Improve process checking on 32-bit systems.

0001-Handle-failure-from-sysconf.patch

@@ -0,0 +1,42 @@
+From 00349771f69aa23f4ece4d0ec42566755460fce2 Mon Sep 17 00:00:00 2001
+From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+Date: Wed, 5 Sep 2018 04:50:12 -0400
+Subject: [PATCH 1/3] Handle failure from sysconf.
+
+Signed-off-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+---
+ src/api-linux.c | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/src/api-linux.c b/src/api-linux.c
+index f2995df..02f6268 100644
+--- a/src/api-linux.c
++++ b/src/api-linux.c
+@@ -261,8 +261,12 @@ int psll_linux_get_boot_time() {
+   return 0;
+ }
+ 
+-int psll_linux_get_clock_ticks() {
++int psll_linux_get_clock_ticks(void) {
+   psll_linux_clock_ticks = sysconf(_SC_CLK_TCK);
++  if (psll_linux_clock_ticks == -1) {
++    ps__set_error_from_errno();
++    return -1;
++  }
+   return 0;
+ }
+ 
+@@ -278,7 +282,9 @@ int psll_linux_ctime(long pid, double *ctime) {
+ 
+   if (!psll_linux_clock_ticks) {
+     ret = psll_linux_get_clock_ticks();
+-    if (ret) return ret;
++    if (ret) {
++      ps__throw_error();
++    }
+   }
+ 
+   *ctime = psll_linux_boot_time + stat.starttime / psll_linux_clock_ticks;
+-- 
+2.17.1
+

0002-Invert-the-sense-of-psll_linux_clock_ticks.patch

@@ -0,0 +1,98 @@
+From 161c21384b91799c2b26f1aa776e081eed002add Mon Sep 17 00:00:00 2001
+From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+Date: Wed, 5 Sep 2018 13:51:43 -0400
+Subject: [PATCH 2/3] Invert the sense of psll_linux_clock_ticks.
+
+It is always used to divide some other number, so instead save its
+reciprocal. Since division is generally slower than multiplication,
+doing one reciprocal and multiplication everywhere else should be
+slightly faster.
+
+Signed-off-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+---
+ src/api-linux.c | 25 +++++++++++++------------
+ 1 file changed, 13 insertions(+), 12 deletions(-)
+
+diff --git a/src/api-linux.c b/src/api-linux.c
+index 02f6268..d2b6193 100644
+--- a/src/api-linux.c
++++ b/src/api-linux.c
+@@ -15,7 +15,7 @@
+ #include "common.h"
+ 
+ double psll_linux_boot_time = 0;
+-double psll_linux_clock_ticks = 0;
++double psll_linux_clock_period = 0;
+ 
+ typedef struct {
+   char state;
+@@ -29,7 +29,7 @@ typedef struct {
+ #define PS__TV2DOUBLE(t) ((t).tv_sec + (t).tv_usec / 1000000.0)
+ 
+ #define PS__CHECK_STAT(stat, handle)					\
+-  if (psll_linux_boot_time + (stat).starttime / psll_linux_clock_ticks != \
++  if (psll_linux_boot_time + (stat).starttime * psll_linux_clock_period != \
+       handle->create_time) {						\
+     ps__no_such_process(handle->pid, 0);				\
+     ps__throw_error();							\
+@@ -226,7 +226,7 @@ void ps__check_for_zombie(ps_handle_t *handle, int err) {
+     ps__throw_error();
+   }
+ 
+-  if (psll_linux_boot_time + stat.starttime / psll_linux_clock_ticks !=
++  if (psll_linux_boot_time + stat.starttime * psll_linux_clock_period !=
+       handle->create_time) {
+     ps__no_such_process(handle->pid, 0);
+     err = 1;
+@@ -261,12 +261,13 @@ int psll_linux_get_boot_time() {
+   return 0;
+ }
+ 
+-int psll_linux_get_clock_ticks(void) {
+-  psll_linux_clock_ticks = sysconf(_SC_CLK_TCK);
++int psll_linux_get_clock_period(void) {
++  double psll_linux_clock_ticks = sysconf(_SC_CLK_TCK);
+   if (psll_linux_clock_ticks == -1) {
+     ps__set_error_from_errno();
+     return -1;
+   }
++  psll_linux_clock_period = 1.0 / psll_linux_clock_ticks;
+   return 0;
+ }
+ 
+@@ -280,14 +281,14 @@ int psll_linux_ctime(long pid, double *ctime) {
+     if (ret) return ret;
+   }
+ 
+-  if (!psll_linux_clock_ticks) {
+-    ret = psll_linux_get_clock_ticks();
++  if (!psll_linux_clock_period) {
++    ret = psll_linux_get_clock_period();
+     if (ret) {
+       ps__throw_error();
+     }
+   }
+ 
+-  *ctime = psll_linux_boot_time + stat.starttime / psll_linux_clock_ticks;
++  *ctime = psll_linux_boot_time + stat.starttime * psll_linux_clock_period;
+ 
+   return 0;
+ }
+@@ -716,10 +717,10 @@ SEXP psll_cpu_times(SEXP p) {
+   PS__CHECK_STAT(stat, handle);
+ 
+   PROTECT(result = allocVector(REALSXP, 4));
+-  REAL(result)[0] = stat.utime / psll_linux_clock_ticks;
+-  REAL(result)[1] = stat.stime / psll_linux_clock_ticks;
+-  REAL(result)[2] = stat.cutime / psll_linux_clock_ticks;
+-  REAL(result)[3] = stat.cstime / psll_linux_clock_ticks;
++  REAL(result)[0] = stat.utime * psll_linux_clock_period;
++  REAL(result)[1] = stat.stime * psll_linux_clock_period;
++  REAL(result)[2] = stat.cutime * psll_linux_clock_period;
++  REAL(result)[3] = stat.cstime * psll_linux_clock_period;
+   PROTECT(names = ps__build_string("user", "system", "childen_user",
+ 				   "children_system", NULL));
+   setAttrib(result, R_NamesSymbol, names);
+-- 
+2.17.1
+

