Build tool for hunting down flakes

libc/calls/shm_path_np.c

@@ -35,9 +35,8 @@ void shm_path_np(const char *name, char buf[hasatleast 78]) {
   const char *a;
   uint8_t digest[BLAKE2B256_DIGEST_LENGTH];
   a = "/tmp/", n = 5;
-  if (IsLinux() && isdirectory("/dev/shm")) {
+  if (IsLinux() && isdirectory("/dev/shm"))
     a = "/dev/shm/", n = 9;
-  }
   BLAKE2B256(name, strlen(name), digest);
   p = mempcpy(buf, a, n);
   p = hexpcpy(p, digest, BLAKE2B256_DIGEST_LENGTH);

libc/intrin/pthread_mutex_lock.c

@@ -242,7 +242,6 @@ static errno_t pthread_mutex_lock_impl(pthread_mutex_t *mutex,
  *
  * - `PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP`
  * - `PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP`
- * - `PTHREAD_SIGNAL_SAFE_MUTEX_INITIALIZER_NP`
  * - `PTHREAD_NORMAL_MUTEX_INITIALIZER_NP`
  *
  * Locking a mutex that's already locked by the calling thread will make

libc/thread/thread.h

@@ -52,9 +52,6 @@ COSMOPOLITAN_C_START_
 #define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP  {0, PTHREAD_MUTEX_RECURSIVE}
 #define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP {0, PTHREAD_MUTEX_ERRORCHECK}
 
-#define PTHREAD_SIGNAL_SAFE_MUTEX_INITIALIZER_NP \
-  {0, PTHREAD_MUTEX_RECURSIVE | PTHREAD_PROCESS_SHARED}
-
 #ifndef __cplusplus
 #define _PTHREAD_ATOMIC(x) _Atomic(x)
 #else

test/libc/calls/cachestat_test.c

@@ -29,6 +29,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/sysconf.h"
 #include "libc/stdio/rand.h"
+#include "libc/stdio/stdio.h"
 #include "libc/sysv/consts/auxv.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/testlib/testlib.h"
@@ -104,12 +105,14 @@ done:
 }
 
 TEST(cachestat, testCachestatShmem) {
+  char name[64];
+  sprintf(name, "/cachestat_test-%ld", _rand64());
   size_t filesize = 512 * 2 * pagesize;  // 2 2MB huge pages.
   size_t compute_len = 512 * pagesize;
   unsigned long num_pages = compute_len / pagesize;
   char *data = gc(xmalloc(filesize));
   ASSERT_SYS(0, filesize, getrandom(data, filesize, 0));
-  ASSERT_SYS(0, 3, shm_open("tmpshmcstat", O_CREAT | O_RDWR, 0600));
+  ASSERT_SYS(0, 3, shm_open(name, O_CREAT | O_RDWR, 0600));
   ASSERT_SYS(0, 0, ftruncate(3, filesize));
   ASSERT_SYS(0, filesize, write(3, data, filesize));
   struct cachestat_range range = {pagesize, compute_len};
@@ -117,6 +120,6 @@ TEST(cachestat, testCachestatShmem) {
   ASSERT_SYS(0, 0, cachestat(3, &range, &cs, 0));
   ASSERT_EQ(num_pages, cs.nr_cache + cs.nr_evicted,
             "total number of cached and evicted pages is off.\n");
-  ASSERT_SYS(0, 0, shm_unlink("tmpshmcstat"));
+  ASSERT_SYS(0, 0, shm_unlink(name));
   ASSERT_SYS(0, 0, close(3));
 }

test/libc/calls/raise_test.c

@@ -56,9 +56,8 @@ int threadid;
 
 void WorkerQuit(int sig, siginfo_t *si, void *ctx) {
   ASSERT_EQ(SIGILL, sig);
-  if (!IsXnu() && !IsOpenbsd()) {
+  if (!IsXnu() && !IsOpenbsd())
     ASSERT_EQ(SI_TKILL, si->si_code);
-  }
   ASSERT_EQ(threadid, gettid());
 }
 

test/libc/calls/shm_open_test.c

@@ -9,6 +9,7 @@
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/runtime/runtime.h"
+#include "libc/stdio/rand.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/map.h"
@@ -18,7 +19,6 @@
 #include "libc/sysv/consts/sig.h"
 #include "libc/thread/semaphore.h"
 
