support for linux scheduler and timer

.travis.yml

@@ -19,8 +19,8 @@ addons:
     - llvm-toolchain-trusty
     packages:
     - python2.7
-    - clang-6.0
-    - lld-6.0
+    - clang-7
+    - lld-7
     - ninja-build
 
 cache:
@@ -37,12 +37,12 @@ env:
   - CMAKE_VERSION="3.9.1"
 matrix:
   include:
-  - env: RELEASE=debug ARCH=x64 CLANG_VERSION=6.0
-  - env: RELEASE=optimised ARCH=x64 CLANG_VERSION=6.0
+  - env: RELEASE=debug ARCH=x64 CLANG_VERSION=7
+  - env: RELEASE=optimised ARCH=x64 CLANG_VERSION=7
   allow_failures:
   # Clang 6.0~svn320382 has a bug that causes optimised builds to fail.
   # See https://bugs.llvm.org/show_bug.cgi?id=34897
-  - env: RELEASE=optimised ARCH=x64 CLANG_VERSION=6.0
+  - env: RELEASE=optimised ARCH=x64 CLANG_VERSION=7
 
 before_install:
 - export CC="$CC-$CLANG_VERSION"

README.md

@@ -1854,7 +1854,7 @@ task<> example()
 ```
 
 API Summary:
-```
+```c++
 // <cppcoro/schedule_on.hpp>
 namespace cppcoro
 {

appveyor.yml

@@ -1,9 +1,8 @@
-
 version: 1.0.{build}
 
 image:
 - Visual Studio 2017
-#- Visual Studio 2017 Preview
+- Visual Studio 2017 Preview
 
 platform:
 - x64
@@ -13,6 +12,13 @@ configuration:
 - debug
 - optimised
 
+matrix:
+  # Allow failures under MSVC x86 optimised since there are some known compiler
+  # bugs causing failures here.
+  allow_failures:
+    - platform: x86
+      configuration: optimised
+
 clone_script:
 - ps: git clone -q $("--branch=" + $env:APPVEYOR_REPO_BRANCH) $("https://github.com/" + $env:APPVEYOR_REPO_NAME + ".git") $env:APPVEYOR_BUILD_FOLDER
 - ps: if (!$env:APPVEYOR_PULL_REQUEST_NUMBER) {$("git checkout -qf " + $env:APPVEYOR_REPO_COMMIT)}

config.cake

@@ -117,6 +117,8 @@ if cake.system.isWindows() or cake.system.isCygwin():
       # Enable C++17 features like std::optional<>
       compiler.addCppFlag('/std:c++latest')
 
+      compiler.addDefine('_SILENCE_CXX17_RESULT_OF_DEPRECATION_WARNING')
+
       compiler.addProgramFlag('/nodefaultlib')
       compiler.addModuleFlag('/nodefaultlib')
 
@@ -137,7 +139,7 @@ if cake.system.isWindows() or cake.system.isCygwin():
       compiler.runtimeLibraries = 'debug-dll'
       compiler.addLibrary('msvcrtd')
       compiler.addLibrary('msvcprtd')
-      compiler.addLibrary('msvcurtd')
+      compiler.addLibrary('vcruntimed')
       compiler.addLibrary('ucrtd')
       compiler.addLibrary('oldnames')
 
@@ -159,7 +161,7 @@ if cake.system.isWindows() or cake.system.isCygwin():
       compiler.runtimeLibraries = 'release-dll'
       compiler.addLibrary('msvcrt')
       compiler.addLibrary('msvcprt')
-      compiler.addLibrary('msvcurt')
+      compiler.addLibrary('vcruntime')
       compiler.addLibrary('ucrt')
       compiler.addLibrary('oldnames')
 
@@ -293,6 +295,8 @@ elif cake.system.isLinux() or cake.system.isDarwin():
   compiler.addLibrary('c++')
   compiler.addLibrary('c')
   compiler.addLibrary('pthread')
+  compiler.addLibrary('rt')
+  compiler.addLibrary('uuid')
 
   #compiler.addProgramFlag('-Wl,--trace')
   #compiler.addProgramFlag('-Wl,-v')

include/cppcoro/async_generator.hpp

@@ -117,8 +117,8 @@ namespace cppcoro
 			// State transition diagram
