tweak the heck out of some command line help text
This patch began as just an attempt to make any option
which also included an argument a little more readable
by adding one space before the '=ARGUMENT' convention.

[ by the way, i don't agree with most of those other ]
[ procps-ng programs that use an '<arg>' convention. ]
[ it's too easily misread as an 'optional' argument. ]

[ top uses a convention like that found in coreutils ]
[ albeit now with one extra space before the equals. ]

In adjusting those arguments it was apparent that many
explanations already lined up nicely at the right hand
margin. So, this commit will force right-justification
with all explanations (as we do with commit messages).

[ and as a final challenge, for those options taking ]
[ an argument, that argument was repeated within the ]
[ explanation and made the rightmost item on a line. ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-31 18:10:48 +11:00
Jim Warner
bc8b5a06b8 top: eliminate the potential warnings '-Wsign-compare'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-31 18:10:48 +11:00
Jim Warner
d1c6a69a61 top: avoid a potential warning '-Wmaybe-uninitialized'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-31 18:10:48 +11:00
Jim Warner
b9b0f408b8 top: avoid a possible warning '-Wimplicit-fallthrough'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-31 18:10:48 +11:00
Jim Warner
1387c7f84b top: add visual clue when focus toggle ('F') is active
When in forest view mode, that focus toggle ('F') is a
useful tool occasionally. But, if a focused parent has
enough cloned siblings to exceed screen rows, it could
be hard to remember that such a toggle remains active.

So, this patch will provide a subtle visual clue added
to the leftmost position in the COMMAND column. Now if
the focus toggle was active, regardless of total tasks
affected, the users will always know when it's active.

Reference(s):
. -7/24/21, introduced new focus toggle
commit 3e922e671d
. 09/23/21, ensure focused tasks stay focused
commit 69978e3650

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-17 20:26:17 +11:00
Jim Warner
99c1f0578f top: correct one source comment plus one man page oops
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-17 20:26:17 +11:00
Jim Warner
a6c564361b top: banish one more warning for '-Wformat-truncation'
In the commit referenced below, I fixed what I thought
was all the top 'truncation' warnings. For that commit
I had been using CFLAGS='-ggdb -Wall'. However, if one
uses just a vanilla './configure', then a hidden extra
warning will surface. This patch will finally kill it.

[ thanks a bunch gcc - we love this kind of behavior ]

Reference(s):
. 01/08/22, original warning fix
commit 44ca06f1a0

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-17 20:26:17 +11:00
Jim Warner
7418b97344 sysctl: eliminate a warning '-Wmisleading-indentation'
[ and in the affected function, we'll also eliminate ]
[ all those f**king tab characters making a hot mess ]
[ of any attempt at a properly formatted C function! ]

[ plus i adjusted a little non-tab misalignment too! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-13 19:34:39 +11:00
Jim Warner
14281269f8 top: eliminate warnings for '-Wmisleading-indentation'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-13 19:34:39 +11:00
Jim Warner
44ca06f1a0 top: eliminate every warning for '-Wformat-truncation'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-13 19:34:39 +11:00
Jim Warner
4fdba9627a library: Better PID file checks (with one small tweak)
Since gcc no longer warns of 'unreachable code', we'll
just deal with any such possibility ourselves I guess.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-13 19:34:39 +11:00
Craig Small
39d4d147d7 library: Better PID file checks
This started off with fixing the compilier warning:

proc/readproc.c: In function ‘simple_nextpid’:
proc/readproc.c:1373:38: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 58 [-Wformat-truncation=]
 1373 |   snprintf(path, PROCPATHLEN, "/proc/%s", ent->d_name);
      |                                      ^~
proc/readproc.c:1373:3: note: ‘snprintf’ output between 7 and 262 bytes into a destination of size 64
 1373 |   snprintf(path, PROCPATHLEN, "/proc/%s", ent->d_name);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We know that ent->d_name will fit under 64 bytes because we check the
name starts with a digit. The first change was simple and changed the
printf to use tgid like the task function below it.

Is everything under /proc that starts with a digit a directory with a
PID only? Today, it is but there are no guarantees.

The entire function works ok if every non-pid directory doesn't start
with a number. We don't check for strtoul() having an issue nor
if the for loop just falls off the end. The moment the kernel guys
(or some module writer) think "/proc/12mykernelval" is a neat idea this
function is in trouble. We won't get buffer overflow as we are
using snprintf at least.

