[vm] Print some resource usage and limits when pthread_create fails.

TEST=ulimit
Bug: flutter/flutter#164591
Change-Id: Ica782d6e9dbf8da3017f6cf65196564bbed40f2f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/419988
Reviewed-by: Alexander Aprelev <[email protected]>
Commit-Queue: Ryan Macnak <[email protected]>

Author: rmacnak-google

runtime/vm/os_thread_linux.cc

@@ -8,11 +8,12 @@
 
 #include "vm/os_thread.h"
 
-#include <errno.h>  // NOLINT
+#include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
-#include <sys/resource.h>  // NOLINT
-#include <sys/syscall.h>   // NOLINT
-#include <sys/time.h>      // NOLINT
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/time.h>
 
 #include "platform/address_sanitizer.h"
 #include "platform/assert.h"
@@ -114,6 +115,39 @@ int OSThread::TryStart(const char* name,
 
   pthread_t tid;
   result = pthread_create(&tid, &attr, ThreadStart, data);
+  if (result != 0) {
+    fprintf(stderr, "pthread_create failed\n");
+    const char* const kPaths[] = {
+        "/proc/self/limits",
+        "/proc/sys/kernel/threads-max",
+        "/proc/sys/kernel/pid_max",
+        "/sys/fs/cgroup/user.slice/memory.current",
+        "/sys/fs/cgroup/user.slice/memory.max",
+        "/sys/fs/cgroup/user.slice/memory.peak",
+        "/sys/fs/cgroup/user.slice/pids.current",
+        "/sys/fs/cgroup/user.slice/pids.max",
+        "/sys/fs/cgroup/user.slice/pids.peak",
+    };
+    for (uintptr_t i = 0; i < ARRAY_SIZE(kPaths); i++) {
+      const char* path = kPaths[i];
+
+      int fd = open(path, O_RDONLY | O_CLOEXEC);
+      if (fd < 0) {
+        fprintf(stderr, "%s: Failed to open\n", path);
+        continue;
+      }
+      const intptr_t kBufferSize = 2048;
+      char buffer[kBufferSize];
+      memset(buffer, 0, kBufferSize);
+      ssize_t red = read(fd, buffer, kBufferSize - 1);
+      close(fd);
+      if (red < 0) {
+        fprintf(stderr, "%s: Failed to read\n", path);
+        continue;
+      }
+      fprintf(stderr, "%s: %s\n", path, buffer);
+    }
+  }
   RETURN_ON_PTHREAD_FAILURE(result);
 
   result = pthread_attr_destroy(&attr);