Interprocess communication via pipes (#2009)

* #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.

1 files changed, 73 insertions, 0 deletions

diff --git a/source/core/slang-process.h b/source/core/slang-process.h
new file mode 100644
index 000000000..ddbe7cbf0
--- /dev/null
+++ b/source/core/slang-process.h
@@ -0,0 +1,73 @@
+// slang-process.h
+#ifndef SLANG_PROCESS_H
+#define SLANG_PROCESS_H
+
+#include "slang-string.h"
+#include "slang-list.h"
+#include "slang-stream.h"
+#include "slang-io.h"
+
+#include "slang-string-escape-util.h"
+
+#include "slang-command-line.h"
+
+namespace Slang {
+
+class Process : public RefObject
+{
+public:
+    enum class StreamType
+    {
+        ErrorOut,
+        StdOut,
+        StdIn,
+        CountOf,
+    };
+
+    typedef uint32_t Flags;
+    struct Flag
+    {
+        enum Enum : Flags
+        {
+            AttachDebugger = 0x01,
+        };
+    };
+
+        /// Get the stream for the type
+    Stream* getStream(StreamType type) const { return m_streams[Index(type)]; }
+    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;
+
+
+        /// The quoting style used for the command line on this target. Currently just uses Space,
+        /// but in future may take into account platform sec
+    static StringEscapeHandler* getEscapeHandler();
+
+        /// Get the suffix used on this platform
+    static UnownedStringSlice getExecutableSuffix();
+
+        /// Create a process using the executable/args defined from the commandLine
+    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);
+
+        /// Get a standard stream 
+    static SlangResult getStdStream(StreamType type, RefPtr<Stream>& out);
+
+    static uint64_t getClockFrequency();
+
+    static uint64_t getClockTick();
+
+protected:
+    int32_t m_returnValue = 0;                              ///< Value returned if process terminated
+    RefPtr<Stream> m_streams[Index(StreamType::CountOf)];   ///< Streams to communicate with the process
+};
+
+}
+
+#endif // SLANG_PROCESS_H