Annotation of parser3/src/include/pa_pool.h, revision 1.38
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:
1.38 ! paf 8: $Id: pa_pool.h,v 1.37 2001/03/19 18:00:26 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: */
28:
1.1 paf 29: class Pool {
1.25 paf 30: friend Temp_exception;
1.1 paf 31: public:
1.18 paf 32:
1.31 paf 33: Pool() : fexception(0) {}
1.18 paf 34: ~Pool() {}
35:
1.34 paf 36: /// current exception object of the pool
1.31 paf 37: Exception& exception() const { return *fexception; }
1.18 paf 38:
1.34 paf 39: /// allocates some bytes on pool
1.18 paf 40: void *malloc(size_t size) {
41: return check(real_malloc(size), size);
42: }
1.34 paf 43: /// allocates some bytes clearing them with zeros
1.18 paf 44: void *calloc(size_t size) {
45: return check(real_calloc(size), size);
46: }
1.8 paf 47:
1.23 paf 48: private: // implementation defined
1.18 paf 49:
1.20 paf 50: void *real_malloc(size_t size);
51: void *real_calloc(size_t size);
1.17 paf 52:
1.23 paf 53: private:
1.17 paf 54:
1.34 paf 55: /// checks whether mem allocated OK. throws exception otherwise
1.23 paf 56: void *check(void *ptr, size_t size) {
57: if(ptr)
58: return ptr;
59:
60: fail(size);
61:
62: // never reached
63: return 0;
64: }
1.34 paf 65: /// throws proper exception
1.23 paf 66: void fail(size_t size) const;
67:
1.34 paf 68: private: // exception handling
1.17 paf 69:
1.23 paf 70: // exception replacement mechanism is 'protected' from direct usage
1.34 paf 71: // Temp_exception object enforces paired set/restore
1.23 paf 72: Exception *set_exception(Exception *e){
1.31 paf 73: Exception *r=fexception;
74: fexception=e;
1.23 paf 75: return r;
76: }
77: void restore_exception(Exception *e) {
1.31 paf 78: fexception=e;
1.23 paf 79: }
80:
81: private:
82:
83: // current request's exception object
1.31 paf 84: Exception *fexception;
1.17 paf 85:
1.8 paf 86: private: //disabled
87:
1.18 paf 88: // Pool(const Pool&) {}
1.16 paf 89: Pool& operator = (const Pool&) { return *this; }
1.21 paf 90: };
91:
1.35 paf 92: /**
1.34 paf 93: Base for all classes that are allocated in 'pools'.
94:
95: Holds Pool object. Contains useful wrappers to it's methods.
1.38 ! paf 96:
! 97: @see NEW, Temp_exception
1.34 paf 98: */
1.21 paf 99: class Pooled {
1.23 paf 100: // the pool i'm allocated on
101: Pool& fpool;
1.21 paf 102: public:
1.37 paf 103:
104: /// the Pooled-sole: Pooled instances can be allocated in Pool rather then on heap
1.21 paf 105: static void *operator new(size_t size, Pool& apool) {
106: return apool.malloc(size);
107: }
108:
1.23 paf 109: Pooled(Pool& apool) : fpool(apool) {
110: }
111:
1.34 paf 112: /// my pool
1.22 paf 113: Pool& pool() const { return fpool; }
1.21 paf 114:
1.34 paf 115: /// useful wrapper around pool
1.23 paf 116: void *malloc(size_t size) const { return fpool.malloc(size); }
1.34 paf 117: /// useful wrapper around pool
1.23 paf 118: void *calloc(size_t size) const { return fpool.calloc(size); }
1.34 paf 119: /// useful wrapper around pool
1.31 paf 120: Exception& exception() const { return fpool.exception(); }
1.23 paf 121: };
1.34 paf 122: /// useful macro for creating objects on current Pooled object Pooled::pool()
1.23 paf 123: #define NEW new(pool())
124:
1.35 paf 125: /**
1.34 paf 126: Auto-object used for temporary changing Pool's exception().
127:
128: Use by with these macros:
1.38 ! paf 129: @code
1.34 paf 130: TRY {
1.38 ! paf 131: // ...
1.34 paf 132: if(?)
133: THROW(?);
1.38 ! paf 134: // ...
1.34 paf 135: } CATCH(e) {
1.38 ! paf 136: // code, using e fields
! 137: // e.comment()
1.34 paf 138: }
139: END_CATCH
1.38 ! paf 140: @endcode
! 141:
! 142: @see TRY, THROW
1.34 paf 143: */
1.25 paf 144: class Temp_exception {
1.29 paf 145: Pool& fpool;
1.23 paf 146: Exception *saved_exception;
147: public:
1.25 paf 148: Temp_exception(Pool& apool, Exception& exception) :
1.29 paf 149: fpool(apool),
1.23 paf 150: saved_exception(apool.set_exception(&exception)) {
151: }
1.25 paf 152: ~Temp_exception() {
1.29 paf 153: fpool.restore_exception(saved_exception);
1.23 paf 154: }
1.1 paf 155: };
1.23 paf 156:
1.33 paf 157: #define XTRY(pool) \
1.24 paf 158: { \
159: Exception temp_exception; \
1.33 paf 160: Temp_exception le(pool, temp_exception); \
1.24 paf 161: if(setjmp(temp_exception.mark)==0)
1.31 paf 162:
1.33 paf 163: #define XTHROW(exception) exception._throw
164: #define XCATCH(e) \
1.24 paf 165: else{ \
166: Exception& e=temp_exception;
1.31 paf 167:
1.33 paf 168: #define XEND_CATCH \
1.24 paf 169: } \
170: }
1.33 paf 171:
1.34 paf 172: //@{
173: /// @see Temp_exception
1.33 paf 174: #define TRY XTRY(pool())
175: #define THROW XTHROW(exception())
176: #define CATCH(e) XCATCH(e)
177: #define END_CATCH XEND_CATCH
178:
179: #define PTRY XTRY(pool)
180: #define PTHROW XTHROW(pool.exception())
181: #define PCATCH(e) XCATCH(e)
182: #define PEND_CATCH XEND_CATCH
183:
184: #define RTHROW XTHROW(r.pool().exception())
1.34 paf 185: //@}
1.1 paf 186:
187: #endif
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