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commit: 46fca763f7d08171d5c08c1c5fd1f40ce340ba56 |
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Author: Zac Medico <zmedico <AT> gentoo <DOT> org> |
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AuthorDate: Mon Dec 31 03:16:11 2012 +0000 |
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Commit: Zac Medico <zmedico <AT> gentoo <DOT> org> |
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CommitDate: Mon Dec 31 03:16:11 2012 +0000 |
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URL: http://git.overlays.gentoo.org/gitweb/?p=proj/portage.git;a=commit;h=46fca763 |
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|
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EventLoop.iteration: no IO blocking if possible |
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|
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Avoid blocking for IO if there are any timeout or idle callback events |
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available to process. This will prevent starvation of the idle |
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callbacks, which are much more common since commit |
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a3100be184ba1cac2f672f0a1cadcf01690c6d3f. We don't want these idle |
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callbacks to be delayed by long periods of IO blocking. |
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|
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--- |
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pym/portage/util/_eventloop/EventLoop.py | 22 ++++++++++++++++++---- |
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1 files changed, 18 insertions(+), 4 deletions(-) |
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|
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diff --git a/pym/portage/util/_eventloop/EventLoop.py b/pym/portage/util/_eventloop/EventLoop.py |
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index b77e819..d2d4963 100644 |
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--- a/pym/portage/util/_eventloop/EventLoop.py |
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+++ b/pym/portage/util/_eventloop/EventLoop.py |
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@@ -182,11 +182,13 @@ class EventLoop(object): |
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event_queue = self._poll_event_queue |
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event_handlers = self._poll_event_handlers |
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events_handled = 0 |
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+ timeouts_checked = False |
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|
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if not event_handlers: |
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with self._thread_condition: |
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if self._run_timeouts(): |
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events_handled += 1 |
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+ timeouts_checked = True |
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if not event_handlers and not events_handled and may_block: |
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# Block so that we don't waste cpu time by looping too |
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# quickly. This makes EventLoop useful for code that needs |
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@@ -205,6 +207,7 @@ class EventLoop(object): |
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self._thread_condition.wait(wait_timeout) |
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if self._run_timeouts(): |
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events_handled += 1 |
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+ timeouts_checked = True |
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|
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# If any timeouts have executed, then return immediately, |
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# in order to minimize latency in termination of iteration |
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@@ -216,6 +219,17 @@ class EventLoop(object): |
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|
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if may_block: |
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timeout = self._get_poll_timeout() |
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+ |
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+ # Avoid blocking for IO if there are any timeout |
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+ # or idle callbacks available to process. |
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+ if timeout != 0 and not timeouts_checked: |
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+ if self._run_timeouts(): |
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+ events_handled += 1 |
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+ timeouts_checked = True |
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+ if events_handled: |
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+ # Minimize latency for loops controlled |
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+ # by timeout or idle callback events. |
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+ timeout = 0 |
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else: |
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timeout = 0 |
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|
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@@ -235,10 +249,10 @@ class EventLoop(object): |
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if not x.callback(f, event, *x.args): |
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self.source_remove(x.source_id) |
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|
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- # Run timeouts last, in order to minimize latency in |
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- # termination of iteration loops that they may control. |
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- if self._run_timeouts(): |
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- events_handled += 1 |
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+ if not timeouts_checked: |
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+ if self._run_timeouts(): |
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+ events_handled += 1 |
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+ timeouts_checked = True |
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|
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return bool(events_handled) |
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