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author | Brad Fitzpatrick <bradfitz@android.com> | 2011-03-23 11:57:49 -0700 |
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committer | Android Code Review <code-review@android.com> | 2011-03-23 11:57:49 -0700 |
commit | 7c556549079dbcc3f6f7ef4376978cd8c598aa62 (patch) | |
tree | 7667b9535a0f4d95d755f2e544182f04e9993879 | |
parent | 499b45a3597bc2434bcc0974660470192ab4ff06 (diff) | |
parent | 3549b0dc2829184f9911d27a6ab0cf39b19764f1 (diff) | |
download | system_core-7c556549079dbcc3f6f7ef4376978cd8c598aa62.zip system_core-7c556549079dbcc3f6f7ef4376978cd8c598aa62.tar.gz system_core-7c556549079dbcc3f6f7ef4376978cd8c598aa62.tar.bz2 |
Merge changes Icdefb5ff,Icd7f5f03
* changes:
Fix potential race introduced in Icd7f5f03
SocketClient: add optional reference counting
-rw-r--r-- | include/sysutils/SocketClient.h | 11 | ||||
-rw-r--r-- | libsysutils/src/SocketClient.cpp | 24 | ||||
-rw-r--r-- | libsysutils/src/SocketListener.cpp | 9 |
3 files changed, 41 insertions, 3 deletions
diff --git a/include/sysutils/SocketClient.h b/include/sysutils/SocketClient.h index 2fcc331..d6bb7d5 100644 --- a/include/sysutils/SocketClient.h +++ b/include/sysutils/SocketClient.h @@ -19,6 +19,10 @@ class SocketClient { /* Peer group ID */ gid_t mGid; + /* Reference count (starts at 1) */ + pthread_mutex_t mRefCountMutex; + int mRefCount; + public: SocketClient(int sock); virtual ~SocketClient() {} @@ -34,6 +38,13 @@ public: // Sending binary data: int sendData(const void *data, int len); + + // Optional reference counting. Reference count starts at 1. If + // it's decremented to 0, it deletes itself. + // SocketListener creates a SocketClient (at refcount 1) and calls + // decRef() when it's done with the client. + void incRef(); + bool decRef(); // returns true at 0 (but note: SocketClient already deleted) }; typedef android::List<SocketClient *> SocketClientCollection; diff --git a/libsysutils/src/SocketClient.cpp b/libsysutils/src/SocketClient.cpp index a6aed26..90ca52e 100644 --- a/libsysutils/src/SocketClient.cpp +++ b/libsysutils/src/SocketClient.cpp @@ -15,8 +15,10 @@ SocketClient::SocketClient(int socket) , mPid(-1) , mUid(-1) , mGid(-1) + , mRefCount(1) { pthread_mutex_init(&mWriteMutex, NULL); + pthread_mutex_init(&mRefCountMutex, NULL); struct ucred creds; socklen_t szCreds = sizeof(creds); @@ -100,3 +102,25 @@ int SocketClient::sendData(const void* data, int len) { pthread_mutex_unlock(&mWriteMutex); return 0; } + +void SocketClient::incRef() { + pthread_mutex_lock(&mRefCountMutex); + mRefCount++; + pthread_mutex_unlock(&mRefCountMutex); +} + +bool SocketClient::decRef() { + bool deleteSelf = false; + pthread_mutex_lock(&mRefCountMutex); + mRefCount--; + if (mRefCount == 0) { + deleteSelf = true; + } else if (mRefCount < 0) { + SLOGE("SocketClient refcount went negative!"); + } + pthread_mutex_unlock(&mRefCountMutex); + if (deleteSelf) { + delete this; + } + return deleteSelf; +} diff --git a/libsysutils/src/SocketListener.cpp b/libsysutils/src/SocketListener.cpp index 611d5fe..69ed79e 100644 --- a/libsysutils/src/SocketListener.cpp +++ b/libsysutils/src/SocketListener.cpp @@ -55,7 +55,7 @@ SocketListener::~SocketListener() { } SocketClientCollection::iterator it; for (it = mClients->begin(); it != mClients->end();) { - delete (*it); + (*it)->decRef(); it = mClients->erase(it); } delete mClients; @@ -225,8 +225,11 @@ void SocketListener::runListener() { } pthread_mutex_unlock(&mClientsLock); /* Destroy the client */ - close(c->getSocket()); - delete c; + int socket = c->getSocket(); + if (c->decRef()) { + // Note: 'c' is deleted memory at this point. + close(socket); + } } } } |