Support around JSON-RPC (#2014)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Use 'Process' to communicate with an command line tool.

* Remove slang-win-stream

* Tidy up windows ProcessUtil.

* First version of BufferedReadStream.

* Windows working IPC for steams.

* Test proxy count option.

* Split Process/ProcessUtil. Process is platform dependant. ProcessUtil are functions that are platform independent.

* First implementation of Unix Process interface.

* Unix process compiles on cygwin.

* Fix typo in unix process.

* Separate unix pipe stream error of invalid access, from pipe availability.

* Fix in standard line extraction.

* Make fd non blocking.

* Fix issues with Windows Process streams.

* Added UnixPipe.

* Some fixes around UnixPipeStream.

* Make a unix stream closed explicit.

* Hack to debug linux process/stream.

* Revert to old linux pipe handling.

* Pass executable path for unit tests.
Split out CommandLine into own source.

* Small improvements in process/command line.

* Check process behavior with crash.

* Make stderr and stdout unbuffered for crash testing.

* Only turn disable buffering in crash test.

* Disable crash test on CI.

* Fix crash on clang/linux.

* Enable crash test.
Remove _appendBuffer as can use StreamUtil functionality.

* Added inital processing for http headers.

* Small improvements to HttpHeader.

* First pass HTTPPacketConnection working on windows.

* Enable other Process communication tests.

* Update comments.

* WIP JSON RPC.

* Add terminate to Process.
Made JSONRPC a Util.

* Small tidy up around HTTPPacketConnection.

* Improve process termination options.

Co-authored-by: Yong He <yonghe@outlook.com>

5 files changed, 125 insertions, 25 deletions

diff --git a/source/core/slang-http.cpp b/source/core/slang-http.cpp
index ea76d82a9..43be26c1c 100644
--- a/source/core/slang-http.cpp
+++ b/source/core/slang-http.cpp
@@ -287,7 +287,7 @@ SlangResult HTTPPacketConnection::update()
     return m_readResult;
 }
 
-SlangResult HTTPPacketConnection::waitForContent()
+SlangResult HTTPPacketConnection::waitForResult()
 {
     while (m_readState == ReadState::Header ||
         m_readState == ReadState::Content)
diff --git a/source/core/slang-http.h b/source/core/slang-http.h
index a7c6f6628..a298e9e27 100644
--- a/source/core/slang-http.h
+++ b/source/core/slang-http.h
@@ -123,8 +123,8 @@ public:
         /// Write. Will potentially block if write stream is blocking.
     SlangResult write(const void* content, size_t sizeInBytes);
 
-        /// Blocks until full read packet is available or the stream is appropriately closed
-    SlangResult waitForContent();
+        /// Blocks until some result - a packet, closure, or some kind of error
+    SlangResult waitForResult();
         /// Consume the content - so can read next content
     void consumeContent();
 
diff --git a/source/core/slang-process.h b/source/core/slang-process.h
index ddbe7cbf0..7cd7596ae 100644
--- a/source/core/slang-process.h
+++ b/source/core/slang-process.h
@@ -35,13 +35,27 @@ public:
 
         /// Get the stream for the type
     Stream* getStream(StreamType type) const { return m_streams[Index(type)]; }
+
+        /// Get the value returned from the process when it exited/returned. 
     int32_t getReturnValue() const { return m_returnValue;  }
 
         /// True if the process has terminated
     virtual bool isTerminated() = 0;
-        /// Blocks until the process has completed
-    virtual void waitForTermination() = 0;
 
+        /// Blocks until the process has terminated or the timeout completes
+        /// Can optionally supply a timeout time. -1 means 'infinite' and is the default.
+        /// Note that the timeOut is only used approximately. 
+        /// Returns true if has terminated.
+    virtual bool waitForTermination(Int timeOutInMs = -1) = 0;
+
+        /// Terminate the process gracefully.
+        /// After calling it may take time before the process actually terminates
+        /// Ie calling isTerminated directly after `terminate` may return false.
+        /// The return code depending on implementation/termination style, may not be set.
+    virtual void terminate(int32_t returnCode) = 0;
+
+        /// Kill the process - attempt to terminate immediately. 
+    virtual void kill(int32_t returnCode) = 0;
 
