Split the "threads" configuration option into "iothreads" and "cputhreads".

native/src/iocontext.cpp

@@ -71,7 +71,8 @@ SeismicStoreIOContext::SeismicStoreIOContext()
   aligned(Environment::getNumericEnv("OPENZGY_ALIGNED_MB", 0));
   segsize(Environment::getNumericEnv("OPENZGY_SEGSIZE_MB", 256));
   segsplit(Environment::getNumericEnv("OPENZGY_SEGSPLIT", 8));
-  threads(Environment::getNumericEnv("OPENZGY_NUMTHREADS", 1));
+  iothreads(Environment::getNumericEnv("OPENZGY_NUMTHREADS_IO", 1));
+  cputhreads(Environment::getNumericEnv("OPENZGY_NUMTHREADS_CPU", 1));
   legaltag(Environment::getStringEnv("OPENZGY_LEGALTAG"));
   writeid(Environment::getStringEnv("OPENZGY_WRITEID"));
   seismicmeta(Environment::getStringEnv("OPENZGY_SEISMICMETA"));
@@ -90,7 +91,7 @@ SeismicStoreIOContext::toString() const
      << "  aligned:  " << _aligned / (1024*1024) << " MB\n"
      << "  segsize:  " << _segsize / (1024*1024) << " MB\n"
      << "  segsplit: " << _segsplit << "\n"
-     << "  threads:  " << _threads << "\n"
+     << "  threads:  " << _iothreads << " I/O, " << _cputhreads << " CPU.\n"
      << "  legaltag: \"" << _legaltag << "\"\n"
      << "  writeid:  \"" << _writeid << "\"\n"
      << "  seismeta: \"" << _seismicmeta << "\"\n";

native/src/iocontext.h

@@ -103,7 +103,8 @@ private:
   std::int64_t _aligned;
   std::int64_t _segsize;
   std::int64_t _segsplit;
-  std::int64_t _threads;
+  std::int64_t _iothreads;
+  std::int64_t _cputhreads;
   std::string  _legaltag;
   std::string  _writeid;
   std::string  _seismicmeta;
@@ -319,10 +320,10 @@ public:
 
   /**
    * Use up to this many parallel requests to seismic store in order
-   * to speed up processing. Set between 1 and 1024, This applies to
+   * to speed up processing. Set between 1 and 1024. This applies to
    * individual reads in the main API. So the reads must be for a
    * large area (i.e. covering many bricks) for the setting to be
-   * of any use. Set to $OPENZGY_NUMTHREADS if not found, and 1
+   * of any use. Set to $OPENZGY_NUMTHREADS_IO if not set here, and 1
    * (i.e. no threading) if the environment setting is also missing.
    *
    * Whether it is useful to set the variable depends on the
@@ -330,12 +331,37 @@ public:
    * multi threading, issuing multiple read requests to the high level
    * API in parallel. In that case it might not be useful to also
    * parallelize individual requests.
+   * It might even be a very bad idea if the total number of pending
+   * requests hits some service- or network limit.
+   *
+   * If the application normally asks for small regions or moderately
+   * sized regions that are contiguous on the file then this setting
+   * has no effect. Contrariwise, requesting an entire horizontal
+   * slice can use a lot of threads if it is allowed to. And if the
+   * application is single threaded it really should allow this.
+   */
+  SeismicStoreIOContext& iothreads(int value)
+  {
+    if (value < 1 || value > 1024)
+      throw OpenZGY::Errors::ZgyUserError("iothreads must be between 1 and 1024");
+    this->_iothreads = value;
+    return *this;
+  }
+
+  /**
+   * Use up to this many parallel requests for cpu-intensive
+   * operations such as decompression. Set between 1 and 1024.
+   * Set to $OPENZGY_NUMTHREADS_CPU if not set here, and 1
+   * (i.e. no threading) if the environment setting is also missing.
+   *
+   * As with iothreads it might not be much use for Petrel but
+   * it is worth trying. There is less risk of hitting hard limits.
    */
-  SeismicStoreIOContext& threads(int value)
+  SeismicStoreIOContext& cputhreads(int value)
   {
     if (value < 1 || value > 1024)
-      throw OpenZGY::Errors::ZgyUserError("threads must be between 1 and 1024");
-    this->_threads = value;
+      throw OpenZGY::Errors::ZgyUserError("cputhreads must be between 1 and 1024");
+    this->_cputhreads = value;
     return *this;
   }
 

