TinyProfiler: A few updates

* Make it safe for Initialize and Finalize being called multiple times.

* Delay the reading of tiny_profiler.output_file so that if the user wants
  to override the default, they do not have to do it by passing a function
  to amrex::Initialize.

* Update the documentation, thanks to @ax3l's suggestion.

Docs/sphinx_documentation/source/RuntimeParameters.rst

@@ -1234,5 +1234,5 @@ enabled.
 
  If this parameter is empty, the output of tiny profiling is dumped on the
  default out stream of AMReX. If it's not empty, it specifies the file
- name for the output. Note that ``/dev/null`` is a special name that mean
- a null file.
+ name for the output. Note that ``/dev/null`` is a special name that means
+ no output.

Src/Base/AMReX_TinyProfiler.H

@@ -143,6 +143,7 @@ private:
  static bool memprof_enabled;
  static std::string output_file;
 
+ static std::string const& get_output_file ();
  static void PrintStats (std::map<std::string,Stats>& regstats, double dt_max,
  std::ostream* os);
  static void PrintMemStats (std::map<std::string, MemStat>& memstats,

Src/Base/AMReX_TinyProfiler.cpp

@@ -56,6 +56,8 @@ std::string TinyProfiler::output_file;
 
 namespace {
  constexpr char mainregion[] = "main";
+ bool finalized = false;
+ bool memprof_finalized = false;
 }
 
 TinyProfiler::TinyProfiler (std::string funcname) noexcept
@@ -318,23 +320,14 @@ TinyProfiler::Initialize () noexcept
  pp.queryAdd("print_threshold", print_threshold);
 
  pp.queryAdd("enabled", enabled);
- pp.queryAdd("output_file", output_file);
  }
 
  if (!enabled) { return; }
 
- if (ParallelDescriptor::IOProcessor()) {
- static bool first = true;
- if (first && !output_file.empty() && output_file != "/dev/null") {
- if (FileSystem::Exists(output_file)) {
- FileSystem::Remove(output_file);
- }
- first = false;
- }
- }
-
  regionstack.emplace_back(mainregion);
  t_init = amrex::second();
+
+ finalized = false;
 }
 
 void
@@ -352,14 +345,15 @@ TinyProfiler::MemoryInitialize () noexcept
 #ifdef AMREX_USE_OMP
  mem_stack_thread_private.resize(omp_get_max_threads());
 #endif
+
+ memprof_finalized = false;
 }
 
 void
 TinyProfiler::Finalize (bool bFlushing) noexcept
 {
  if (!enabled) { return; }
 
- static bool finalized = false;
  if (!bFlushing) { // If flushing, don't make this the last time!
  if (finalized) {
  return;
@@ -388,12 +382,13 @@ TinyProfiler::Finalize (bool bFlushing) noexcept
  std::ostream* os = nullptr;
  std::streamsize oldprec = 0;
  if (ParallelDescriptor::IOProcessor()) {
- if (output_file.empty()) {
+ auto const& ofile = get_output_file();
+ if (ofile.empty()) {
  os = &(amrex::OutStream());
- } else if (output_file != "/dev/null") {
- ofs.open(output_file, std::ios_base::app);
+ } else if (ofile != "/dev/null") {
+ ofs.open(ofile, std::ios_base::app);
  if (!ofs.is_open()) {
- amrex::Error("TinyProfiler failed to open "+output_file);
+ amrex::Error("TinyProfiler failed to open "+ofile);
  }
  os = static_cast<std::ostream*>(&ofs);
  }
@@ -439,6 +434,12 @@ TinyProfiler::Finalize (bool bFlushing) noexcept
  }
  }
 
+ if (!bFlushing) {
+ regionstack.clear();
+ ttstack.clear();
+ statsmap.clear();
+ }
+
  if(os) { os->precision(oldprec); }
 }
 
@@ -449,12 +450,11 @@ TinyProfiler::MemoryFinalize (bool bFlushing) noexcept
 
  // This function must be called BEFORE the profiled arenas are deleted
 
- static bool finalized = false;
  if (!bFlushing) { // If flushing, don't make this the last time!
- if (finalized) {
+ if (memprof_finalized) {
  return;
  } else {
- finalized = true;
+ memprof_finalized = true;
  }
  }
 
@@ -467,12 +467,13 @@ TinyProfiler::MemoryFinalize (bool bFlushing) noexcept
  std::ostream* os = nullptr;
  std::streamsize oldprec = 0;
  if (ParallelDescriptor::IOProcessor()) {
- if (output_file.empty()) {
+ auto const& ofile = get_output_file();
+ if (ofile.empty()) {
  os = &(amrex::OutStream());
- } else if (output_file != "/dev/null") {
- ofs.open(output_file, std::ios_base::app);
+ } else if (ofile != "/dev/null") {
+ ofs.open(ofile, std::ios_base::app);
  if (!ofs.is_open()) {
- amrex::Error("TinyProfiler failed to open "+output_file);
+ amrex::Error("TinyProfiler failed to open "+ofile);
  }
  os = static_cast<std::ostream*>(&ofs);
  }
@@ -950,4 +951,26 @@ TinyProfiler::PrintCallStack (std::ostream& os)
  }
 }
 
+std::string const&
+TinyProfiler::get_output_file ()
+{
+ // Instead of reading it only once, we could try to read the parameter
+ // everytime. But I am not sure how useful that could be.
+ static bool first = true;
+ if (first) {
+ first = false;
+
+ amrex::ParmParse pp("tiny_profiler");
+ pp.query("output_file", output_file);
+
+ if (!output_file.empty() && output_file != "/dev/null") {
+ if (FileSystem::Exists(output_file)) {
+ FileSystem::Remove(output_file);
+ }
+ }
+ }
+
+ return output_file;
+}
+
 }