Annotation of parser3/src/include/pa_pool.h, revision 1.50
1.34 paf 1: /** @file
1.36 paf 2: Parser: pool class decl.
3:
1.27 paf 4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
1.36 paf 5:
1.28 paf 6: Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
1.27 paf 7:
1.50 ! parser 8: $Id: pa_pool.h,v 1.49 2001/04/04 10:50:34 paf Exp $
1.1 paf 9: */
10:
11: #ifndef PA_POOL_H
12: #define PA_POOL_H
13:
14: #include <stddef.h>
15:
1.21 paf 16: class Exception;
1.25 paf 17: class Temp_exception;
1.1 paf 18:
1.35 paf 19: /**
1.34 paf 20: Pool mechanizm allows users not to free up allocated memory,
21: leaving that problem to 'pools'.
22:
23: Also holds Exception object, which can be temporary set using
24: Temp_exception auto-object.
1.38 paf 25:
26: @see Pooled
1.34 paf 27: */
1.47 paf 28:
1.1 paf 29: class Pool {
1.25 paf 30: friend Temp_exception;
1.1 paf 31: public:
1.18 paf 32:
1.47 paf 33: Pool(void *astorage) : fstorage(astorage), fcontext(0), ftag(0), fexception(0) {}
1.18 paf 34:
1.40 paf 35: void set_context(void *acontext) { fcontext=acontext; }
36: void *context() { return fcontext; }
1.39 paf 37:
1.47 paf 38: void set_tag(void *atag) { ftag=atag; }
39: void *tag() { return ftag; }
1.44 paf 40:
1.34 paf 41: /// current exception object of the pool
1.31 paf 42: Exception& exception() const { return *fexception; }
1.18 paf 43:
1.34 paf 44: /// allocates some bytes on pool
1.50 ! parser 45: void *malloc(size_t size, int place=0) {
! 46: return check(real_malloc(size, place), size);
1.18 paf 47: }
1.34 paf 48: /// allocates some bytes clearing them with zeros
1.18 paf 49: void *calloc(size_t size) {
50: return check(real_calloc(size), size);
51: }
1.39 paf 52:
53: private:
54:
55: void *fstorage;
1.40 paf 56: void *fcontext;
1.47 paf 57: void *ftag;
1.8 paf 58:
1.50 ! parser 59: private:
! 60:
! 61: //{
! 62: /// @name implementation defined
! 63: void *real_malloc(size_t size, int place);
1.20 paf 64: void *real_calloc(size_t size);
1.50 ! parser 65: //}
1.17 paf 66:
1.23 paf 67: private:
1.17 paf 68:
1.34 paf 69: /// checks whether mem allocated OK. throws exception otherwise
1.23 paf 70: void *check(void *ptr, size_t size) {
71: if(ptr)
72: return ptr;
73:
74: fail(size);
75:
76: // never reached
77: return 0;
78: }
1.34 paf 79: /// throws proper exception
1.23 paf 80: void fail(size_t size) const;
81:
1.34 paf 82: private: // exception handling
1.17 paf 83:
1.45 paf 84: // exception replacement mechanism is 'private'zed from direct usage
1.34 paf 85: // Temp_exception object enforces paired set/restore
1.23 paf 86: Exception *set_exception(Exception *e){
1.31 paf 87: Exception *r=fexception;
88: fexception=e;
1.23 paf 89: return r;
90: }
91: void restore_exception(Exception *e) {
1.31 paf 92: fexception=e;
1.23 paf 93: }
94:
95: private:
96:
97: // current request's exception object
1.31 paf 98: Exception *fexception;
1.17 paf 99:
1.8 paf 100: private: //disabled
101:
1.18 paf 102: // Pool(const Pool&) {}
1.16 paf 103: Pool& operator = (const Pool&) { return *this; }
1.21 paf 104: };
105:
1.35 paf 106: /**
1.34 paf 107: Base for all classes that are allocated in 'pools'.
