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https://github.com/jart/cosmopolitan.git
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90460ceb3c
While we have always licked glibc and musl libc on gnu/systemd sadly the Apple Libc implementation of pthread_mutex_t is better than ours. It may be due to how the XNU kernel and M2 microprocessor are in league when it comes to scheduling processes and the NSYNC behavior is being penalized. We can solve this by leaning more heavily on ulock using Drepper's algo. It's kind of ironic that Linux's official mutexes work terribly on Linux but almost as good as Apple Libc if used on MacOS.
113 lines
3.8 KiB
C
113 lines
3.8 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2024 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/atomic.h"
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#include "libc/calls/calls.h"
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#include "libc/dce.h"
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#include "libc/intrin/atomic.h"
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#include "libc/macros.h"
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#include "libc/runtime/runtime.h"
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#include "libc/testlib/subprocess.h"
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#include "libc/testlib/testlib.h"
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#include "libc/thread/thread.h"
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#include "libc/thread/thread2.h"
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int cpu_count;
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void SetUpOnce(void) {
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cpu_count = __get_cpu_count();
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}
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////////////////////////////////////////////////////////////////////////////////
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// AFFINITY TEST
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TEST(sched_getcpu, affinity_test) {
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if (IsXnu())
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return;
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if (IsNetbsd())
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return;
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if (IsOpenbsd())
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return;
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SPAWN(fork);
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int n = cpu_count;
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for (int i = 0; i < n; ++i) {
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cpu_set_t affinity;
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CPU_ZERO(&affinity);
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CPU_SET(i, &affinity);
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ASSERT_EQ(
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0, pthread_setaffinity_np(pthread_self(), sizeof(affinity), &affinity));
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EXPECT_EQ(i, sched_getcpu());
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}
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EXITS(0);
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}
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////////////////////////////////////////////////////////////////////////////////
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// KLUDGE TEST
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#define THREADS 2
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#define ITERATIONS 100000
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int g_hits[256];
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atomic_int g_sync;
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int call_sched_getcpu(void) {
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int res = sched_getcpu();
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ASSERT_NE(-1, res);
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ASSERT_GE(res, 0);
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ASSERT_LT(res, cpu_count);
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return res;
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}
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void *worker(void *arg) {
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int ith = (long)arg;
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int nth = THREADS;
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for (int i = 0; i < ITERATIONS; ++i) {
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// help execution of threads be interleaved
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int sync = atomic_fetch_add(&g_sync, 1);
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if (sync % nth == ith) {
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g_hits[call_sched_getcpu() % ARRAYLEN(g_hits)]++;
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}
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}
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return 0;
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}
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TEST(sched_getcpu, kludge_test) {
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#ifdef __x86_64__
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if (IsXnu())
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return;
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#endif
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if (IsNetbsd())
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return;
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if (IsOpenbsd())
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return;
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if (cpu_count < THREADS)
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return;
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pthread_t th[THREADS];
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for (int i = 0; i < THREADS; ++i)
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ASSERT_EQ(0, pthread_create(th + i, 0, worker, (void *)(long)i));
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for (int i = 0; i < THREADS; ++i)
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ASSERT_EQ(0, pthread_join(th[i], 0));
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int hit = 0;
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for (int i = 0; i < ARRAYLEN(g_hits); ++i)
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hit += !!g_hits[i];
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ASSERT_GE(hit, THREADS);
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}
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