-#define SHM_PATH    "/fc7261622dd420d8"
 #define STRING_SEND "hello"
 #define STRING_RECV "HELLO"
 
@@ -29,13 +29,14 @@ struct shmbuf {
   char buf[256]; /* Data being transferred */
 };
 
+char shm_path[64];
 atomic_bool *ready;
 
 wontreturn void Bouncer(void) {
 
   /* Create shared memory object and set its size to the size
      of our structure. */
-  int fd = shm_open(SHM_PATH, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
+  int fd = shm_open(shm_path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
   if (fd == -1) {
     perror("shm_open(bouncer)");
     exit(1);
@@ -96,7 +97,7 @@ wontreturn void Sender(void) {
 
   /* Open the existing shared memory object and map it
      into the caller's address space. */
-  int fd = shm_open(SHM_PATH, O_RDWR, 0);
+  int fd = shm_open(shm_path, O_RDWR, 0);
   if (fd == -1) {
     perror("shm_open(sender)");
     exit(1);
@@ -136,7 +137,7 @@ wontreturn void Sender(void) {
   /* Unlink the shared memory object. Even if the peer process
      is still using the object, this is okay. The object will
      be removed only after all open references are closed. */
-  if (shm_unlink(SHM_PATH)) {
+  if (shm_unlink(shm_path)) {
     if (IsWindows() && errno == EACCES) {
       // TODO(jart): Make unlink() work better on Windows.
     } else {
@@ -154,7 +155,7 @@ int pid2;
 void OnExit(void) {
   kill(pid1, SIGKILL);
   kill(pid2, SIGKILL);
-  shm_unlink(SHM_PATH);
+  shm_unlink(shm_path);
 }
 
 void OnTimeout(int sig) {
@@ -164,6 +165,9 @@ void OnTimeout(int sig) {
 
 int main(int argc, char *argv[]) {
 
+  // create random shared memory name
+  sprintf(shm_path, "/shm_open_test-%ld", _rand64());
+
   // create synchronization object
   ready = _mapshared(1);
 

test/posix/mutex_async_signal_safety_test.c

@@ -1,114 +0,0 @@
-// Copyright 2024 Justine Alexandra Roberts Tunney
-//
-// Permission to use, copy, modify, and/or distribute this software for
-// any purpose with or without fee is hereby granted, provided that the
-// above copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
-// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
-// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
-// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
-// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
-// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
-
-#include <cosmo.h>
-#include <pthread.h>
-#include <signal.h>
-#include <stdatomic.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-// tests that recursive mutexes are implemented atomically
-//
-// glibc fails this test
-// musl passes this test
-// cosmo only guarantees this in process-shared non-debug mode
-
-atomic_bool done;
-atomic_bool ready;
-pthread_mutex_t lock;
-
-void hand(int sig) {
-  if (pthread_mutex_lock(&lock))
-    _Exit(50);
-  if (pthread_mutex_unlock(&lock))
-    _Exit(51);
-}
-
-void* work(void* arg) {
-  ready = true;
-  while (!done) {
-    if (pthread_mutex_lock(&lock))
-      _Exit(60);
-    if (pthread_mutex_unlock(&lock))
-      _Exit(61);
-  }
-  return 0;
-}
-
-int main() {
-
-  if (IsQemuUser()) {
-    // qemu is believed to be the one at fault
-    kprintf("mutex_async_signal_safety_test flakes on qemu\n");
-    return 0;
-  }
-
-  if (IsModeDbg()) {
-    // the deadlock detector gets in the way of our glorious spin lock
-    kprintf("mutex_async_signal_safety_test not feasible in debug mode\n");
-    return 0;
-  }
-
-  struct sigaction sa;
-  sa.sa_handler = hand;
-  sa.sa_flags = SA_NODEFER;
-  sigemptyset(&sa.sa_mask);
-  if (sigaction(SIGUSR1, &sa, 0))
-    _Exit(1);
-
-  pthread_mutexattr_t attr;
-  if (pthread_mutexattr_init(&attr))
-    _Exit(2);
-  if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE))
-    _Exit(3);
-  if (pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED))
-    _Exit(3);
-  if (pthread_mutex_init(&lock, &attr))
-    _Exit(4);
-  if (pthread_mutexattr_destroy(&attr))
-    _Exit(5);
-
-  pthread_t th;
-  pthread_attr_t tattr;
-  if (pthread_attr_init(&tattr))
-    _Exit(6);
-  if (pthread_attr_setstacksize(&tattr, 8 * 1024 * 1024))
-    _Exit(7);
-  if (pthread_attr_setguardsize(&tattr, 64 * 1024))
-    _Exit(8);
-  if (pthread_create(&th, &tattr, work, 0))
-    _Exit(9);
-  if (pthread_attr_destroy(&tattr))
-    _Exit(10);
-  for (;;)
-    if (ready)
-      break;
-
-  for (int i = 0; i < 100; ++i) {
-    if (pthread_kill(th, SIGUSR1))
-      _Exit(11);
-    if (pthread_kill(th, SIGUSR1))
-      _Exit(12);
-    usleep(1);
-  }
-
-  done = true;
-  if (pthread_join(th, 0))
-    _Exit(13);
-  if (pthread_mutex_destroy(&lock))
-    _Exit(14);
-}