0003-Use-safer-comparison-for-process-start-time.patch

@@ -0,0 +1,64 @@
+From 37da965d8ae37bb9f00dcced97d44bd446896849 Mon Sep 17 00:00:00 2001
+From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+Date: Wed, 5 Sep 2018 14:27:46 -0400
+Subject: [PATCH 3/3] Use safer comparison for process start time.
+
+Comparing two doubles for equality can be troublesome, especially on
+32-bit systems (possibly due to 80-bit registers). Checking for some
+epsilon is safer.
+
+Signed-off-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>
+---
+ src/api-linux.c | 22 ++++++++++++++--------
+ 1 file changed, 14 insertions(+), 8 deletions(-)
+
+diff --git a/src/api-linux.c b/src/api-linux.c
+index d2b6193..8162f1d 100644
+--- a/src/api-linux.c
++++ b/src/api-linux.c
+@@ -28,12 +28,16 @@ typedef struct {
+ 
+ #define PS__TV2DOUBLE(t) ((t).tv_sec + (t).tv_usec / 1000000.0)
+ 
+-#define PS__CHECK_STAT(stat, handle)					\
+-  if (psll_linux_boot_time + (stat).starttime * psll_linux_clock_period != \
+-      handle->create_time) {						\
+-    ps__no_such_process(handle->pid, 0);				\
+-    ps__throw_error();							\
+-  }
++#define PS__CHECK_STAT(stat, handle)			\
++  do {							\
++    double starttime = psll_linux_boot_time +		\
++      (stat).starttime * psll_linux_clock_period;	\
++    double diff = starttime - (handle)->create_time;	\
++    if (fabs(diff) > psll_linux_clock_period) {		\
++      ps__no_such_process((handle)->pid, 0);		\
++      ps__throw_error();				\
++    }							\
++  } while (0)
+ 
+ #define PS__CHECK_HANDLE(handle)			\
+   do {							\
+@@ -218,6 +222,7 @@ int psll__parse_stat_file(long pid, psl_stat_t *stat, char **name) {
+ 
+ void ps__check_for_zombie(ps_handle_t *handle, int err) {
+   psl_stat_t stat;
++  double diff;
+ 
+   if (!handle) error("Process pointer cleaned up already");
+ 
+@@ -226,8 +231,9 @@ void ps__check_for_zombie(ps_handle_t *handle, int err) {
+     ps__throw_error();
+   }
+ 
+-  if (psll_linux_boot_time + stat.starttime * psll_linux_clock_period !=
+-      handle->create_time) {
++  diff = (psll_linux_boot_time + stat.starttime * psll_linux_clock_period) -
++         handle->create_time;
++  if (fabs(diff) > psll_linux_clock_period) {
+     ps__no_such_process(handle->pid, 0);
+     err = 1;
+   } else if (stat.state == 'Z') {
+-- 
+2.17.1
+

R-ps.spec

@@ -6,12 +6,16 @@
 
 Name:             R-%{packname}
 Version:          1.1.0
-Release:          2%{?dist}
+Release:          3%{?dist}
 Summary:          List, Query, Manipulate System Processes
 
 License:          BSD
 URL:              https://cran.r-project.org/web/packages/%{packname}/index.html
 Source0:          https://cran.r-project.org/src/contrib/%{packname}_%{version}.tar.gz
+# https://github.com/r-lib/ps/pull/42
+Patch0001:        0001-Handle-failure-from-sysconf.patch
+Patch0002:        0002-Invert-the-sense-of-psll_linux_clock_ticks.patch
+Patch0003:        0003-Use-safer-comparison-for-process-start-time.patch
 
 # Here's the R view of the dependencies world:
 # Depends:
@@ -42,6 +46,12 @@ List, query and manipulate all system processes, on 'Windows', 'Linux' and
 %prep
 %setup -q -c -n %{packname}
 
+pushd %{packname}
+%patch0001 -p1
+%patch0002 -p1
+%patch0003 -p1
+popd
+
 # Don't need coverage; it's not packaged either.
 sed -i 's/covr, //g' %{packname}/DESCRIPTION
 
@@ -82,6 +92,9 @@ _R_CHECK_FORCE_SUGGESTS_=0 %{_bindir}/R CMD check %{packname} --no-tests
 
 
 %changelog
+* Wed Sep 05 2018 Elliott Sales de Andrade <quantum.analyst@gmail.com> - 1.1.0-3
+- Improve process checking on 32-bit systems
+
 * Mon Aug 20 2018 Elliott Sales de Andrade <quantum.analyst@gmail.com> - 1.1.0-2
 - Add option to disable tests due to dependency loop