diff options
Diffstat (limited to 'chrome/common/mach_ipc_mac.h')
| -rw-r--r-- | chrome/common/mach_ipc_mac.h | 128 |
1 files changed, 86 insertions, 42 deletions
diff --git a/chrome/common/mach_ipc_mac.h b/chrome/common/mach_ipc_mac.h index 58fdc9f..74b84cf 100644 --- a/chrome/common/mach_ipc_mac.h +++ b/chrome/common/mach_ipc_mac.h @@ -5,12 +5,14 @@ #ifndef BASE_MACH_IPC_MAC_H_ #define BASE_MACH_IPC_MAC_H_ -#import <mach/mach.h> -#import <mach/message.h> -#import <servers/bootstrap.h> -#import <sys/types.h> +#include <mach/mach.h> +#include <mach/message.h> +#include <servers/bootstrap.h> +#include <sys/types.h> -#import <CoreServices/CoreServices.h> +#include <CoreServices/CoreServices.h> + +#include "base/basictypes.h" //============================================================================== // DISCUSSION: @@ -39,13 +41,13 @@ // // MachReceiveMessage message; // kern_return_t result = receivePort.WaitForMessage(&message, 0); -// +// // if (result == KERN_SUCCESS && message.GetMessageID() == 57) { // mach_port_t task = message.GetTranslatedPort(0); // mach_port_t thread = message.GetTranslatedPort(1); // // char *messageString = message.GetData(); -// +// // printf("message string = %s\n", messageString); // } // @@ -58,7 +60,7 @@ // // add some ports to be translated for us // message.AddDescriptor(mach_task_self()); // our task // message.AddDescriptor(mach_thread_self()); // this thread -// +// // char messageString[] = "Hello server!\n"; // message.SetData(messageString, strlen(messageString)+1); // @@ -82,7 +84,7 @@ class MachMsgPortDescriptor : public mach_msg_port_descriptor_t { disposition = in_disposition; type = MACH_MSG_PORT_DESCRIPTOR; } - + // For passing send rights to a port MachMsgPortDescriptor(mach_port_t in_name) { name = in_name; @@ -104,11 +106,11 @@ class MachMsgPortDescriptor : public mach_msg_port_descriptor_t { mach_port_t GetMachPort() const { return name; } - + mach_msg_type_name_t GetDisposition() const { return disposition; } - + // We're just a simple wrapper for mach_msg_port_descriptor_t // and have the same memory layout operator mach_msg_port_descriptor_t&() { @@ -128,10 +130,13 @@ class MachMsgPortDescriptor : public mach_msg_port_descriptor_t { // This considerably simplifies the construction of a message for sending // and the getting at relevant data and descriptors for the receiver. // -// Currently the combined size of the descriptors plus data must be -// less than 1024. But as a benefit no memory allocation is necessary. -// -// TODO: could consider adding malloc() support for very large messages +// This class can be initialized using external storage of an arbitrary size +// or it can manage storage internally. +// 1. If storage is allocated internally, the combined size of the descriptors +// plus data must be less than 1024. But as a benefit no memory allocation is +// necessary. +// 2. For external storage, a buffer of at least EmptyMessageSize() must be +// provided. // // A MachMessage object is used by ReceivePort::WaitForMessage // and MachPortSender::SendMessage @@ -139,11 +144,13 @@ class MachMsgPortDescriptor : public mach_msg_port_descriptor_t { class MachMessage { public: + virtual ~MachMessage(); + // The receiver of the message can retrieve the raw data this way u_int8_t *GetData() { return GetDataLength() > 0 ? GetDataPacket()->data : NULL; } - + u_int32_t GetDataLength() { return EndianU32_LtoN(GetDataPacket()->data_length); } @@ -152,14 +159,16 @@ class MachMessage { void SetMessageID(int32_t message_id) { GetDataPacket()->id = EndianU32_NtoL(message_id); } - + int32_t GetMessageID() { return EndianU32_LtoN(GetDataPacket()->id); } // Adds a descriptor (typically a mach port) to be translated // returns true if successful, otherwise not enough space - bool AddDescriptor(const MachMsgPortDescriptor &desc); + bool AddDescriptor(const MachMsgPortDescriptor &desc); - int GetDescriptorCount() const { return body.msgh_descriptor_count; } + int GetDescriptorCount() const { + return storage_->body.msgh_descriptor_count; + } MachMsgPortDescriptor *GetDescriptor(int n); // Convenience method which gets the mach port described by the descriptor @@ -169,15 +178,16 @@ class MachMessage { bool IsSimpleMessage() const { return GetDescriptorCount() == 0; } // Sets raw data for the message (returns false if not enough space) - bool SetData(void *data, int32_t data_length); + bool SetData(const void* data, int32_t