Add set_rtprio_limit utility for OpenSmalltalk VMs

.travis.yml

@@ -41,7 +41,7 @@ matrix:
     - language: bash
       smalltalk:
       sudo: false
-      script: bash tests/all_tests.sh
+      script: tests/all_tests.sh
 
     # Test that smalltalkCI can fail
     - smalltalk: Squeak-5.0

tests/all_tests.sh

@@ -12,5 +12,7 @@ echo "======================================================"
 echo "======================================================"
 "${BASE}/squeak_tests.sh" || status=$?
 echo "======================================================"
+"${BASE}/utils_tests.sh" || status=$?
+echo "======================================================"
 
 exit "${status}"

tests/utils_tests.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+readonly BASE="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+source "${BASE}/helpers.sh"
+
+
+test_set_rtprio() {
+  if [[ "$(uname -s)" != "Linux" ]]; then
+    return
+  fi
+  gcc -o "set_rtprio_limit" "${BASE}/utils/set_rtprio_limit.c"
+  if [[ ! -f "set_rtprio_limit" ]]; then
+    fail "set_rtprio_limit should exist"
+  fi
+}
+
+source "${BASE}/lib/shunit2"

utils/set_rtprio_limit.c

@@ -0,0 +1,46 @@
+// Set rtprio to 2:2 for a given pid (required to run OpenSmalltalk VMs).
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/resource.h>
+
+#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
+ } while (0)
+
+int main(int argc, char *argv[]) {
+  struct rlimit old, new;
+  struct rlimit *newp;
+  pid_t pid;
+
+  if (!(argc == 2)) {
+    fprintf(stderr, "Usage: %s <pid>\n", argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
+  pid = atoi(argv[1]); /* PID of target process */
+
+  new.rlim_cur = 2;
+  new.rlim_max = 2;
+  newp = &new;
+
+  /* Set RTPRIO limit of target process; retrieve and display
+  previous limit */
+
+  if (prlimit(pid, RLIMIT_RTPRIO, newp, &old) == -1)
+    errExit("prlimit-rtprio-1");
+  printf("Previous limits: soft=%lld; hard=%lld\n",
+    (long long) old.rlim_cur, (long long) old.rlim_max);
+
+  /* Retrieve and display new RTPRIO limit */
+
+  if (prlimit(pid, RLIMIT_RTPRIO, NULL, &old) == -1)
+    errExit("prlimit-rtprio-2");
+  printf("New limits: soft=%lld; hard=%lld\n",
+    (long long) old.rlim_cur, (long long) old.rlim_max);
+
+  exit(EXIT_SUCCESS);
+}