[coll] Move the rabit poll helper.

CMakeLists.txt

@@ -346,7 +346,6 @@ if(BUILD_DEPRECATED_CLI)
     PRIVATE
     ${xgboost_SOURCE_DIR}/include
     ${xgboost_SOURCE_DIR}/dmlc-core/include
-    ${xgboost_SOURCE_DIR}/rabit/include
   )
   set_target_properties(runxgboost PROPERTIES OUTPUT_NAME xgboost)
   xgboost_target_properties(runxgboost)

R-package/CMakeLists.txt

@@ -29,15 +29,13 @@ target_compile_definitions(
   -DDMLC_LOG_BEFORE_THROW=0
   -DDMLC_DISABLE_STDIN=1
   -DDMLC_LOG_CUSTOMIZE=1
-  -DRABIT_STRICT_CXX98_
 )
 
 target_include_directories(
   xgboost-r PRIVATE
   ${LIBR_INCLUDE_DIRS}
   ${PROJECT_SOURCE_DIR}/include
   ${PROJECT_SOURCE_DIR}/dmlc-core/include
-  ${PROJECT_SOURCE_DIR}/rabit/include
 )
 
 target_link_libraries(xgboost-r PUBLIC ${LIBR_CORE_LIBRARY})

R-package/src/Makevars.in

@@ -21,7 +21,6 @@ $(foreach v, $(XGB_RFLAGS), $(warning $(v)))
 PKG_CPPFLAGS = \
     -I$(PKGROOT)/include \
     -I$(PKGROOT)/dmlc-core/include \
-    -I$(PKGROOT)/rabit/include \
     -I$(PKGROOT) \
     $(XGB_RFLAGS)
 

R-package/src/Makevars.win

@@ -21,7 +21,6 @@ $(foreach v, $(XGB_RFLAGS), $(warning $(v)))
 PKG_CPPFLAGS = \
     -I$(PKGROOT)/include \
     -I$(PKGROOT)/dmlc-core/include \
-    -I$(PKGROOT)/rabit/include \
     -I$(PKGROOT) \
     $(XGB_RFLAGS)
 

cmake/Utils.cmake

@@ -151,7 +151,6 @@ function(xgboost_set_cuda_flags target)
   target_include_directories(
     ${target} PRIVATE
     ${xgboost_SOURCE_DIR}/gputreeshap
-    ${xgboost_SOURCE_DIR}/rabit/include
     ${CUDAToolkit_INCLUDE_DIRS})
 
   if(MSVC)

demo/c-api/basic/Makefile

@@ -4,7 +4,7 @@ TGT=c-api-demo
 cc=cc
 CFLAGS ?=-O3
 XGBOOST_ROOT ?=../..
-INCLUDE_DIR=-I$(XGBOOST_ROOT)/include -I$(XGBOOST_ROOT)/dmlc-core/include -I$(XGBOOST_ROOT)/rabit/include
+INCLUDE_DIR=-I$(XGBOOST_ROOT)/include -I$(XGBOOST_ROOT)/dmlc-core/include
 LIB_DIR=-L$(XGBOOST_ROOT)/lib
 
 build: $(TGT)

doc/build.rst

@@ -138,7 +138,7 @@ From the command line on Linux starting from the XGBoost directory:
 
 .. note:: Faster distributed GPU training with NCCL
 
-  By default, distributed GPU training is enabled and uses Rabit for communication. For faster training, set the option ``USE_NCCL=ON``. Faster distributed GPU training depends on NCCL2, available at `this link <https://developer.nvidia.com/nccl>`_. Since NCCL2 is only available for Linux machines, **faster distributed GPU training is available only for Linux**.
+  By default, distributed GPU training is enabled with the option ``USE_NCCL=ON``. Distributed GPU training depends on NCCL2, available at `this link <https://developer.nvidia.com/nccl>`_. Since NCCL2 is only available for Linux machines, **Distributed GPU training is available only for Linux**.
 
   .. code-block:: bash
 

doc/faq.rst

@@ -37,7 +37,7 @@ The ultimate question will still come back to how to push the limit of each comp
 and use less resources to complete the task (thus with less communication and chance of failure).
 
