Correct pid_t type return from Platform_getMaxPid function

Coverity scanning shows we end up passing an integer into the
Row_setPidColumnWidth routine which requires a pid_t - update
each platform to return the correct type (and never return -1
as a failure code, this was being ignored).

18 files changed, 25 insertions, 22 deletions

diff --git a/darwin/Platform.c b/darwin/Platform.c
index bb1ae92f..6a9c2184 100644
--- a/darwin/Platform.c
+++ b/darwin/Platform.c
@@ -227,7 +227,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    }
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    /* http://opensource.apple.com/source/xnu/xnu-2782.1.97/bsd/sys/proc_internal.hh */
    return 99999;
 }
diff --git a/darwin/Platform.h b/darwin/Platform.h
index cf00919f..f67db8ff 100644
--- a/darwin/Platform.h
+++ b/darwin/Platform.h
@@ -54,7 +54,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* mtr, unsigned int cpu);
 
diff --git a/dragonflybsd/Platform.c b/dragonflybsd/Platform.c
index 95f0bec6..d94d7a18 100644
--- a/dragonflybsd/Platform.c
+++ b/dragonflybsd/Platform.c
@@ -163,7 +163,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = (double) loadAverage.ldavg[2] / loadAverage.fscale;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    int maxPid;
    size_t size = sizeof(maxPid);
    int err = sysctlbyname("kern.pid_max", &maxPid, &size, NULL, 0);
diff --git a/dragonflybsd/Platform.h b/dragonflybsd/Platform.h
index 91616d4f..606b004c 100644
--- a/dragonflybsd/Platform.h
+++ b/dragonflybsd/Platform.h
@@ -49,7 +49,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);
 
diff --git a/freebsd/Platform.c b/freebsd/Platform.c
index 66e1463d..9b8981ad 100644
--- a/freebsd/Platform.c
+++ b/freebsd/Platform.c
@@ -181,7 +181,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = (double) loadAverage.ldavg[2] / loadAverage.fscale;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    int maxPid;
    size_t size = sizeof(maxPid);
    int err = sysctlbyname("kern.pid_max", &maxPid, &size, NULL, 0);
diff --git a/freebsd/Platform.h b/freebsd/Platform.h
index cc864569..c358d85d 100644
--- a/freebsd/Platform.h
+++ b/freebsd/Platform.h
@@ -45,7 +45,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);
 
diff --git a/linux/Platform.c b/linux/Platform.c
index 33bd8ced..325f92ed 100644
--- a/linux/Platform.c
+++ b/linux/Platform.c
@@ -291,12 +291,12 @@ err:
    *fifteen = NAN;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
+   pid_t maxPid = 4194303;
    FILE* file = fopen(PROCDIR "/sys/kernel/pid_max", "r");
    if (!file)
-      return -1;
+      return maxPid;
 
-   int maxPid = 4194303;
    int match = fscanf(file, "%32d", &maxPid);
    (void) match;
    fclose(file);
diff --git a/linux/Platform.h b/linux/Platform.h
index a64e54a7..763edadd 100644
--- a/linux/Platform.h
+++ b/linux/Platform.h
@@ -59,7 +59,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);
 
diff --git a/netbsd/Platform.c b/netbsd/Platform.c
index 1d6509ff..8231cdfd 100644
--- a/netbsd/Platform.c
+++ b/netbsd/Platform.c
@@ -229,7 +229,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = (double) loadAverage.ldavg[2] / loadAverage.fscale;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    // https://nxr.netbsd.org/xref/src/sys/sys/ansi.h#__pid_t
    // pid is assigned as a 32bit Integer.
    return INT32_MAX;
diff --git a/netbsd/Platform.h b/netbsd/Platform.h
index ae34198c..a543f52d 100644
--- a/netbsd/Platform.h
+++ b/netbsd/Platform.h
@@ -55,7 +55,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, int cpu);
 
diff --git a/openbsd/Platform.c b/openbsd/Platform.c
index 06594089..267da703 100644
--- a/openbsd/Platform.c
+++ b/openbsd/Platform.c
@@ -175,7 +175,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = (double) loadAverage.ldavg[2] / loadAverage.fscale;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    return 2 * THREAD_PID_OFFSET;
 }
 
diff --git a/openbsd/Platform.h b/openbsd/Platform.h
index 790dc473..339616c1 100644
--- a/openbsd/Platform.h
+++ b/openbsd/Platform.h
@@ -47,7 +47,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);
 
diff --git a/pcp/Platform.c b/pcp/Platform.c
index 83313338..9fb3770e 100644
--- a/pcp/Platform.c
+++ b/pcp/Platform.c
@@ -472,13 +472,13 @@ unsigned int Platform_getMaxCPU(void) {
    return pcp->ncpu;
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    if (pcp->pidmax)
       return pcp->pidmax;
 
    pmAtomValue value;
    if (Metric_values(PCP_PID_MAX, &value, 1, PM_TYPE_32) == NULL)
-      return -1;
+      return UINT_MAX;
    pcp->pidmax = value.l;
    return pcp->pidmax;
 }
diff --git a/pcp/Platform.h b/pcp/Platform.h
index ce21f845..f43ed54f 100644
--- a/pcp/Platform.h
+++ b/pcp/Platform.h
@@ -84,7 +84,7 @@ long long Platform_getBootTime(void);
 
 unsigned int Platform_getMaxCPU(void);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, int cpu);
 
diff --git a/solaris/Platform.c b/solaris/Platform.c
index f14ae2e9..5117a448 100644
--- a/solaris/Platform.c
+++ b/solaris/Platform.c
@@ -175,7 +175,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = plat_loadavg[LOADAVG_15MIN];
 }
 
-int Platform_getMaxPid(void) {
+pid_t Platform_getMaxPid(void) {
    int vproc = 32778; // Reasonable Solaris default
 
    kstat_ctl_t* kc = kstat_open();
diff --git a/solaris/Platform.h b/solaris/Platform.h
index 00bc5832..96feeebe 100644
--- a/solaris/Platform.h
+++ b/solaris/Platform.h
@@ -72,7 +72,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);
 
diff --git a/unsupported/Platform.c b/unsupported/Platform.c
index df7f3600..dbfddd91 100644
--- a/unsupported/Platform.c
+++ b/unsupported/Platform.c
@@ -102,8 +102,8 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = 0;
 }
 
-int Platform_getMaxPid(void) {
-   return 1;
+pid_t Platform_getMaxPid(void) {
+   return INT_MAX;
 }
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu) {
diff --git a/unsupported/Platform.h b/unsupported/Platform.h
index 8e08dc23..c4cd06a0 100644
--- a/unsupported/Platform.h
+++ b/unsupported/Platform.h
@@ -8,6 +8,9 @@ Released under the GNU GPLv2+, see the COPYING file
 in the source distribution for its full text.
 */
 
+#include <stdbool.h>
+#include <sys/types.h>
+
 #include "Action.h"
 #include "BatteryMeter.h"
 #include "DiskIOMeter.h"
@@ -40,7 +43,7 @@ int Platform_getUptime(void);
 
 void Platform_getLoadAverage(double* one, double* five, double* fifteen);
 
-int Platform_getMaxPid(void);
+pid_t Platform_getMaxPid(void);
 
 double Platform_setCPUValues(Meter* this, unsigned int cpu);