mmap atomic

v1
Brett 2024-08-18 14:00:45 -04:00
parent 97990401e2
commit a0a855463d
6 changed files with 179 additions and 76 deletions

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@ -1,6 +1,6 @@
cmake_minimum_required(VERSION 3.20) cmake_minimum_required(VERSION 3.20)
include(cmake/color.cmake) include(cmake/color.cmake)
set(BLT_VERSION 0.18.35) set(BLT_VERSION 0.18.36)
set(BLT_TEST_VERSION 0.0.1) set(BLT_TEST_VERSION 0.0.1)
set(BLT_TARGET BLT) set(BLT_TARGET BLT)

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@ -25,18 +25,11 @@
#include <blt/std/utility.h> #include <blt/std/utility.h>
#include <blt/std/types.h> #include <blt/std/types.h>
#include <blt/std/assert.h> #include <blt/std/assert.h>
// TODO: remove #include <blt/std/mmap.h>
//#include <blt/std/hashmap.h>
#include <blt/compatibility.h> #include <blt/compatibility.h>
#include <stdexcept> #include <stdexcept>
#include "logging.h" #include "logging.h"
#include <cstdlib> #include <cstdlib>
#ifdef __unix__
#include <sys/mman.h>
#endif
namespace blt namespace blt
{ {
@ -543,77 +536,12 @@ namespace blt
} }
}; };
// size of 2mb in bytes
inline constexpr blt::size_t BLT_2MB_SIZE = 4096 * 512;
/**
* Logging function used for handling mmap errors. call after a failed mmap call.
* @param LOG_FUNC function to log with, must be a BLT_*_STREAM
*/
template<typename LOG_FUNC>
static void handle_mmap_error(LOG_FUNC func = BLT_ERROR_STREAM)
{
#define BLT_WRITE(arg) func << arg << '\n';
switch (errno)
{
case EACCES:
BLT_WRITE("fd not set to open!");
break;
case EAGAIN:
BLT_WRITE("The file has been locked, or too much memory has been locked");
break;
case EBADF:
BLT_WRITE("fd is not a valid file descriptor");
break;
case EEXIST:
BLT_WRITE("MAP_FIXED_NOREPLACE was specified in flags, and the range covered "
"by addr and length clashes with an existing mapping.");
break;
case EINVAL:
BLT_WRITE("We don't like addr, length, or offset (e.g., they are too large, or not aligned on a page boundary).");
BLT_WRITE("Or length was 0");
BLT_WRITE("Or flags contained none of MAP_PRIVATE, MAP_SHARED, or MAP_SHARED_VALIDATE.");
break;
case ENFILE:
BLT_WRITE("The system-wide limit on the total number of open files has been reached.");
break;
case ENODEV:
BLT_WRITE("The underlying filesystem of the specified file does not support memory mapping.");
break;
case ENOMEM:
BLT_WRITE("No memory is available.");
BLT_WRITE("Or The process's maximum number of mappings would have been exceeded. "
"This error can also occur for munmap(), when unmapping a region in the middle of an existing mapping, "
"since this results in two smaller mappings on either side of the region being unmapped.");
BLT_WRITE("Or The process's RLIMIT_DATA limit, described in getrlimit(2), would have been exceeded.");
BLT_WRITE("Or We don't like addr, because it exceeds the virtual address space of the CPU.");
break;
case EOVERFLOW:
BLT_WRITE("On 32-bit architecture together with the large file extension (i.e., using 64-bit off_t): "
"the number of pages used for length plus number of "
"pages used for offset would overflow unsigned long (32 bits).");
break;
case EPERM:
BLT_WRITE("The prot argument asks for PROT_EXEC but the mapped area "
"belongs to a file on a filesystem that was mounted no-exec.");
BLT_WRITE("Or The operation_t was prevented by a file seal");
BLT_WRITE("Or The MAP_HUGETLB flag was specified, but the caller "
"was not privileged (did not have the CAP_IPC_LOCK capability) "
"and is not a member of the sysctl_hugetlb_shm_group group; "
"see the description of /proc/sys/vm/sysctl_hugetlb_shm_group");
break;
case ETXTBSY:
BLT_WRITE("MAP_DENYWRITE was set but the object specified by fd is open for writing.");
break;
}
}
template<typename T, bool WARN_ON_FAIL = false> template<typename T, bool WARN_ON_FAIL = false>
static inline T* allocate_huge_page(blt::size_t BLOCK_SIZE, blt::size_t HUGE_PAGE_SIZE = BLT_2MB_SIZE) static inline T* allocate_huge_page(blt::size_t BLOCK_SIZE, blt::size_t HUGE_PAGE_SIZE = BLT_2MB_SIZE)
{ {
BLT_ASSERT((BLOCK_SIZE & (HUGE_PAGE_SIZE - 1)) == 0 && "Must be multiple of the huge page size!"); BLT_ASSERT((BLOCK_SIZE & (HUGE_PAGE_SIZE - 1)) == 0 && "Must be multiple of the huge page size!");
T* buffer = static_cast<T*>(mmap(nullptr, BLOCK_SIZE, PROT_READ | PROT_WRITE, T* buffer = static_cast<T*>(mmap(nullptr, BLOCK_SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_POPULATE, -1, 0)); MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_POPULATE, -1, 0));
// if we fail to allocate a huge page we can try to allocate normally // if we fail to allocate a huge page we can try to allocate normally
if (buffer == MAP_FAILED) if (buffer == MAP_FAILED)
{ {