108:
109: Holds Pool object. Contains useful wrappers to it's methods.
1.38 paf 110:
111: @see NEW, Temp_exception
1.34 paf 112: */
1.21 paf 113: class Pooled {
1.23 paf 114: // the pool i'm allocated on
1.49 paf 115: Pool *fpool;
1.21 paf 116: public:
1.37 paf 117:
118: /// the Pooled-sole: Pooled instances can be allocated in Pool rather then on heap
1.21 paf 119: static void *operator new(size_t size, Pool& apool) {
1.50 ! parser 120: return apool.malloc(size, 1);
1.21 paf 121: }
122:
1.49 paf 123: Pooled(Pool& apool) : fpool(&apool) {}
1.23 paf 124:
1.34 paf 125: /// my pool
1.49 paf 126: Pool& pool() const { return *fpool; }
127:
128: /** used for moving objects from one pool to another.
129: in between object can have no pool and can not be used
130: @see SQL_Driver_manager
131: */
132: void set_pool(Pool *apool) { fpool=apool; }
1.21 paf 133:
1.34 paf 134: /// useful wrapper around pool
1.49 paf 135: void *malloc(size_t size) const { return fpool->malloc(size); }
1.34 paf 136: /// useful wrapper around pool
1.49 paf 137: void *calloc(size_t size) const { return fpool->calloc(size); }
1.34 paf 138: /// useful wrapper around pool
1.49 paf 139: Exception& exception() const { return fpool->exception(); }
1.23 paf 140: };
1.34 paf 141: /// useful macro for creating objects on current Pooled object Pooled::pool()
1.23 paf 142: #define NEW new(pool())
143:
1.35 paf 144: /**
1.34 paf 145: Auto-object used for temporary changing Pool's exception().
146:
147: Use by with these macros:
1.38 paf 148: @code
1.34 paf 149: TRY {
1.38 paf 150: // ...
1.34 paf 151: if(?)
152: THROW(?);
1.38 paf 153: // ...
1.34 paf 154: } CATCH(e) {
1.38 paf 155: // code, using e fields
156: // e.comment()
1.34 paf 157: }
158: END_CATCH
1.38 paf 159: @endcode
160:
161: @see TRY, THROW
1.34 paf 162: */
1.25 paf 163: class Temp_exception {
1.29 paf 164: Pool& fpool;
1.23 paf 165: Exception *saved_exception;
166: public:
1.25 paf 167: Temp_exception(Pool& apool, Exception& exception) :
1.29 paf 168: fpool(apool),
1.23 paf 169: saved_exception(apool.set_exception(&exception)) {
170: }
1.25 paf 171: ~Temp_exception() {
1.29 paf 172: fpool.restore_exception(saved_exception);
1.23 paf 173: }
1.1 paf 174: };
1.23 paf 175:
1.33 paf 176: #define XTRY(pool) \
1.24 paf 177: { \
178: Exception temp_exception; \
1.33 paf 179: Temp_exception le(pool, temp_exception); \
1.24 paf 180: if(setjmp(temp_exception.mark)==0)
1.31 paf 181:
1.33 paf 182: #define XTHROW(exception) exception._throw
183: #define XCATCH(e) \
1.24 paf 184: else{ \
185: Exception& e=temp_exception;
1.31 paf 186:
1.33 paf 187: #define XEND_CATCH \
1.24 paf 188: } \
189: }
1.33 paf 190:
1.34 paf 191: //@{
192: /// @see Temp_exception
1.33 paf 193: #define TRY XTRY(pool())
194: #define THROW XTHROW(exception())
195: #define CATCH(e) XCATCH(e)
196: #define END_CATCH XEND_CATCH
197:
198: #define PTRY XTRY(pool)
199: #define PTHROW XTHROW(pool.exception())
200: #define PCATCH(e) XCATCH(e)
201: #define PEND_CATCH XEND_CATCH
1.34 paf 202: //@}
1.1 paf 203:
204: #endif
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