From 41a9dfefb68fb2337a250c97c3c24b28d8ab686f Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Wed, 29 Mar 2017 16:44:21 -0400
Subject: [PATCH] SystemInformation: Fix dynamic loader failure on WinXP SP2
MIME-Version: 1.0
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Load the `GetLogicalProcessorInformation` function address at runtime.
If it is not available use a fallback implementation.
Co-Author: Nicolás Bértolo <nicolasbertolo@gmail.com>
Issue: cmake/cmake#16751
---
SystemInformation.cxx | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/SystemInformation.cxx b/SystemInformation.cxx
index 93312e9d..70f1a434 100644
--- a/SystemInformation.cxx
+++ b/SystemInformation.cxx
@@ -4341,18 +4341,35 @@ unsigned char SystemInformationImplementation::GetAPICId()
void SystemInformationImplementation::CPUCountWindows()
{
#if defined(_WIN32)
- std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> ProcInfo;
this->NumberOfPhysicalCPU = 0;
this->NumberOfLogicalCPU = 0;
+ typedef BOOL(WINAPI * GetLogicalProcessorInformationType)(
+ PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);
+ static GetLogicalProcessorInformationType pGetLogicalProcessorInformation =
+ (GetLogicalProcessorInformationType)GetProcAddress(
+ GetModuleHandleW(L"kernel32"), "GetLogicalProcessorInformation");
+
+ if (!pGetLogicalProcessorInformation) {
+ // Fallback to approximate implementation on ancient Windows versions.
+ SYSTEM_INFO info;
+ ZeroMemory(&info, sizeof(info));
+ GetSystemInfo(&info);
+ this->NumberOfPhysicalCPU =
+ static_cast<unsigned int>(info.dwNumberOfProcessors);
+ this->NumberOfLogicalCPU = this->NumberOfPhysicalCPU;
+ return;
+ }
+
+ std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> ProcInfo;
{
DWORD Length = 0;
- DWORD rc = GetLogicalProcessorInformation(NULL, &Length);
+ DWORD rc = pGetLogicalProcessorInformation(NULL, &Length);
assert(FALSE == rc);
(void)rc; // Silence unused variable warning in Borland C++ 5.81
assert(GetLastError() == ERROR_INSUFFICIENT_BUFFER);
ProcInfo.resize(Length / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION));
- rc = GetLogicalProcessorInformation(&ProcInfo[0], &Length);
+ rc = pGetLogicalProcessorInformation(&ProcInfo[0], &Length);
assert(rc != FALSE);
(void)rc; // Silence unused variable warning in Borland C++ 5.81
}
--
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