Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

	if flag == syscall.O_RDONLY {
		// https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-lockfileex
		//lint:ignore SA4016 Reasons
		lockType = lockFileFailImmediately // Set this to enable shared lock and fail immediately.
	}
	return lockedOpenFile(path, flag, perm, lockType)
}

// LockedOpenFile - initializes a new lock and protects
// the file from concurrent access.

  // Views

  /**
   * Returns the set of distinct elements contained in this multiset. The element set is backed by
   * the same data as the multiset, so any change to either is immediately reflected in the other.
   * The order of the elements in the element set is unspecified.
   *
   * <p>If the element set supports any removal operations, these necessarily cause <b>all</b>

            // If this CAS succeeds, we know that the provided callable will never be invoked,
            // so when oldFuture completes it is safe to allow the next submitted task to
            // proceed. Doing this immediately here lets the next task run without waiting for
            // the cancelled task's executor to run the noop AsyncCallable.
            //
            // ---
            //

   * For example, the cache may evict an entry because it hasn't been used recently or very often.
   *
   * <p>If {@code maximumSize} is zero, elements will be evicted immediately after being loaded into
   * cache. This can be useful in testing, or to disable caching temporarily.
   *
   * <p>This feature cannot be used in conjunction with {@link #maximumWeight}.
   *

          throw t;
        }
      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires
     * the lock to check again. Since an IDLE state was observed inside the preceding synchronized
     * block, and reference field assignment is atomic, this may save reacquiring the lock when

          throw t;
        }
      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires
     * the lock to check again. Since an IDLE state was observed inside the preceding synchronized
     * block, and reference field assignment is atomic, this may save reacquiring the lock when

 * Returns true if new reads and writes should be attempted on this.
 *
 * Unfortunately Java's networking APIs don't offer a good health check, so we go on our own by
 * attempting to read with a short timeout. If the fails immediately we know the socket is
 * unhealthy.
 *
 * @param source the source used to read bytes from the socket.
 */
internal fun Socket.isHealthy(source: BufferedSource): Boolean =
  try {

        : Iterators.retainAll(removeFrom.iterator(), elementsToRetain);
  }

  /**
   * Removes, from an iterable, every element that satisfies the provided predicate.
   *
   * <p>Removals may or may not happen immediately as each element is tested against the predicate.
   * The behavior of this method is not specified if {@code predicate} is dependent on {@code
   * removeFrom}.
   *

  // Views

  /**
   * Returns the set of distinct elements contained in this multiset. The element set is backed by
   * the same data as the multiset, so any change to either is immediately reflected in the other.
   * The order of the elements in the element set is unspecified.
   *
   * <p>If the element set supports any removal operations, these necessarily cause <b>all</b>