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107 lines
4.1 KiB
C
107 lines
4.1 KiB
C
/***********************************************************************************************************************************
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Wait Handler
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***********************************************************************************************************************************/
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#include "common/memContext.h"
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#include "common/time.h"
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#include "common/wait.h"
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/***********************************************************************************************************************************
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Contains information about the wait handler
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***********************************************************************************************************************************/
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struct Wait
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{
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MemContext *memContext; // Context that contains the wait handler
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TimeUSec waitTime; // Total time to wait (in usec)
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TimeUSec sleepTime; // Next sleep time (in usec)
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TimeUSec sleepPrevTime; // Previous time slept (in usec)
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TimeUSec beginTime; // Time the wait began (in epoch usec)
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};
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/***********************************************************************************************************************************
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New wait handler
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***********************************************************************************************************************************/
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Wait *
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waitNew(double waitTime)
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{
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// Make sure wait time is valid
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if (waitTime < 0.1 || waitTime > 999999.0)
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THROW(AssertError, "waitTime must be >= 0.1 and <= 999999.0");
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// Allocate wait object
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Wait *this = NULL;
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MEM_CONTEXT_NEW_BEGIN("wait")
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{
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// Create object
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this = memNew(sizeof(Wait));
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this->memContext = MEM_CONTEXT_NEW();
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// Store time
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this->waitTime = (TimeUSec)(waitTime * USEC_PER_SEC);
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// Calculate first sleep time -- start with 1/10th of a second for anything >= 1 second
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if (this->waitTime >= USEC_PER_SEC)
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this->sleepTime = USEC_PER_SEC / 10;
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// Unless the wait time is really small -- in that case divide wait time by 10
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else
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this->sleepTime = this->waitTime / 10;
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// Get beginning time
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this->beginTime = timeUSec();
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}
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MEM_CONTEXT_NEW_END();
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return this;
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}
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/***********************************************************************************************************************************
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Wait and return whether the caller has more time left
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***********************************************************************************************************************************/
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bool
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waitMore(Wait *this)
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{
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bool result = false;
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// If sleep is 0 then the wait time has already ended
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if (this->sleepTime > 0)
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{
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// Sleep required amount
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sleepUSec(this->sleepTime);
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// Get the end time
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TimeUSec elapsedTime = timeUSec() - this->beginTime;
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// Is there more time to go?
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if (elapsedTime < this->waitTime)
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{
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// Calculate sleep time as a sum of current and last (a Fibonacci-type sequence)
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TimeUSec sleepNextTime = this->sleepTime + this->sleepPrevTime;
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// Make sure sleep time does not go beyond end time (this won't be negative because of the if condition above)
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if (sleepNextTime > this->waitTime - elapsedTime)
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sleepNextTime = this->waitTime - elapsedTime;
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// Store new sleep times
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this->sleepPrevTime = this->sleepTime;
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this->sleepTime = sleepNextTime;
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}
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// Else set sleep to zero so next call will return false
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else
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this->sleepTime = 0;
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// Need to wait more
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result = true;
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}
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return result;
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}
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/***********************************************************************************************************************************
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Free the wait
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***********************************************************************************************************************************/
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void
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waitFree(Wait *this)
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{
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memContextFree(this->memContext);
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}
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