6721093: -XX:AppendRatio=N not supported

Add mechanism to ignore unsupported flags for a set period of time

Reviewed-by: acorn, never, coleenp

hotspot/src/os/linux/vm/os_linux.cpp

@@ -94,6 +94,9 @@ static pid_t _initial_pid = 0;
 static int SR_signum = SIGUSR2;
 sigset_t SR_sigset;
 
+/* Used to protect dlsym() calls */
+static pthread_mutex_t dl_mutex;
+
 ////////////////////////////////////////////////////////////////////////////////
 // utility functions
 
@@ -1493,6 +1496,24 @@ const char* os::dll_file_extension() { return ".so"; }
 
 const char* os::get_temp_directory() { return "/tmp/"; }
 
+void os::dll_build_name(
+    char* buffer, size_t buflen, const char* pname, const char* fname) {
+  // copied from libhpi
+  const size_t pnamelen = pname ? strlen(pname) : 0;
+
+  /* Quietly truncate on buffer overflow.  Should be an error. */
+  if (pnamelen + strlen(fname) + 10 > (size_t) buflen) {
+      *buffer = '\0';
+      return;
+  }
+
+  if (pnamelen == 0) {
+      sprintf(buffer, "lib%s.so", fname);
+  } else {
+      sprintf(buffer, "%s/lib%s.so", pname, fname);
+  }
+}
+
 const char* os::get_current_directory(char *buf, int buflen) {
   return getcwd(buf, buflen);
 }
@@ -1742,7 +1763,17 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
   return NULL;
 }
 
-
+/*
+ * glibc-2.0 libdl is not MT safe.  If you are building with any glibc,
+ * chances are you might want to run the generated bits against glibc-2.0
+ * libdl.so, so always use locking for any version of glibc.
+ */
+void* os::dll_lookup(void* handle, const char* name) {
+  pthread_mutex_lock(&dl_mutex);
+  void* res = dlsym(handle, name);
+  pthread_mutex_unlock(&dl_mutex);
+  return res;
+}
 
 
 bool _print_ascii_file(const char* filename, outputStream* st) {
@@ -3581,6 +3612,7 @@ void os::init(void) {
 
   Linux::clock_init();
   initial_time_count = os::elapsed_counter();
+  pthread_mutex_init(&dl_mutex, NULL);
 }
 
 // To install functions for atexit system call

hotspot/src/os/solaris/vm/os_solaris.cpp

@@ -1783,6 +1783,24 @@ const char* os::dll_file_extension() { return ".so"; }
 
 const char* os::get_temp_directory() { return "/tmp/"; }
 
+void os::dll_build_name(
+    char* buffer, size_t buflen, const char* pname, const char* fname) {
+  // copied from libhpi
+  const size_t pnamelen = pname ? strlen(pname) : 0;
+
+  /* Quietly truncate on buffer overflow.  Should be an error. */
+  if (pnamelen + strlen(fname) + 10 > (size_t) buflen) {
+      *buffer = '\0';
+      return;
+  }
+
+  if (pnamelen == 0) {
+      sprintf(buffer, "lib%s.so", fname);
+  } else {
+      sprintf(buffer, "%s/lib%s.so", pname, fname);
+  }
+}
+
 const char* os::get_current_directory(char *buf, int buflen) {
   return getcwd(buf, buflen);
 }
@@ -2034,6 +2052,9 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
   return NULL;
 }
 
+void* os::dll_lookup(void* handle, const char* name) {
+  return dlsym(handle, name);
+}
 
 
 bool _print_ascii_file(const char* filename, outputStream* st) {

hotspot/src/os/windows/vm/os_windows.cpp

@@ -985,6 +985,28 @@ const char * os::get_temp_directory()
     }
 }
 
+void os::dll_build_name(char *holder, size_t holderlen,
+                        const char* pname, const char* fname)
+{
+    // copied from libhpi
+    const size_t pnamelen = pname ? strlen(pname) : 0;
+    const char c = (pnamelen > 0) ? pname[pnamelen-1] : 0;
+
+    /* Quietly truncates on buffer overflow. Should be an error. */
+    if (pnamelen + strlen(fname) + 10 > holderlen) {
+        *holder = '\0';
+        return;
+    }
+
+    if (pnamelen == 0) {
+        sprintf(holder, "%s.dll", fname);
+    } else if (c == ':' || c == '\\') {
+        sprintf(holder, "%s%s.dll", pname, fname);
+    } else {
+        sprintf(holder, "%s\\%s.dll", pname, fname);
+    }
+}
+
 // Needs to be in os specific directory because windows requires another
 // header file <direct.h>
 const char* os::get_current_directory(char *buf, int buflen) {
@@ -1248,6 +1270,10 @@ bool os::dll_address_to_function_name(address addr, char *buf,
   return false;
 }
 
+void* os::dll_lookup(void* handle, const char* name) {
+  return GetProcAddress((HMODULE)handle, name);
+}
+
 // save the start and end address of jvm.dll into param[0] and param[1]
 static int _locate_jvm_dll(int pid, char* mod_fname, address base_addr,
                     unsigned size, void * param) {