fixes for queue length and push/pop operations #29

Job	Run time
windows (x64, 3.8)	9m 27s
windows (x64, 3.8)	9m 27s
linux (docker/Dockerfile.manylinux_2_28_ARM64, manylinux-arm, linux/arm64, ARM64)	15m 39s
linux (docker/Dockerfile.manylinux_2_28_ARM64, manylinux-arm, linux/arm64, ARM64)	15m 39s
windows (x64, 3.9)	9m 21s
windows (x64, 3.9)	9m 21s
linux (docker/Dockerfile.manylinux_2_28_X64, manylinux-x86, linux/amd64, X64)	9m 21s
linux (docker/Dockerfile.manylinux_2_28_X64, manylinux-x86, linux/amd64, X64)	9m 23s
windows (x64, 3.10)	9m 22s
windows (x64, 3.10)	9m 22s
windows (x64, 3.11)	9m 21s
windows (x64, 3.11)	9m 21s
windows (x64, 3.12)	9m 42s
windows (x64, 3.12)	9m 42s
	2h 24m 28s

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