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@ -0,0 +1,43 @@
#pragma once
/*
* Copyright (C) 2024 Brett Terpstra
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_ATOMIC_ALLOCATOR_H
#define BLT_ATOMIC_ALLOCATOR_H
#include <optional>
#include <limits>
#include <vector>
#include <blt/std/ranges.h>
#include <blt/std/utility.h>
#include <blt/std/types.h>
#include <blt/std/assert.h>
#include <blt/std/mmap.h>
#include <blt/compatibility.h>
#include <stdexcept>
#include "logging.h"
#include <cstdlib>
namespace blt
{
}
#endif //BLT_ATOMIC_ALLOCATOR_H

51
include/blt/std/mmap.h Normal file
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@ -0,0 +1,51 @@
#pragma once
/*
* Copyright (C) 2024 Brett Terpstra
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_MMAP_H
#define BLT_MMAP_H
#include <blt/std/logging.h>
#include <blt/std/types.h>
#ifdef __unix__
#include <sys/mman.h>
#endif
// size of 2mb in bytes
inline constexpr blt::size_t BLT_2MB_SIZE = 4096 * 512;
namespace blt
{
/**
* Logging function used for handling mmap errors. call after a failed mmap call.
*/
void handle_mmap_error(blt::logging::logger func);
inline static constexpr blt::size_t align_to_size(blt::size_t in, blt::size_t align)
{
return 0;
}
void* allocate_2mb_huge_pages(blt::size_t bytes);
}
#endif //BLT_MMAP_H

@ -1 +1 @@
Subproject commit d88c5e15079047777b418132ece5879e7c9aaa2b Subproject commit 8a889d3699b3c09ade435641fb034427f3fd12b6

81
src/blt/std/mmap.cpp Normal file
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@ -0,0 +1,81 @@
/*
* <Short Description>
* Copyright (C) 2024 Brett Terpstra
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <blt/std/mmap.h>
namespace blt
{
void handle_mmap_error(blt::logging::logger func)
{
{
#define BLT_WRITE(arg) func << arg << '\n';
switch (errno)
{
case EACCES:
BLT_WRITE("fd not set to open!");
break;
case EAGAIN:
BLT_WRITE("The file has been locked, or too much memory has been locked");
break;
case EBADF:
BLT_WRITE("fd is not a valid file descriptor");
break;
case EEXIST:
BLT_WRITE("MAP_FIXED_NOREPLACE was specified in flags, and the range covered "
"by addr and length clashes with an existing mapping.");
break;
case EINVAL:
BLT_WRITE("We don't like addr, length, or offset (e.g., they are too large, or not aligned on a page boundary).");
BLT_WRITE("Or length was 0");
BLT_WRITE("Or flags contained none of MAP_PRIVATE, MAP_SHARED, or MAP_SHARED_VALIDATE.");
break;
case ENFILE:
BLT_WRITE("The system-wide limit on the total number of open files has been reached.");
break;
case ENODEV:
BLT_WRITE("The underlying filesystem of the specified file does not support memory mapping.");
break;
case ENOMEM:
BLT_WRITE("No memory is available.");
BLT_WRITE("Or The process's maximum number of mappings would have been exceeded. "
"This error can also occur for munmap(), when unmapping a region in the middle of an existing mapping, "
"since this results in two smaller mappings on either side of the region being unmapped.");
BLT_WRITE("Or The process's RLIMIT_DATA limit, described in getrlimit(2), would have been exceeded.");
BLT_WRITE("Or We don't like addr, because it exceeds the virtual address space of the CPU.");
break;
case EOVERFLOW:
BLT_WRITE("On 32-bit architecture together with the large file extension (i.e., using 64-bit off_t): "
"the number of pages used for length plus number of "
"pages used for offset would overflow unsigned long (32 bits).");
break;
case EPERM:
BLT_WRITE("The prot argument asks for PROT_EXEC but the mapped area "
"belongs to a file on a filesystem that was mounted no-exec.");
BLT_WRITE("Or The operation_t was prevented by a file seal");
BLT_WRITE("Or The MAP_HUGETLB flag was specified, but the caller "
"was not privileged (did not have the CAP_IPC_LOCK capability) "
"and is not a member of the sysctl_hugetlb_shm_group group; "
"see the description of /proc/sys/vm/sysctl_hugetlb_shm_group");
break;
case ETXTBSY:
BLT_WRITE("MAP_DENYWRITE was set but the object specified by fd is open for writing.");
break;
}
}
}
}