 			//   VNRCA - value_not_ready_consumer_active
 			//   VNRCS - value_not_ready_consumer_suspended
-			//   VRPA  - value_ready_consumer_active
-			//   VRPS  - value_ready_consumer_suspended
+			//   VRPA  - value_ready_producer_active
+			//   VRPS  - value_ready_producer_suspended
 			//
 			//       A         +---  VNRCA --[C]--> VNRCS   yield_value()
 			//       |         |     |  A           |  A       |   .

include/cppcoro/detail/linux.hpp

@@ -0,0 +1,133 @@
+///////////////////////////////////////////////////////////////////////////////
+// Copyright (c) Microsoft
+// Licenced under MIT license. See LICENSE.txt for details.
+///////////////////////////////////////////////////////////////////////////////
+#pragma once
+
+#include <mqueue.h>
+#include <sys/epoll.h>
+#include <sys/timerfd.h>
+#include <sys/eventfd.h>
+#include <fcntl.h>
+#include <uuid/uuid.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <linux/limits.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+#include <utility>
+
+namespace cppcoro
+{
+	namespace detail
+	{
+		namespace linux
+		{
+			using fd_t = int;
+
+			enum message_type
+				{
+					CALLBACK_TYPE,
+					RESUME_TYPE
+				};
+
+			class safe_fd
+			{
+			public:
+
+				safe_fd()
+					: m_fd(-1)
+				{}
+
+				explicit safe_fd(fd_t fd)
+					: m_fd(fd)
+				{}
+
+				safe_fd(const safe_fd& other) = delete;
+
+				safe_fd(safe_fd&& other) noexcept
+					: m_fd(other.m_fd)
+				{
+					other.m_fd = -1;
+				}
+
+				~safe_fd()
+				{
+					close();
+				}
+
+				safe_fd& operator=(safe_fd fd) noexcept
+				{
+					swap(fd);
+					return *this;
+				}
+
+				constexpr fd_t fd() const { return m_fd; }
+
+				/// Calls close() and sets the fd to -1.
+				void close() noexcept;
+
+				void swap(safe_fd& other) noexcept
+				{
+					std::swap(m_fd, other.m_fd);
+				}
+
+				bool operator==(const safe_fd& other) const
+				{
+					return m_fd == other.m_fd;
+				}
+
+				bool operator!=(const safe_fd& other) const
+				{
+					return m_fd != other.m_fd;
+				}
+
+				bool operator==(fd_t fd) const
+				{
+					return m_fd == fd;
+				}
+
+				bool operator!=(fd_t fd) const
+				{
+					return m_fd != fd;
+				}
+
+			private:
+
+				fd_t m_fd;
+
+			};
+
+			struct message
+			{
+				enum message_type m_type;
+				void* m_ptr;
+			};
+
+			struct io_state : linux::message
+			{
+				using callback_type = void(io_state* state);
+				callback_type* m_callback;
+			};
+
+			class message_queue
+			{
+			private:
+				mqd_t m_mqdt;
+				char m_qname[NAME_MAX];
+				safe_fd m_epollfd;
+				struct epoll_event m_ev;
+				message_queue();
+			public:
+				message_queue(size_t queue_length);
+				~message_queue();
+				bool enqueue_message(void* message, message_type type);
+				bool dequeue_message(void*& message, message_type& type, bool wait);
+			};
+
+			safe_fd create_event_fd();
+			safe_fd create_timer_fd();
+			safe_fd create_epoll_fd();
+		}
+	}
+}

include/cppcoro/file_write_operation.hpp

@@ -66,7 +66,7 @@ namespace cppcoro
 
 	private:
 
-		friend class cppcoro::detail::win32_overlapped_operation<file_write_operation>;