 To achieve these, we decide to reuse the optimizations in the single node XGBoost and build the distributed version on top of it.
-The demand for communication in machine learning is rather simple, in the sense that we can depend on a limited set of APIs (in our case rabit).
+The demand for communication in machine learning is rather simple, in the sense that we can depend on a limited set of APIs.
 Such design allows us to reuse most of the code, while being portable to major platforms such as Hadoop/Yarn, MPI, SGE.
 Most importantly, it pushes the limit of the computation resources we can use.
 

rabit/include/rabit/internal/socket.h → include/xgboost/collective/poll_utils.h

@@ -3,8 +3,7 @@
  * \file socket.h
  * \author Tianqi Chen
  */
-#ifndef RABIT_INTERNAL_SOCKET_H_
-#define RABIT_INTERNAL_SOCKET_H_
+#pragma once
 #include "xgboost/collective/result.h"
 #include "xgboost/collective/socket.h"
 
@@ -61,8 +60,8 @@ using sock_size_t = size_t;  // NOLINT
 #pragma message("Distributed training on mingw is not supported.")
 typedef struct pollfd {
   SOCKET fd;
-  short  events;
-  short  revents;
+  short  events;  // NOLINT
+  short  revents;  // NOLINT
 } WSAPOLLFD, *PWSAPOLLFD, *LPWSAPOLLFD;
 
 // POLLRDNORM | POLLRDBAND
@@ -97,7 +96,8 @@ std::enable_if_t<std::is_integral_v<E>, xgboost::collective::Result> PollError(E
   if ((revents & POLLERR) != 0) {
     auto err = errno;
     auto str = strerror(err);
-    return xgboost::system::FailWithCode(std::string{"Poll error condition:"} + std::string{str} +
+    return xgboost::system::FailWithCode(std::string{"Poll error condition:"} +  // NOLINT
+                                         std::string{str} +                      // NOLINT
                                          " code:" + std::to_string(err));
   }
   if ((revents & POLLNVAL) != 0) {
@@ -229,5 +229,3 @@ struct PollHelper {
 #undef POLLPRI
 #undef POLLOUT
 #endif  // IS_MINGW()
-
-#endif  // RABIT_INTERNAL_SOCKET_H_

jvm-packages/CMakeLists.txt

@@ -21,7 +21,6 @@ target_include_directories(xgboost4j
   ${JNI_INCLUDE_DIRS}
   ${PROJECT_SOURCE_DIR}/jvm-packages/xgboost4j/src/native
   ${PROJECT_SOURCE_DIR}/include
-  ${PROJECT_SOURCE_DIR}/dmlc-core/include
-  ${PROJECT_SOURCE_DIR}/rabit/include)
+  ${PROJECT_SOURCE_DIR}/dmlc-core/include)
 
 set_output_directory(xgboost4j ${PROJECT_SOURCE_DIR}/lib)

python-package/packager/sdist.py

@@ -18,7 +18,6 @@ def copy_cpp_src_tree(
         "include",
         "dmlc-core",
         "gputreeshap",
-        "rabit",
         "cmake",
         "plugin",
     ]:

src/collective/loop.cc

@@ -14,10 +14,10 @@
 #include <thread>     // for thread
 #include <utility>    // for move
 
-#include "rabit/internal/socket.h"      // for PollHelper
-#include "xgboost/collective/result.h"  // for Fail, Success
-#include "xgboost/collective/socket.h"  // for FailWithCode
-#include "xgboost/logging.h"            // for CHECK
+#include "xgboost/collective/poll_utils.h"  // for PollHelper
+#include "xgboost/collective/result.h"      // for Fail, Success
+#include "xgboost/collective/socket.h"      // for FailWithCode
+#include "xgboost/logging.h"                // for CHECK
 
 namespace xgboost::collective {
 Result Loop::ProcessQueue(std::queue<Op>* p_queue) const {

src/collective/socket.cc

@@ -11,8 +11,8 @@
 #include <system_error>  // for error_code, system_category
 #include <thread>        // for sleep_for
 
-#include "rabit/internal/socket.h"      // for PollHelper
-#include "xgboost/collective/result.h"  // for Result
+#include "xgboost/collective/poll_utils.h"  // for PollHelper
+#include "xgboost/collective/result.h"      // for Result
 
