src/os/posix/vm/os_posix.hpp

rev 8957 : 8223147: JFR Backport
8199712: Flight Recorder
8203346: JFR: Inconsistent signature of jfr_add_string_constant
8195817: JFR.stop should require name of recording
8195818: JFR.start should increase autogenerated name by one
8195819: Remove recording=x from jcmd JFR.check output
8203921: JFR thread sampling is missing fixes from JDK-8194552
8203929: Limit amount of data for JFR.dump
8203664: JFR start failure after AppCDS archive created with JFR StartFlightRecording
8003209: JFR events for network utilization
8207392: [PPC64] Implement JFR profiling

*** 60,69 ****
--- 60,96 ----
    static void print_siginfo_brief(outputStream* os, const siginfo_t* si);
  
  };
  
  /*
+  * Crash protection utility used by JFR. Wrap the callback
+  * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
+  * back.
+  * To be able to use this - don't take locks, don't rely on destructors,
+  * don't make OS library calls, don't allocate memory, don't print,
+  * don't call code that could leave the heap / memory in an inconsistent state,
+  * or anything else where we are not in control if we suddenly jump out.
+  */
+ class ThreadCrashProtection : public StackObj {
+ public:
+   static bool is_crash_protected(Thread* thr) {
+     return _crash_protection != NULL && _protected_thread == thr;
+   }
+ 
+   ThreadCrashProtection();
+   bool call(os::CrashProtectionCallback& cb);
+ 
+   static void check_crash_protection(int signal, Thread* thread);
+ private:
+   static Thread* _protected_thread;
+   static ThreadCrashProtection* _crash_protection;
+   static volatile intptr_t _crash_mux;
+   void restore();
+   sigjmp_buf _jmpbuf;
+ };
+ 
+ /*
   * Crash protection for the watcher thread. Wrap the callback
   * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
   * back.
   * To be able to use this - don't take locks, don't rely on destructors,
   * don't make OS library calls, don't allocate memory, don't print,