#2513 test the computation of active processors in light of processor affinity...

#2513 test the computation of active processors in light of processor affinity and the TOKU_NCPUS env variable refs[t:2513]

git-svn-id: file:///svn/toku/tokudb@24904 c7de825b-a66e-492c-adef-691d508d4ae1

linux/tests/test-active-cpus.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <toku_stdint.h>
+#include <unistd.h>
+#include <toku_assert.h>
+#include "toku_os.h"
+#include <sched.h>
+
+static void set_cpuset(cpu_set_t *cpuset, int ncpus) {
+    CPU_ZERO(cpuset);
+    for (int i = 0; i < ncpus; i++)
+        CPU_SET(i, cpuset);
+}
+
+int main(void) {
+    int r;
+
+    int max_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+    assert(toku_os_get_number_active_processors() == max_cpus);
+
+    // change the processor affinity and verify that the correct number is computed
+    for (int ncpus = 1; ncpus <= max_cpus; ncpus++) {
+        cpu_set_t cpuset; 
+        set_cpuset(&cpuset, ncpus);
+        r = sched_setaffinity(getpid(), sizeof cpuset, &cpuset);
+        assert(r == 0);
+
+        assert(toku_os_get_number_active_processors() == ncpus);
+    }
+
+    // change the TOKU_NCPUS env variable and verify that the correct number is computed
+    for (int ncpus = 1; ncpus <= max_cpus; ncpus++) {
+        char ncpus_str[32];
+        sprintf(ncpus_str, "%d", ncpus);
+        r = setenv("TOKU_NCPUS", ncpus_str, 1);
+        assert(r == 0);
+
+        assert(toku_os_get_number_active_processors() == ncpus);
+    }
+
+    return 0;
+}