From 02ba913dc7bb5d711471b27f2ea23a897d0f2e28 Mon Sep 17 00:00:00 2001
From: lichao <lichao@aiotlink.com>
Date: 星期五, 23 四月 2021 15:34:26 +0800
Subject: [PATCH] bind msgi to shm, change offset_ptr to abs offset.
---
src/msg.h | 173 ++++++++++++++++++++++++++++++++++++++++-----------------
1 files changed, 122 insertions(+), 51 deletions(-)
diff --git a/src/msg.h b/src/msg.h
index 452567e..99b3a09 100644
--- a/src/msg.h
+++ b/src/msg.h
@@ -31,83 +31,150 @@
{
using namespace bhome_shm;
-// MsgI is safe to be stored in shared memory, so POD data or offset_ptr is required.
-// message format: header(meta) + body(data).
+// ShmMsg is safe to be stored in shared memory, so POD data or offset_ptr is required.
+// message content layout: (meta) / header_size + header + data_size + data
typedef boost::uuids::uuid MQId;
-// store ref count, msgs shareing the same data should also hold a pointer of the same RefCount object.
-class RefCount : private boost::noncopyable
-{
- std::atomic<int> num_;
-
-public:
- RefCount() :
- num_(1) { static_assert(std::is_pod<decltype(num_)>::value); }
- int Inc() { return ++num_; }
- int Dec() { return --num_; }
- int Get() { return num_.load(); }
-};
-
-// message content layout: header_size + header + data_size + data
-class MsgI
+class ShmMsg
{
private:
+ // store ref count, msgs shareing the same data should also hold a pointer of the same RefCount object.
+ class RefCount : private boost::noncopyable
+ {
+ std::atomic<int> num_;
+
+ public:
+ RefCount() :
+ num_(1) { static_assert(std::is_pod<decltype(num_)>::value); }
+ int Inc() { return ++num_; }
+ int Dec() { return --num_; }
+ int Get() { return num_.load(); }
+ };
+ typedef int64_t Offset;
+ static Offset Addr(void *ptr) { return reinterpret_cast<Offset>(ptr); }
+ static void *Ptr(const Offset offset) { return reinterpret_cast<void *>(offset); }
+ static inline Offset BaseAddr()
+ {
+ static const Offset base = Addr(shm().get_address()); // cache value.
+ return base;
+ }
+ static inline SharedMemory &shm()
+ {
+ if (!pshm()) { throw std::string("Must set ShmMsg shm before use!"); }
+ return *pshm();
+ }
+ static inline SharedMemory *&pshm()
+ {
+ static SharedMemory *pshm = 0;
+ return pshm;
+ }
+
struct Meta {
RefCount count_;
};
- offset_ptr<void> ptr_;
- void *Alloc(SharedMemory &shm, const size_t size);
- void Free(SharedMemory &shm);
+ Offset offset_;
+ void *Alloc(const size_t size)
+ {
+ void *p = shm().Alloc(sizeof(Meta) + size);
+ if (p) {
+ auto pmeta = new (p) Meta;
+ p = pmeta + 1;
+ }
+ return p;
+ }
+ void Free()
+ {
+ assert(valid());
+ shm().Dealloc(meta());
+ offset_ = 0;
+ assert(!valid());
+ }
Meta *meta() const { return get<Meta>() - 1; }
typedef std::function<void(void *p, int len)> ToArray;
- void *Pack(SharedMemory &shm,
- const uint32_t head_len, const ToArray &headToArray,
- const uint32_t body_len, const ToArray &bodyToArray);
+ void *Pack(const uint32_t head_len, const ToArray &headToArray,
+ const uint32_t body_len, const ToArray &bodyToArray)
+ {
+ void *addr = Alloc(sizeof(head_len) + head_len + sizeof(body_len) + body_len);
+ if (addr) {
+ auto p = static_cast<char *>(addr);
+ auto Pack1 = [&p](auto len, auto &writer) {
+ Put32(p, len);
+ p += sizeof(len);
+ writer(p, len);
+ p += len;
+ };