 #if defined(__unix__) || defined(__APPLE__)
 #include <netdb.h>  // getaddrinfo, freeaddrinfo

src/collective/tracker.cc

@@ -1,7 +1,7 @@
 /**
  * Copyright 2023-2024, XGBoost Contributors
  */
-#include "rabit/internal/socket.h"
+
 #if defined(__unix__) || defined(__APPLE__)
 #include <netdb.h>       // gethostbyname
 #include <sys/socket.h>  // socket, AF_INET6, AF_INET, connect, getsockname
@@ -27,9 +27,10 @@
 #include "comm.h"
 #include "protocol.h"  // for kMagic, PeerInfo
 #include "tracker.h"
-#include "xgboost/collective/result.h"  // for Result, Fail, Success
-#include "xgboost/collective/socket.h"  // for GetHostName, FailWithCode, MakeSockAddress, ...
-#include "xgboost/json.h"               // for Json
+#include "xgboost/collective/poll_utils.h"  // for PollHelper
+#include "xgboost/collective/result.h"      // for Result, Fail, Success
+#include "xgboost/collective/socket.h"      // for GetHostName, FailWithCode, MakeSockAddress, ...
+#include "xgboost/json.h"                   // for Json
 
 namespace xgboost::collective {
 

tests/ci_build/deploy_jvm_packages.sh

@@ -17,7 +17,7 @@ cd jvm-packages
 rm -rf $(find . -name target)
 rm -rf ../build/
 
-# Re-build package without Mock Rabit
+# Re-build package
 # Maven profiles:
 # `default`           includes modules: xgboost4j, xgboost4j-spark, xgboost4j-flink, xgboost4j-example
 # `gpu`               includes modules: xgboost4j-gpu, xgboost4j-spark-gpu, sets `use.cuda = ON`

tests/ci_build/test_r_package.py

@@ -50,10 +50,6 @@ def pkgroot(path: str) -> None:
     shutil.copytree("src", dest / "src" / "src")
     shutil.copytree("include", dest / "src" / "include")
     shutil.copytree("amalgamation", dest / "src" / "amalgamation")
-    # rabit
-    rabit = Path("rabit")
-    os.mkdir(dest / "src" / rabit)
-    shutil.copytree(rabit / "include", dest / "src" / "rabit" / "include")
     # dmlc-core
     dmlc_core = Path("dmlc-core")
     os.mkdir(dest / "src" / dmlc_core)

tests/ci_build/tidy.py

@@ -192,8 +192,7 @@ def _configure(self):
         def should_lint(path):
             if not self.cpp_lint and path.endswith('.cc'):
                 return False
-            isxgb = path.find('rabit') == -1
-            isxgb = isxgb and path.find('dmlc-core') == -1
+            isxgb = path.find('dmlc-core') == -1
             isxgb = isxgb and (not path.startswith(self.cdb_path))
             if isxgb:
                 print(path)

tests/cpp/CMakeLists.txt

@@ -25,8 +25,7 @@ if(PLUGIN_SYCL)
     PRIVATE
     ${gtest_SOURCE_DIR}/include
     ${xgboost_SOURCE_DIR}/include
-    ${xgboost_SOURCE_DIR}/dmlc-core/include
-    ${xgboost_SOURCE_DIR}/rabit/include)
+    ${xgboost_SOURCE_DIR}/dmlc-core/include)
 
   target_compile_definitions(plugin_sycl_test PUBLIC -DXGBOOST_USE_SYCL=1)
   target_link_libraries(plugin_sycl_test PUBLIC -fsycl)
@@ -66,8 +65,7 @@ target_include_directories(testxgboost
   PRIVATE
   ${GTEST_INCLUDE_DIRS}
   ${xgboost_SOURCE_DIR}/include
-  ${xgboost_SOURCE_DIR}/dmlc-core/include
-  ${xgboost_SOURCE_DIR}/rabit/include)
+  ${xgboost_SOURCE_DIR}/dmlc-core/include)
 target_link_libraries(testxgboost
   PRIVATE
   GTest::gtest GTest::gmock)