⚗️ Experiment with multi-processing by burgholzer · Pull Request #818 · munich-quantum-toolkit/qcec

burgholzer · 2026-01-09T23:31:07Z

Description

This is a draft to play around with multi-procesing over multi-threading.

If this were merged, it would solve #815

Checklist:

The pull request only contains commits that are focused and relevant to this change.
I have added appropriate tests that cover the new/changed functionality.
I have updated the documentation to reflect these changes.
I have added entries to the changelog for any noteworthy additions, changes, fixes, or removals.
I have added migration instructions to the upgrade guide (if needed).
The changes follow the project's style guidelines and introduce no new warnings.
The changes are fully tested and pass the CI checks.
I have reviewed my own code changes.

Signed-off-by: burgholzer <burgholzer@me.com>

github-actions · 2026-01-09T23:35:04Z

Cpp-Linter Report ⚠️

Some files did not pass the configured checks!

clang-tidy (v20.1.8) reports: 47 concern(s)

src/EquivalenceCheckingManager.cpp:35:1: warning: [misc-include-cleaner]

included header mutex is not used directly
```
   35 | #include <mutex>
      | ^~~~~~~~~~~~~~~~
   36 | #include <nlohmann/json.hpp>
```
src/EquivalenceCheckingManager.cpp:335:15: warning: [misc-include-cleaner]

no header providing "nlohmann::json" is directly included
```
   37 |     nlohmann::json j;
      |               ^
```
src/EquivalenceCheckingManager.cpp:430:50: warning: [readability-convert-member-functions-to-static]

method 'executeWithOptionalTimeout' can be made static
```
  430 | EquivalenceCriterion EquivalenceCheckingManager::executeWithOptionalTimeout(
      |                                                  ^
```
src/EquivalenceCheckingManager.cpp:512:14: warning: [performance-enum-size]

enum 'ProcessType' uses a larger base type ('int', size: 4 bytes) than necessary for its value set, consider using 'std::uint8_t' (1 byte) as the base type to reduce its size
```
  512 |   enum class ProcessType { Alternating, Construction, ZX, Simulation };
      |              ^
```

src/EquivalenceCheckingManager.cpp:557:7: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  557 |       done = true;
      |       ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:557:7: note: Value stored to 'done' is never read
  557 |       done = true;
      |       ^      ~~~~

src/EquivalenceCheckingManager.cpp:599:11: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  599 |           done = true;
      |           ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:599:11: note: Value stored to 'done' is never read
  599 |           done = true;
      |           ^      ~~~~

src/EquivalenceCheckingManager.cpp:607:7: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  607 |       done = true;
      |       ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:607:7: note: Value stored to 'done' is never read
  607 |       done = true;
      |       ^      ~~~~

src/EquivalenceCheckingManager.cpp:622:7: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  622 |       done = true;
      |       ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:622:7: note: Value stored to 'done' is never read
  622 |       done = true;
      |       ^      ~~~~

src/EquivalenceCheckingManager.cpp:630:7: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  630 |       done = true;
      |       ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:630:7: note: Value stored to 'done' is never read
  630 |       done = true;
      |       ^      ~~~~

src/EquivalenceCheckingManager.cpp:639:9: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  639 |         done = true;
      |         ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:639:9: note: Value stored to 'done' is never read
  639 |         done = true;
      |         ^      ~~~~

src/EquivalenceCheckingManager.cpp:651:13: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  651 |             done = true;
      |             ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:651:13: note: Value stored to 'done' is never read
  651 |             done = true;
      |             ^      ~~~~

src/EquivalenceCheckingManager.cpp:661:13: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  661 |             done = true;
      |             ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:661:13: note: Value stored to 'done' is never read
  661 |             done = true;
      |             ^      ~~~~

src/EquivalenceCheckingManager.cpp:679:11: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  679 |           done = true;
      |           ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:679:11: note: Value stored to 'done' is never read
  679 |           done = true;
      |           ^      ~~~~

src/EquivalenceCheckingManager.cpp:690:11: warning: [clang-analyzer-deadcode.DeadStores]

Value stored to 'done' is never read

  690 |           done = true;
      |           ^      ~~~~
/home/runner/work/qcec/qcec/src/EquivalenceCheckingManager.cpp:690:11: note: Value stored to 'done' is never read
  690 |           done = true;
      |           ^      ~~~~

src/EquivalenceCheckingManager.cpp:808:9: warning: [readability-else-after-return]

do not use 'else' after 'return'