This change now:
 We check if strtoul() actually came across a number
 Process the pid directory as a conditional branch
 Treat falling off the for loop as a not-found

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2022-01-08 07:49:13 +11:00
Craig Small
8b67402a25 pmap: Fix minor compiler warning
/usr/include/x86_64-linux-gnu/bits/error.h:40:5: warning: ‘%s’ directive argument is null [-Wformat-overflow=]
   40 |     __error_noreturn (__status, __errnum, __format, __va_arg_pack ());
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pmap.c: In function ‘main’:
pmap.c:760:35: note: format string is defined here
  760 |         xerrx(EXIT_FAILURE, "%s: '%s'", _("failed to parse argument"), optarg);

A simple check for optarg being null silenced this, not sure why only
this one was a problem.

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2022-01-08 07:47:46 +11:00
Jim Warner
91ffe81734 misc: fixed several inconsistencies in email addresses
[ you wouldn't believe how many back-and-forths were ]
[ involved in Craig convincing me there were several ]
[ inconsistencies. i am so dense sometimes (often?). ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-08 07:15:59 +11:00
Craig Small
c83cd6e6c0 top: Fix my email address
Signed-off-by: Craig Small <csmall@dropbear.xyz>
2022-01-07 19:29:23 +11:00
Jim Warner
e243721f22 doc: updated 3 man pages for 'LIBPROC_HIDE_KERNEL' var
This patch was prompted by Björn Fischer's merge #147
request referenced below. And since the library change
may impact all users, multiple man pages were updated.

[ and thanks to Björn for initiating this extension ]

Reference(s):
https://gitlab.com/procps-ng/procps/-/merge_requests/147

Prototyped-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
2a7ec67ac8 library: add support for the 'LIBPROC_HIDE_KERNEL' var
This patch was prompted by Björn Fischer's merge #147
request referenced below. It has been generalized such
that it now embraces both of those 'pids_fetch' types.

[ and thanks to Björn for initiating this extension ]

Reference(s):
https://gitlab.com/procps-ng/procps/-/merge_requests/147

Prototyped-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
cbff1dd106 top: bust up that overly large 'summary_show' function
Over the years the summary_show function has increased
from around 77 lines of code & comments to its current
size of 243 lines. This is well beyond an ideal length
of available screen rows. So this patch will split it.

We'll take the cpu and memory duties and make separate
functions out of them. Of course, this will incur some
additional call overhead but, given current cpu/memory
logic, any such increase really becomes insignificant.

Now summary_show's a svelte 57 lines of code/comments.

[ this is like what was done to that do_key function ]
[ a decade ago except overhead of new function calls ]
[ plus table lookup was even less of a concern since ]
[ a human was involved, not normal iterative output. ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
0e744d3656 top: provide for avoiding task focus ('F') distortions
In the patch referenced below the focus task logic was
improved to ensure that newly cloned tasks 'above' the
focused task did not force an effect like the up arrow
key. That commit also acknowledged that when some task
'above' ended, it *would* act like the down arrow key.

Well, with this commit a task ending 'above' a focused
task no longer distorts the focus. That's assuming the
new '#define FOCUS_HARD_Y' is specified plus the total
focused tasks does not exceed the current screen rows.

Thus, the manual scrolling with up and down arrow keys
is allowed when the total focused exceeds screen rows.

[ but keep in mind that when a focused task has been ]
[ hardened some otherwise useful toggles will not be ]
[ available. keystrokes like 'v' and even 'F' itself ]
[ can not be applied to another task with no scroll. ]

Reference(s):
. Sep, 2021 - 'focus' logic improved
commit 69978e3650

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
4b4dfd57aa sysctl: eliminate a warning of '-Wmaybe-uninitialized'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
2f00186730 sysctl: eliminate some warnings of '-Wunused-function'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
4985a11f00 sysctl: eliminate some warnings of '-Wunused-variable'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
7d8df62faa library: eliminate that warning of '-Wunused-variable'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
4599117190 library: eliminate warning '-Wunused-but-set-variable'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
915b07f4ff library: eliminate those warnings for '-Wpointer-sign'
Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Jim Warner
afdd4690fc misc: amend the man page & source file copyright dates
This just updates the copyright dates in the documents
where I was already represented. Others are unchanged.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2022-01-07 19:19:15 +11:00
Craig Small
707534eb91 nls: Update man translations
Fixed comment in Makefile.am too, thanks to Göran Uddeborg

