d8e19cd79a
This adds a P/V style semaphore mechanism to the resource graph. This enables the user to specify a number of "id:count" tags associated with each resource which will reduce the parallelism of the CheckApply operation to that maximum count. This is particularly interesting because (assuming I'm not mistaken) the implementation is dead-lock free assuming that no individual resource permanently ever blocks during execution! I don't have a formal proof of this, but I was able to convince myself on paper that it was the case. An actual proof that N P/V counting semaphores in a DAG won't ever dead-lock would be particularly welcome! Hint: the trick is to acquire them in alphabetical order while respecting the DAG flow. Disclaimer, this assumes that the lock count is always > 0 of course.
129 lines
1.9 KiB
YAML
129 lines
1.9 KiB
YAML
---
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graph: mygraph
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comment: simple exec fan in to fan out example with semaphore
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resources:
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exec:
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- name: exec1
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec2
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec3
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec4
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec5
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec6
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec7
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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- name: exec8
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cmd: sleep 10s
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shell: ''
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timeout: 0
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watchcmd: ''
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watchshell: ''
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ifcmd: ''
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ifshell: ''
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pollint: 0
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state: present
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edges:
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- name: e1
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from:
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kind: exec
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name: exec1
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to:
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kind: exec
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name: exec4
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- name: e2
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from:
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kind: exec
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name: exec2
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to:
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kind: exec
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name: exec4
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- name: e3
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from:
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kind: exec
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name: exec3
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to:
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kind: exec
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name: exec4
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- name: e4
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from:
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kind: exec
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name: exec4
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to:
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kind: exec
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name: exec5
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- name: e5
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from:
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kind: exec
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name: exec4
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to:
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kind: exec
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name: exec6
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- name: e6
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from:
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kind: exec
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name: exec4
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to:
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kind: exec
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name: exec7
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