  808 |       } else if (result == EquivalenceCriterion::ProbablyNotEquivalent) {
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  809 |         if (localEquivalence == EquivalenceCriterion::ProbablyEquivalent) {
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  810 |           return EquivalenceCriterion::NoInformation;
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  811 |         }
      |         ~
  812 |         return result;
      |         ~~~~~~~~~~~~~~
  813 |       } else if (result == EquivalenceCriterion::NoInformation &&
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  814 |                  configuration.onlyZXCheckerConfigured()) {
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  815 |         return EquivalenceCriterion::NoInformation;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  816 |       }
      |       ~

src/ProcessManager.cpp:13:1: warning: [misc-include-cleaner]

included header algorithm is not used directly
```
   13 | #include <algorithm>
      | ^~~~~~~~~~~~~~~~~~~~
   14 | #include <iostream>
```
src/ProcessManager.cpp:38:23: warning: [misc-include-cleaner]

no header providing "std::invalid_argument" is directly included
```
   15 |   } catch (const std::invalid_argument&) {
      |                       ^
```
src/ProcessManager.cpp:40:23: warning: [misc-include-cleaner]

no header providing "std::runtime_error" is directly included
```
   40 |   } catch (const std::runtime_error&) {
      |                       ^
```
src/ProcessManager.cpp:42:23: warning: [misc-include-cleaner]

no header providing "std::logic_error" is directly included
```
   42 |   } catch (const std::logic_error&) {
      |                       ^
```

src/ProcessManager.cpp:58:39: warning: [misc-include-cleaner]

no header providing "std::function" is directly included

   14 |                            const std::function<EquivalenceCriterion()>& task) {
      |                                       ^

src/ProcessManager.cpp:58:48: warning: [misc-include-cleaner]

no header providing "ec::EquivalenceCriterion" is directly included

   12 |                            const std::function<EquivalenceCriterion()>& task) {
      |                                                ^

src/ProcessManager.cpp:59:3: warning: [cppcoreguidelines-avoid-c-arrays]

do not declare C-style arrays, use 'std::array' instead
```
   59 |   int pipeFds[2];
      |   ^
```
src/ProcessManager.cpp:60:12: warning: [cppcoreguidelines-pro-bounds-array-to-pointer-decay]

do not implicitly decay an array into a pointer; consider using gsl::array_view or an explicit cast instead
```
   60 |   if (pipe(pipeFds) == -1) {
      |            ^
```

src/ProcessManager.cpp:61:61: warning: [misc-include-cleaner]

no header providing "errno" is directly included

   14 |     std::cerr << "Failed to create pipe: " << std::strerror(errno) << '\n';
      |                                                             ^

src/ProcessManager.cpp:65:9: warning: [misc-include-cleaner]

no header providing "pid_t" is directly included
```
   15 |   const pid_t pid = fork();
      |         ^
```
src/ProcessManager.cpp:101:6: warning: [misc-include-cleaner]

no header providing "std::optional" is directly included
```
   15 | std::optional<ProcessResult>
      |      ^
```

src/ProcessManager.cpp:102:41: warning: [misc-include-cleaner]

no header providing "std::chrono::duration" is directly included

   14 | ProcessManager::waitForAny(std::chrono::duration<double> timeout) {
      |                                         ^

src/ProcessManager.cpp:104:17: warning: [misc-include-cleaner]

no header providing "std::nullopt" is directly included
```
  104 |     return std::nullopt;
      |                 ^
```
src/ProcessManager.cpp:108:8: warning: [misc-include-cleaner]

no header providing "std::vector" is directly included
```
   15 |   std::vector<pollfd> fds;
      |        ^
```
src/ProcessManager.cpp:108:15: warning: [misc-include-cleaner]

no header providing "pollfd" is directly included
```
   15 |   std::vector<pollfd> fds;
      |               ^
```
src/ProcessManager.cpp:111:33: warning: [misc-include-cleaner]

no header providing "POLLIN" is directly included
```
  111 |     fds.push_back({proc.pipeFd, POLLIN, 0});
      |                                 ^
```

src/ProcessManager.cpp:120:26: warning: [misc-include-cleaner]

no header providing "poll" is directly included

  120 |   const int pollResult = poll(fds.data(), fds.size(), timeoutMs);
      |                          ^

src/ProcessManager.cpp:145:7: warning: [cppcoreguidelines-pro-type-member-init]

uninitialized record type: 'procResult'

