Fix some tests.

[lightning.git] / tilelib.go

diff --git a/tilelib.go b/tilelib.go
index 8d35fa4ef8599ab99b7df54937d2b3061f993acd..7d4599d4e254bda48a7c0b6436e6ffcaf1d44f30 100644 (file)
--- a/tilelib.go
+++ b/tilelib.go
@@ -11,6 +11,7 @@ import (
        "encoding/gob"
        "fmt"
        "io"
+       "math/rand"
        "os"
        "regexp"
        "runtime"
@@ -643,32 +644,34 @@ readall:
                }
 
                log.Infof("%s %s getting %d librefs", filelabel, seqlabel, len(found))
-               throttle := &throttle{Max: runtime.NumCPU()}
                path = path[:len(found)]
                var lowquality int64
-               for i, f := range found {
-                       i, f := i, f
-                       throttle.Acquire()
-                       go func() {
-                               defer throttle.Release()
-                               var startpos, endpos int
-                               if i == 0 {
-                                       startpos = 0
-                               } else {
-                                       startpos = f.pos
-                               }
-                               if i == len(found)-1 {
-                                       endpos = fasta.Len()
-                               } else {
-                                       endpos = found[i+1].pos + taglen
-                               }
-                               path[i] = tilelib.getRef(f.tagid, fasta.Bytes()[startpos:endpos], isRef)
-                               if countBases(fasta.Bytes()[startpos:endpos]) != endpos-startpos {
-                                       atomic.AddInt64(&lowquality, 1)
-                               }
-                       }()
+               // Visit each element of found, but start at a random
+               // index, to reduce the likelihood of lock contention
+               // when importing many samples concurrently.
+               startpoint := rand.Int() % len(found)
+               for offset := range found {
+                       i := startpoint + offset
+                       if i >= len(found) {
+                               i -= len(found)
+                       }
+                       f := found[i]
+                       var startpos, endpos int
+                       if i == 0 {
+                               startpos = 0
+                       } else {
+                               startpos = f.pos
+                       }
+                       if i == len(found)-1 {
+                               endpos = fasta.Len()
+                       } else {
+                               endpos = found[i+1].pos + taglen
+                       }
+                       path[i] = tilelib.getRef(f.tagid, fasta.Bytes()[startpos:endpos], isRef)
+                       if countBases(fasta.Bytes()[startpos:endpos]) != endpos-startpos {
+                               lowquality++
+                       }
                }
-               throttle.Wait()
 
                log.Infof("%s %s copying path", filelabel, seqlabel)