Replace use of pstack with direct invocation of gdb.

This switches from the system pstack script to using gdb directly. Ideally, this will be more usable on non-Linux platforms. NOTE that this will pull the gdb from the environment (i.e., probably CMSSW's gdb instead of the system one). CMSSW's gdb can parse the debug symbols we ship, meaning that the backtrace will include niceties like filenames, line numbers, and decode arguments. The downside of this is that CMSSW's gdb requires 10 minutes and about 1GB RAM to generate the traceback.
bbockelm · Jul 8, 2015 · b6d0bae · b6d0bae
1 parent cff10d3
commit b6d0bae
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Showing 2 changed files with 13 additions and 6 deletions.
diff --git a/FWCore/Services/src/InitRootHandlers.cc b/FWCore/Services/src/InitRootHandlers.cc
@@ -269,14 +269,15 @@ namespace edm {
     int cmssw_stacktrace(void * /*arg*/)
     {
       char *const *argv = edm::service::InitRootHandlers::getPstackArgv();
-      execv("/usr/bin/pstack", argv);
+      execv("/bin/sh", argv);
       ::abort();
       return 1;
     }
 
-    static char pstackName[] = "pstack";
+    static char pstackName[] = "(CMSSW stack trace helper)";
+    static char dashC[] = "-c";
     char InitRootHandlers::pidString_[InitRootHandlers::pidStringLength_] = {};
-    char * const InitRootHandlers::pstackArgv_[3] = {pstackName, InitRootHandlers::pidString_, nullptr};
+    char * const InitRootHandlers::pstackArgv_[] = {pstackName, dashC, InitRootHandlers::pidString_, nullptr};
 
     InitRootHandlers::InitRootHandlers (ParameterSet const& pset, ActivityRegistry& iReg)
       : RootHandlers(),
@@ -416,7 +417,13 @@ namespace edm {
     void
     InitRootHandlers::cachePidInfo()
     {
-      assert(snprintf(pidString_, pidStringLength_-1, "%d", getpid()) < pidStringLength_);
+      assert(snprintf(pidString_, pidStringLength_-1, "gdb -quiet -p %d 2>&1 <<EOF |\n"
+        "set width 0\n"
+        "set height 0\n"
+        "set pagination no\n"
+        "thread apply all bt\n"
+        "EOF\n"
+        "/bin/sed -n -e 's/^\\((gdb) \\)*//' -e '/^#/p' -e '/^Thread/p'", getpid()) < pidStringLength_);
     }
 
   }  // end of namespace service

diff --git a/FWCore/Services/src/InitRootHandlers.h b/FWCore/Services/src/InitRootHandlers.h
@@ -30,9 +30,9 @@ namespace edm {
       void cachePidInfoHandler(unsigned int, unsigned int) {cachePidInfo();}
       void cachePidInfo();
 
-      static const int pidStringLength_ = 50;
+      static const int pidStringLength_ = 200;
       static char pidString_[pidStringLength_];
-      static char * const pstackArgv_[3];
+      static char * const pstackArgv_[];
       bool unloadSigHandler_;
       bool resetErrHandler_;
       bool loadAllDictionaries_;