         /// The quoting style used for the command line on this target. Currently just uses Space,
         /// but in future may take into account platform sec
@@ -54,13 +68,15 @@ public:
     static SlangResult create(const CommandLine& commandLine, Process::Flags flags, RefPtr<Process>& outProcess);
 
         /// Sleep the current thread for time specified in milliseconds. 0 indicates to OS ok to yield this thread.
-    static void sleepCurrentThread(Index timeInMs);
+    static void sleepCurrentThread(Int timeInMs);
 
         /// Get a standard stream 
     static SlangResult getStdStream(StreamType type, RefPtr<Stream>& out);
 
+        /// Get the clock frequency
     static uint64_t getClockFrequency();
 
+        /// Get the clock tick.
     static uint64_t getClockTick();
 
 protected:
diff --git a/source/core/unix/slang-unix-process.cpp b/source/core/unix/slang-unix-process.cpp
index 083160f02..5131e37ec 100644
--- a/source/core/unix/slang-unix-process.cpp
+++ b/source/core/unix/slang-unix-process.cpp
@@ -28,7 +28,9 @@ class UnixProcess : public Process
 public:
     // Process 
     virtual bool isTerminated() SLANG_OVERRIDE;
-    virtual void waitForTermination() SLANG_OVERRIDE;
+    virtual bool waitForTermination(Int timeInMs) SLANG_OVERRIDE;
+    virtual void terminate(int32_t returnValue) SLANG_OVERRIDE;
+    virtual void kill(int32_t returnValue) SLANG_OVERRIDE;
 
     UnixProcess(pid_t pid, Stream*const* streams);
 
@@ -133,9 +135,64 @@ bool UnixProcess::isTerminated()
     return _updateTerminationState(WNOHANG);
 }
 
-void UnixProcess::waitForTermination()
+bool UnixProcess::waitForTermination(Int timeInMs)
 {
-    while (!_updateTerminationState(0));
+    // If < 0 we will wait blocking until terminated
+    if (timeInMs < 0)
+    {
+        while (!_updateTerminationState(0));
+        return true;
+    }
+
+    // Note that the amount of time waiting is very approximate (we are relying on sleeps time and don't take into
+    // account time outside of sleeping)
+
+    // How often to test
+    const Int checkRateMs = 100;            /// Check every 0.1 seconds
+
+    while (timeInMs > 0)
+    {
+        if (_updateTerminationState(WNOHANG))
+        {
+            return true;
+        }
+
+        // Work out how long to sleep for
+        const Int sleepMs = (timeInMs >= checkRateMs) ? checkRateMs : timeInMs;
+
+        // Sleep
+        sleepCurrentThread(sleepMs);
+
+        timeInMs -= sleepMs;
+    }
+
+    return _updateTerminationState(WNOHANG);
+}
+
+void UnixProcess::terminate(int32_t returnValue)
+{
+    // Using this mechanism, we can't set a returnValue so just ignore
+    SLANG_UNUSED(returnValue);
+
+    if (!isTerminated())
+    {
+        // Request the process terminates
+        ::kill(m_pid, SIGTERM);
+    }
+}
+
+void UnixProcess::kill(int32_t returnValue)
+{
+    if (!isTerminated())
+    {
+        // We waited, lets just terminate with kill
+        ::kill(m_pid, SIGKILL);
+
+        // Set the return value
+        m_returnValue = returnValue;
+        // Mark as terminated
+        m_isTerminated = true;
+    }
 }
 
 /* !!!!!!!!!!!!!!!!!!!!!! UnixPipeStream !!!!!!!!!!!!!!!!!!!!!!!!!!!! */
@@ -386,15 +443,20 @@ SlangResult UnixPipeStream::write(const void* buffer, size_t length)
     return uint64_t(now.tv_sec) * 1000000000 + now.tv_nsec;
 }
 