native/src/test/test_iocontext.cpp

@@ -68,7 +68,8 @@ void Test::TestIOContext::test_defaults()
   TEST_CHECK(ctx._aligned ==    0 * 1024*1024);
   TEST_CHECK(ctx._segsize ==  256 * 1024*1024 * ctx._segsplit);
   TEST_CHECK(ctx._segsplit == 8);
-  TEST_CHECK(ctx._threads == 1);
+  TEST_CHECK(ctx._iothreads == 1);
+  TEST_CHECK(ctx._cputhreads == 1);
   TEST_CHECK(ctx._legaltag == "");
   TEST_CHECK(ctx._writeid == "");
   TEST_CHECK(ctx._seismicmeta == "");
@@ -85,7 +86,8 @@ void Test::TestIOContext::test_setters()
     .aligned(1)
     .segsize(15)
     .segsplit(3)
-    .threads(8)
+    .iothreads(8)
+    .cputhreads(5)
     .legaltag("illegal")
     .writeid("WID")
     .seismicmeta("{\"foo\": 42}");
@@ -99,7 +101,8 @@ void Test::TestIOContext::test_setters()
   TEST_CHECK(ctx._aligned ==    1 * 1024*1024);
   TEST_CHECK(ctx._segsize ==   15 * 1024*1024 * ctx._segsplit);
   TEST_CHECK(ctx._segsplit ==  3);
-  TEST_CHECK(ctx._threads == 8);
+  TEST_CHECK(ctx._iothreads == 8);
+  TEST_CHECK(ctx._cputhreads== 5);
   TEST_CHECK(ctx._legaltag == "illegal");
   TEST_CHECK(ctx._writeid == "WID");
   TEST_CHECK(ctx._seismicmeta == "{\"foo\": 42}");
@@ -115,7 +118,8 @@ void Test::TestIOContext::test_errors()
   must_throw("must be between", [&](){ctx.aligned(2000);});
   must_throw("must be between", [&](){ctx.segsize(200000);});
   must_throw("must be between", [&](){ctx.segsplit(0);});
-  must_throw("must be between", [&](){ctx.threads(0);});
+  must_throw("must be between", [&](){ctx.iothreads(0);});
+  must_throw("must be between", [&](){ctx.cputhreads(0);});
 }
 
 namespace {

wrapper/openzgycppmodule.cpp

@@ -516,8 +516,10 @@ ZgyCommon_getIOContext(ZgyClass *self, const char *filename, PyObject* obj)
       result->segsize((int)ivalue);
     if ((ivalue = getLongValuedAttr(obj, "segsplit", -1)) != -1)
       result->segsplit((int)ivalue);
-    if ((ivalue = getLongValuedAttr(obj, "threads", -1)) != -1)
-      result->threads((int)ivalue);
+    if ((ivalue = getLongValuedAttr(obj, "iothreads", -1)) != -1)
+      result->iothreads((int)ivalue);
+    if ((ivalue = getLongValuedAttr(obj, "cputhreads", -1)) != -1)
+      result->cputhreads((int)ivalue);
     if (!(value = getStringValuedAttr(obj, "legaltag")).empty())
       result->legaltag(value);
     if (!(value = getStringValuedAttr(obj, "writeid")).empty())
@@ -2086,7 +2088,7 @@ static PyMethodDef ZgyUtils_methods[] = {
 static PyGetSetDef ZgyCommon_getseters[] = {
   {const_cast<char*>("numthreads"),
      (getter)ZgyReader_getnumthreads, (setter)ZgyReader_setnumthreads,
-     const_cast<char*>("How many threads to use when reading. Currently ignored when writing."),
+     const_cast<char*>("How many threads to use when reading. Currently ignored. Use iocontext instead."),
      NULL},
   {const_cast<char*>("verbose"),
      (getter)ZgyReader_getverbose, (setter)ZgyReader_setverbose,
@@ -2205,7 +2207,7 @@ static PyGetSetDef ZgyCommon_getseters[] = {
 static PyGetSetDef ZgyUtils_getseters[] = {
   {const_cast<char*>("numthreads"),
      (getter)ZgyReader_getnumthreads, (setter)ZgyReader_setnumthreads,
-     const_cast<char*>("How many threads to use. Currently ignored."),
+     const_cast<char*>("How many threads to use. Currently ignored. Use iocontext instead."),
      NULL},
   {const_cast<char*>("verbose"),
      (getter)ZgyReader_getverbose, (setter)ZgyReader_setverbose,