data_length); protected: // Consider this an abstract base class - must create an actual instance // of MachReceiveMessage or MachSendMessage - - MachMessage() { - memset(this, 0, sizeof(MachMessage)); - } + MachMessage(); + + // Constructor for use with preallocate storage. + // storage_length must be >= EmptyMessageSize() + MachMessage(void *storage, size_t storage_length); friend class ReceivePort; friend class MachPortSender; @@ -186,39 +196,73 @@ class MachMessage { struct MessageDataPacket { int32_t id; // little-endian int32_t data_length; // little-endian - u_int8_t data[1]; // actual size limited by sizeof(MachMessage) + u_int8_t data[1]; // actual size limited by storage_length_bytes_ }; MessageDataPacket* GetDataPacket(); void SetDescriptorCount(int n); - void SetDescriptor(int n, const MachMsgPortDescriptor &desc); + void SetDescriptor(int n, const MachMsgPortDescriptor &desc); - // Returns total message size setting msgh_size in the header to this value + // Returns total message size setting msgh_size in the header to this value int CalculateSize(); - mach_msg_header_t head; - mach_msg_body_t body; - u_int8_t padding[1024]; // descriptors and data may be embedded here + // Returns total storage size that this object can grow to, this is inclusive + // of the mach header. + size_t MaxSize() const { return storage_length_bytes_; } + + protected: + mach_msg_header_t *Head() { return &(storage_->head); } + + private: + struct MachMessageData { + mach_msg_header_t head; + mach_msg_body_t body; + // descriptors and data may be embedded here. + u_int8_t padding[1024]; + }; + + // kEmptyMessageSize needs to have the definition of MachMessageData before it.NNN + public: + // The size of an empty message with no data. + static const size_t kEmptyMessageSize = sizeof(mach_msg_header_t) + + sizeof(mach_msg_body_t) + + sizeof(MessageDataPacket); + + private: + MachMessageData *storage_; + size_t storage_length_bytes_; + bool own_storage_; // Is storage owned by this object? }; //============================================================================== // MachReceiveMessage and MachSendMessage are useful to separate the idea // of a mach message being sent and being received, and adds increased type // safety: -// ReceivePort::WaitForMessage() only accepts a MachReceiveMessage -// MachPortSender::SendMessage() only accepts a MachSendMessage +// ReceivePort::WaitForMessage() only accepts a MachReceiveMessage +// MachPortSender::SendMessage() only accepts a MachSendMessage //============================================================================== class MachReceiveMessage : public MachMessage { public: - MachReceiveMessage() : MachMessage() {}; + MachReceiveMessage() : MachMessage() {} + MachReceiveMessage(void *storage, size_t storage_length) + : MachMessage(storage, storage_length) {} + + private: + DISALLOW_COPY_AND_ASSIGN(MachReceiveMessage); }; //============================================================================== class MachSendMessage : public MachMessage { public: MachSendMessage(int32_t message_id); + MachSendMessage(void *storage, size_t storage_length, int32_t message_id); + + private: + void Initialize(int32_t message_id); + + DISALLOW_COPY_AND_ASSIGN(MachSendMessage); }; //============================================================================== @@ -236,19 +280,19 @@ class ReceivePort { ReceivePort(); ~ReceivePort(); - + // Waits on the mach port until message received or timeout kern_return_t WaitForMessage(MachReceiveMessage *out_message, mach_msg_timeout_t timeout); - + // The underlying mach port that we wrap mach_port_t GetPort() const { return port_; } private: - ReceivePort(const ReceivePort&); // disable copy c-tor - mach_port_t port_; kern_return_t init_result_; + + DISALLOW_COPY_AND_ASSIGN(ReceivePort); }; //============================================================================== @@ -258,18 +302,18 @@ class MachPortSender { // get a port with send rights corresponding to a named registered service MachPortSender(const char *receive_port_name); - + // Given an already existing mach port, use it. MachPortSender(mach_port_t send_port); - + kern_return_t SendMessage(MachSendMessage &message, mach_msg_timeout_t timeout); - + private: - MachPortSender(const MachPortSender&); // disable copy c-tor - mach_port_t send_port_; kern_return_t init_result_; + + DISALLOW_COPY_AND_ASSIGN(MachPortSender); }; #endif // BASE_MACH_IPC_MAC_H_ |