diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/host_memory.cpp | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/common/host_memory.cpp b/src/common/host_memory.cpp index 8e4f1f97a..01457d8c6 100644 --- a/src/common/host_memory.cpp +++ b/src/common/host_memory.cpp @@ -14,6 +14,7 @@ #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif +#include <boost/icl/interval_set.hpp> #include <fcntl.h> #include <sys/mman.h> #include <unistd.h> @@ -415,6 +416,7 @@ public: madvise(virtual_base, virtual_size, MADV_HUGEPAGE); #endif + placeholders.add({0, virtual_size}); good = true; } @@ -423,6 +425,10 @@ public: } void Map(size_t virtual_offset, size_t host_offset, size_t length) { + { + std::scoped_lock lock{placeholder_mutex}; + placeholders.subtract({virtual_offset, virtual_offset + length}); + } void* ret = mmap(virtual_base + virtual_offset, length, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, host_offset); @@ -433,6 +439,19 @@ public: // The method name is wrong. We're still talking about the virtual range. // We don't want to unmap, we want to reserve this memory. + { + std::scoped_lock lock{placeholder_mutex}; + auto it = placeholders.find({virtual_offset - 1, virtual_offset + length + 1}); + + if (it != placeholders.end()) { + size_t prev_upper = virtual_offset + length; + virtual_offset = std::min(virtual_offset, it->lower()); + length = std::max(it->upper(), prev_upper) - virtual_offset; + } + + placeholders.add({virtual_offset, virtual_offset + length}); + } + void* ret = mmap(virtual_base + virtual_offset, length, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); ASSERT_MSG(ret != MAP_FAILED, "mmap failed: {}", strerror(errno)); @@ -476,6 +495,9 @@ private: } int fd{-1}; // memfd file descriptor, -1 is the error value of memfd_create + + boost::icl::interval_set<size_t> placeholders; ///< Mapped placeholders + std::mutex placeholder_mutex; ///< Mutex for placeholders }; #else // ^^^ Linux ^^^ vvv Generic vvv |