Home | History | Annotate | Download | only in graphics 
      1 #include "AutoDecodeCancel.h"
      2 
      3 static SkMutex  gAutoDecoderCancelMutex;
      4 static AutoDecoderCancel* gAutoDecoderCancel;
      5 #ifdef SK_DEBUG
      6 static int gAutoDecoderCancelCount;
      7 #endif
      8 
      9 AutoDecoderCancel::AutoDecoderCancel(jobject joptions,
     10                                        SkImageDecoder* decoder) {
     11     fJOptions = joptions;
     12     fDecoder = decoder;
     13 
     14     if (NULL != joptions) {
     15         SkAutoMutexAcquire ac(gAutoDecoderCancelMutex);
     16 
     17         // Add us as the head of the list
     18         fPrev = NULL;
     19         fNext = gAutoDecoderCancel;
     20         if (gAutoDecoderCancel) {
     21             gAutoDecoderCancel->fPrev = this;
     22         }
     23         gAutoDecoderCancel = this;
     24 
     25         SkDEBUGCODE(gAutoDecoderCancelCount += 1;)
     26         Validate();
     27     }
     28 }
     29 
     30 AutoDecoderCancel::~AutoDecoderCancel() {
     31     if (NULL != fJOptions) {
     32         SkAutoMutexAcquire ac(gAutoDecoderCancelMutex);
     33 
     34         // take us out of the dllist
     35         AutoDecoderCancel* prev = fPrev;
     36         AutoDecoderCancel* next = fNext;
     37 
     38         if (prev) {
     39             SkASSERT(prev->fNext == this);
     40             prev->fNext = next;
     41         } else {
     42             SkASSERT(gAutoDecoderCancel == this);
     43             gAutoDecoderCancel = next;
     44         }
     45         if (next) {
     46             SkASSERT(next->fPrev == this);
     47             next->fPrev = prev;
     48         }
     49 
     50         SkDEBUGCODE(gAutoDecoderCancelCount -= 1;)
     51         Validate();
     52     }
     53 }
     54 
     55 bool AutoDecoderCancel::RequestCancel(jobject joptions) {
     56     SkAutoMutexAcquire ac(gAutoDecoderCancelMutex);
     57 
     58     Validate();
     59 
     60     AutoDecoderCancel* pair = gAutoDecoderCancel;
     61     while (pair != NULL) {
     62         if (pair->fJOptions == joptions) {
     63             pair->fDecoder->cancelDecode();
     64             return true;
     65         }
     66         pair = pair->fNext;
     67     }
     68     return false;
     69 }
     70 
     71 #ifdef SK_DEBUG
     72 // can only call this inside a lock on gAutoDecoderCancelMutex
     73 void AutoDecoderCancel::Validate() {
     74     const int gCount = gAutoDecoderCancelCount;
     75 
     76     if (gCount == 0) {
     77         SkASSERT(gAutoDecoderCancel == NULL);
     78     } else {
     79         SkASSERT(gCount > 0);
     80 
     81         AutoDecoderCancel* curr = gAutoDecoderCancel;
     82         SkASSERT(curr);
     83         SkASSERT(curr->fPrev == NULL);
     84 
     85         int count = 0;
     86         while (curr) {
     87             count += 1;
     88             SkASSERT(count <= gCount);
     89             if (curr->fPrev) {
     90                 SkASSERT(curr->fPrev->fNext == curr);
     91             }
     92             if (curr->fNext) {
     93                 SkASSERT(curr->fNext->fPrev == curr);
     94             }
     95             curr = curr->fNext;
     96         }
     97         SkASSERT(count == gCount);
     98     }
     99 }
    100 #endif
    101