  145 |       ProcessResult procResult;
      |       ^                       
      |                               {}

src/ProcessManager.cpp:166:28: warning: [misc-include-cleaner]

no header providing "POLLERR" is directly included

  166 |     if ((fds[i].revents & (POLLERR | POLLHUP | POLLNVAL)) != 0) {
      |                            ^

src/ProcessManager.cpp:166:38: warning: [misc-include-cleaner]

no header providing "POLLHUP" is directly included

  166 |     if ((fds[i].revents & (POLLERR | POLLHUP | POLLNVAL)) != 0) {
      |                                      ^

src/ProcessManager.cpp:166:48: warning: [misc-include-cleaner]

no header providing "POLLNVAL" is directly included

  166 |     if ((fds[i].revents & (POLLERR | POLLHUP | POLLNVAL)) != 0) {
      |                                                ^

src/ProcessManager.cpp:173:7: warning: [cppcoreguidelines-pro-type-member-init]

uninitialized record type: 'procResult'

  173 |       ProcessResult procResult;
      |       ^                       
      |                               {}

src/ProcessManager.cpp:200:22: warning: [readability-convert-member-functions-to-static]

method 'killProcess' can be made static
```
  200 | void ProcessManager::killProcess(pid_t pid) {
      |                      ^
```
src/ProcessManager.cpp:202:3: warning: [misc-include-cleaner]

no header providing "kill" is directly included
```
   15 |   kill(pid, SIGTERM);
      |   ^
```

src/ProcessManager.cpp:206:46: warning: [misc-include-cleaner]

no header providing "WNOHANG" is directly included

   15 |   const pid_t result = waitpid(pid, &status, WNOHANG);
      |                                              ^

src/ProcessManager.cpp:210:15: warning: [misc-include-cleaner]

no header providing "SIGKILL" is directly included
```
  210 |     kill(pid, SIGKILL);
      |               ^
```
src/ProcessManager.cpp:216:17: warning: [readability-convert-member-functions-to-static]

method 'readResult' can be made static
```
  216 | ProcessManager::readResult(int fd, ExceptionType& exceptionType) {
      |                 ^
```

src/ProcessManager.cpp:217:3: warning: [cppcoreguidelines-pro-type-member-init]

uninitialized record type: 'data'

  217 |   struct {
      |   ^
  218 |     int equivalence;
  219 |     int exception;
  220 |   } data;
      |         
      |         {}

src/ProcessManager.cpp:222:9: warning: [misc-include-cleaner]

no header providing "ssize_t" is directly included
```
   15 |   const ssize_t bytesRead = read(fd, &data, sizeof(data));
      |         ^
```
src/ProcessManager.cpp:233:22: warning: [readability-convert-member-functions-to-static]

method 'writeResult' can be made static
```
  233 | bool ProcessManager::writeResult(int fd, EquivalenceCriterion result,
      |                      ^
```

src/ProcessManager.cpp:235:3: warning: [cppcoreguidelines-pro-type-member-init]

uninitialized record type: 'data'

  235 |   struct {
      |   ^
  236 |     int equivalence;
  237 |     int exception;
  238 |   } data;
      |         
      |         {}

src/ProcessManager.cpp:417:58: warning: [misc-include-cleaner]

no header providing "std::ptrdiff_t" is directly included

   14 |     processes.erase(processes.begin() + static_cast<std::ptrdiff_t>(idx));
      |                                                          ^

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codecov · 2026-01-09T23:36:19Z

Codecov Report

❌ Patch coverage is 74.65753% with 74 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/ProcessManager.cpp	55.0%	49 Missing ⚠️
src/EquivalenceCheckingManager.cpp	86.0%	22 Missing ⚠️
include/EquivalenceCheckingManager.hpp	57.1%	3 Missing ⚠️

📢 Thoughts on this report? Let us know!

⚗️ Experiment with multi-processing

8fcaf75

Signed-off-by: burgholzer <burgholzer@me.com>

burgholzer self-assigned this Jan 9, 2026

burgholzer added feature New feature or request c++ Anything related to C++ code labels Jan 9, 2026

github-project-automation bot added this to MQT Verification Jan 9, 2026

github-project-automation bot moved this to In Progress in MQT Verification Jan 9, 2026

burgholzer linked an issue Jan 12, 2026 that may be closed by this pull request

🐛 Endless execution of MQT QCEC's verify method #815

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⚗️ Experiment with multi-processing#818

⚗️ Experiment with multi-processing#818
burgholzer wants to merge 1 commit intomainfrom
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burgholzer commented Jan 9, 2026 •

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Description

Checklist:

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Cpp-Linter Report ⚠️

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burgholzer commented Jan 9, 2026 •

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