-/* static */void Process::sleepCurrentThread(Index timeInMs)
+/* static */void Process::sleepCurrentThread(Int timeInMs)
 {
     struct timespec timeSpec;
 
-    if (timeInMs > 0)
+    if (timeInMs >= 1000)
     {
         timeSpec.tv_sec = timeInMs / 1000;
         timeSpec.tv_nsec = (timeInMs % 1000) * 1000 * 1000;
     }
+    else if (timeInMs > 0)
+    {
+        timeSpec.tv_sec = 0;
+        timeSpec.tv_nsec = timeInMs * 1000 * 1000;
+    }
     else
     {
         timeSpec.tv_sec = 0;
diff --git a/source/core/windows/slang-win-process.cpp b/source/core/windows/slang-win-process.cpp
index c37936a30..ed06f5692 100644
--- a/source/core/windows/slang-win-process.cpp
+++ b/source/core/windows/slang-win-process.cpp
@@ -111,8 +111,11 @@ class WinProcess : public Process
 {
 public:
 
+    // Process
     virtual bool isTerminated() SLANG_OVERRIDE;
-    virtual void waitForTermination() SLANG_OVERRIDE;
+    virtual bool waitForTermination(Int timeInMs) SLANG_OVERRIDE;
+    virtual void terminate(int32_t returnCode) SLANG_OVERRIDE;
+    virtual void kill(int32_t returnCode) SLANG_OVERRIDE;
 
     WinProcess(HANDLE handle, Stream* const* streams) :
         m_processHandle(handle)
@@ -300,7 +303,7 @@ void WinProcess::_hasTerminated()
         // https://docs.microsoft.com/en-us/windows/desktop/api/processthreadsapi/nf-processthreadsapi-getexitcodeprocess
 
         DWORD childExitCode = 0;
-        if (GetExitCodeProcess(m_processHandle, &childExitCode))
+        if (::GetExitCodeProcess(m_processHandle, &childExitCode))
         {
             m_returnValue = int32_t(childExitCode);
         }
@@ -308,35 +311,54 @@ void WinProcess::_hasTerminated()
     }
 }
 
-void WinProcess::waitForTermination()
+bool WinProcess::waitForTermination(Int timeInMs)
 {
     if (m_processHandle.isNull())
     {
-        return;
+        return true;
     }
 
+    const DWORD timeOutTime = (timeInMs < 0) ? INFINITE : DWORD(timeInMs);
+
     // wait for the process to exit
     // TODO: set a timeout as a safety measure...
-    WaitForSingleObject(m_processHandle, INFINITE);
+    auto res = ::WaitForSingleObject(m_processHandle, timeOutTime);
+
+    if (res == WAIT_TIMEOUT)
+    {
+        return false;
+    }
 
     _hasTerminated();
+    return true;
 }
 
 bool WinProcess::isTerminated()
 {
-    if (m_processHandle.isNull())
+    return waitForTermination(0);
+}
+
+void WinProcess::terminate(int32_t returnCode)
+{
+    if (!isTerminated())
     {
-        return true;
+        // If it's not terminated, try terminating.
+        // Might take time, so use isTerminated to check
+        ::TerminateProcess(m_processHandle, UINT32(returnCode));
     }
+}
 
-    auto res = WaitForSingleObject(m_processHandle, 0);
-
-    if (res == WAIT_TIMEOUT)
+void WinProcess::kill(int32_t returnCode)
+{
+    if (!isTerminated())
     {
-        return false;
+        // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-terminateprocess
+        ::TerminateProcess(m_processHandle, UINT32(returnCode));
+
+        // Just assume it's done and set the return code
+        m_returnValue = returnCode;
+        m_processHandle.setNull();
     }
-    _hasTerminated();
-    return true;
 }
 
 /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
@@ -505,7 +527,7 @@ bool WinProcess::isTerminated()
     return SLANG_OK;
 }
 
-/* static */void Process::sleepCurrentThread(Index timeInMs)
+/* static */void Process::sleepCurrentThread(Int timeInMs)
 {
     ::Sleep(DWORD(timeInMs));
 }