Changeset 28405 for trunk/psphot/src/psphotSourceStats.c

Timestamp:

Jun 18, 2010, 2:25:38 PM (16 years ago)

Author:

Paul Price

Message:

Discovered a race condition in the threading process. The thread process was: psThreadJobAlloc, populate job with arguments, psThreadJobAddPending, psFree the job. This is not thread-safe, because we're decrementing the job's reference counter while the reference count is also being fiddled within the thread system (psThread.c; by pulling the job off the 'pending' queue and putting it on the 'done' queue). The reference count fiddling within the thread system was protected by a mutex, but the external free was not. Therefore, I'm pulling the free into the thread system so it can be protected (without the user having to worry about locks to do the simple case). This means that the user should no longer touch the job once he hands it over to the thread system (unless it's protected by calls to psThreadLock/psThreadUnlock, or it's on the other side of psThreadPoolWait from all the adds so that the threads aren't doing anything).

File:

• trunk/psphot/src/psphotSourceStats.c (modified) (8 diffs)

trunk/psphot/src/psphotSourceStats.c

@@ -3 +3 @@
 // convert detections to sources and measure their basic properties (moments, local sky, sky
 // variance) Note: this function only generates sources for the new peaks (peak->assigned).
-// The new sources are added to any existing sources on detections->newSources.  The sources 
+// The new sources are added to any existing sources on detections->newSources.  The sources
 // on detections->allSources are ignored.
 bool psphotSourceStats (pmConfig *config, const pmFPAview *view, const char *filerule, bool setWindow)
@@ -22 +22 @@
     // loop over the available readouts
     for (int i = 0; i < num; i++) {
-        // if (i == chisqNum) continue; // skip chisq image
+        // if (i == chisqNum) continue; // skip chisq image
         if (!psphotSourceStatsReadout (config, view, filerule, i, recipe, setWindow)) {
             psError (PSPHOT_ERR_CONFIG, false, "failed to find initial detections for %s entry %d", filerule, i);
@@ -91 +91 @@
     // generate the array of sources, define the associated pixel
     if (!detections->newSources) {
-        detections->newSources = psArrayAllocEmpty (peaks->n);
+        detections->newSources = psArrayAllocEmpty (peaks->n);
     }
     sources = detections->newSources;
@@ -107 +107 @@
         // create a new source
         pmSource *source = pmSourceAlloc();
-        source->imageID = index;
+        source->imageID = index;
 
         // add the peak
@@ -184 +184 @@
             if (!psThreadJobAddPending(job)) {
                 psError(PS_ERR_UNKNOWN, false, "Unable to launch thread job PSPHOT_SOURCE_STATS");
-                psFree (job);
                 psFree(detections->newSources);
                 return false;
             }
-            psFree(job);
         }
 
@@ -194 +192 @@
         if (!psThreadPoolWait (false)) {
             psError(PS_ERR_UNKNOWN, false, "Failure in thread job PSPHOT_SOURCE_STATS");
-            psFree(detections->newSources);
+            psFree(detections->newSources);
             return false;
         }
@@ -315 +313 @@
             if (!psThreadJobAddPending(job)) {
                 psError(PS_ERR_UNKNOWN, false, "Unable to launch thread job PSPHOT_SOURCE_STATS");
-                psFree (job);
                 return NULL;
             }
-            psFree(job);
         }
 
@@ -380 +376 @@
         pmSource *source = sources->data[i];
 
-        if (source->tmpFlags & PM_SOURCE_TMPF_MOMENTS_MEASURED) continue;
-        source->tmpFlags |= PM_SOURCE_TMPF_MOMENTS_MEASURED;
+        if (source->tmpFlags & PM_SOURCE_TMPF_MOMENTS_MEASURED) continue;
+        source->tmpFlags |= PM_SOURCE_TMPF_MOMENTS_MEASURED;
 
         // skip faint sources for moments measurement