Replace std::string_view usage with std::string (#115)

A `std::string_view` doesn't guarantee null-terminated strings and thus cannot be safely used with UCX and UCXX loggers. Replace `std::string_view` with `std::string` to guarantee safe conversion.

Authors:
  - Peter Andreas Entschev (https://github.com/pentschev)

Approvers:
  - Mads R. B. Kristensen (https://github.com/madsbk)

URL: #115

cpp/include/ucxx/delayed_submission.h

@@ -7,7 +7,7 @@
 #include <functional>
 #include <memory>
 #include <mutex>
-#include <string_view>
+#include <string>
 #include <utility>
 #include <vector>
 
@@ -60,8 +60,7 @@ class DelayedSubmission {
 template <typename T>
 class BaseDelayedSubmissionCollection {
  protected:
-  std::string_view _name{
-    "undefined"};       ///< The human-readable name of the collection, used for logging
+  std::string _name{"undefined"};  ///< The human-readable name of the collection, used for logging
   bool _enabled{true};  ///< Whether the resource required to process the collection is enabled.
   std::vector<T> _collection{};  ///< The collection.
   std::mutex _mutex{};           ///< Mutex to provide access to `_collection`.
@@ -96,7 +95,7 @@ class BaseDelayedSubmissionCollection {
    *
    * @param[in] name  human-readable name of the collection, used for logging.
    */
-  explicit BaseDelayedSubmissionCollection(const std::string_view name, const bool enabled)
+  explicit BaseDelayedSubmissionCollection(const std::string name, const bool enabled)
     : _name{name}, _enabled{enabled}
   {
   }
@@ -150,7 +149,7 @@ class BaseDelayedSubmissionCollection {
     }
 
     if (itemsToProcess.size() > 0) {
-      ucxx_trace_req("Submitting %lu %s callbacks", itemsToProcess.size(), _name);
+      ucxx_trace_req("Submitting %lu %s callbacks", itemsToProcess.size(), _name.c_str());
       for (auto& item : itemsToProcess)
         processItem(item);
     }
@@ -168,7 +167,7 @@ class RequestDelayedSubmissionCollection
     std::pair<std::shared_ptr<Request>, DelayedSubmissionCallbackType> item) override;
 
  public:
-  explicit RequestDelayedSubmissionCollection(const std::string_view name, const bool enabled);
+  explicit RequestDelayedSubmissionCollection(const std::string name, const bool enabled);
 };
 
 class GenericDelayedSubmissionCollection
@@ -179,7 +178,7 @@ class GenericDelayedSubmissionCollection
   void processItem(DelayedSubmissionCallbackType callback) override;
 
  public:
-  explicit GenericDelayedSubmissionCollection(const std::string_view name);
+  explicit GenericDelayedSubmissionCollection(const std::string name);
 };
 
 class DelayedSubmissionCollection {

cpp/src/delayed_submission.cpp

@@ -22,7 +22,7 @@ DelayedSubmission::DelayedSubmission(const bool send,
 {
 }
 
-RequestDelayedSubmissionCollection::RequestDelayedSubmissionCollection(const std::string_view name,
+RequestDelayedSubmissionCollection::RequestDelayedSubmissionCollection(const std::string name,
                                                                        const bool enabled)
   : BaseDelayedSubmissionCollection<
       std::pair<std::shared_ptr<Request>, DelayedSubmissionCallbackType>>{name, enabled}
@@ -32,7 +32,7 @@ RequestDelayedSubmissionCollection::RequestDelayedSubmissionCollection(const std
 void RequestDelayedSubmissionCollection::scheduleLog(
   std::pair<std::shared_ptr<Request>, DelayedSubmissionCallbackType> item)
 {
-  ucxx_trace_req("Registered %s: %p", _name, item.first.get());
+  ucxx_trace_req("Registered %s: %p", _name.c_str(), item.first.get());
 }
 
 void RequestDelayedSubmissionCollection::processItem(
@@ -41,24 +41,24 @@ void RequestDelayedSubmissionCollection::processItem(
   auto& req      = item.first;
   auto& callback = item.second;
 
-  ucxx_trace_req("Submitting %s callbacks: %p", _name, req.get());
+  ucxx_trace_req("Submitting %s callbacks: %p", _name.c_str(), req.get());
 
   if (callback) callback();
 }
 
-GenericDelayedSubmissionCollection::GenericDelayedSubmissionCollection(const std::string_view name)
+GenericDelayedSubmissionCollection::GenericDelayedSubmissionCollection(const std::string name)
   : BaseDelayedSubmissionCollection<DelayedSubmissionCallbackType>{name, true}
 {
 }
 
 void GenericDelayedSubmissionCollection::scheduleLog(DelayedSubmissionCallbackType item)
 {
-  ucxx_trace_req("Registered %s", _name);
+  ucxx_trace_req("Registered %s", _name.c_str());
 }
 
 void GenericDelayedSubmissionCollection::processItem(DelayedSubmissionCallbackType callback)
 {
-  ucxx_trace_req("Submitting %s callback", _name);
+  ucxx_trace_req("Submitting %s callback", _name.c_str());
 
   if (callback) callback();
 }

cpp/src/utils/callback_notifier.cpp

@@ -18,7 +18,7 @@ namespace utils {
 
 #ifdef __GLIBC__
 static const bool _useSpinlock = []() {
-  auto const libcVersion = std::string_view{gnu_get_libc_version()};
+  auto const libcVersion = std::string{gnu_get_libc_version()};
   auto const dot         = libcVersion.find(".");
   if (dot == std::string::npos) {
     return false;
@@ -27,7 +27,7 @@ static const bool _useSpinlock = []() {
     auto const glibcMajor = std::stoi(libcVersion.substr(0, dot).data());
     auto const glibcMinor = std::stoi(libcVersion.substr(dot + 1).data());
     auto const use        = glibcMajor < 2 || (glibcMajor == 2 && glibcMinor < 25);
-    ucxx_debug("glibc version %s detected, spinlock use is %d", libcVersion.data(), use);
+    ucxx_debug("glibc version %s detected, spinlock use is %d", libcVersion.c_str(), use);
     return use;
   }
 }();