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Can you define what the yielded thread (Ty) and current thread (Tc) are?</div>
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Naively I would think that the current thread is the one invoking ABT_thread_yield_to(), but that also means that it is the yielded thread as well
<span id="🙂">🙂</span></div>
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At any rate, does the target thread run on the ES that was previously executing the thread that called yield_to()?</div>
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thanks,</div>
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-Phil<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Iwasaki, Shintaro <siwasaki@anl.gov><br>
<b>Sent:</b> Wednesday, August 12, 2020 11:31 AM<br>
<b>To:</b> discuss@lists.argobots.org <discuss@lists.argobots.org><br>
<b>Cc:</b> Carns, Philip H. <carns@mcs.anl.gov><br>
<b>Subject:</b> Re: ABT_thread_yield_to() semantics when crossing pools</font>
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Hi Phil,</div>
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This is not explicitly mentioned, but <span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">ABT_thread_yield_to() works as follows:</span></div>
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- The yielded thread (Ty) is removed from Ty's pool. If failed (e.g., Ty is being executed by another ES), it causes an undefined behavior (NO ERROR CHECK).</div>
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- The current thread (Tc) suspends and is pushed to Tc's pool.</div>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt"><br>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">So unless the target thread is "ready" in the pool (i.e., not running, not completed), there is no problem.</span><br>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">It should work even if Ty and Tc are in separate or customized </span><span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">pools</span><span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">.</span><br>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt"><br>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">(This "NO ERROR CHECK" part cannot be easily fixed because of the current ABT_pool_remove() specification.</span></div>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">If you want to use this feature with an error check, please tell us (or create a GitHub issue) so that we can fix it.)</span><br>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">Thanks,</span></div>
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<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">Shintaro Iwasaki</span></div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Carns, Philip H. via discuss <discuss@lists.argobots.org><br>
<b>Sent:</b> Wednesday, August 12, 2020 9:56 AM<br>
<b>To:</b> discuss@lists.argobots.org <discuss@lists.argobots.org><br>
<b>Cc:</b> Carns, Philip H. <carns@mcs.anl.gov><br>
<b>Subject:</b> [argobots-discuss] ABT_thread_yield_to() semantics when crossing pools</font>
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Hi,</div>
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I was just curious: what happens if you create a thread on a separate pool (with it's own execution streams) and then call ABT_thread_yield_to()?</div>
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Nothing? Error? Or maybe it pulls the ULT back to the local execution stream?</div>
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thanks!</div>
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-Phil<br>
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