A 42 y.o. patient complains of pain in the epigastral area, vomiting; vomit masses have the colour of "coffee-grounds", the patient has also melena. Anamnesis records gastric ulcer. Blood formula: erythrocytes - 2,8 × 1012/l, leukocytes - 8 × 109/l, Hb- 90 g/l. What complication is it?