Signed-off-by: Craig Small <csmall@dropbear.xyz>

References:
 https://www.freelists.org/post/procps/A-comment-needing-an-update
2021-12-22 09:02:45 +11:00
Jim Warner
d79157db51 top: make the __LINE__ usage and whitespace consistent
Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-20 21:38:16 +11:00
Jim Warner
9b24a423b1 top: touch up that code for proc mounted as subset=pid
Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-20 21:38:16 +11:00
Jim Warner
16145af663 top: adapt for running with proc mounted as subset=pid
As the issue cited below illustrates, a pids namespace
with proc mounted as subset=pid denies our library any
access to non-task data. In top's case, the result was
a fatal error message which involved "cpu statistics".

With this patch top will now assume an error involving
global cpu (stat) or memory (meminfo) data means we're
running under a restricted pids namespace. As such, an
attempt will be made to still display task level data.

[ if our assumption is incorrect, it's of no matter. ]
[ instead of a fatal error, we'll still try to offer ]
[ a user some minimally useful bit of functionality. ]

Reference(s):
https://gitlab.com/procps-ng/procps/-/issues/227
https://www.freelists.org/post/procps/three-for-newlib,1
. 1st cut at subset=pid
commit bcb837b8c7

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-17 07:21:51 +11:00
Jim Warner
b2c4fcfddb library: reposition those 'info' structures in headers
For some unknown reason all the 'info' structures were
declared between macros and function prototypes rather
than right after all the other structure declarations.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-16 20:50:07 +11:00
Jim Warner
957b74292f ps,top: convert 'PIDS_PROCESSOR' into a signed integer
Not only does that library tweak help to simplify some
top code, but now that ps snprintf fmtstr will finally
be accurate. That is two birdies with a single pebble!

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-16 20:50:07 +11:00
Jim Warner
aeb35b18da library: change 'PIDS_PROCESSOR' into a signed integer
This change is really being made on behalf of the ps &
top programs. Besides, over 2 billion CPUs are plenty!

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-12-16 20:50:07 +11:00
Craig Small
bcb837b8c7 First cut at subset=pid proc mount handling
The procfs mount option subset=pid only shows the processes, not things
such as /proc/stat etc.

For certain programs, this should mean they still work, but have reduced
functionality. This is the first cut at some of them.

pgrep - Removed always loading uptime which we never used anyway. The
program now works fine unless we use --older. Add note in man page
stating it will silently fail.

ps - Load boot time and memory total only when required instead of
always. Changed the error messages to something the user actually
cares about "can't get system boot time" vs "create a structure".
Works for most fields except starts and percent memory.

uptime - Give more useful error messages if uptime not available.

vmstat - move header generation after testing for required proc
files, makes the default output more consistent with the rest
of the options.

References:
 procps-ng/procps#227
 https://www.kernel.org/doc/html/latest/filesystems/proc.html#chapter-4-configuring-procfs
 6814ef2d99

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-12-16 20:36:00 +11:00
Craig Small
dae897b54d vmstat: Use KiB instead of pages for paged in/out
While the kernel calls the fields pgpgin and pgpgout, the units
here are not pages, but KiB (or 2x 512 sectors).

The comments come from the referenced merged request, this commit fixes
the "vmstat -s lies" part:

https://elixir.bootlin.com/linux/v5.15-rc7/source/block/blk-core.c#L1057
has submit_bio() which includes the count_vm_events(PGPGIN, count) but what
is count? it is usually what bio_sectors() returns.

bio_sectors() is a macro in
https://elixir.bootlin.com/linux/v5.15-rc7/source/include/linux/bio.h#L49
that defines that as bio->bi_iter.bi_size >> 9. 2^9 is 512 or the sector
size. So our count is incremented by the number of 512-byte sectors.

As @dublio has already pointed out before this result is printed to vmstat,
it is /= 2 to give the number of kibibytes (as the sectors were 512 bytes,
we now made the block size 2*512 or 1024). The code even has
"sectors -> kbytes".

So unless there is something very strange going on, pgpgin and pgpgout in
/proc/vmstat return kibibytes.

What about pages (which is sort of implied in the name) or blocks (as
described on the man page)?