tool/build/BUILD.mk

@@ -138,8 +138,8 @@ o/$(MODE)/tool/build/dso/dlopen_helper.so:				\
 		o/$(MODE)/tool/build/dso/dlopen_helper.o		\
 		$(OUTPUT_OPTION)
 
-o/$(MODE)/tool/build/dlopen_test.runs:					\
+o/$(MODE)/tool/build/dlopen_tester.runs:				\
-		o/$(MODE)/tool/build/dlopen_test			\
+		o/$(MODE)/tool/build/dlopen_tester			\
 		o/$(MODE)/tool/build/dso/dlopen_helper.so
 	$< o/$(MODE)/tool/build/dso/dlopen_helper.so
 

tool/scripts/flakes

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+import os
+import sys
+import subprocess
+import concurrent.futures
+from collections import Counter
+from typing import List, Dict, Tuple
+
+NUM_PARALLEL = int(os.cpu_count() * 1.5)
+
+def find_test_files(root_dir: str) -> List[str]:
+    """Find all executable files ending with _test recursively."""
+    test_files = []
+    for root, _, files in os.walk(root_dir):
+        for file in files:
+            if file.endswith('_test'):
+                file_path = os.path.join(root, file)
+                if os.access(file_path, os.X_OK):
+                    test_files.append(file_path)
+    return test_files
+
+def run_single_test(test_path: str) -> int:
+    """Run a single test and return its exit code."""
+    try:
+        result = subprocess.run([test_path], capture_output=False)
+        return result.returncode
+    except Exception as e:
+        print(f"Error running {test_path}: {e}")
+        return -1
+
+def run_test_multiple_times(test_path: str, iterations: int = NUM_PARALLEL) -> List[int]:
+    """Run a test multiple times in parallel and collect exit codes."""
+    with concurrent.futures.ProcessPoolExecutor() as executor:
+        futures = [executor.submit(run_single_test, test_path) for _ in range(iterations)]
+        return [f.result() for f in concurrent.futures.as_completed(futures)]
+
+def analyze_results(test_path: str, exit_codes: List[int]) -> Tuple[bool, Dict[int, int]]:
+    """Analyze test results and return if it flaked and error distribution."""
+    error_counts = Counter(code for code in exit_codes if code != 0)
+    return bool(error_counts), dict(error_counts)
+
+def print_flaky_report(test_path: str, error_distribution: Dict[int, int], total_runs: int):
+    """Print a report for a flaky test."""
+    print(f"{test_path} flaked!")
+    for exit_code, count in error_distribution.items():
+        print(f"* {count}/{total_runs} processes died with exit code {exit_code}")
+
+def main(directory = "o"):
+    test_files = find_test_files(directory)
+    for i, test_path in enumerate(test_files):
+        print("testing [%d/%d] %s..." % (i, len(test_files), test_path))
+        sys.stdout.flush()
+        exit_codes = run_test_multiple_times(test_path)
+        is_flaky, error_distribution = analyze_results(test_path, exit_codes)
+        if is_flaky:
+            print_flaky_report(test_path, error_distribution, len(exit_codes))
+            sys.exit(1)
+
+if __name__ == "__main__":
+    main(*sys.argv[1:])