Index: base/shared_memory_posix.cc |
diff --git a/base/shared_memory_posix.cc b/base/shared_memory_posix.cc |
index 7a238ed880b12a641b7461fc01285b7d169d9cc2..95216843e1af42b76527b6a34bcce0e0e8ebab3f 100644 |
--- a/base/shared_memory_posix.cc |
+++ b/base/shared_memory_posix.cc |
@@ -17,6 +17,14 @@ |
#include "base/threading/thread_restrictions.h" |
#include "base/utf_string_conversions.h" |
+#if defined(OS_ANDROID) |
+// For Android, we use ashmem to implement SharedMemory. ashmem_create_region |
+// will automatically pin the region. We never explicitly call pin/unpin. When |
+// all the file descriptors from different processes associated with the region |
+// are closed, the memory buffer will go away. |
+#include "third_party/ashmem/ashmem.h" |
+#endif |
+ |
#if defined(OS_MACOSX) |
#include "base/mac/foundation_util.h" |
#endif // OS_MACOSX |
@@ -103,6 +111,26 @@ bool SharedMemory::CreateAnonymous(uint32 size) { |
// of mem_filename after FilePathForMemoryName(). |
bool SharedMemory::CreateNamed(const std::string& name, |
bool open_existing, uint32 size) { |
+#if defined(OS_ANDROID) |
darin (slow to review)
2011/06/17 16:29:29
it seems like almost all of the code in this file
michaelbai
2011/06/17 22:41:29
I moved fully android specific methods into shared
|
+ DCHECK(mapped_file_ == -1); |
joth
2011/06/17 11:25:54
DCHECK_EQ(-1, mapped_file_)
michaelbai
2011/06/17 22:41:29
Done.
|
+ |
+ // "name" is just a label in ashmem. It is visible in /proc/pid/maps. |
+ mapped_file_ = ashmem_create_region(name.data(), size); |
joth
2011/06/17 11:25:54
name.c_str(), to ensure it is null terminated
michaelbai
2011/06/17 22:41:29
Done, thanks
|
+ if (-1 == mapped_file_) { |
+ LOG(ERROR) << "Shared memory creation failed"; |
darin (slow to review)
2011/06/17 16:29:29
nit: do you really need these log statements to be
michaelbai
2011/06/17 22:41:29
Done.
|
+ return false; |
+ } |
+ |
+ int err = ashmem_set_prot_region(mapped_file_, |
+ PROT_READ | PROT_WRITE | PROT_EXEC); |
+ if (err < 0) { |
+ LOG(ERROR) << "Error " << err << " when setting protection of ashmem"; |
+ return false; |
+ } |
+ created_size_ = size; |
+ |
+ return true; |
+#else |
DCHECK_EQ(-1, mapped_file_); |
if (size == 0) return false; |
@@ -171,12 +199,19 @@ bool SharedMemory::CreateNamed(const std::string& name, |
} |
return PrepareMapFile(fp); |
+#endif // defined(OS_ANDROID) |
} |
// Our current implementation of shmem is with mmap()ing of files. |
// These files need to be deleted explicitly. |
// In practice this call is only needed for unit tests. |
bool SharedMemory::Delete(const std::string& name) { |
+#if defined(OS_ANDROID) |
+ // ashmem doesn't support name mapping |
+ NOTIMPLEMENTED(); |
+ return false; |
+#endif |
+ |
FilePath path; |
if (!FilePathForMemoryName(name, &path)) |
return false; |
@@ -196,6 +231,12 @@ bool SharedMemory::Open(const std::string& name, bool read_only) { |
read_only_ = read_only; |
+#if defined(OS_ANDROID) |
+ // ashmem doesn't support name mapping |
+ NOTIMPLEMENTED(); |
+ return false; |
+#endif |
+ |
const char *mode = read_only ? "r" : "r+"; |
FILE *fp = file_util::OpenFile(path, mode); |
return PrepareMapFile(fp); |
@@ -205,6 +246,21 @@ bool SharedMemory::Map(uint32 bytes) { |
if (mapped_file_ == -1) |
return false; |
+#if defined(OS_ANDROID) |
+ const uint32 ashmem_bytes = ashmem_get_size_region(mapped_file_); |
joth
2011/06/17 11:25:54
ashmem_get_size_region appears to return 'int', pr
michaelbai
2011/06/17 22:41:29
Done.
|
+ DCHECK_GE(ashmem_bytes, bytes); |
+ if (bytes == 0) { |
+ // The caller wants to determine the map region size from ashmem. |
+ bytes = ashmem_bytes; |
+ // HACK: we set the created size here so that it is available in |
+ // transport_dib_android.cc. Other choices would be to add an accessor to |
+ // mapped_size_ (apparently undesirable, see the comment for created_size() |
+ // in shared_memory.h) or to duplicate the ashmem_get_size_region call above |
+ // in TransportDIB::Map(). |
joth
2011/06/17 11:25:54
can we fix this? It seems to be abusing both Map(0
michaelbai
2011/06/17 22:41:29
Method added, I will have another CL to handle the
|
+ created_size_ = bytes; |
+ } |
+#endif |
+ |
memory_ = mmap(NULL, bytes, PROT_READ | (read_only_ ? 0 : PROT_WRITE), |
MAP_SHARED, mapped_file_, 0); |
@@ -240,6 +296,16 @@ void SharedMemory::Close() { |
} |
} |
+// The lockf() function is not available on Android; we translate to flock(). |
+#if defined(OS_ANDROID) |
+#define F_LOCK LOCK_EX |
+#define F_ULOCK LOCK_UN |
+static inline int lockf(int fd, int cmd, off_t ignored_len) { |
joth
2011/06/17 11:25:54
nit: use anon namespace rather than static (unless
michaelbai
2011/06/17 22:41:29
Done.
|
+ return flock(fd, cmd); |
+} |
+#endif |
+ |
+ |
void SharedMemory::Lock() { |
LockOrUnlockCommon(F_LOCK); |
} |
@@ -248,6 +314,7 @@ void SharedMemory::Unlock() { |
LockOrUnlockCommon(F_ULOCK); |
} |
+#if !defined(OS_ANDROID) |
bool SharedMemory::PrepareMapFile(FILE *fp) { |
DCHECK_EQ(-1, mapped_file_); |
if (fp == NULL) return false; |
@@ -276,6 +343,7 @@ bool SharedMemory::PrepareMapFile(FILE *fp) { |
return true; |
} |
+#endif |
// For the given shmem named |mem_name|, return a filename to mmap() |
// (and possibly create). Modifies |filename|. Return false on |