Pages can vary, but they are generally 4 KiB so they're out. That also means
vmstat -s lies :(

Blocks are harder to discount. While these too can vary, they can be 1 KiB;
they could also be something else (e.g dd its 512, filesystems 4096).
However, for memory management inside the kernel, there are sectors and
there are (near userland export) KiB, nothing else. It's probably more
accurate to say sectors are shifted in and out of block devices and the
kernel expresses these transfers to userland as KiB by halving the numbers.

What all this means is that using KiB for bi/bo aka pgpgin/pgpgout is more
accurate than saying blocks or pages.

Signed-off-by: Craig Small <csmall@dropbear.xyz>

References:
 procps-ng/procps!64
2021-11-14 18:50:58 +11:00
Weiping Zhang
992a37e5ed vmstat: use KiB/s for bi/bo instead of blocks/s
/proc/vmstat provide kbytes to pgpgin and pgpgout instead of blocks,
correct unit for bi/bo.

References:
 procps-ng/procps!64

Signed-off-by: Weiping Zhang <zhangweiping@didichuxing.com>
Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-11-14 18:48:12 +11:00
Jim Warner
eafd8e3112 library: refine support for multiple concurrent access
Our new library's now well protected against potential
problems which arise when a multi-threaded application
opens more than one context within the same API at the
same time. However, with a single-threaded application
designed along those same lines, some problems remain.

So, to avoid potential corruption of some data (which
was classified as local 'static __thread') from those
single-threaded designs, we'll move several variables
to the info structure itself and remove the '__thread'
qualifier. Now they're protected against both designs.

[ we'll not be protected against some multi-threaded ]
[ application that shares a single context yet calls ]
[ that interface from separate threads. this is just ]
[ bad application design & no different than sharing ]
[ other modifiable global data between such threads! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-11-14 16:23:07 +11:00
Jim Warner
126b14470e library: this is why we hate those darn tab characters
Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-11-14 16:23:07 +11:00
Craig Small
10824b0655 lib: Initialise uptime variables
upminutes and uphours could both not get initialised in the
procps_uptime_sprint_short() function.

Error was probably introduced at the referenced commit.

References:
 Coverity 240787 Uninitialized scalar variable
 Coverity 240776 Uninitialized scalar variable
 commit 0496b39876

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-11-02 17:23:37 +11:00
Craig Small
2e0e865ca5 pgrep: Fix format security
do_regcomp() error message didn't use a string literal for the format string.

pgrep.c:538:24: error: format not a string literal and no format arguments
[-Werror=format-security]

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-11-02 17:19:37 +11:00
Craig Small
f3e5290012 pmap: minor Coverity fix for -N option
99126 Explicit null dereferenced
Not 100% sure this is valid (the same branch that sets the variable
is the one that sets N_option) but not too hard to fix.

Signed-off-by: Craig Small <csmall@dropbear.xyz>
2021-11-02 17:14:29 +11:00
Jim Warner
ad51fef1aa top: tweak some end-of-job logic when separate threads
The separate threads for background updates were added
to top in the commit shown below. At that time cleanup
logic was added to end-of-job processing to cancel any
active threads and destroy any semaphores then in use.

That seemed like simple good stewardship with an added
benefit of avoiding potential valgrind 'possibly lost'
warnings for 320 byte blocks. Those blocks represented
an initial stack allocation for each of three threads.

All of that worked perfectly if such code was executed
under the main thread. In other words, if the keyboard
or a signal directed to any thread was used to trigger
program end. However, it might not always be the case.

Each of those 'refresh' routines supporting a separate
thread interacts with a newlib interface. As a result,
each is required to check the library's return result.
Should some error be detected, 'error_exit' is called.
Now we've got big problems with that eoj cleanup code.

One can't 'pthread_cancel' and 'pthread_join' a thread
from withing that same thread. Thus, when an error was
returned by the library with threads active, top would
hang with no possibility of removal short of a reboot.

So, this commit only executes that cancel/join cleanup
code when we are running under the main thread. Should
program end be triggered by a library error under some
sibling thread, all such cleanup will now be bypassed.
In the latter case, we will rely on documentation that
says any thread calling exit(3) will end every thread.

[ now, the only time we'll see any valgrind warnings ]
[ is with a library error, which is the least likely ]
[ scenario for running valgrind & top to begin with. ]

[ besides, if the valgrind warnings became a problem ]
[ one could easily add a 'warning-suppression' file. ]

Reference(s):
. Sep 2021, top introduced threads
commit 29f0a674a8

Signed-off-by: Jim Warner <james.warner@comcast.net>
2021-10-31 17:12:32 +11:00