Add a handler to DM to print out what was running when we crash.

This is an experiment to see if we can use something like this
rather than today's extremely verbose logging.

Now, hopefully something crashes.

BUG=skia:4978
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1725543002

Review URL: https://codereview.chromium.org/1725543002

1 files changed, 30 insertions, 5 deletions

diff --git a/dm/DM.cpp b/dm/DM.cpp
index c7c3628d8a..a046421908 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -22,6 +22,7 @@
 #include "SkMD5.h"
 #include "SkMutex.h"
 #include "SkOSFile.h"
+#include "SkSpinlock.h"
 #include "SkTHash.h"
 #include "SkTaskGroup.h"
 #include "SkThreadUtils.h"
@@ -83,7 +84,8 @@ static void fail(ImplicitString err) {
 
 static int32_t gPending = 0;  // Atomic.  Total number of running and queued tasks.
 
-SK_DECLARE_STATIC_MUTEX(gRunningAndTallyMutex);
+// We use a spinlock to make locking this in a signal handler _somewhat_ safe.
+SK_DECLARE_STATIC_SPINLOCK(gRunningAndTallyMutex);
 static SkTArray<SkString>        gRunning;
 static SkTHashMap<SkString, int> gNoteTally;
 
@@ -93,7 +95,7 @@ static void done(double ms,
     SkString id = SkStringPrintf("%s %s %s %s", config.c_str(), src.c_str(),
                                                 srcOptions.c_str(), name.c_str());
     {
-        SkAutoMutexAcquire lock(gRunningAndTallyMutex);
+        SkAutoTAcquire<SkPODSpinlock> lock(gRunningAndTallyMutex);
         for (int i = 0; i < gRunning.count(); i++) {
             if (gRunning[i] == id) {
                 gRunning.removeShuffle(i);
@@ -132,10 +134,33 @@ static void start(ImplicitString config, ImplicitString src,
                   ImplicitString srcOptions, ImplicitString name) {
     SkString id = SkStringPrintf("%s %s %s %s", config.c_str(), src.c_str(),
                                                 srcOptions.c_str(), name.c_str());
-    SkAutoMutexAcquire lock(gRunningAndTallyMutex);
+    SkAutoTAcquire<SkPODSpinlock> lock(gRunningAndTallyMutex);
     gRunning.push_back(id);
 }
 
+#if defined(SK_BUILD_FOR_WIN32)
+    static void setup_crash_handler() {
+        // TODO: custom crash handler like below to print out what was running
+        SetupCrashHandler();
+    }
+
+#else
+    #include <signal.h>
+    static void setup_crash_handler() {
+        const int kSignals[] = { SIGABRT, SIGBUS, SIGFPE, SIGILL, SIGSEGV };
+        for (int sig : kSignals) {
+            signal(sig, [](int sig) {
+                SkAutoTAcquire<SkPODSpinlock> lock(gRunningAndTallyMutex);
+                SkDebugf("\nCaught signal %d [%s] while running %d tasks:\n",
+                         sig, strsignal(sig), gRunning.count());
+                for (auto& task : gRunning) {
+                    SkDebugf("\t%s\n", task.c_str());
+                }
+            });
+        }
+    }
+#endif
+
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 struct Gold : public SkString {
@@ -1101,7 +1126,7 @@ static void start_keepalive() {
             #endif
                 SkString running;
                 {
-                    SkAutoMutexAcquire lock(gRunningAndTallyMutex);
+                    SkAutoTAcquire<SkPODSpinlock> lock(gRunningAndTallyMutex);
                     for (int i = 0; i < gRunning.count(); i++) {
                         running.appendf("\n\t%s", gRunning[i].c_str());
                     }
@@ -1130,7 +1155,7 @@ extern SkTypeface* (*gCreateTypefaceDelegate)(const char [], SkTypeface::Style )
 
 int dm_main();
 int dm_main() {
-    SetupCrashHandler();
+    setup_crash_handler();
     JsonWriter::DumpJson();  // It's handy for the bots to assume this is ~never missing.
     SkAutoGraphics ag;
     SkTaskGroup::Enabler enabled(FLAGS_threads);