Find the decreasing range of the function: $f(x)=xe^{\sin x}$

Question

Find the decreasing range of the function:

$$f(x)=xe^{\sin x}.$$

I found derivative $$f'(x)=(xe^{\sin x})'=e^{\sin x} (x \cos x + 1)$$

But I couldn't solve this inequality:

$$f'(x)≤0 \Longrightarrow e^{\sin x} (x \cos x + 1)≤0$$

$$x \cos x + 1≤0$$