thirdparty/ppsspp
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Make the Loader API thread-safe

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Since the majority of the code is using ReadAt API already, map this to
a `readp` "syscall" which does not mutate any state about the file
descriptor therefore making it fairly safe multi-threading wise.

This allows to get rid of read-time mutexes in RamCachedFileLoader and
therefore fixes #9803
This commit is contained in:
Simonas Kazlauskas 2017-06-23 17:23:43 +03:00
parent 3249d81654
commit 3c3596dbf2
14 changed files with 7 additions and 107 deletions
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24
Core/FileLoaders/LocalFileLoader.cpp
View file

@ -15,14 +15,15 @@
// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
#include <cstdio>
#include "file/file_util.h"
#include "Common/FileUtil.h"
#include "Core/FileLoaders/LocalFileLoader.h"
LocalFileLoader::LocalFileLoader(const std::string &filename)
: fd_(0), f_(nullptr), filesize_(0), filename_(filename) {
// FIXME: perhaps at this point we should just use plain open?
f_ = File::OpenCFile(filename, "rb");
fd_ = fileno(f_);
if (!f_) {
return;
}
@ -30,8 +31,6 @@ LocalFileLoader::LocalFileLoader(const std::string &filename)
#ifdef __ANDROID__
// Android NDK does not support 64-bit file I/O using C streams
// so we fall back onto syscalls
fd_ = fileno(f_);
off64_t off = lseek64(fd_, 0, SEEK_END);
filesize_ = off;
lseek64(fd_, 0, SEEK_SET);
@ -73,23 +72,6 @@ std::string LocalFileLoader::Path() const {
return filename_;
}
void LocalFileLoader::Seek(s64 absolutePos) {
#ifdef __ANDROID__
lseek64(fd_, absolutePos, SEEK_SET);
#else
fseeko(f_, absolutePos, SEEK_SET);
#endif
}
size_t LocalFileLoader::Read(size_t bytes, size_t count, void *data, Flags flags) {
#ifdef __ANDROID__
return read(fd_, data, bytes * count) / bytes;
#else
return fread(data, bytes, count, f_);
#endif
}
size_t LocalFileLoader::ReadAt(s64 absolutePos, size_t bytes, size_t count, void *data, Flags flags) {
Seek(absolutePos);
return Read(bytes, count, data);
return pread(fd_, data, bytes * count, absolutePos) / bytes;
}