+ Pack1(head_len, headToArray);
+ Pack1(body_len, bodyToArray);
+ }
+ return addr;
+ }
template <class Body>
- void *Pack(SharedMemory &shm, const BHMsgHead &head, const Body &body)
+ void *Pack(const BHMsgHead &head, const Body &body)
{
return Pack(
- shm,
uint32_t(head.ByteSizeLong()), [&](void *p, int len) { head.SerializeToArray(p, len); },
uint32_t(body.ByteSizeLong()), [&](void *p, int len) { body.SerializeToArray(p, len); });
}
- void *Pack(SharedMemory &shm, const std::string &content)
+ void *Pack(const std::string &content)
{
- void *addr = Alloc(shm, content.size());
+ void *addr = Alloc(content.size());
if (addr) {
memcpy(addr, content.data(), content.size());
}
return addr;
}
- bool Make(SharedMemory &shm, void *addr);
- MsgI(void *p) :
- ptr_(p) {}
+ bool Make(void *addr)
+ {
+ if (!addr) {
+ return false;
+ }
+ ShmMsg(addr).swap(*this);
+ return true;
+ }
+ ShmMsg(void *p) :
+ offset_(p ? (Addr(p) - BaseAddr()) : 0) {}
+
+ template <class T = void>
+ T *get() const { return static_cast<T *>(Ptr(offset_ + BaseAddr())); }
public:
- MsgI() :
- MsgI(nullptr) {}
- MsgI(SharedMemory &shm, const size_t size) :
- MsgI(Alloc(shm, size)) {}
- void swap(MsgI &a) { std::swap(ptr_, a.ptr_); }
- bool valid() const { return static_cast<bool>(ptr_); }
- template <class T = void>
- T *get() const { return static_cast<T *>(ptr_.get()); }
+ static bool BindShm(SharedMemory &shm)
+ {
+ assert(!pshm());
+ pshm() = &shm;
+ return true;
+ }
+
+ ShmMsg() :
+ ShmMsg(nullptr) {}
+ explicit ShmMsg(const size_t size) :
+ ShmMsg(Alloc(size)) {}
+ void swap(ShmMsg &a) { std::swap(offset_, a.offset_); }
+ bool valid() const { return static_cast<bool>(offset_); }
// AddRef and Release works for both counted and not counted msg.
int AddRef() const { return valid() ? meta()->count_.Inc() : 1; }
- int Release(SharedMemory &shm);
+ int Release()
+ {
+ if (!valid()) {
+ return 0;
+ }
+ auto n = meta()->count_.Dec();
+ if (n == 0) {
+ Free();
+ }
+ return n;
+ }
int Count() const { return valid() ? meta()->count_.Get() : 1; }
template <class Body>
- inline bool Make(SharedMemory &shm, const BHMsgHead &head, const Body &body)
- {
- return Make(shm, Pack(shm, head, body));
- }
+ inline bool Make(const BHMsgHead &head, const Body &body) { return Make(Pack(head, body)); }
+ inline bool Make(const std::string &content) { return Make(Pack(content)); }
template <class Body>
static inline std::string Serialize(const BHMsgHead &head, const Body &body)
{
@@ -126,17 +193,19 @@
assert(pos == s.size());
return s;
}
- inline bool Make(SharedMemory &shm, const std::string &content)
- {
- void *p = Pack(shm, content);
- return Make(shm, p);
- }
- bool ParseHead(BHMsgHead &head) const;
+ bool ParseHead(BHMsgHead &head) const
+ {
+ auto p = get<char>();
+ assert(p);
+ uint32_t msg_size = Get32(p);
+ p += 4;
+ return head.ParseFromArray(p, msg_size);
+ }
template <class Body>
bool ParseBody(Body &body) const
{
- auto p = static_cast<char *>(ptr_.get());
+ auto p = get<char>();
assert(p);
uint32_t size = Get32(p);
p += 4;
@@ -147,7 +216,9 @@
}
};
-inline void swap(MsgI &m1, MsgI &m2) { m1.swap(m2); }
+inline void swap(ShmMsg &m1, ShmMsg &m2) { m1.swap(m2); }
+
+typedef ShmMsg MsgI;
} // namespace bhome_msg
--
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