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authorredpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f>2010-10-18 23:24:01 +0000
committerredpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f>2010-10-18 23:24:01 +0000
commite0ef743090038ee02d656cee11debd2246624ba0 (patch)
treee5e1d32402c8dcb490c574e24c087c56d4cc172e /klm/util/mmap.cc
parent0c2514868f58bbfe422aa275e2905182cf2f57eb (diff)
kenneth's LM preliminary integration
git-svn-id: https://ws10smt.googlecode.com/svn/trunk@681 ec762483-ff6d-05da-a07a-a48fb63a330f
Diffstat (limited to 'klm/util/mmap.cc')
-rw-r--r--klm/util/mmap.cc95
1 files changed, 95 insertions, 0 deletions
diff --git a/klm/util/mmap.cc b/klm/util/mmap.cc
new file mode 100644
index 00000000..648b5d0a
--- /dev/null
+++ b/klm/util/mmap.cc
@@ -0,0 +1,95 @@
+#include "util/exception.hh"
+#include "util/mmap.hh"
+#include "util/scoped.hh"
+
+#include <assert.h>
+#include <err.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+namespace util {
+
+scoped_mmap::~scoped_mmap() {
+ if (data_ != (void*)-1) {
+ if (munmap(data_, size_))
+ err(1, "munmap failed ");
+ }
+}
+
+void scoped_memory::reset(void *data, std::size_t size, Alloc source) {
+ switch(source_) {
+ case MMAP_ALLOCATED:
+ scoped_mmap(data_, size_);
+ break;
+ case ARRAY_ALLOCATED:
+ delete [] reinterpret_cast<char*>(data_);
+ break;
+ case MALLOC_ALLOCATED:
+ free(data_);
+ break;
+ case NONE_ALLOCATED:
+ break;
+ }
+ data_ = data;
+ size_ = size;
+ source_ = source;
+}
+
+void scoped_memory::call_realloc(std::size_t size) {
+ assert(source_ == MALLOC_ALLOCATED || source_ == NONE_ALLOCATED);
+ void *new_data = realloc(data_, size);
+ if (!new_data) {
+ reset();
+ } else {
+ reset(new_data, size, MALLOC_ALLOCATED);
+ }
+}
+
+void *MapOrThrow(std::size_t size, bool for_write, int flags, bool prefault, int fd, off_t offset) {
+#ifdef MAP_POPULATE // Linux specific
+ if (prefault) {
+ flags |= MAP_POPULATE;
+ }
+ int protect = for_write ? (PROT_READ | PROT_WRITE) : PROT_READ;
+#else
+ int protect = for_write ? (PROT_READ | PROT_WRITE) : PROT_READ;
+#endif
+ void *ret = mmap(NULL, size, protect, flags, fd, offset);
+ if (ret == MAP_FAILED) {
+ UTIL_THROW(ErrnoException, "mmap failed for size " << size << " at offset " << offset);
+ }
+ return ret;
+}
+
+void *MapForRead(std::size_t size, bool prefault, int fd, off_t offset) {
+ return MapOrThrow(size, false, MAP_FILE | MAP_PRIVATE, prefault, fd, offset);
+}
+
+void *MapAnonymous(std::size_t size) {
+ return MapOrThrow(size, true,
+#ifdef MAP_ANONYMOUS
+ MAP_ANONYMOUS // Linux
+#else
+ MAP_ANON // BSD
+#endif
+ | MAP_PRIVATE, false, -1, 0);
+}
+
+void MapZeroedWrite(const char *name, std::size_t size, scoped_fd &file, scoped_mmap &mem) {
+ file.reset(open(name, O_CREAT | O_RDWR | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH));
+ if (-1 == file.get())
+ UTIL_THROW(ErrnoException, "Failed to open " << name << " for writing");
+ if (-1 == ftruncate(file.get(), size))
+ UTIL_THROW(ErrnoException, "ftruncate on " << name << " to " << size << " failed");
+ try {
+ mem.reset(MapOrThrow(size, true, MAP_FILE | MAP_SHARED, false, file.get(), 0), size);
+ } catch (ErrnoException &e) {
+ e << " in file " << name;
+ throw;
+ }
+}
+
+} // namespace util