+		friend class cppcoro::detail::win32_overlapped_operation_cancellable<file_write_operation_cancellable>;
 
 		bool try_start() noexcept;
 		void cancel() noexcept;

include/cppcoro/io_service.hpp

@@ -13,12 +13,17 @@
 # include <cppcoro/detail/win32.hpp>
 #endif
 
+#if CPPCORO_OS_LINUX
+#include <cppcoro/detail/linux.hpp>
+#endif
+
 #include <optional>
 #include <chrono>
 #include <cstdint>
 #include <atomic>
 #include <utility>
 #include <experimental/coroutine>
+#include <vector>
 
 namespace cppcoro
 {
@@ -42,8 +47,11 @@ namespace cppcoro
 		/// actively processing events.
 		/// Note that the number of active threads may temporarily go
 		/// above this number.
+#if CPPCORO_OS_WINNT
 		io_service(std::uint32_t concurrencyHint);
-
+#elif CPPCORO_OS_LINUX
+		io_service(size_t queue_length);
+#endif
 		~io_service();
 
 		io_service(io_service&& other) = delete;
@@ -147,6 +155,10 @@ namespace cppcoro
 
 		void try_reschedule_overflow_operations() noexcept;
 
+		void queue_overflow_operation_to_head(schedule_operation* operation) noexcept;
+
+		void queue_overflow_operation_to_tail(schedule_operation* operation) noexcept;
+
 		bool try_enter_event_loop() noexcept;
 		void exit_event_loop() noexcept;
 
@@ -169,6 +181,9 @@ namespace cppcoro
 		detail::win32::safe_handle m_iocpHandle;
 #endif
 
+#if CPPCORO_OS_LINUX
+		detail::linux::message_queue* m_mq;
+#endif
 		// Head of a linked-list of schedule operations that are
 		// ready to run but that failed to be queued to the I/O
 		// completion port (eg. due to low memory).

lib/build.cake

@@ -82,21 +82,29 @@ sources = script.cwd([
   'ipv4_endpoint.cpp',
   'ipv6_address.cpp',
   'ipv6_endpoint.cpp',
+  'io_service.cpp',
   ])
 
 extras = script.cwd([
   'build.cake',
   'use.cake',
   ])
 
+if variant.platform == "linux":
+  detailIncludes.extend(cake.path.join(env.expand('${CPPCORO}'), 'include', 'cppcoro', 'detail', [
+    'linux.hpp',
+    ]))
+  sources.extend(script.cwd([
+    'linux.cpp',
+    ]))
+
 if variant.platform == "windows":
   detailIncludes.extend(cake.path.join(env.expand('${CPPCORO}'), 'include', 'cppcoro', 'detail', [
     'win32.hpp',
 	'win32_overlapped_operation.hpp',
     ]))
   sources.extend(script.cwd([
     'win32.cpp',
-    'io_service.cpp',
     'file.cpp',
     'readable_file.cpp',
     'writable_file.cpp',

lib/file.cpp

@@ -10,7 +10,9 @@
 #include <cassert>
 
 #if CPPCORO_OS_WINNT
-# define WIN32_LEAN_AND_MEAN
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
 # include <Windows.h>
 #endif
 

lib/file_read_operation.cpp

@@ -6,7 +6,9 @@
 #include <cppcoro/file_read_operation.hpp>
 
 #if CPPCORO_OS_WINNT
-# define WIN32_LEAN_AND_MEAN
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
 # include <Windows.h>
 
 bool cppcoro::file_read_operation::try_start() noexcept

lib/file_write_operation.cpp

@@ -6,7 +6,9 @@
 #include <cppcoro/file_write_operation.hpp>
 
 #if CPPCORO_OS_WINNT
-# define WIN32_LEAN_AND_MEAN
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
 # include <Windows.h>
 
 bool cppcoro::file_write_operation::try_start() noexcept